Current Issue February 2012, Vol. 95, No. 2
Full Table of ContentsFeatured Article
Hormones, metabolites, and reproduction in Holsteins, Jerseys, and their crosses
Holsteins, Jerseys, and their crosses in first (n = 157) and second (n = 107) lactation were observed to determine if reproduction, insulin-like growth factor 1 (IGF-1), insulin, nonesterified fatty acids (NEFA), and milk production differed between genetic groups. Days open and service number were affected by genetic group. The genetic group by week interaction affected NEFA concentrations. Insulin was affected by genetic group. The genetic group by lactation number interaction affected IGF-1 concentrations. Genetic group affected hormones and metabolites, which may partially explain differences in reproductive measures and milk yield.
Other Issue Highlights
- Accuracy of noninvasive breath methane measurements using Fourier transform infrared methods on individual cows
Emission of greenhouse gases is a great concern today. In this study, we evaluated a method for individual recording of methane production from large numbers of dairy cows. The measurements are based on Fourier transform infrared (FTIR) analysis of breath from cows during visits to feeding stations. We found that 22 to 46% of the total variation was attributable to individual cows differences. Other components in breath can be measured simultaneously. This technique has high capacity, making it suitable for large-scale, on-farm recording of methane useful to improve management and for genetic evaluation. - Proteomic analysis and immunodetection of the bovine milk osteopontin isoforms
Osteopontin is an immunostimulatory protein secreted in substantial amounts in bovine milk. Whereas human milk contains only one protein, several isoforms have been found in bovine milk. Human isoforms of the protein have previously been reported as the product of alternative spliced transcripts associated with metastasis. In the present study, the genomic and proteomic analysis of bovine osteopontin have confirmed the absence of alternative splicing. Milk-secreted bovine milk contains cleaved and mature proteins, and both were characterized by immunodetection and mass spectroscopy. - Association between bovine leukemia virus, production, and population age in Michigan dairy herds
Bovine leukemia virus (BLV) is an infectious disease that causes lymphosarcoma in a small percentage of infected cattle. However, the effect of this disease on cattle with subclinical infections is controversial. In this study, the prevalence of BLV in 104 dairy herds in Michigan was determined by detecting anti-BLV antibodies in milk by enzyme-linked immunosorbent assay. A significant association between higher herd prevalence of BLV and reduced milk production was determined. Additionally, dairy herds with a higher prevalence of BLV had a lower proportion of older cows (>3 lactations) within herd populations. Our results provide evidence that BLV infection is associated with herd-level economic effects in high-performing dairy herds.
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Effects of Heat-Stress on Production in Dairy CattleJune 2003 (Vol. 86 | No. 6 | Pages 2131-2144)
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Nutritional Management of Transition Dairy Cows: Strategies to Optimize Metabolic HealthJuly 2004 (Vol. 87 | Pages E105-E119)
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Invited review: Body condition score and its association with dairy cow productivity, health, and welfareDecember 2009 (Vol. 92 | No. 12 | Pages 5769-5801)
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Methods for Dietary Fiber, Neutral Detergent Fiber, and Nonstarch Polysaccharides in Relation to Animal NutritionOctober 1991 (Vol. 74 | No. 10 | Pages 3583-3597)
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Use of individual cow milk recording data at the start of lactation to predict the calving to conception intervalOctober 2010 (Vol. 93 | No. 10 | Pages 4677-4690)
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