Chemical and fatty acid composition of milk from crossbred cows subjected to feed restriction (original) (raw)
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Scientia Agricola, 2013
Feed shortages are relatively frequent in subtropical pasture-based dairy production systems. The effect of feed restriction on milk yield and physical-chemical traits was evaluated in this study. The experiment was carried out in Brazil's south region. Treatments consisted of control and restricted diet. Six multiparous and six primiparous cows, with 499 ± 47.20 kg body weight (BW), at mid-lactation (188 ± 124 days in milk), producing 19.35 ± 4.10 kg of milk were assigned to two groups, balanced for parity, each group receiving a different sequence of the dietary treatments for 56 days, in a crossover design. Diet nominated as control included 8 kg DM 100 kg BW -1 of Bermuda grass var. Tifton pasture (Cynodon dactylon (L.) Pers.), 5.00 kg of concentrate and 2.50 kg of Tifton hay per day. The restriction diet consisted of 50 % of the quantity offered in the control diet. Milk production and physicochemical composition were evaluated. Feed restriction reduced milk production by 40 %, body condition score by 5 %, milk magnesium by 14.3 %, lactose by 1.7 %, titratable acidity by 10 % and stability to the ethanol test by 9 % and it tended to increase (7 %) milk potassium content. No changes were found for the remaining characteristics. Since feed restriction is quite frequent in Brazil's extensive dairy production systems, our concern is that besides decreased milk production, changes can occur in the physiochemical attributes of the milk, mainly a reduction in the stability to the ethanol test, which may increase the volume of milk rejected by the industry.
Fruscalso et al. Feeding restriction and milk quality Scientia Agricola
Feed shortages are relatively frequent in subtropical pasture-based dairy production systems. The effect of feed restriction on milk yield and physical-chemical traits was evaluated in this study. The experiment was carried out in Brazil's south region. Treatments consisted of control and restricted diet. Six multiparous and six primiparous cows, with 499 ± 47.20 kg body weight (BW), at mid-lactation (188 ± 124 days in milk), producing 19.35 ± 4.10 kg of milk were assigned to two groups, balanced for parity, each group receiving a different sequence of the dietary treatments for 56 days, in a crossover design. Diet nominated as control included 8 kg DM 100 kg BW -1 of Bermuda grass var. Tifton pasture (Cynodon dactylon (L.) Pers.), 5.00 kg of concentrate and 2.50 kg of Tifton hay per day. The restriction diet consisted of 50 % of the quantity offered in the control diet. Milk production and physicochemical composition were evaluated. Feed restriction reduced milk production by 40 %, body condition score by 5 %, milk magnesium by 14.3 %, lactose by 1.7 %, titratable acidity by 10 % and stability to the ethanol test by 9 % and it tended to increase (7 %) milk potassium content. No changes were found for the remaining characteristics. Since feed restriction is quite frequent in Brazil's extensive dairy production systems, our concern is that besides decreased milk production, changes can occur in the physiochemical attributes of the milk, mainly a reduction in the stability to the ethanol test, which may increase the volume of milk rejected by the industry.
Milk traits of lactating cows submitted to feed restriction
Tropical Animal Health and Production, 2015
Data from five experiments with dairy cows where feed was restricted to 0, 40, and 50 % of the ad libitum amount, with 259 observations, were subjected to multivariate analyses to determine the effects of severity and duration of feed restriction on production, physical-chemical characteristics, ethanol stability, and somatic cell score of milk. A negative relationship was seen between the severity and duration of feed restriction with milk production, lactose content, titratable acidity, and milk stability to the ethanol test. The milk stability to the ethanol test, protein content, milk yield, and somatic cells score were the most important attributes retained by the discriminant analysis. Milk stability to the ethanol test, live weight, days in restriction, and pH were the most important characteristics explaining the variance within the different levels of feed restriction. Milk production and ethanol stability were significantly lower in both levels of feed restriction compared with the group fed ad libitum. When feed restriction was followed by refeeding, the difference observed in ethanol stability was the first discriminant variable, followed by the difference in unstable milk frequency and titratable acidity. Increments in the severity and duration of feed restriction negatively affect milk production and milk ethanol stability.
Agricultural Sciences, 2018
The aim of the study was to determine the effect of supplementing an oat winter pasture with a total mixed ration (TMR) on lactation performance of dairy cows. Nine multiparous Holstein cows were used in a 3 × 3 Latin square design with three TMR: pasture ratios at 79:21 (T1), 58:42 (T2) and 33:67 (T3) on a dry matter (DM) basis. The response to the 100% TMR diet (TMR-100) was tested using an extra period of 14 days inmediately after finishing the Latin square schedule using the nine experimental cows. Total DM intake resulted higher in TMR-100 (28.2 (kg/cow•day) and decreased by 2.64 kg/cow•day in T1, 5.02 kg in T2 and 6.68 kg in T3. Yields of milk (31.2 kg/cow•day) and fat corrected milk (26.8 kg/cow•day) was similar between T1, T2 and T3. Milk yield resulted higher in TMR-100 (32.1 kg/cow•day) compared to T2 (30.7 kg/cow•day). Milk fat concentration (g/100 g) was higher in T2 (3.13) and T3 (3.20) compared to T1 (2.96) and TMR-100 (2.85) and milk fat yield did not differ. Milk protein content resulted higher in TMR-100 and T2 averaging 3.37 g/100 g compared to T1 (3.32 g/100 g). The lowest milk protein concentration was observed in T3 (3.29 g/100 g) that resulted only different to T2. Milk protein yield did not differ between T1, T2 and T3 averaging 1.03 kg/cow•day. A lower protein yield was detected in T2 (1.03) and T3 (1.00) when compared to TMR-100 (1.07). Efficiency of milk production (kg milk/kg DM intake) resulted higher in T3 (1.42) compared to T1 (1.25). Treatments that included pasture yielded a higher efficiency of milk production when compared to TMR-100 (1.13). Plasma urea concentration resulted lower in TMR-100 (33.8 mg/dl
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2020
This study aimed to evaluate the effects of different nutritional plans on the productive, physiological and metabolic parameters of F1 ½ Holstein x ½ Zebu cows in different stages of lactation. Sixty lactating cows were allotted to a completely randomized 5 x 3 factorial design with five feed allowances and three lactation periods. The dry matter intake, milk yield and heart rate were reduced by 5.69kg, 2.41kg and 10.36 beats/min (morning) and 10.25 beats/min (afternoon) for each 1% feed restriction, respectively. There was no difference in the concentration of glucose, total protein, albumin, cholesterol and non-esterified fatty acids for cows subjected to different feed allowances, with means of 95.25, 7.98, 2.95, 121.68 and 0.45mg/dL, respectively. Feed restriction of up to 2.50% BW is a cost reduction strategy that does not alter milk yield, regardless of the stage of lactation.
Diet and bioclimatic conditions on production and milk quality
2017
It was aimed to analyze the productive performance of lactating cows on isoprotein fed diets, at differentiated environmental conditions. Eight Holstein cows were used, grouped in two 4 × 4 balanced Latin squares design. The treatments were evaluated in 2 × 2 factorial designs: sources of roughage (corn silage – CS plus concentrate, and the combination of corn silage with sugarcane - CSSC, 1:1 on DM, plus concentrate) and distinct environment (with= WS and without= OS, fan and nebulizers system= Sfn). The estimation of dry matter intake (DMI), productive performance and physicochemical parameters of milk were evaluated. There was no interaction effect of environment factors and source of forage. There was signiÀ cant effects for the source forage factors, where the DMI for the CSSC based diet was higher than the CS based diet in the effect of forage (4.22 vs. 4.06% BW, and 22.3 vs. 21.7 kg/d, respectively, P≤0.05), but with similar milk production correcting 3.5% fat (23.01 vs. 22.62, CSSC and CS; 22.85 vs. 22.78 kg/day, WS and OS, respectively, P≥0.05). The feed efÀ ciency and conversion was similar in both factors (102.8 vs. 104.7% and 0.99 vs. 1.0, CSSC and CS; 102.5 vs. 104.9% and 1.0 vs. 0.99, WS and OS, respectively, P≥0.05). The beneÀ t-diet cost ratio was higher for CS-based diet than for CSSC (7.44 vs. 6.97, P≤0.05). There were effects only in the forage factor for CP milk (3.26 vs. 3.23%, P≤0.05), lactose (4.54 vs. 4.49%, P≤0.05) and urea nitrogen in milk (23.21 vs. 20.71 mg/dL, P≤0.05) and the superiority arising from the CSSC-based diet in comparison to the CS diet. There was higher for T and THI (28.1 vs. 23.6°C and 75.1 vs. 71.1, respectively, P≤0.05), and lower RH to 2:00 pm (47.7 vs. 64.5%, P≤0.05). The linear score showed negative correlations with DMI, milk production, lactose and urea nitrogen (-0.36, -0.69, -0.44 and -0.32, P≤0.05, respectively). The use of the diet based on CSSC proposed increases in DMI and milk quality without affecting production, but with smaller beneÀ t-diet cost ratio. The use of the environmental cooling system did not improve the production, qualitative parameters of milk and thermal comfort of dairy cows under the conditions evaluated.
Potentials to differentiate milk composition by different feeding strategies
Journal of dairy science, 2009
To investigate the effect of the dietary intake of the cow on milk composition, bulk-tank milk was collected on 5 occasions from conventional (n = 15) and organic (n = 10) farms in Denmark and on 4 occasions from low-input nonorganic farms in the United Kingdom, along with management and production parameters. Production of milk based on feeding a high intake of cereals, pasture, and grass silage resulted in milk with a high concentration of alpha-linolenic acid (9.4 +/- 0.2 mg/kg of fatty acids), polyunsaturated fatty acids (3.66 +/- 0.07 mg/kg of fatty acids), and natural stereoisomer of alpha-tocopherol (RRR-alpha-tocopherol, 18.6 +/- 0.5 mg/kg of milk fat). A milk production system using a high proportion of maize silage, by-products, and commercial concentrate mix was associated with milk with high concentrations of linoleic acid (LA; 19.7 +/- 0.4 g/kg of fatty acids), monounsaturated fatty acids (27.5 +/- 0.3 mg/kg of fatty acids), and a high ratio between LA and alpha-linolen...
Revista Brasileira de Zootecnia, 2019
The objective of this study was to evaluate the effect of quantitative feed restriction level on nutrient intake and digestibility, nitrogen balance, efficiency and feeding behavior, and productive performance of F1 Holstein × Zebu cows in late lactation. Sixty F1 Holstein × Zebu cows were used at the stage of late lactation (183.0±17.5 days of lactation) and with initial body weight (BW) of 499±30 kg. The experimental arrangement adopted was the completely randomized design, with five feed restriction levels (3.39, 2.75, 2.50, 2.25, and 2.00% of BW) and twelve cows as replicates for each treatment. The roughage:concentrate ratio was of 75:25 in the total dry matter of the diet. The restriction of dietary supply from 3.39 to 2.0% of BW linearly reduced dry matter intake by 51.74%. The restriction in diet supply linearly increased dry matter digestibility in 13.76%. For each 1% BW restriction in the diet supply for the animals, there was a linear reduction of 3 h in feeding time. Restriction in diet supply of crossbred cows from 3.39 to 2.0% of BW reduced milk production by 24.84%. For each 1% restriction on supply, 2.17 L of milk were not produced. Milk production corrected to 3.5% fat was not altered with the feed restriction. Final BW decreased 41 kg for each percentage unit of diet restriction. Feed efficiency increased 28.72% with feed restriction. For F1 Holstein × Zebu cows in the late lactation, the restriction of dietary supply up to 2.0% of body weight decreases nutrient intake, nitrogen balance, rumination time, and milk production; however, it improves nutrient digestibility and feed efficiency of the animals.
Performance of lactating dairy cows fed varying levels of total mixed ration and pasture
Journal of Dairy Research, 2008
for their generous guidance and patience. My gratitude is also extended to Sarah Jo McLeod for her invaluable contribution assisting with sample collection, sample analyses, and overall infinite patience and kindness, and to Ellen Leonard for her contribution in sample analyses, and patience. Without all of your advice and support, this dissertation would not have been possible. Huge thanks too to Pete Thompson, Justin Garrett, and Dr. Jim Green for your time, enthusiasm, and efforts in making the forage data collection possible, along with Weston McCorkle, Wayne McLamb, and the entire LWDEU crew. I would also like to thank Marian Correll and Mebane Galloway for their kindness and infinite patience. Also, to my colleagues and friends Ziggy, Diego, Carlos, Leo, and Tim; and to my soccer mates Hugo, Ivo, Claudiney, Eric, and Gonzalo, to all of you my deepest gratitude. Most of all, I would like to thank my wife Celina, who supported my efforts with unconditional love, patience, and pragmatic advice, and my son Martin, both of whom make me a better person. iv
Czech Journal of Animal Science, 2023
The aim of this study was to improve the understanding of the contribution of components typically found in milk, but which are not often included in analyses, to the nutritional status of dairy cows. This was undertaken by analysing the amount and composition of milk produced by Simmental dairy cows, a dual-purpose breed farmed in the Czech Republic. Apart from the more frequently analysed group of components in milk, a less frequently analysed group of components were also investigated. This group, typically, consists of the following components: urea, casein, citric acid, beta hydroxy butyrate (BHB) ketones and free fatty acids. The average content of urea, casein and citric acid in milk is 25.75 mg/100 ml, 2.96%, 0.15%, respectively. The influence of environmental factors on these indicators was evaluated, as well as the degree of hereditary establishment. These less frequently analysed components (indicators), as well as the more frequently analysed components of milk, are subject to several external influences, especially the influence of the breeder, the year and the season of calving. The content of these components varied significantly statistically during the lactation period and also in the order of lactation. The influence of a cow's individuality and the degree of additive genetic background are evident, with estimated heritability coefficients ranging from 0.04 for the BHB ketone content to higher values, e.g., 0.28 for citric acid or 0.31 for the lactose content in milk. The relationships between the components of milk and the daily milk yield were also evaluated, and statistically significant negative correlations were found between the content of casein and the daily milk yield (-0.47) and between the lactose content and the number of somatic cells (-0.37).