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Lembeye F.,Massey University | Lopez-Villalobos N.,Massey University | Burke J.L.,Massey University | Davis S.R.,Livestock Improvement Corporation LIC
New Zealand Journal of Agricultural Research | Year: 2016

The objective of this study was to compare Holstein-Friesian (F), Jersey (J) and crossbred (F × J) cows milked once-a-day (OAD) or twice-a-day (TAD) in New Zealand for milk, fat and protein yield, lactation persistency and average somatic cell score (SCS). Data consisted of 223,149 herd-test records (89,297 and 133,852 OAD and TAD, respectively) from 11,848 F; 11,677 J and 27,720 F × J spring-calving cows between 2008 and 2012. Compared to TAD systems, cows milked OAD yielded 722, 28.0 and 22.2 kg less milk, fat and protein, respectively. Crossbred and J cows were less affected than F cows by OAD milking with a reduction in milk yield traits of ≤ 19.0%, while in F cows the reduction ranged between 19%–25%. Cows milked OAD had higher SCS than cows milked TAD (6.20 vs. 6.08). The greatest SCS difference in OAD and TAD systems was in first-lactation cows (6.40 vs. 6.02). Persistency of production traits was greater in F and F × J cows milked OAD than in F and F × J cows milked TAD, but J cows had similar milk and protein persistency in both systems. Overall, cows milked OAD had greater persistency than cows milked TAD (79%–90% vs. 76%–85%). These results show that, in commercial herds, the relative difference in production traits between OAD and TAD systems was smaller than those reported in experimental trials. © 2016 The Royal Society of New Zealand Source

Davis S.R.,Vialactia Biosciences Ltd. | Davis S.R.,Livestock Improvement Corporation LIC | South C.R.,Vialactia Biosciences Ltd. | South C.R.,Novogy Inc.
Journal of Dairy Science | Year: 2015

Lactoferrin is a multifunctional glycoprotein with a range of antimicrobial and immune-related properties that is found at >10-fold higher concentration in human milk (~1.7. g/L) relative to bovine milk (~0.15. g/L). Consumer demand is increasing for bovine lactoferrin through a wide range of nutritional and cosmetic consumer products. Increasing lactoferrin yield and concentration in bovine milk could assist in satisfying this increasing demand and may also help in increasing resistance to bovine mammary infection. Two experiments with cows in mid and late lactation were carried out to examine milking strategies to increase milk lactoferrin concentration and yield. Milking was suspended in cows normally milked twice daily, for periods of 2, 4, or 7. d (mid lactation) or 2 or 4. d (late lactation) after which cows were milked out and twice-daily milking resumed for 4. d. In all groups, lactoferrin concentration was significantly increased during the remilking period, approaching concentrations similar to those found in human milk (~1. g/L). Lactoferrin yields were significantly higher in all treatment groups, although increasing the nonmilking period beyond 2. d offered no advantage. Milk yield was lower initially after resumption of milking but recovered to preexperimental values by the fourth day of remilking in all groups, except the 4-d nonmilking group in late lactation. Milk somatic cell count was significantly elevated in all groups at the start of remilking but had substantially reduced by d 4 and reached a preexperimental level in the 2-d nonmilking group of mid-lactation cows. In summary, extended milking intervals can be used as a tool to produce a short-term increase in the concentration and yield of lactoferrin from bovine milk during established lactation, without any apparent long-term effects on milk yield and quality. © 2015 American Dairy Science Association. Source

Karim L.,University of Liege | Takeda H.,University of Liege | Lin L.,University of Liege | Druet T.,University of Liege | And 12 more authors.
Nature Genetics | Year: 2011

We report mapping of a quantitative trait locus (QTL) with a major effect on bovine stature to a ∼1/4780-kb interval using a Hidden Markov Model-based approach that simultaneously exploits linkage and linkage disequilibrium. We re-sequenced the interval in six sires with known QTL genotype and identified 13 clustered candidate quantitative trait nucleotides (QTNs) out of >9,572 discovered variants. We eliminated five candidate QTNs by studying the phenotypic effect of a recombinant haplotype identified in a breed diversity panel. We show that the QTL influences fetal expression of seven of the nine genes mapping to the ∼1/4780-kb interval. We further show that two of the eight candidate QTNs, mapping to the PLAG1-CHCHD7 intergenic region, influence bidirectional promoter strength and affect binding of nuclear factors. By performing expression QTL analyses, we identified a splice site variant in CHCHD7 and exploited this naturally occurring null allele to exclude CHCHD7 as single causative gene. © 2011 Nature America, Inc. All rights reserved. Source

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