Livestock Improvement Association of Japan

Tokyo, Japan

Livestock Improvement Association of Japan

Tokyo, Japan
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Yamazaki T.,Japan National Agriculture and Food Research Organization | Hagiya K.,Japan National Agriculture and Food Research Organization | Takeda H.,National Institute of Livestock and Grassland Science | Sasaki O.,National Institute of Livestock and Grassland Science | And 7 more authors.
Livestock Science | Year: 2013

The genetic correlations between milk production traits (daily milk yield, 305-day milk yield, and lactation persistency as the difference between milk yields at days 240 and 60) and daily somatic cell score (SCS) within and across first and second lactations in Holstein cows were estimated by using a multiple trait test day (TD) animal model. The data set consisted of 200,095 TD milk and SCS records from 21,238 cows in their first lactations and 143,051 records from 15,281 cows in their second. Data were analyzed by using a two-trait, two-lactation random regression animal model. Genetic correlations between daily SCS and milk production traits were estimated from additive genetic variance component estimates of random regression coefficients. Genetic correlations between daily milk yield in first lactation and daily SCS in both lactations were positive and peaked in early lactation stage. In contrast, the genetic correlations between persistency and daily SCS in both lactations were negative, except in very early lactation stage. These correlations suggested that focusing selection on increasing milk yield early in the first lactation would likely increase SCS, whereas selecting for increased persistency would decrease SCS during both lactations. The genetic correlations between 305-day milk yield and persistency were positive within and across the first and second lactations. These results suggested that selection for lactation persistency could help to increase lactation yield overall in the first and second lactations without increasing SCS. © 2013 Elsevier B.V.


Yamazaki T.,Japan National Agriculture and Food Research Organization | Hagiya K.,Obihiro University of Agriculture and Veterinary Medicine | Takeda H.,Japan National Agriculture and Food Research Organization | Osawa T.,National Livestock Breeding Center | And 2 more authors.
Animal | Year: 2016

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. © The Animal Consortium 2016


Hagiya K.,Japan National Agriculture and Food Research Organization | Yamazaki T.,Japan National Agriculture and Food Research Organization | Nagamine Y.,Nihon University | Togashi K.,Livestock Improvement Association of Japan | And 5 more authors.
Animal | Year: 2014

The aim of this study was to estimate genetic correlations between milk yield, somatic cell score (SCS), mastitis, and claw and leg disorders (CLDs) during first lactation in Holstein cows by using a threshold-linear random regression test-day model. We used daily records of milk, fat and protein yields; somatic cell count (SCC); and mastitis and CLD incidences from 46 771 first-lactation Holstein cows in Hokkaido, Japan, that calved between 2000 and 2009. A threshold animal model for binary records (mastitis and CLDs) and linear animal model for yield traits were applied in our multiple trait analysis. For both liabilities and yield traits, additive genetic effects were used as random regression on cubic Legendre polynomials of days on milk. The highest positive genetic correlations between yields and disease incidences (0.36 for milk and mastitis, 0.56 for fat and mastitis, 0.24 for protein and mastitis, 0.32 for milk and CLD, 0.44 for fat and CLD and 0.31 for protein and CLD) were estimated at about the time of peak milk yield (36 to 65 days in milk). Selection focused on early lactation yield may therefore increase the risk of mastitis and CLDs. The positive genetic correlations of SCS with mastitis or CLD incidence imply that selection to reduce SCS in the early stages of lactation would decrease the incidence of both mastitis and CLD. © 2013 The Animal Consortium.


Togashi K.,Livestock Improvement Association of Japan | Moribe K.,Livestock Improvement Association of Japan | Iwama S.,Livestock Improvement Association of Japan | Matsumoto S.,Livestock Improvement Association of Japan | And 7 more authors.
Livestock Science | Year: 2016

The objective of this study was to examine the genetic relationships between first-lactation persistency and four measures of conception accounting for heterogeneous genetic (co)variances over a wide range of milk production and fertility management environments. The combination of genotype and management environment conditions (genotype-by-environment (GE) interaction) was studied by using a reaction norm model. Data were obtained on 421,999 cows from 9296 herds for first parity and 257,815 cows from 8318 herds for second parity. Conception status during the first two parities from calving to 70 days in milk (DIM) and 180 DIM were evaluated, leading to a total of four conception measures. Under poor reproductive management, the genetic correlations between first parity lactation persistency and conception to 70. DIM were 0.408 and 0.242 for the first and second parities, respectively, compared with 0.178 and 0.116 for the respective genetic correlations between lactation persistency and conception to 180. DIM. These positive correlations indicate that increased persistency would help to improve conception to 70. DIM or 180. DIM. The genetic correlation between persistency and conception to 180 DIM during the first parity was -0.211 under a high level of reproductive management and moderately high milk production, suggesting that conception to 180. DIM for low-persistency cows of first parity was increased by improving reproductive management under this situation. In contrast, the genetic correlation between persistency and conception to 180. DIM in second parity was 0.351 under high management of milk production and reproduction. The genetic correlations between lactation persistency and conception to 70. DIM or 180. DIM for the first two parities ranged from negative to positive, depending on the combination of genotype and management environment conditions. Therefore, it is important to consider GE interaction when combining lactation persistency, conception measures, and milk yield to select for sustainable milk production systems. © 2015 Elsevier B.V.


Yamazaki T.,Japan National Agriculture and Food Research Organization | Hagiya K.,Japan National Agriculture and Food Research Organization | Takeda H.,Japan National Agriculture and Food Research Organization | Yamaguchi S.,Livestock Improvement Association of Japan | And 2 more authors.
Livestock Science | Year: 2014

The genetic correlations between reproductive traits in cows and milk-production traits (305-day milk yield and lactation persistency) were estimated by using first-lactation records (representing 476,284 Japanese Holstein cows), second-lactation records (380,474 cows), and third-lactation records (267,344 cows). The reproductive traits evaluated were: days from calving to the first insemination (. DCF); conception rate for the first insemination (. CR); number of inseminations (. NI); and days open (. DO). Persistency was defined as the difference between milk yields at 240 and 60 days in milk. Genetic parameters for reproductive traits (. DCF, CR, NI, and DO) were estimated within each lactation by using a four-trait animal model. The genetic correlations between reproductive traits and milk-production traits were estimated by using a three-trait (one reproductive trait and two milk production traits) linear model. The genetic correlation estimates within the first lactation were similar to those of the other lactations, suggesting that the genetic relationships among fertility, 305-day milk yield, and lactation persistency were constant over the first three lactations. The genetic correlations among reproductive traits were fairly strong, but those of DCF with CR and NI were relatively weak. Antagonistic genetic correlations, which ranged from 0.17 to 0.39 in absolute value, between reproductive traits and persistency were revealed. Therefore, when selecting to increase lactation persistency, indicators of female fertility have to be included in the genetic evaluation to reduce undesirable side effects on fertility in cows. © 2014 Elsevier B.V.


PubMed | Japan National Agriculture and Food Research Organization and Livestock Improvement Association of Japan
Type: Journal Article | Journal: Animal science journal = Nihon chikusan Gakkaiho | Year: 2015

We estimated the genetic parameters of fat-to-protein ratio (FPR) and the genetic correlations between FPR and milk yield or somatic cell score in the first three lactations in dairy cows. Data included 3,079,517 test-day records of 201,138 Holstein cows in Japan from 2006 to 2011. Genetic parameters were estimated with a multiple-trait random regression model in which the records within and between parities were treated as separate traits. The phenotypic values of FPR increased soon after parturition and peaked at 10 to 20 days in milk, then decreased slowly in mid- and late lactation. Heritability estimates for FPR yielded moderate values. Genetic correlations of FPR among parities were low in early lactation. Genetic correlations between FPR and milk yield were positive and low in early lactation, but only in the first lactation. Genetic correlations between FPR and somatic cell score were positive in early lactation and decreased to become negative in mid- to late lactation. By using these results for genetic evaluation it should be possible to improve energy balance in dairy cows.


Inoue K.,National Livestock Breeding Center | Kobayashi M.,Yamagata General Agricultural Research Center | Shoji N.,Yamagata General Agricultural Research Center | Kato K.,Livestock Improvement Association of Japan
Animal | Year: 2011

We estimated the genetic parameters related to feed intake (FI), feed efficiency traits (including feed conversion ratio (FCR) and residual feed intake (RFI) of digestible crude protein (DCP) and total digestible nutrients (TDN)), beef marbling score (BMS), melting point of fat (MP) and fatty acid composition. Fat and meat (Musculus trapezius) samples were taken from the carcasses of 863 Japanese Black steers derived from 65 sires, for determination of the MP and fatty acid composition of the total lipid in intramuscular adipose tissue. Genetic parameters were estimated using uni- and bivariate animal models. In addition, pedigree information for 4841 animals was used. Heritability estimates for BMS, MP, individual fatty acids, monounsaturated fatty acids (MUFA), the ratio of saturated fatty acids to MUFA (MUS) and the ratio of elongation (ELONG) were generally high. The FI values of TDN and DCP were also high, but FCRs and RFIs of those were low (0.09 to 0.22). Genetic correlation of BMS with MP was -0.34 (favorable) and with C18:1, MUFA, MUS and ELONG values were 0.40, 0.28, 0.29 and 0.37, respectively (favorable). Genetic correlations of MP with C18:1, MUFA, MUS and ELONG were negative (also favorable) and high (-0.85, -0.98, -1.00 (-0.996) and -0.66, respectively). The correlation estimates for feed efficiency traits of DCP were quite similar to those of TDN. Genetic correlations of BMS with FCRs and RFIs of TDN and DCP were all positive (unfavorable; 0.21 to 0.51), and in particular, the correlations with RFIs of those were high. The correlations of C18:1, MUFA, MUS and ELONG with RFIs of TDN and DCP were positive (unfavorable) but low (0.06 to 0.17), whereas the corresponding correlations with FCRs of those were all negative (favorable; -0.38 to -0.10). These results suggest that the quantity and quality of beef fat can be simultaneously improved and that the quality of beef fat (fatty acid composition) can be improved directly or indirectly with MP. Furthermore, selecting MP or fatty acid traits does not significantly affect feed efficiency. © 2011 The Animal Consortium.

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