Emily Miller-Cushon | University of Florida (original) (raw)

Papers by Emily Miller-Cushon

Research paper thumbnail of Identifying the optimal course delivery platform in an undergraduate animal behavior research course1

Translational Animal Science

There is a critical need to evaluate pedagogical delivery platforms best suited for undergraduate... more There is a critical need to evaluate pedagogical delivery platforms best suited for undergraduates in the information age. Our goal was to identify the optimum course delivery platform for a basic research course based on student performance and critical thinking scores. Students were expected to plan, conduct, and report on an animal behavior research project of their own design. The course was taught in three different formats: traditional, online, and flipped, over 2 yr by the same instructor at both the University of Florida and Santa Fe College. Student assessments included weekly quizzes, assignments, a written report, a poster presentation, and attendance. We conducted pre- and postassessments using the Cornell Critical Thinking Test (CCTT). Students’ grades differed depending on format delivery and were also different between University of Florida and Santa Fe College students. For students at the University of Florida, quiz grades and poster grades did not differ (P < 0....

Research paper thumbnail of Contrasting Science Learning Gains and Attitudes of Students in an Early Research-Based Experience

NACTA Journal, 2019

Retention of students in Science, Technology, Engineering and Mathematic (STEM) degrees is declin... more Retention of students in Science, Technology, Engineering and Mathematic (STEM) degrees is declining and it has been suggested that undergraduate research experiences early in students' collegiate careers may increase this trend. We developed an animal behavior research course for freshman and sophomores, and found that students enrolled in this course had improved opinions, learning gains, and attitudes towards science. We also found numerically higher STEM retention in students enrolled in this course (98.1%) compared to college and university-level STEM retention data. Descriptive feedback from the students also indicated that they enjoyed their research experience and that the experience generated enthusiasm for research and scientific careers. These results suggest that this course may be a good working model for further undergraduate research courses at other institutions and may keep students interested in STEM careers.

Research paper thumbnail of Feeding amount affects the sorting behavior of lactating dairy cows

Canadian Journal of Animal Science, 2010

The objective of this study was to determine whether feed sorting behavior in dairy cattle is inf... more The objective of this study was to determine whether feed sorting behavior in dairy cattle is influenced by the amount of feed provided. Six lactating Holstein cows, individually fed a total mixed ration once daily, were exposed to two treatments in a crossover design with 7-d periods. The treatments were:(1) lower feed amount (LFA; target 10% orts), and (2) higher feed amount (HFA; target 20% orts). Dry matter intake (DMI) was monitored daily for each animal. On the final 4 d of each treatment period, fresh feed and orts were sampled for ...

Research paper thumbnail of Effect of early feed type exposure on diet-selection behavior of dairy calves

Journal of dairy science, 2011

Dairy cattle exhibit characteristic feeding behavior patterns that may be influenced by early exp... more Dairy cattle exhibit characteristic feeding behavior patterns that may be influenced by early experiences. The objective of this study was to determine how early exposure to different feed types affects diet selection behavior of dairy calves once fed a mixed ration after weaning off milk. Eight Holstein bull calves were randomly assigned at birth to a feed exposure treatment: concentrate or grass/alfalfa hay, offered ad libitum. All calves were offered 8 L/d of milk replacer [1.2 kg of dry matter (DM)] from birth, which was incrementally reduced after 4 wk to enable weaning by the end of wk 7. After milk weaning, all calves were fed a mixed ration containing (on a DM basis) 60% concentrate and 40% grass/alfalfa hay for 9 wk. Intake was recorded daily, and calves were weighed 3 times/wk. Samples of fresh feed and orts were taken in wk 8, 12, and 16 for particle size analysis. The separator had 3 screens (19, 8, and 1.18 mm) producing long, medium, short, and fine particle fractions. Sorting of each fraction was calculated as actual intake as a percentage of predicted intake. Calves exposed to concentrate tended to have greater DM intake than calves exposed to hay both before (0.49 vs. 0.16 kg/d) and after weaning off milk (3.3 vs. 2.6 kg/d). Weights were similar during the milk-feeding stage, but calves exposed to concentrate had greater weights overall in the postweaning stage (129.8 vs. 112.6 kg). Initially after weaning, calves sorted for familiar feed; calves previously exposed to concentrate sorted for short particles (126.4%), which were primarily concentrate, whereas calves previously exposed to hay did not (94.2%). Calves previously exposed to hay tended to sort for long particles (113.4%), which were solely hay, whereas calves previously exposed to concentrate sorted against them (56.4%). The sorting observed for short particles was associated with consuming a diet with a greater concentration of protein, nonfiber carbohydrates, and metabolizable energy, whereas sorting for long particles was associated with consuming a diet with a greater concentration of neutral detergent fiber. After 4 wk of exposure to the mixed ration, sorting was similar between treatments, with calves in both treatment groups sorting for short (117.4 and 120.5%) and against long (62.4 and 54.4%) particles, and consuming a diet with a similar concentration of nutrients and energy. These results indicate that feed familiarity affected initial diet selection postweaning, but may not have a lasting effect, with all calves developing similar feed-sorting patterns.

Research paper thumbnail of Effect of dietary dry matter concentration on the sorting behavior of lactating dairy cows fed a total mixed ration

Journal of dairy science, 2009

The objective of this study was to determine whether addition of water to a high-moisture total m... more The objective of this study was to determine whether addition of water to a high-moisture total mixed ration reduces feed sorting by dairy cattle. Twelve lactating Holstein cows, individually fed once per day, were tested on 2 diets in a crossover design with 21-d periods. Diets had the same dietary composition and differed only in dry matter content, which was reduced by the addition of water. Treatment diets were 1) dry (57.6% DM) and 2) wet (47.9% DM). Dry matter intake (DMI) and milk production were monitored for each animal for the last 7 d of both treatment periods. For the final 3 d of each period, milk samples were taken for composition analysis and fresh feed and orts were sampled for particle size analysis. The particle size separator had 3 screens (19, 8, and 1.18 mm) and a bottom pan, resulting in 4 fractions (long, medium, short, fine). Sorting was calculated as the actual intake of each particle size fraction expressed as a percentage of the predicted intake of that fraction. Contrary to the hypothesis, cows sorted the wet diet more extensively than the dry diet. Sorting of the dry diet was limited to a tendency to refuse short particles, whereas the wet diet was sorted against long particles and for short and fine particles. Water addition reduced DMI, neutral detergent fiber intake, and starch intake of cows on the wet diet. Increased sorting on the wet diet resulted in a tendency for decreased concentration of dietary neutral detergent fiber consumed and also resulted in increased starch concentration of the diet consumed. Milk production and components were unaffected by treatment. Our results suggest that water addition to high-moisture total mixed rations, containing primarily haylage and silage forage sources, may not be an effective method to reduce sorting. Furthermore, water addition may negatively affect DMI and encourage sorting, resulting in the consumption of a ration with different nutrient composition than intended.

Research paper thumbnail of Technical note: validation of methodology for characterization of feeding behavior in dairy calves

Journal of dairy science, 2011

Research paper thumbnail of Effect of physical form of forage on performance, feeding behavior, and digestibility of Holstein calves

Journal of dairy science, 2013

The physical form of forage may influence rumen development and, consequently, the body weight ga... more The physical form of forage may influence rumen development and, consequently, the body weight gain, dry matter (DM) consumption, digestibility, and welfare of dairy calves. The objective of this study was to determine the effect of 2 different physical forms of forage on performance, apparent digestibility, and feeding behavior of young calves. Twenty Holstein male calves (46.8 ± 1.2 kg) were randomly assigned at birth to 1 of 2 feeding treatments in which they were exposed to a mixed ration containing (on a DM basis) 90% crumb starter concentrate and either (1) 10% coarsely chopped (3 to 4 cm) grass hay (CRS; n = 10) or (2) 10% finely ground (2 mm) grass hay (FN; n = 10). All calves were offered 8 L/d of milk replacer (MR; 1.2 kg of DM) from birth; the amount of MR was progressively reduced after 5 wk to enable weaning by the end of wk 7. The study finished after wk 8. Consumption of the mixed ration, MR, and water was recorded daily, and calves were weighed twice weekly. Samples of feed and orts were taken in wk 7 and 8 for nutrient content analysis. Behavioral data for each calf were obtained for 2 h/d during wk 6 and 8, for a total observation time per animal of 28 h. Total feces were collected during wk 8 to determine apparent digestibility. Calves fed CRS had greater DM intake than those fed FN (2.70 vs. 2.45 ± 0.11 kg/d, respectively) during the week after weaning (wk 8). Body weight gain was similar between treatments; however, calves fed CRS tended to have a greater gain-to-feed ratio than calves fed FN (0.68 vs. 0.63 ± 0.02 kg of gain/kg of DM intake). No differences were observed in crude protein and acid detergent fiber consumption between treatments; however, calves fed CRS tended to consume more neutral detergent fiber than calves fed FN during the last week of the study (719.2 vs. 610.5 ± 25.84 g/d). Calves receiving CRS sorted in favor of neutral detergent fiber to a greater extent than calves consuming FN, whereas calves fed FN sorted in favor of crude protein to a greater extent than calves fed CRS. Apparent DM, crude protein, neutral detergent fiber, and acid detergent fiber digestibility values were greater in calves fed CRS than in those fed FN (72.3, 77.4, 40.7, and 42.7% vs. 69.2, 74.5, 34.0, and 35.6%, respectively). Calves fed FN spent more time performing nonnutritive oral behaviors than those fed CRS, and calves fed FN tended to spend less time idle (either lying or standing) than those fed CRS. In conclusion, providing chopped hay to young calves improved feed intake, DM, crude protein, neutral detergent fiber, and acid detergent fiber digestibility values during the week after weaning, and reduced nonnutritive oral behaviors compared with offering ground hay.

Research paper thumbnail of Effect of feed presentation on feeding patterns of dairy calves

Journal of dairy science, 2013

The objectives of this study were to determine the effect of feed presentation on meal frequency ... more The objectives of this study were to determine the effect of feed presentation on meal frequency and duration, as well as diurnal feeding patterns of dairy calves, and to assess any longer-term differences in feeding patterns resulting from previous experience. Twenty Holstein bull calves were exposed from wk 1 to 8 of life to 1 of 2 feed presentation treatments: concentrate and chopped grass hay (<2.5 cm) offered at a ratio of 7:3 as a mixture (MIX), or as separate components (COM). Feed was provided ad libitum. Calves received 8 L/d of milk replacer (1.2 kg of dry matter), with the amount progressively reduced after 5 wk to facilitate weaning by the end of wk 7. At the beginning of wk 9, all calves received the MIX diet and remained on trial for an additional 3 wk. Feeding behavior was recorded from video for 4 d during wk 6, 8, 9, and 11. In wk 6, calves fed MIX spent more time feeding than calves fed COM (56.7 vs. 46.8 min/d). In wk 8, calves fed MIX spent more time feeding (174.0 vs. 139.1 min/d) and had a lower rate of intake (11.5 vs. 14.7 g/min) compared with calves fed COM. Meal frequency was similar between treatments (12.2 meals/d). Diurnal feeding patterns in wk 8 were also affected by feed presentation, with calves fed MIX spending less time feeding at time of feed delivery and more time feeding throughout the rest of the daylight hours than calves fed COM. Diurnal feeding patterns of hay and concentrate in wk 8 differed for calves fed COM, with more time spent consuming hay at time of feed delivery and less time spent consuming hay throughout the rest of the day. Once calves previously fed COM were transitioned to the MIX diet in wk 9, meal frequency, meal duration, and diurnal feeding patterns were similar between treatments: both treatments spent similar amounts of time feeding (173.9 min/d) and had similar peaks in feeding activity at time of feed delivery, sunrise, and sunset. Provision of hay and concentrate to young calves as a mixed ration, compared with separate components, increases time spent feeding and results in more evenly distributed diurnal feeding patterns. However, differences in feeding patterns resulting from feed presentation did not persist after 8 wk of age, when all calves were fed a mixed ration.

Research paper thumbnail of Effect of early exposure to different feed presentations on feed sorting of dairy calves

Journal of dairy science, 2013

This study examined how early exposure to different feed presentations affects development of fee... more This study examined how early exposure to different feed presentations affects development of feed sorting in dairy calves. Twenty Holstein bull calves were exposed for the first 8 wk of life to 1 of 2 feed presentation treatments: concentrate and chopped grass hay (<2.5 cm) offered ad libitum at a ratio of 7:3 as a mixture (MIX), or as separate components (COM). Calves received 8 L/d of milk replacer (1.2 kg of dry matter), with the amount progressively reduced after 5 wk to facilitate weaning by the end of wk 7. All calves received the MIX diet in wk 9 to 11 and, subsequently, a novel total mixed ration (TMR; containing 40.5% corn silage, 22.0% haylage, 21.5% high-moisture corn, and 16.0% protein supplement) in wk 12 to 13. Intake was recorded daily and calves were weighed twice a week. Fresh feed and orts were sampled on d 1 to 4 of wk 6, 8, 9, 11, 12, and 13 for analysis of feed sorting, which was assessed through nutrient analysis for the MIX diet and particle size analysis for the TMR. The particle separator had 3 screens (19, 8, and 1.18 mm) producing long, medium, short, and fine particle fractions. Sorting of nutrients or particle fractions was calculated as the actual intake as a percentage of predicted intake; values >100% indicate sorting for, whereas values <100% indicate sorting against. Feed presentation did not affect dry matter intake or growth. Prior to weaning, all calves selected in favor of hay; MIX calves consumed more neutral detergent fiber (NDF) than predicted (103.6%) and less nonfiber carbohydrates (NFC) than predicted (92.6%), and COM calves consumed, as a percentage of dry matter intake, 40.3% hay (vs. 30% offered rate). In wk 8, calves fed COM consumed more NFC than calves fed MIX (1.0 vs. 0.95 kg/d) and less NDF (0.43 vs. 0.54 kg/d), indicating greater selection in favor of concentrate. However, when provided the MIX diet, calves previously fed COM did not sort, whereas calves previously fed MIX consumed more NFC intake than predicted (103.2%) and less NDF intake than predicted (97.6%). Calves previously fed MIX maintained increased sorting after transition to the novel TMR, sorting against long particles (86.5%) and for short (101.8%) and fine (101.2%) particles. These results indicate that initially providing dairy calves with solid feeds as separate components, compared with as a mixed ration, reduces the extent of feed sorting in the weeks after transition to a common ration.

Research paper thumbnail of Dietary preference in dairy calves for feed ingredients high in energy and protein

Journal of dairy science, 2014

In 3 experiments, we assessed preference of recently weaned dairy calves for (1) 8 high-energy fe... more In 3 experiments, we assessed preference of recently weaned dairy calves for (1) 8 high-energy feed types [barley meal, corn meal, corn gluten feed (CGF), oat meal, rice meal, sorghum meal, wheat meal, and wheat middlings meal]; (2) 6 high-protein feed types [corn gluten meal (CGM), wheat distillers dried grains, rapeseed meal, soybean meal (SBM), sunflower meal, and pea meal]; and (3) 4 mixtures (50:50) of the highest-and lowest-ranked high-energy and high-protein feeds, to assess whether calves maintain preference for feed ingredients that are included in a mixture. In all experiments, pairwise preference tests were conducted between all feed types (28 different pairwise preference tests in experiment 1, 15 tests in experiment 2, and 6 tests in experiment 3). Each pairwise preference test was conducted by offering ad libitum access to both feed types for 6 h. All tests were repeated with 20 Holstein calves. Before this study, calves were offered milk replacer at a rate of 4 L/d and a pelleted starter feed ad libitum. After weaning at 62 d of age, each calf was involved in a pairwise preference test at 3 and 5 d postweaning. A preference ratio was calculated for each calf in each test as (intake of feed type A)/(intake of feed type A + intake of feed type B). Preference for feed types was ranked across tests in each experiment using pairwise comparison charts. In experiment 1, the highest-ranked high-energy feed type was wheat meal and the lowest ranked were rice meal and CGF. In experiment 2, the highest-ranked high-protein feed type was SBM and the lowest ranked was CGM. According to the preference rankings from experiments 1 and 2, experiment 3 evaluated (50:50) mixtures of SBM + wheat meal, SBM + CGF, CGM + wheat meal, and CGM + CGF. The mixture of SBM + wheat meal was highest ranked, CGM + CGF was lowest ranked, and the mixtures containing one high-ranked and one low-ranked feed ingredient (SBM + CGF and CGM + wheat meal) were ranked equally. The results of this study indicate that young calves exhibit clear preferences for certain high-energy and high-protein feeds that may be considered highly palatable. Further, preference ranking of feed types provided as 50:50 mixtures was consistent with ranking of individual feed types, suggesting that palatability of mixed starter rations can be improved by inclusion of a preferred feed type.

Research paper thumbnail of Effect of early exposure to mixed rations differing in forage particle size on feed sorting of dairy calves

Journal of dairy science, 2013

Feed sorting of dairy cattle is influenced by dietary forage particle size. The objective of this... more Feed sorting of dairy cattle is influenced by dietary forage particle size. The objective of this study was to determine the effect of early exposure to rations differing in forage particle size on development of feed sorting in dairy calves. Twenty Holstein bull calves were exposed for 8 wk to 1 of 2 mixed rations containing (on a dry-matter basis) 90% crumb starter concentrate and either (1) 10% coarsely chopped (3-to 4-cm) grass hay (CRS; n = 10) or (2) 10% finely ground (2mm) grass hay (FN; n = 10), both offered ad libitum. Calves received 8 L of milk replacer/d (1.2 kg of dry matter/d), with the amount progressively reduced after 5 wk, to facilitate weaning by the end of wk 7. At the beginning of wk 9, all calves received the CRS diet and were followed for 3 wk. Intake was recorded daily and calves were weighed twice per week. Samples of fresh feed and orts were taken on d 1 to 4 of wk 9 and 11 for analysis of feed sorting. Sorting of the ration was assessed through analysis of nutrient intake. Actual intake of each nutrient was expressed as a percentage of predicted intake of that nutrient, based on the concentration in the fresh sample. Daily dry matter intake (DMI) was similar between treatments after transition to the common CRS ration (3.20 kg/d, standard error = 0.25 kg/d). However, feed efficiency was subject to a treatment-by-week interaction, with calves previously fed the FN diet having an initially greater gain-to-feed ratio than those fed the CRS diet [in wk 9, 0.60 vs. 0.47 kg of average daily gain (ADG)/kg of DMI] and similar feed efficiency in the following weeks (in wk 10, 0.43 vs. 0.43 kg of ADG/kg of DMI). A corresponding tendency was observed for ADG and body weight to evolve differently, depending on treatment, with calves previously fed the FN diet having greater ADG initially (in wk 9, 1.60 vs. 1.32 kg/d) but similar ADG to those fed the CRS diet in the following weeks (in wk 10, 1.39 vs. 1.33 kg/d and in wk 11, 1.32 vs. 1.31 kg/d). Calves previously fed the FN diet consumed less neutral detergent fiber as a percentage of predicted intake and tended to consume less acid detergent fiber and more nonfiber carbohydrates, as a percentage of predicted intakes, than calves previously fed the CRS diet. Given the nutrient compositions of hay and concentrate, this indicates that calves previously fed the FN diet were sorting for concentrate. These results indicate that the pattern and extent of feed sorting may be affected by early experience with rations differing in forage particle size.

Research paper thumbnail of The effect of palatability of protein source on dietary selection in dairy calves

Journal of dairy science, 2014

Evidence has shown that soybean meal is perceived as more palatable than canola meal by dairy cal... more Evidence has shown that soybean meal is perceived as more palatable than canola meal by dairy calves in short-term preference tests. This study evaluated the effect of protein source on longer-term dietary selection of dairy calves. In experiment 1, 40 Holstein bull calves (11.4 ± 4.3 d of age) were randomly assigned to 1 of 2 choice diets for 6 wk: base starter pellet (S; 12% crude protein; CP) and high-protein pellet (40% CP) containing either (1) soybean meal (SB) or (2) canola meal (CM). In wk 7 to 8, all calves were offered a single pelleted diet containing the protein source to which they were previously exposed. In experiment 2, 22 Holstein bull calves (9.9 ± 4.6 d of age) were offered, for 6 wk, a choice of 2 mixed pelleted diets: (1) 70% S and 30% SB (SB mix), or (2) 70% S and 30% CM (CM mix). In wk 7 to 8, calves were randomly assigned to 1 of 2 choice diets, as in experiment 1: (1) SB + S, or (2) CM + S. All feeds were provided ad libitum. Calves received 6 L/d of milk replacer [0.75 kg/d of dry matter (DM)] for the duration of both experiments. Feed intake was recorded daily and calves were weighed every 14 d. Feeds were sampled weekly to analyze DM and nutrient intake. Mixed diets in experiment 2 were analyzed for CP in wk 4 and 6 to assess feed sorting (calculated as actual CP intake as a percentage of predicted intake). In experiment 1, calves offered SB + S in wk 1 to 6 consumed more high-protein pellet than calves offered CM + S [73 vs. 42% of DM intake (DMI)] and, consequently, more CP (168 vs. 117 g/d). Solid feed DMI and average daily gain were similar between treatments. When offered a single diet in wk 7 to 8, calves offered starter containing soybean meal increased intake to a greater extent than calves offered the starter containing canola meal. In experiment 2, calves preferred the SB mix to CM mix (preference ratio: 0.7). Calves consumed more CP than predicted from SB mix in wk 4 and 6 (108 ± 2.0%), indicating that they were sorting in favor of SB. In contrast, calves consumed less CP than predicted from CM mix in wk 4 (81.48 ± 4.1%), indicating that they were sorting against CM. When assigned to choice treatments in wk 7 to 8 of experiment 2, calves offered SB + S consumed more protein pellet than calves offered CM + S (81 vs. 31% DMI) and consumed more CP (378 vs. 196 g/d). Average daily gain was greater for calves offered SB + S but DMI was similar. Overall, these results suggest that dietary selection was influenced by innate feed preferences, and milk-fed calves may not be sensitive to protein imbalances in their diet.

Research paper thumbnail of Effect of milk feeding level on development of feeding behavior in dairy calves

Journal of dairy science, 2013

Evidence exists that early life experiences may influence development of characteristic feeding p... more Evidence exists that early life experiences may influence development of characteristic feeding patterns in dairy cattle. The objective of this study was to determine the effect of milk feeding level on performance and development of feeding patterns in dairy calves. Twenty Holstein bull calves were assigned at birth to a milk replacer feeding level, fed via a teat: (1) ad libitum (ADL) or (2) restricted feeding at 5 L/d (0.75 kg of milk replacer) in 2 feedings/d (RES). All calves were offered concentrate ad libitum during the milk feeding stage. Calves were weaned gradually during wk 7 and then fed a pelleted diet ad libitum for 7 wk. Calves were weighed 2 times/wk. Feed and milk intakes were recorded daily. Feeding behavior was recorded from video for 5 d in each of wk 3, 6, 8, 11, and 14. Calves fed ADL consumed 2.6 times more milk, had greater weight gain (1.2 vs. 0.6 kg/d), and consumed less solid feed (45.2 vs. 98.0 g/d) during the milk feeding period than did calves fed RES. As expected, providing milk ADL resulted in more frequent meals (in wk 6, 7.1 vs. 2.0) and more evenly distributed diurnal patterns of feeding activity compared with the RES milk level. When considering all sucking bouts (milk feeding and nonnutritive sucking), no difference was observed between treatments in daily bout frequency or sucking time/ bout. Postweaning, calves fed RES had initially greater rate of intake (24.9 vs. 17.8 g/min) and meal size (160.8 vs. 117.2 g/meal). Diurnal feeding patterns also differed in the first week after weaning, with ADL calves feeding less continuously at the time of feed delivery. Meal characteristics and diurnal patterns of feeding activity were similar between calves by the end of the trial. However, milk feeding level had a longer-term effect on variability in feeding behavior, with calves fed RES having greater day-to-day variability in feeding time and meal size. Variability of meal characteristics also decreased over time across treatments. These results suggest that milk feeding level may have a short-term influence on postweaning feeding behavior. However, differences in early feeding patterns due to milk feeding level do not appear to affect longer-term development of feeding patterns.

Research paper thumbnail of Identifying the optimal course delivery platform in an undergraduate animal behavior research course1

Translational Animal Science

There is a critical need to evaluate pedagogical delivery platforms best suited for undergraduate... more There is a critical need to evaluate pedagogical delivery platforms best suited for undergraduates in the information age. Our goal was to identify the optimum course delivery platform for a basic research course based on student performance and critical thinking scores. Students were expected to plan, conduct, and report on an animal behavior research project of their own design. The course was taught in three different formats: traditional, online, and flipped, over 2 yr by the same instructor at both the University of Florida and Santa Fe College. Student assessments included weekly quizzes, assignments, a written report, a poster presentation, and attendance. We conducted pre- and postassessments using the Cornell Critical Thinking Test (CCTT). Students’ grades differed depending on format delivery and were also different between University of Florida and Santa Fe College students. For students at the University of Florida, quiz grades and poster grades did not differ (P < 0....

Research paper thumbnail of Contrasting Science Learning Gains and Attitudes of Students in an Early Research-Based Experience

NACTA Journal, 2019

Retention of students in Science, Technology, Engineering and Mathematic (STEM) degrees is declin... more Retention of students in Science, Technology, Engineering and Mathematic (STEM) degrees is declining and it has been suggested that undergraduate research experiences early in students' collegiate careers may increase this trend. We developed an animal behavior research course for freshman and sophomores, and found that students enrolled in this course had improved opinions, learning gains, and attitudes towards science. We also found numerically higher STEM retention in students enrolled in this course (98.1%) compared to college and university-level STEM retention data. Descriptive feedback from the students also indicated that they enjoyed their research experience and that the experience generated enthusiasm for research and scientific careers. These results suggest that this course may be a good working model for further undergraduate research courses at other institutions and may keep students interested in STEM careers.

Research paper thumbnail of Feeding amount affects the sorting behavior of lactating dairy cows

Canadian Journal of Animal Science, 2010

The objective of this study was to determine whether feed sorting behavior in dairy cattle is inf... more The objective of this study was to determine whether feed sorting behavior in dairy cattle is influenced by the amount of feed provided. Six lactating Holstein cows, individually fed a total mixed ration once daily, were exposed to two treatments in a crossover design with 7-d periods. The treatments were:(1) lower feed amount (LFA; target 10% orts), and (2) higher feed amount (HFA; target 20% orts). Dry matter intake (DMI) was monitored daily for each animal. On the final 4 d of each treatment period, fresh feed and orts were sampled for ...

Research paper thumbnail of Effect of early feed type exposure on diet-selection behavior of dairy calves

Journal of dairy science, 2011

Dairy cattle exhibit characteristic feeding behavior patterns that may be influenced by early exp... more Dairy cattle exhibit characteristic feeding behavior patterns that may be influenced by early experiences. The objective of this study was to determine how early exposure to different feed types affects diet selection behavior of dairy calves once fed a mixed ration after weaning off milk. Eight Holstein bull calves were randomly assigned at birth to a feed exposure treatment: concentrate or grass/alfalfa hay, offered ad libitum. All calves were offered 8 L/d of milk replacer [1.2 kg of dry matter (DM)] from birth, which was incrementally reduced after 4 wk to enable weaning by the end of wk 7. After milk weaning, all calves were fed a mixed ration containing (on a DM basis) 60% concentrate and 40% grass/alfalfa hay for 9 wk. Intake was recorded daily, and calves were weighed 3 times/wk. Samples of fresh feed and orts were taken in wk 8, 12, and 16 for particle size analysis. The separator had 3 screens (19, 8, and 1.18 mm) producing long, medium, short, and fine particle fractions. Sorting of each fraction was calculated as actual intake as a percentage of predicted intake. Calves exposed to concentrate tended to have greater DM intake than calves exposed to hay both before (0.49 vs. 0.16 kg/d) and after weaning off milk (3.3 vs. 2.6 kg/d). Weights were similar during the milk-feeding stage, but calves exposed to concentrate had greater weights overall in the postweaning stage (129.8 vs. 112.6 kg). Initially after weaning, calves sorted for familiar feed; calves previously exposed to concentrate sorted for short particles (126.4%), which were primarily concentrate, whereas calves previously exposed to hay did not (94.2%). Calves previously exposed to hay tended to sort for long particles (113.4%), which were solely hay, whereas calves previously exposed to concentrate sorted against them (56.4%). The sorting observed for short particles was associated with consuming a diet with a greater concentration of protein, nonfiber carbohydrates, and metabolizable energy, whereas sorting for long particles was associated with consuming a diet with a greater concentration of neutral detergent fiber. After 4 wk of exposure to the mixed ration, sorting was similar between treatments, with calves in both treatment groups sorting for short (117.4 and 120.5%) and against long (62.4 and 54.4%) particles, and consuming a diet with a similar concentration of nutrients and energy. These results indicate that feed familiarity affected initial diet selection postweaning, but may not have a lasting effect, with all calves developing similar feed-sorting patterns.

Research paper thumbnail of Effect of dietary dry matter concentration on the sorting behavior of lactating dairy cows fed a total mixed ration

Journal of dairy science, 2009

The objective of this study was to determine whether addition of water to a high-moisture total m... more The objective of this study was to determine whether addition of water to a high-moisture total mixed ration reduces feed sorting by dairy cattle. Twelve lactating Holstein cows, individually fed once per day, were tested on 2 diets in a crossover design with 21-d periods. Diets had the same dietary composition and differed only in dry matter content, which was reduced by the addition of water. Treatment diets were 1) dry (57.6% DM) and 2) wet (47.9% DM). Dry matter intake (DMI) and milk production were monitored for each animal for the last 7 d of both treatment periods. For the final 3 d of each period, milk samples were taken for composition analysis and fresh feed and orts were sampled for particle size analysis. The particle size separator had 3 screens (19, 8, and 1.18 mm) and a bottom pan, resulting in 4 fractions (long, medium, short, fine). Sorting was calculated as the actual intake of each particle size fraction expressed as a percentage of the predicted intake of that fraction. Contrary to the hypothesis, cows sorted the wet diet more extensively than the dry diet. Sorting of the dry diet was limited to a tendency to refuse short particles, whereas the wet diet was sorted against long particles and for short and fine particles. Water addition reduced DMI, neutral detergent fiber intake, and starch intake of cows on the wet diet. Increased sorting on the wet diet resulted in a tendency for decreased concentration of dietary neutral detergent fiber consumed and also resulted in increased starch concentration of the diet consumed. Milk production and components were unaffected by treatment. Our results suggest that water addition to high-moisture total mixed rations, containing primarily haylage and silage forage sources, may not be an effective method to reduce sorting. Furthermore, water addition may negatively affect DMI and encourage sorting, resulting in the consumption of a ration with different nutrient composition than intended.

Research paper thumbnail of Technical note: validation of methodology for characterization of feeding behavior in dairy calves

Journal of dairy science, 2011

Research paper thumbnail of Effect of physical form of forage on performance, feeding behavior, and digestibility of Holstein calves

Journal of dairy science, 2013

The physical form of forage may influence rumen development and, consequently, the body weight ga... more The physical form of forage may influence rumen development and, consequently, the body weight gain, dry matter (DM) consumption, digestibility, and welfare of dairy calves. The objective of this study was to determine the effect of 2 different physical forms of forage on performance, apparent digestibility, and feeding behavior of young calves. Twenty Holstein male calves (46.8 ± 1.2 kg) were randomly assigned at birth to 1 of 2 feeding treatments in which they were exposed to a mixed ration containing (on a DM basis) 90% crumb starter concentrate and either (1) 10% coarsely chopped (3 to 4 cm) grass hay (CRS; n = 10) or (2) 10% finely ground (2 mm) grass hay (FN; n = 10). All calves were offered 8 L/d of milk replacer (MR; 1.2 kg of DM) from birth; the amount of MR was progressively reduced after 5 wk to enable weaning by the end of wk 7. The study finished after wk 8. Consumption of the mixed ration, MR, and water was recorded daily, and calves were weighed twice weekly. Samples of feed and orts were taken in wk 7 and 8 for nutrient content analysis. Behavioral data for each calf were obtained for 2 h/d during wk 6 and 8, for a total observation time per animal of 28 h. Total feces were collected during wk 8 to determine apparent digestibility. Calves fed CRS had greater DM intake than those fed FN (2.70 vs. 2.45 ± 0.11 kg/d, respectively) during the week after weaning (wk 8). Body weight gain was similar between treatments; however, calves fed CRS tended to have a greater gain-to-feed ratio than calves fed FN (0.68 vs. 0.63 ± 0.02 kg of gain/kg of DM intake). No differences were observed in crude protein and acid detergent fiber consumption between treatments; however, calves fed CRS tended to consume more neutral detergent fiber than calves fed FN during the last week of the study (719.2 vs. 610.5 ± 25.84 g/d). Calves receiving CRS sorted in favor of neutral detergent fiber to a greater extent than calves consuming FN, whereas calves fed FN sorted in favor of crude protein to a greater extent than calves fed CRS. Apparent DM, crude protein, neutral detergent fiber, and acid detergent fiber digestibility values were greater in calves fed CRS than in those fed FN (72.3, 77.4, 40.7, and 42.7% vs. 69.2, 74.5, 34.0, and 35.6%, respectively). Calves fed FN spent more time performing nonnutritive oral behaviors than those fed CRS, and calves fed FN tended to spend less time idle (either lying or standing) than those fed CRS. In conclusion, providing chopped hay to young calves improved feed intake, DM, crude protein, neutral detergent fiber, and acid detergent fiber digestibility values during the week after weaning, and reduced nonnutritive oral behaviors compared with offering ground hay.

Research paper thumbnail of Effect of feed presentation on feeding patterns of dairy calves

Journal of dairy science, 2013

The objectives of this study were to determine the effect of feed presentation on meal frequency ... more The objectives of this study were to determine the effect of feed presentation on meal frequency and duration, as well as diurnal feeding patterns of dairy calves, and to assess any longer-term differences in feeding patterns resulting from previous experience. Twenty Holstein bull calves were exposed from wk 1 to 8 of life to 1 of 2 feed presentation treatments: concentrate and chopped grass hay (<2.5 cm) offered at a ratio of 7:3 as a mixture (MIX), or as separate components (COM). Feed was provided ad libitum. Calves received 8 L/d of milk replacer (1.2 kg of dry matter), with the amount progressively reduced after 5 wk to facilitate weaning by the end of wk 7. At the beginning of wk 9, all calves received the MIX diet and remained on trial for an additional 3 wk. Feeding behavior was recorded from video for 4 d during wk 6, 8, 9, and 11. In wk 6, calves fed MIX spent more time feeding than calves fed COM (56.7 vs. 46.8 min/d). In wk 8, calves fed MIX spent more time feeding (174.0 vs. 139.1 min/d) and had a lower rate of intake (11.5 vs. 14.7 g/min) compared with calves fed COM. Meal frequency was similar between treatments (12.2 meals/d). Diurnal feeding patterns in wk 8 were also affected by feed presentation, with calves fed MIX spending less time feeding at time of feed delivery and more time feeding throughout the rest of the daylight hours than calves fed COM. Diurnal feeding patterns of hay and concentrate in wk 8 differed for calves fed COM, with more time spent consuming hay at time of feed delivery and less time spent consuming hay throughout the rest of the day. Once calves previously fed COM were transitioned to the MIX diet in wk 9, meal frequency, meal duration, and diurnal feeding patterns were similar between treatments: both treatments spent similar amounts of time feeding (173.9 min/d) and had similar peaks in feeding activity at time of feed delivery, sunrise, and sunset. Provision of hay and concentrate to young calves as a mixed ration, compared with separate components, increases time spent feeding and results in more evenly distributed diurnal feeding patterns. However, differences in feeding patterns resulting from feed presentation did not persist after 8 wk of age, when all calves were fed a mixed ration.

Research paper thumbnail of Effect of early exposure to different feed presentations on feed sorting of dairy calves

Journal of dairy science, 2013

This study examined how early exposure to different feed presentations affects development of fee... more This study examined how early exposure to different feed presentations affects development of feed sorting in dairy calves. Twenty Holstein bull calves were exposed for the first 8 wk of life to 1 of 2 feed presentation treatments: concentrate and chopped grass hay (<2.5 cm) offered ad libitum at a ratio of 7:3 as a mixture (MIX), or as separate components (COM). Calves received 8 L/d of milk replacer (1.2 kg of dry matter), with the amount progressively reduced after 5 wk to facilitate weaning by the end of wk 7. All calves received the MIX diet in wk 9 to 11 and, subsequently, a novel total mixed ration (TMR; containing 40.5% corn silage, 22.0% haylage, 21.5% high-moisture corn, and 16.0% protein supplement) in wk 12 to 13. Intake was recorded daily and calves were weighed twice a week. Fresh feed and orts were sampled on d 1 to 4 of wk 6, 8, 9, 11, 12, and 13 for analysis of feed sorting, which was assessed through nutrient analysis for the MIX diet and particle size analysis for the TMR. The particle separator had 3 screens (19, 8, and 1.18 mm) producing long, medium, short, and fine particle fractions. Sorting of nutrients or particle fractions was calculated as the actual intake as a percentage of predicted intake; values >100% indicate sorting for, whereas values <100% indicate sorting against. Feed presentation did not affect dry matter intake or growth. Prior to weaning, all calves selected in favor of hay; MIX calves consumed more neutral detergent fiber (NDF) than predicted (103.6%) and less nonfiber carbohydrates (NFC) than predicted (92.6%), and COM calves consumed, as a percentage of dry matter intake, 40.3% hay (vs. 30% offered rate). In wk 8, calves fed COM consumed more NFC than calves fed MIX (1.0 vs. 0.95 kg/d) and less NDF (0.43 vs. 0.54 kg/d), indicating greater selection in favor of concentrate. However, when provided the MIX diet, calves previously fed COM did not sort, whereas calves previously fed MIX consumed more NFC intake than predicted (103.2%) and less NDF intake than predicted (97.6%). Calves previously fed MIX maintained increased sorting after transition to the novel TMR, sorting against long particles (86.5%) and for short (101.8%) and fine (101.2%) particles. These results indicate that initially providing dairy calves with solid feeds as separate components, compared with as a mixed ration, reduces the extent of feed sorting in the weeks after transition to a common ration.

Research paper thumbnail of Dietary preference in dairy calves for feed ingredients high in energy and protein

Journal of dairy science, 2014

In 3 experiments, we assessed preference of recently weaned dairy calves for (1) 8 high-energy fe... more In 3 experiments, we assessed preference of recently weaned dairy calves for (1) 8 high-energy feed types [barley meal, corn meal, corn gluten feed (CGF), oat meal, rice meal, sorghum meal, wheat meal, and wheat middlings meal]; (2) 6 high-protein feed types [corn gluten meal (CGM), wheat distillers dried grains, rapeseed meal, soybean meal (SBM), sunflower meal, and pea meal]; and (3) 4 mixtures (50:50) of the highest-and lowest-ranked high-energy and high-protein feeds, to assess whether calves maintain preference for feed ingredients that are included in a mixture. In all experiments, pairwise preference tests were conducted between all feed types (28 different pairwise preference tests in experiment 1, 15 tests in experiment 2, and 6 tests in experiment 3). Each pairwise preference test was conducted by offering ad libitum access to both feed types for 6 h. All tests were repeated with 20 Holstein calves. Before this study, calves were offered milk replacer at a rate of 4 L/d and a pelleted starter feed ad libitum. After weaning at 62 d of age, each calf was involved in a pairwise preference test at 3 and 5 d postweaning. A preference ratio was calculated for each calf in each test as (intake of feed type A)/(intake of feed type A + intake of feed type B). Preference for feed types was ranked across tests in each experiment using pairwise comparison charts. In experiment 1, the highest-ranked high-energy feed type was wheat meal and the lowest ranked were rice meal and CGF. In experiment 2, the highest-ranked high-protein feed type was SBM and the lowest ranked was CGM. According to the preference rankings from experiments 1 and 2, experiment 3 evaluated (50:50) mixtures of SBM + wheat meal, SBM + CGF, CGM + wheat meal, and CGM + CGF. The mixture of SBM + wheat meal was highest ranked, CGM + CGF was lowest ranked, and the mixtures containing one high-ranked and one low-ranked feed ingredient (SBM + CGF and CGM + wheat meal) were ranked equally. The results of this study indicate that young calves exhibit clear preferences for certain high-energy and high-protein feeds that may be considered highly palatable. Further, preference ranking of feed types provided as 50:50 mixtures was consistent with ranking of individual feed types, suggesting that palatability of mixed starter rations can be improved by inclusion of a preferred feed type.

Research paper thumbnail of Effect of early exposure to mixed rations differing in forage particle size on feed sorting of dairy calves

Journal of dairy science, 2013

Feed sorting of dairy cattle is influenced by dietary forage particle size. The objective of this... more Feed sorting of dairy cattle is influenced by dietary forage particle size. The objective of this study was to determine the effect of early exposure to rations differing in forage particle size on development of feed sorting in dairy calves. Twenty Holstein bull calves were exposed for 8 wk to 1 of 2 mixed rations containing (on a dry-matter basis) 90% crumb starter concentrate and either (1) 10% coarsely chopped (3-to 4-cm) grass hay (CRS; n = 10) or (2) 10% finely ground (2mm) grass hay (FN; n = 10), both offered ad libitum. Calves received 8 L of milk replacer/d (1.2 kg of dry matter/d), with the amount progressively reduced after 5 wk, to facilitate weaning by the end of wk 7. At the beginning of wk 9, all calves received the CRS diet and were followed for 3 wk. Intake was recorded daily and calves were weighed twice per week. Samples of fresh feed and orts were taken on d 1 to 4 of wk 9 and 11 for analysis of feed sorting. Sorting of the ration was assessed through analysis of nutrient intake. Actual intake of each nutrient was expressed as a percentage of predicted intake of that nutrient, based on the concentration in the fresh sample. Daily dry matter intake (DMI) was similar between treatments after transition to the common CRS ration (3.20 kg/d, standard error = 0.25 kg/d). However, feed efficiency was subject to a treatment-by-week interaction, with calves previously fed the FN diet having an initially greater gain-to-feed ratio than those fed the CRS diet [in wk 9, 0.60 vs. 0.47 kg of average daily gain (ADG)/kg of DMI] and similar feed efficiency in the following weeks (in wk 10, 0.43 vs. 0.43 kg of ADG/kg of DMI). A corresponding tendency was observed for ADG and body weight to evolve differently, depending on treatment, with calves previously fed the FN diet having greater ADG initially (in wk 9, 1.60 vs. 1.32 kg/d) but similar ADG to those fed the CRS diet in the following weeks (in wk 10, 1.39 vs. 1.33 kg/d and in wk 11, 1.32 vs. 1.31 kg/d). Calves previously fed the FN diet consumed less neutral detergent fiber as a percentage of predicted intake and tended to consume less acid detergent fiber and more nonfiber carbohydrates, as a percentage of predicted intakes, than calves previously fed the CRS diet. Given the nutrient compositions of hay and concentrate, this indicates that calves previously fed the FN diet were sorting for concentrate. These results indicate that the pattern and extent of feed sorting may be affected by early experience with rations differing in forage particle size.

Research paper thumbnail of The effect of palatability of protein source on dietary selection in dairy calves

Journal of dairy science, 2014

Evidence has shown that soybean meal is perceived as more palatable than canola meal by dairy cal... more Evidence has shown that soybean meal is perceived as more palatable than canola meal by dairy calves in short-term preference tests. This study evaluated the effect of protein source on longer-term dietary selection of dairy calves. In experiment 1, 40 Holstein bull calves (11.4 ± 4.3 d of age) were randomly assigned to 1 of 2 choice diets for 6 wk: base starter pellet (S; 12% crude protein; CP) and high-protein pellet (40% CP) containing either (1) soybean meal (SB) or (2) canola meal (CM). In wk 7 to 8, all calves were offered a single pelleted diet containing the protein source to which they were previously exposed. In experiment 2, 22 Holstein bull calves (9.9 ± 4.6 d of age) were offered, for 6 wk, a choice of 2 mixed pelleted diets: (1) 70% S and 30% SB (SB mix), or (2) 70% S and 30% CM (CM mix). In wk 7 to 8, calves were randomly assigned to 1 of 2 choice diets, as in experiment 1: (1) SB + S, or (2) CM + S. All feeds were provided ad libitum. Calves received 6 L/d of milk replacer [0.75 kg/d of dry matter (DM)] for the duration of both experiments. Feed intake was recorded daily and calves were weighed every 14 d. Feeds were sampled weekly to analyze DM and nutrient intake. Mixed diets in experiment 2 were analyzed for CP in wk 4 and 6 to assess feed sorting (calculated as actual CP intake as a percentage of predicted intake). In experiment 1, calves offered SB + S in wk 1 to 6 consumed more high-protein pellet than calves offered CM + S [73 vs. 42% of DM intake (DMI)] and, consequently, more CP (168 vs. 117 g/d). Solid feed DMI and average daily gain were similar between treatments. When offered a single diet in wk 7 to 8, calves offered starter containing soybean meal increased intake to a greater extent than calves offered the starter containing canola meal. In experiment 2, calves preferred the SB mix to CM mix (preference ratio: 0.7). Calves consumed more CP than predicted from SB mix in wk 4 and 6 (108 ± 2.0%), indicating that they were sorting in favor of SB. In contrast, calves consumed less CP than predicted from CM mix in wk 4 (81.48 ± 4.1%), indicating that they were sorting against CM. When assigned to choice treatments in wk 7 to 8 of experiment 2, calves offered SB + S consumed more protein pellet than calves offered CM + S (81 vs. 31% DMI) and consumed more CP (378 vs. 196 g/d). Average daily gain was greater for calves offered SB + S but DMI was similar. Overall, these results suggest that dietary selection was influenced by innate feed preferences, and milk-fed calves may not be sensitive to protein imbalances in their diet.

Research paper thumbnail of Effect of milk feeding level on development of feeding behavior in dairy calves

Journal of dairy science, 2013

Evidence exists that early life experiences may influence development of characteristic feeding p... more Evidence exists that early life experiences may influence development of characteristic feeding patterns in dairy cattle. The objective of this study was to determine the effect of milk feeding level on performance and development of feeding patterns in dairy calves. Twenty Holstein bull calves were assigned at birth to a milk replacer feeding level, fed via a teat: (1) ad libitum (ADL) or (2) restricted feeding at 5 L/d (0.75 kg of milk replacer) in 2 feedings/d (RES). All calves were offered concentrate ad libitum during the milk feeding stage. Calves were weaned gradually during wk 7 and then fed a pelleted diet ad libitum for 7 wk. Calves were weighed 2 times/wk. Feed and milk intakes were recorded daily. Feeding behavior was recorded from video for 5 d in each of wk 3, 6, 8, 11, and 14. Calves fed ADL consumed 2.6 times more milk, had greater weight gain (1.2 vs. 0.6 kg/d), and consumed less solid feed (45.2 vs. 98.0 g/d) during the milk feeding period than did calves fed RES. As expected, providing milk ADL resulted in more frequent meals (in wk 6, 7.1 vs. 2.0) and more evenly distributed diurnal patterns of feeding activity compared with the RES milk level. When considering all sucking bouts (milk feeding and nonnutritive sucking), no difference was observed between treatments in daily bout frequency or sucking time/ bout. Postweaning, calves fed RES had initially greater rate of intake (24.9 vs. 17.8 g/min) and meal size (160.8 vs. 117.2 g/meal). Diurnal feeding patterns also differed in the first week after weaning, with ADL calves feeding less continuously at the time of feed delivery. Meal characteristics and diurnal patterns of feeding activity were similar between calves by the end of the trial. However, milk feeding level had a longer-term effect on variability in feeding behavior, with calves fed RES having greater day-to-day variability in feeding time and meal size. Variability of meal characteristics also decreased over time across treatments. These results suggest that milk feeding level may have a short-term influence on postweaning feeding behavior. However, differences in early feeding patterns due to milk feeding level do not appear to affect longer-term development of feeding patterns.