scholarly journals Genetic Correlations of Milk Production and Type Traits with Somatic Cell Score from Holstein Cows in Hokkaido

2005 ◽  
Vol 76 (4) ◽  
pp. 401-406 ◽  
Author(s):  
Shinya MIURA ◽  
Mitsuyoshi SUZUKI
Keyword(s):  
Somatic Cell ◽  
Milk Production ◽  
Genetic Correlations ◽  
Somatic Cell Score ◽  
Holstein Cows ◽  
Type Traits

Relationship between somatic cell score and longevity of Holstein cows in Brazil using a piecewise Weibull proportional-hazard model

2019 ◽  
Vol 59 (8) ◽  
pp. 1546
Author(s):  
Elisandra Lurdes Kern ◽  
Jaime Araujo Cobuci ◽  
José Braccini Neto ◽  
Darlene dos Santos Daltro
Keyword(s):  
Somatic Cell ◽  
Milk Production ◽  
Hazard Model ◽  
Somatic Cell Score ◽  
Holstein Cows ◽  
Independent Effect ◽  
Proportional Hazard ◽  
Proportional Hazard Model ◽  
Weibull Proportional Hazard ◽  
The Impact

The objective of the present work was to evaluate the effect of somatic cell score on the longevity of Holstein cows raised all over Brazil, using a piecewise Weibull proportional-hazard model. The following two longevity traits were defined: true longevity, number of days from first calving to culling; and functional longevity, approximated by correcting true longevity to within-herd-year production. Records on productive life of 131330 cows were used. The model included the time-independent effect of age at first calving. The other effects were time-dependent, and included the following: region by year of calving, variation in herd-size class, milk-production class by year of calving within herd, within-herd milk-production class by number of lactations, within-herd fat content, within-herd protein content, and somatic cell score (SCS). The overall mean of the somatic cell counts (SCC) was 322000 cells/mL. The highest SCC mean was found between 130 to 290 days of lactation. The SCC mean decreased over the years. Cows from Region 5 (Rio Grande do Sul) showed higher SCC means. The risk of culling was slightly higher for functional longevity than for true longevity. The impact of longevity was high in cows from first to fourth lactation with a high SCS, with the risk of culling varying from 0.90 (true longevity: second lactation and Class 2) to 1.2 (functional longevity: fourth lactation and Class 5). Cows at the fifth lactation with a lower SCS had a higher risk of culling (1.4). Including the effect of SCS class by stage of lactation in the models was not beneficial. The decrease in SCS, especially from the first to fourth lactation, can be used for indirect selection to improve the longevity of Holstein cows in Brazil.

scholarly journals Heritabilities and genetic correlations of lactational and daily somatic cell score with conformation traits in Polish Holstein cattle

2011 ◽  
Vol 56 (No. 5) ◽  
pp. 205-212 ◽  
Author(s):  
E. Ptak ◽  
W. Jagusiak ◽  
A. Żarnecki ◽  
A. Otwinowska-Mindur
Keyword(s):  
Somatic Cell ◽  
Variance Components ◽  
Genetic Correlations ◽  
Somatic Cell Score ◽  
Direct Selection ◽  
Linear Type ◽  
Holstein Friesian ◽  
Type Traits ◽  
Selection For ◽  
Friesian Cows

The objective of this study was to estimate heritabilities and genetic correlations of lactational and daily somatic cell scores with descriptive and linear type traits in Polish Holstein-Friesian cows. Data were: test-day somatic cell scores and conformation evaluations of 24 599 primiparous cows, daughters of 802 sires. Cows calved from 2006 to 2007. The lactational somatic cell score was calculated as the average of four test-day somatic cell scores at least. The daily somatic cell score was the test-day somatic cell score closest to the date of type evaluation. A multi-trait animal model was used to estimate genetic parameters. (Co)variance components were estimated by a Bayesian algorithm via Gibbs sampling. The heritability of lactational somatic cell score was 0.20 and it was much higher than that of daily somatic cell score (0.13). Heritabilities of type traits were high to moderate for height at rump (0.46), size (0.39), overall conformation score (0.30), two linear rump traits (0.28–0.29) and three linear teat traits (0.26–0.29). The genetic correlation between lactational and daily somatic cell scores was 0.84. In many cases, daily somatic cell score showed higher genetic correlations with type traits than lactational somatic cell score. Descriptive udder and feet and legs scores were genetically correlated negatively with both lactational (–0.22 and –0.20) and daily somatic cell scores (–0.28 and –0.33). Somatic cell traits were genetically correlated positively with rump angle (0.21 and 0.19) and negatively with fore udder height (–0.26 and –0.29), udder depth (–0.23 and –0.17) and central ligament (–0.14 and –0.16). Due to higher heritability, direct selection for lower lactational somatic cell score would be more effective than selection for lower daily somatic cell score. The magnitude of obtained heritabilities and the favourable genetic correlations indicate that the selection utilizing some type traits could improve the resistance to mastitis.

scholarly journals Polymorphisms of the ACSL1 Gene Influence Milk Production Traits and Somatic Cell Score in Chinese Holstein Cows

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2282
Author(s):  
Yan Liang ◽  
Qisong Gao ◽  
Qiang Zhang ◽  
Abdelaziz Adam Idriss Arbab ◽  
Mingxun Li ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Milk Production ◽  
Somatic Cell Score ◽  
Holstein Cows ◽  
Production Traits ◽  
Milk Production Traits ◽  
Chinese Holstein ◽  
Chain Acyl ◽  
Chinese Holstein Cows ◽  
Long Chain

Improving the quality of milk is a challenge for zootechnicians and dairy farms across the globe. Long-chain acyl-CoA synthetase 1 (ACSL1) is a significant member of the long-chain acyl-CoA synthetase gene family. It is widely found in various organisms and influences the lactation performance of cows, including fat percentage, milk protein percentage etc. Our study was aimed to investigate the genetic effects of single nucleotide polymorphisms (SNPs) in ACSL1 on milk production traits. Twenty Chinese Holstein cows were randomly selected to extract DNA from their blood samples for PCR amplification and sequencing to identify SNPs of the bovine ACSL1 gene, and six SNPs (5’UTR-g.20523C>G, g.35446C>T, g.35651G>A, g.35827C>T, g.35941G>A and g.51472C>T) were discovered. Then, Holstein cow genotyping (n = 992) was performed by Sequenom MassARRAY based on former SNP information. Associations between SNPs and milk production traits and somatic cell score (SCS) were analyzed by the least-squares method. The results showed that SNP g.35827C>T was in high linkage disequilibrium with g.35941G>A. Significant associations were found between SNPs and test-day milk yield (TDMY), fat content (FC), protein content (PC) and SCS (p < 0.05). Among these SNPs, SNP 5’UTR-g.20523C>G showed an extremely significant effect on PC and SCS (p < 0.01). The SNP g.35446C>T showed a statistically significant effect on FC, PC, and SCS (p < 0.01), and also TDMY (p < 0.05). The SNP g.35651G>A had a statistically significant effect on PC (p < 0.01). The SNP g.35827C>T showed a highly significant effect on TDMY, FC, and SCS (p < 0.01) and significantly influenced PC (p < 0.05). Lastly, SNP g.51472C>T was significantly associated with TDMY, FC, and SCS (p < 0.05). In summary, the pleiotropic effects of bovine ACSL1 for milk production traits were found in this paper, but further investigation will be required on the intrinsic correlation to provide a theoretical basis for the research on molecular genetics of milk quality traits of Holstein cows.

scholarly journals The use of dijkstra mechanistic model for genetic analysis of the lactation curve characteristics and their relationships with age at first calving and somatic cell score of Iranian dairy cows

2020 ◽  
Vol 42 ◽  
pp. e50181
Author(s):  
Mahdi Elahi Torshizi ◽  
Homayoun Farhangfar
Keyword(s):  
Somatic Cell ◽  
Genetic Correlation ◽  
Milk Yield ◽  
Mechanistic Model ◽  
Genetic Correlations ◽  
Somatic Cell Score ◽  
Specific Rate ◽  
Lactation Period ◽  
Age At First Calving ◽  
Lactation Curve

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.

scholarly journals Effects of the inclusion of açai oil in diet of prepartum Holstein cows on milk production, somatic cell counts and future lactation

2020 ◽  
Vol 92 (4) ◽  
Author(s):  
DAIANE S. DOS SANTOS ◽  
VANDERLEI KLAUCK ◽  
CARINE F. SOUZA ◽  
MATHEUS D. BALDISSERA ◽  
CLEITON THEISEN ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Milk Production ◽  
Holstein Cows ◽  
Somatic Cell Counts ◽  
Cell Counts

scholarly journals Genetic relationship between type traits, number of lactations initiated, and lifetime milk performance in Czech Fleckvieh cattle

2017 ◽  
Vol 62 (No. 12) ◽  
pp. 501-510 ◽  
Author(s):  
L. Novotný ◽  
J. Frelich ◽  
J. Beran ◽  
L. Zavadilová
Keyword(s):  
Body Size ◽  
Milk Production ◽  
Genetic Relationship ◽  
Genetic Correlations ◽  
Bivariate Analysis ◽  
Dual Purpose ◽  
Lifetime Performance ◽  
Dual Purpose Cattle ◽  
Type Traits ◽  
Milk Performance

Genetic relationship was analyzed between type traits and longevity measures in dual-purpose cattle. Data from 91 486 Czech Fleckvieh cows first calved between 2003 and 2009 were used. Longevity was defined as the actual number of lactations initiated per cow and also as functional longevity, which incorporated an adjustment to account for variation in voluntary culling based upon milk production. Lifetime performance was defined as cumulative milk production through the 6<sup>th</sup> parity. All cows were scored for conformation traits during their first lactation. Genetic correlations between these traits and longevity measures were estimated by bivariate analysis using the DMU variance component program package. Type trait heritabilities ranged from 0.30 to 0.59, while heritabilities for longevity and functional longevity were 0.06 and 0.05, respectively. Heritability of lifetime performance was 0.08. Genetic correlations between type traits and longevity measures ranged from low to intermediate values. Genetic correlations of the measured body size traits to the real and functional longevity ranged from –0.06 to –0.29, for udder traits from –0.02 to 0.33, and for foot and leg traits from –0.03 to 0.17. Genetic correlations between the measured body size traits and lifetime performance ranged from –0.03 to –0.30, for udder traits from 0.05 to 0.47, for foot and leg traits from –0.07 to 0.15. Genetic correlations of composite trait scores for frame, muscularity, feet and legs, and udder with longevity traits ranged from –0.20 to 0.41 and for lifetime performance –0.14 to 0.51. The highest genetic correlations between a type trait and functional longevity were for composite udder score (0.25), feet and legs (0.26), and udder depth (0.33), suggesting that these traits could serve as indicators of functional longevity. We conclude that selection based upon easily and inexpensively measured type traits could improve functional longevity of cows as well as lifetime milk production.

scholarly journals Genetic parameters of test-day somatic cell scores for the first three lactations of Polish Holstein-Friesian cattle

2011 ◽  
Vol 56 (No. 9) ◽  
pp. 381-389 ◽  
Author(s):  
K. Rzewuska ◽  
J. Jamrozik ◽  
A. Żarnecki ◽  
T. Strabel
Keyword(s):  
Somatic Cell ◽  
Bayesian Methods ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Large Data ◽  
Somatic Cell Score ◽  
Data Set ◽  
Holstein Friesian ◽  
Covariance Components ◽  
Friesian Cattle

&nbsp;Genetic parameters for somatic cell score in the first three lactations of Polish Holstein-Friesian cattle were estimated. A multiple-lactation model was applied with random herd-test-day effect, fixed regressions for herd-year and age-season of calving, and random regressions for the additive genetic and permanent environmental effects. The large data set was used that included over one million test-day records and more than 58 000 cows. Estimates of covariance components and genetic parameters were obtained by Bayesian methods using the Gibbs sampler. Average daily heritabilities of somatic cell score (SCS) in the first three lactations were 0.11, 0.12 and 0.14 for the first, second and third lactation, respectively. Estimates of daily heritabilities were rather independent of days in milk (DIM), with no serious abnormalities at the beginning or the end of lactation. Average genetic correlations between SCS on the same DIM were 0.68, 0.62 and 0.70 for first and second, first and third, and second and third parities, respectively, and did not exceed 0.77. The low level of heritability estimates and relatively low genetic correlations between lactations would suggest that selection based on the first lactation only could limit a response in mastitis resistance for later lactations.

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