Dairy Cow Research Papers - Academia.edu (original) (raw)

BackgroundIn cattle, diseases of abomasum are of great importance and include right and left displacement, torsion, impaction, pyloric stenosis and ulceration. Displacement of the abomasum has become one of the most important metabolic... more

BackgroundIn cattle, diseases of abomasum are of great importance and include right and left displacement, torsion, impaction, pyloric stenosis and ulceration. Displacement of the abomasum has become one of the most important metabolic and organic internal disorders of cattle and the disease is most prevalent in high performing milk breeds. Abomasal displacement occurs most frequently in high yielding cows during early lactation. It has been reported that feeding a large amount of concentrations or corn silage to dairy cows inhibits the motility of the resulting in gas accumulation followed by dilation and atony and thereby causing bovine displaced. Abomasal displacement, ketosis, parturient paresis, retain placenta and endometritis has been often associated with a fatty liver.AimsThis investigation was undertaken to determine the relationship of abomasal displacement and fatty liver syndrome in dairy cows.Methodsthis study, twelve cows with abomasal displacement (7 RDA, 5 LDA) and 10 ...

Nonlipophilic corynebacteria associated with clinical and subclinical mastitis in dairy cows were found to belong to four species: Corynebacterium amycolatum, Corynebacterium ulcerans, Corynebacterium pseudotuberculosis, and... more

Nonlipophilic corynebacteria associated with clinical and subclinical mastitis in dairy cows were found to belong to four species: Corynebacterium amycolatum, Corynebacterium ulcerans, Corynebacterium pseudotuberculosis, and Corynebacterium minutissimum. These species may easily be confused. However, clear-cut differences between C. ulcerans and C. pseudotuberculosis were found in their acid production from maltotriose and ethylene glycol, susceptibility to vibriostatic agent O129, and alkaline phosphatase. Absence of growth at 20 degrees C and lack of alpha-glucosidase and 4MU-alpha-D-glycoside hydrolysis activity differentiated C. amycolatum from C. pseudotuberculosis and C. ulcerans. The mastitis C. pseudotuberculosis strains differed from the biovar equi and ovis reference strains and from caprine field strains in their colony morphologies and in their reduced inhibitory activity on staphylococcal beta-hemolysin. C. amycolatum was the most frequently isolated nonlipophilic coryn...

Protothecosis has been reported in humans (gastroenteritis, bursitis, etc.) and in many other animal species. Bovine mastitis represents the main form of occurrence of protothecosis in cattle. Milk as well as dairy products, when... more

Protothecosis has been reported in humans (gastroenteritis, bursitis, etc.) and in many other animal species. Bovine mastitis represents the main form of occurrence of protothecosis in cattle. Milk as well as dairy products, when contaminated with Prototheca spp., represent a potential means of transmission of this zoonosis. The purpose of this study was to evaluate the susceptibility of forty Prototheca zopfii strains isolated from milk from intramammary infections in dairy cows and also from bulk milk tanks of dairy farms, to the different ratios of temperature/time employed in the thermal treatment of milk: 72-75 degrees C/15 seconds, 72-75 degrees C/20 seconds and 62-65 degrees C/30 minutes. The samples were subjected to these different temperature/time ratios. The evaluation of the thermal susceptibility of the P. zopfii strains showed that 34 strains were resistant in at least one of the tests. The results point out the need to consider the importance of mastitis caused by Pro...

The purpose of this study was to investigate the relationship between conception rate (CR) and climate variables. Data consisted of 24,380 inseminations of Holstein dairy herd in Hidalgo, Mexico. Weather records, including daily... more

The purpose of this study was to investigate the relationship between conception rate (CR) and climate variables. Data consisted of 24,380 inseminations of Holstein dairy herd in Hidalgo, Mexico. Weather records, including daily temperature (T), relative humidity (RH), rainfall, wind speed, and solar radiation, were obtained from a nearby weather station. Means for each climatic variable from 2 days before artificial insemination (AI) to the AI day were calculated for each conception date represented in the study. A significant negative correlation was observed between the CR and mean and minimum T, mean and minimum RH, mean and minimum temperature–humidity index (THI), and rainfall. The overall mean CR was 34.3%. The CR in lactating dairy cows followed a seasonal pattern, lower CRs were observed in summer months than during winter (32.1% vs. 36.9%; P < 0.01). The variables that had the greatest influence on CR were minimum and maximum T, minimum RH, minimum THI, wind speed, and ...

During storage of solid animal manure, biological transformation of nitrogen and carbon may increase the temperature to 60 to 70 o C, i.e. composting. The rise in temperature may cause a substantial loss of ammonia, as the ammonium is... more

During storage of solid animal manure, biological transformation of nitrogen and carbon may increase the temperature to 60 to 70 o C, i.e. composting. The rise in temperature may cause a substantial loss of ammonia, as the ammonium is transformed to ammonia at high temperatures and because the heat is generating a flow of air through the dung heap. In

Flight speed (FS) is an objective measure of the behavioural response to handling procedures in beef cattle but to date there is no published work on dairy cattle. It is useful to determine whether there is consistency in FS in dairy... more

Flight speed (FS) is an objective measure of the behavioural response to handling procedures in beef cattle but to date there is no published work on dairy cattle. It is useful to determine whether there is consistency in FS in dairy cattle, and assess the relationship between FS and other subjective measures of responsiveness in dairy cattle. The aims of

During the last decades, the Italian Alps were characterized by a very high rate of agricultural aban-donment that mainly affected small farms. The remaining farms, especially in the dairy cattle sector, moved towards increasing size,... more

During the last decades, the Italian Alps were characterized by a very high rate of agricultural aban-donment that mainly affected small farms. The remaining farms, especially in the dairy cattle sector, moved towards increasing size, intensified production and abandonment of traditional summer grazing of the herds in high altitude pastures. The aim of the study was to estimate the carbon footprint (CF) of cow milk production in the Italian Alps, comparing the traditional farming system based on summer grazing in the highlands with the emerging more intensive systems. Moreover, a sensitivity analysis was performed to investigate the variations in the outcomes of different allocation methods and of different scenarios of land use change (LUC) emissions for soybean production. A group of 32 dairy farms was analyzed in a " cradle to farm gate " life cycle assessment (LCA); 9 of them transferred the whole herd including lactating cows to the high altitude pastures for three months in the summer season (Summer Grazing ¼ SG) while the remaining 23 (no Summer Grazing ¼ noSG) maintained their lactating cows in the valley barns all over the year. On average the farms had a small herd size (54 AE 61 lactating cows) but a high stocking rate (3.7 AE 2.0 Livestock Unit ha À1). The average milk production was 6206 AE 1892 kg FPCM cow À1 year À1 with a huge difference between the two groups (7017 AE 1445 kg FPCM cow À1 for noSG and 4132 AE 1184 for SG). NoSG farms had also higher feed efficiency than SG ones. The CF values obtained in the baseline scenario were 1.55 AE 0.21 and 1.72 AE 0.37 kg CO 2-eq. kg À1 FPCM for, respectively, noSG and SG farms. Considering different allocation methods, no significant differences were observed between the carbon footprint of the two systems. When LUC emissions were accounted for, CF increased especially in noSG farms due to the high amount of concentrate feed purchased. Traditional activity of summer grazing in high pastureland did not show any mitigation effect on the carbon footprint of milk, mainly as a consequence of low milk yield and low feed efficiency. The sensitivity analysis for different allocation methods and for different LUC emissions underlined the fact that one of LCA's limits is that a change of key assumptions can determine a change of the overall results. In particular including the emissions related to LUC for soybean production significantly affects the final outcome, the amount of feed purchased by the farm becoming one of the major driver of milk CF.

The uterotonic characteristics and effectiveness of a single treatment with either oxytocin or carbetocin were quantified in early postpartum dairy cows after normal, uncomplicated calvings. Both the short-term (within 4 h), and the... more

The uterotonic characteristics and effectiveness of a single treatment with either oxytocin or carbetocin were quantified in early postpartum dairy cows after normal, uncomplicated calvings. Both the short-term (within 4 h), and the long-term effects (between 12 and 36 h) of the two treatments were compared. Between 14 and 16 h after parturition, 27 multiparous Holstein-Friesian dairy cows, without fetal membrane retention, were selected and divided into three groups. The first group (n = 9) was administered 50 IU oxytocin intramuscularly, the second group (n = 10) received 0.35 mg carbetocin, while animals of the third group (n = 8), serving as a control, were administered 5 mL saline solution. A transcervically introduced open tip catheter system was used for the non-invasive acquisition of the intrauterine pressure (IUP) recording. After digitalization, the signals were analyzed, using a specially adapted graphical software program. A significant short-term effect was found both ...

Results of previous studies have shown that increased milking frequency (IMF) during early lactation results in increased milk yield not only during the period of IMF but also after cows have returned to a decreased milking frequency. The... more

Results of previous studies have shown that increased milking frequency (IMF) during early lactation results in increased milk yield not only during the period of IMF but also after cows have returned to a decreased milking frequency. The cellular mechanisms underpinning this increased milk yield and the overall effects of IMF on metabolism have not been well characterized. The objective of this study was to determine the effects of IMF on metabolism and mammary epithelial cell proliferation in dairy cows. Thirty primiparous and 30 multiparous Holstein cows were assigned randomly at calving to 1 of 2 treatments. The control group was milked twice daily (2×) for 119 d, whereas the IMF group was milked 4 times daily (4×) from d 2 postcalving until d 21 and then 2× from d 22 until d 119. Overall milk yield did not differ between treatments throughout the 119 d monitored; however, the interaction of treatment by week was significant in that IMF cows yielded 4.8kg/d more milk than control cows during wk 2 and 3 and had similar levels of milk yield during the remainder of the study period. Reanalysis of data excluding data from cows subjected to mammary biopsy suggested that the mammary biopsy procedure contributed to the lack of overall responses of milk yield, but that responses overall to IMF were greater in primiparous cows compared with multiparous cows. Plasma nonesterified fatty acid concentrations were elevated in multiparous cows subjected to IMF during the period of IMF, but were not influenced by treatment in primiparous cows. Plasma β-hydroxybutyrate concentrations were not affected by treatment. Mammary tissue was collected by biopsy in a subset of cows (n=8 cows per parity and treatment) at calving and at d 21 and 75 postpartum and used for immunohistochemical localization of the cell proliferation antigen, Ki67. Effects of treatment on mammary epithelial cell proliferation were not significant, suggesting that other mechanisms must be responsible for carryover effects of IMF on lactational performance.

A chart for body condition scoring of freely moving Holstein dairy cows was developed using an iterative process consisting of literature review, interviews with experts, field testing, statistical analysis, and comments from chart users.... more

A chart for body condition scoring of freely moving Holstein dairy cows was developed using an iterative process consisting of literature review, interviews with experts, field testing, statistical analysis, and comments from chart users. The chart consists of text and diagrams that ...