Showing papers in "Journal of Dairy Science in 2008"

TL;DR: Efficient methods for processing genomic data were developed to increase reliability of estimated breeding values and to estimate thousands of marker effects simultaneously, and a blend of first- and second-order Jacobi iteration using 2 separate relaxation factors converged well for allele frequencies and effects.

TL;DR: The focus of mastitis prevention and control programs should differ between regions and should be tailored to farms based on housing type and BMSCC.

TL;DR: Overall data suggest that any effort to avoid the acute phase response in the transition period would be useful for optimizing the productive and reproductive performance of high-yielding dairy cows.

TL;DR: The variation in EVHL among animals and the central role that HSF1 has in coordinating thermal tolerance suggest that there is opportunity to improve thermal tolerance via gene manipulation, which will lead to opportunities for improved animal performance via altered nutritional management.

TL;DR: Daily feeding time was the feeding characteristic that changed most consistently in relation to the studied disorders, which suggests that a system that monitors short-term feeding behavior can assist in the early identification of sick cows.

TL;DR: The supramolecular structure of colloidal casein micelles in milk was investigated and an interlocked lattice model was developed in which both casein-calcium phosphate aggregates and casein polymer chains act together to maintain casein micelle integrity, which exhibits the principles of self-aggregation, interdependence, and diversity observed in nature.

TL;DR: The results confirm the high plasticity of milk FA composition, with the widest variations being observed in the percentages of medium-chain versus C18 FA, and among the C18 in 18:0, cis-18:1, and trans- 18:1.

TL;DR: It is suggested that the content of peNDF required to stabilize ruminal pH and maintain milk fat content without compromising milk energy efficiency can be arranged based on grain or starch sources included in the diet, on feed intake level, and on days in milk of the cows.

TL;DR: The concept of a comparative SR is introduced, whereby the carrying capacity of the farm is defined by the BW of the cows, the potential of the land to produce pasture, and the amount of supplement purchased (kg of BW/t of feed dry matter).

TL;DR: The detailed results obtained from this insemination and replacement optimization model can assist farmers in making CM treatment decisions and can assist whole-farm profitability.

TL;DR: Results of this study show that under experimental conditions, supplementing dairy cow diets with CIN, QCT, or YSE had limited effects on digestion, ruminal fermentation characteristics, and protozoal populations, and the lack of effects observed suggests that these antimicrobials require administration at greater doses to favorably alter rumen microbial fermentation.

TL;DR: Estimation of genetic parameters for major milk fatty acids and milk production traits indicated that selection for fat percentage should result in a correlated increase of C16:0, whereas unsaturated C18 fatty acids decreased with increasing fat percentage (-0.74).

TL;DR: It is concluded that selectivebreeding can contribute to higher unsaturation indices, and that selective breeding can capitalize on genotypic information of both the SCD1 A293V and the DGAT1 K232A polymorphism.

TL;DR: Bovine milk oligosaccharides have several potentially important biological activities including the prevention of pathogen binding to the intestinal epithelial and as nutrients for beneficial bacteria.

TL;DR: It is shown that regrouping can disrupt behavior and production in the hours and days following regrouped and suggests the need for future research to identify management changes that reduce these effects.

TL;DR: Both HR and LR cows altered their sorting behavior in response to acidosis challenges, and severe acidosis was associated with increased sorting for the longer particles in the diet and against the shorter particles, likely to lessen the effects of the very.

TL;DR: In conclusion, lame cows have longer lying times and spend less time standing, walking, and expressing an estrous behavior, and are more likely to be of lower body condition score.

TL;DR: Feeding dairy cows high proportions (30 and 45% DM basis) of barley grain was associated with lower feed intake and rumen pH, increased endotoxin in the rumen fluid, and stimulation of an inflammatory response.

TL;DR: It is suggested that to capture useful LD, which is required for whole-genome fine mapping and genomic selection, a denser SNP map would be needed.

TL;DR: By inducing a lower ruminal E(h) and rH, live yeast prevented accumulation of lactate and allowed better fiber digestion, whereas sodium bicarbonate seemed to act only as an exogenous buffer.

TL;DR: The variation in IgG content in colostrum produced by Norwegian dairy cows indicates a need for improved colstrum quality control and subsequent adjustment of the colostrums feeding regimen to ensure a protective immunological status for newborn calves.

TL;DR: The impact of 9 single nucleotide polymorphisms (SNP) in the leptin (LEP), leptin receptor (LEPR), growth hormone receptor (GHR), and diacylglycerol acyltransferase (DGAT1) gene loci on daily milk production, feed intake, and feed conversion, and weekly measures of live weight, BCS, and body energy traits was evaluated using genetic and phenotypic data on 571 Holstein cows.

TL;DR: Almost all calves experienced mild diarrhea during the study, but feeding YC improved fecal scores, reduced days with watery feces, incidence of fever and diarrhea, and risk of health disorders.

TL;DR: The use of sexed semen should lower the cost of progeny-testing programs and embryo transfer and enhance the value of genetic markers, and the economic benefits from the use ofsexed semen will be passed on to consumers.

TL;DR: An algae supplementation level of about 10 g/kg of DMI proved effective to reduce the milk fat content and to modify the milk fatty acid composition toward increased CLA cis-9 trans-11, C18:1 trans, and DHA concentrations.

TL;DR: Selecting for high casein content, milk acidity, and low somatic cell count might be an indirect way to improve MCP without reducing milk yield and quality traits.

TL;DR: Results indicate that slick-haired Holstein cows can regulate body temperature more effectively than wild-type cows during heat stress, and clipping the hair at the site of sweating measurement eliminated the difference.

TL;DR: In this article, a meta-analysis of the impact of monensin on metabolism of dairy cattle was conducted following a search of the literature, where 30 papers and 45 trials contained metabolic data.

TL;DR: Shotgun proteomics, using amine-reactive isobaric tags (iTRAQ), was used to quantify protein changes in milk fat globule membranes (MFGM) that were isolated from d 1 colostrum and compared with MFGM from d 7 milk to demonstrate that quantitative shotgun proteomics has great potential to provide new insights into mammary development.

TL;DR: Investigation of the association of the signal transducer and activator of transcription 5A (STAT5A) gene with fertilization rate, embryonic survival, and milk production and composition in cattle revealed that allele G of SNP12195 was associated with a decrease in both protein and fat percentages, making this SNP an attractive candidate for progeny testing programs in dairy cattle.