Genetic correlations between milk production traits and somatic cell scores on test day within and across first and second lactations in Holstein cows

Yamazaki, Takeshi; Hagiya, Koichi; Takeda, H.; Sasaki, Osamu; Yamaguchi, Shoichiro; Sogabe, Michihiko; Saito, Yûsuke; Nakagawa, Satoshi; Togashi, Kenji; Suzuki, Keiichi; Nagamine, Yoshitaka

doi:10.1016/j.livsci.2012.12.015

Cited by 28 publications

(31 citation statements)

References 31 publications

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“…Our heritability estimates for CR were in the range of those recently reported for CR or NR for dairy cows. In addition, our heritability estimates for 305-day milk in the first two lactations were similar to those of a recent study (0.42 for first lactation and 0.34 for second lactation) of Japanese Holsteins (Yamazaki et al, 2013). Furthermore, our results for heritabilities of TD milk yield during first lactation agree with similar estimates that were obtained by using a random regression model for Holstein cows in Japan (Hagiya et al, 2009).…”

Section: Discussionsupporting

confidence: 91%

Relationships between conception rate in Holstein heifers and cows and milk yield at various stages of lactation

Hagiya

Terawaki

Yamazaki

et al. 2013

Animal

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We investigated the relationships between conception rates (CRs) at first service in Japanese Holstein heifers (i.e. animals that had not yet had their first calf) and cows and their test-day (TD) milk yields. Data included records of artificial insemination (AI) for heifers and cows that had calved for the first time between 2000 and 2008 and their TD milk yields at 6 through 305 days in milk (DIM) from first through third lactations. CR was defined as a binary trait for which first AI was a failure or success. A threshold-linear animal model was applied to estimate genetic correlations between CRs of heifers or cows and TD milk yield at various lactation stages. Two-trait genetic analyses were performed for every combination of CR and TD milk yield by using the Bayesian method with Gibbs sampling. The posterior means of the heritabilities of CR were 0.031 for heifers, 0.034 for first-lactation cows and 0.028 for second-lactation cows. Heritabilities for TD milk yield increased from 0.324 to 0.433 with increasing DIM but decreased slightly after 210 DIM during first lactation. These heritabilities from the second and third lactations were higher during late stages of lactation than during early stages. Posterior means of the genetic correlations between heifer CR and all TD yields were positive (range, 0.082 to 0.287), but those between CR of cows and milk yields during first or second lactation were negative (range, 20.121 to 20.250). Therefore, during every stage of lactation, selection in the direction of increasing milk yield may reduce CR in cows. The genetic relationships between CR and lactation curve shape were quite weak, because the genetic correlations between CR and TD milk yield were constant during the lactation period.

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Section: Discussionsupporting

confidence: 91%

Relationships between conception rate in Holstein heifers and cows and milk yield at various stages of lactation

Hagiya

Terawaki

Yamazaki

et al. 2013

Animal

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“…Vicario et al (2007) state that genetic improvement of lactation persistency results in a reduction in SCS (r g = −0.55) that is simultaneous with persistency of lactation. The negative average genetic correlation between daily SCS and a persistency of −0.23 and −0.22 in the first and second lactations was described by Yamazaki et al (2013). Cole and Null (2008) found a genetic correlation of persistency with SCS yield that ranged from −0.17 to −0.42 and a correlation of persistency for milk with persistency of SCS that ranged from −0.37 to −0.52 for five cattle breeds.…”

Section: Persistence and Somatic Cell Scorementioning

confidence: 97%

Genetic relationship of lactation persistency with milk yield, somatic cell score, reproductive traits, and longevity in Slovak Holstein cattle

2016

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Abstract. The objective of this study was to estimate the breeding values (BVs) of lactation persistency, the test day of milk yield, the somatic cell score, reproductive traits (calving interval, days open), longevity in Slovak Holstein dairy cattle. BVs were used for the detection of relationships among the persistency of lactation and other selected traits. Data for the estimation of BVs of milk production and somatic cell score were collected from 855 240 cows. BVs for reproductive traits were estimated for 352 712 cows and for longevity for 528 362 cows. The highest correlations were confirmed between the BV of persistency and the BV of test day milk yield at 100, 200, and 305 days ( − 0.88, −0.65, and −0.61). Correlations between the BV of lactation persistency and the BV of somatic cell score at day 305 or the BV of somatic cell score persistency were favorable: −0.05 and −0.12, respectively. The relationship between the BV of persistency and the BV of the calving interval or the BV of days open was 0.11 and 0.10 respectively. The selection for the persistency of lactation may not improve longevity because there is no relation between the BV of persistency and the BV of longevity (r g = 0.06).

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“…These covariates are used in dairy sire and cow evaluation model in Japan Hagiya et al, 2014). The covariates of the random-regression animal and environmental effects are third-order Legendre polynomials (Jakobsen et al, 2002;Togashi et al, 2008;Yamazaki et al, 2013).…”

Section: Modelsmentioning

confidence: 99%

“…These intervals were defined as 5 to 45, 46 to 115, 116 to 205 and 206 to 305 DIM (Miglior et al, 2007;Yamazaki et al, 2013). Variance components were estimated by using subsets that consisted of the records for herds that were sampled (~10%) randomly from the complete herds for each lactation.…”

Section: Modelsmentioning

confidence: 99%

Effects of stage of pregnancy on variance components, daily milk yields and 305-day milk yield in Holstein cows, as estimated by using a test-day model

Yamazaki

Hagiya

Takeda

et al. 2016

Animal

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Pregnancy and calving are elements indispensable for dairy production, but the daily milk yield of cows decline as pregnancy progresses, especially during the late stages. Therefore, the effect of stage of pregnancy on daily milk yield must be clarified to accurately estimate the breeding values and lifetime productivity of cows. To improve the genetic evaluation model for daily milk yield and determine the effect of the timing of pregnancy on productivity, we used a test-day model to assess the effects of stage of pregnancy on variance component estimates, daily milk yields and 305-day milk yield during the first three lactations of Holstein cows. Data were 10 646 333 test-day records for the first lactation; 8 222 661 records for the second; and 5 513 039 records for the third. The data were analyzed within each lactation by using three single-trait random regression animal models: one model that did not account for the stage of pregnancy effect and two models that did. The effect of stage of pregnancy on test-day milk yield was included in the model by applying a regression on days pregnant or fitting a separate lactation curve for each days open (days from calving to pregnancy) class (eight levels). Stage of pregnancy did not affect the heritability estimates of daily milk yield, although the additive genetic and permanent environmental variances in late lactation were decreased by accounting for the stage of pregnancy effect. The effects of days pregnant on daily milk yield during late lactation were larger in the second and third lactations than in the first lactation. The rates of reduction of the 305-day milk yield of cows that conceived fewer than 90 days after the second or third calving were significantly ( P < 0.05) greater than that after the first calving. Therefore, we conclude that differences between the negative effects of early pregnancy in the first, compared with later, lactations should be included when determining the optimal number of days open to maximize lifetime productivity in dairy cows. Keywords: dairy cattle, days open, days pregnant, test-day model ImplicationsDaily milk yields of cows decline as pregnancy progresses. By using a test-day model, we revealed that stage of pregnancy did not affect the estimated heritability of daily milk yield. However, 305-day milk yields were decreased in cows with fewer days open, and the rates of reduction associated with decreased days open (⩽90) in the second and third lactations were larger than that in the first lactation. These differences between the effects of stage of pregnancy in the first compared with later lactations should be included when determining the optimal number of days open for lifetime productivity in dairy cows.

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Genetic correlations between milk production traits and somatic cell scores on test day within and across first and second lactations in Holstein cows

Cited by 28 publications

References 31 publications

Relationships between conception rate in Holstein heifers and cows and milk yield at various stages of lactation

Relationships between conception rate in Holstein heifers and cows and milk yield at various stages of lactation

Genetic relationship of lactation persistency with milk yield, somatic cell score, reproductive traits, and longevity in Slovak Holstein cattle

Effects of stage of pregnancy on variance components, daily milk yields and 305-day milk yield in Holstein cows, as estimated by using a test-day model

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