Effect of Herd Environment on the Genetic and Phenotypic Relationships Among Milk Yield, Conception Rate, and Somatic Cell Score in Holstein Cattle

The objective of this study was to estimate lactation curve parameters with Dijkstra mechanistic model and to evaluate genetic and phenotypic relationships between the parameters and the average somatic cell count in primiparous cows. The finding indicated that heritability estimates for partial milk yield (PMY1, PMY2 and PMY3), total 305-day milk yield (TMY305), decay parameter (λ2), age at first calving (AFC) and peak yield (PY) were moderate while the heritability of persistency (PS%), average somatic cell score (AVGSCS), time to peak yield (TP), initial milk production (λ0), specific rate of cell proliferation at parturition (λ1), and specific rate of cell death (λ3) were quite low. Genetic correlations between both AFC and PS% traits with average somatic cell scores was negative (-0.047 and -0.060) but low positive genetic correlation were between partial milk yields (PMY1 and PMY3) while negative genetic correlation (-0.06) was obtained between TMY305 and AVGSCS. Differences between TMY305 of cows with less than 100000 cells mL-1 and cows with >1,500,000 cells mL-1 was approximately 708 Kg and is equivalent to 8% loss of milk yield/cow during lactation period and also loss of persistency (11.1 %( was shown for the extreme classes of SCC in this study.

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Identification of a two-marker-haplotype on Bos taurus autosome 18 associated with somatic cell score in German Holstein cattle

BMC Genetics ◽

10.1186/1471-2156-10-50 ◽

2009 ◽

Vol 10 (1) ◽

pp. 50 ◽

Cited By ~ 8

Author(s):

Bodo Brand ◽

Christine Baes ◽

Manfred Mayer ◽

Norbert Reinsch ◽

Christa Kühn

Keyword(s):

Somatic Cell ◽

Bos Taurus ◽

Somatic Cell Score ◽

Holstein Cattle ◽

Marker Haplotype

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Effect of gradual or abrupt cessation of milking at dry off on milk yield and somatic cell score in the subsequent lactation

Journal of Dairy Science ◽

10.3168/jds.2016-11444 ◽

2017 ◽

Vol 100 (3) ◽

pp. 2080-2089 ◽

Cited By ~ 5

Author(s):

P.N. Gott ◽

P.J. Rajala-Schultz ◽

G.M. Schuenemann ◽

K.L. Proudfoot ◽

J.S. Hogan

Keyword(s):

Somatic Cell ◽

Milk Yield ◽

Somatic Cell Score ◽

Abrupt Cessation

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Heritability of Teat Condition in Italian Holstein Friesian and Its Relationship with Milk Production and Somatic Cell Score

Animals ◽

10.3390/ani10122271 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2271

Author(s):

Francesco Tiezzi ◽

Antonio Marco Maisano ◽

Stefania Chessa ◽

Mario Luini ◽

Stefano Biffani

Keyword(s):

Dairy Cattle ◽

Somatic Cell ◽

Milk Yield ◽

Genetic Factors ◽

Genetic Correlations ◽

Somatic Cell Score ◽

Cattle Industry ◽

Holstein Friesian ◽

Selection For ◽

Current Selection

In spite of the impressive advancements observed on both management and genetic factors, udder health still represents one of most demanding objectives to be attained in the dairy cattle industry. Udder morphology and especially teat condition might represent the first physical barrier to pathogens’ access. The objectives of this study were to investigate the genetic component of teat condition and to elucidate its relationship with both milk yield and somatic cell scores in dairy cattle. Moreover, the effect of selection for both milk yield and somatic cell scores on teat condition was also investigated. A multivariate analysis was conducted on 10,776 teat score records and 30,160 production records from 2469 Italian Holstein cows. Three teat scoring traits were defined and included in the analysis. Heritability estimates for the teat score traits were moderate to low, ranging from 0.084 to 0.238. When teat score was based on a four-classes ordinal scoring, its genetic correlation with milk yields and somatic cell score were 0.862 and 0.439, respectively. The scale used to classify teat-end score has an impact on the magnitude of the estimates. Genetic correlations suggest that selection for milk yield could deteriorate teat health, unless more emphasis is given to somatic cell scores. Considering that both at national and international level, the current selection objectives are giving more emphasis to health traits, a further genetic deterioration in teat condition is not expected.

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