Female fertility in a Guzerat dairy subpopulation: Heterogeneity of variance components for calving intervals

Impact of inbreeding on fitness-related traits in the highly threatened Sorraia horse breed

“…These findings are contrary to those of Panetto et al (2012), where the age of Zebu cows did not cause an increase of calving intervals but inbreeding did. Age at first parturition is also not influenced by the inbreeding coefficient of the mare but is influenced by the stud farm (P¼ 0.0083), and mares from stud farm A foal for the first time at an age almost 1 year younger than mares from stud farm B (average of 61.37 and 72.51 months, respectively).…”

Two-trait random regression model to estimate the genetic association of scrotal circumference with female reproductive performance in Nelore cattle

“…Boligon and Albuquerque [19] and Eler et al [20] estimated heritabilities of 0.10 and 0.18, respectively, for AFC1 in Nelore cattle. Pereira et al [7] and Panetto et al [21] reported estimates of 0.06 and 0.12 for FCI in Nelore and Guzerat cattle, respectively. Using multitrait analysis, Van Melis et al [22,23] and Santana et al [24] reported heritability estimates for STAY in Nelore cattle ranging from 0.10 to 0.25.…”

Random Regression Analysis of Calving Interval of Japanese Black Cows

“…In addition, appropriate mating decisions and management are necessary to avoiding increases in the CI due to increases in the inbreeding coefficient and the age at calving at previous parity ( Figure 6 ). The number of records analyzed (92,019) and the number of individuals in pedigree (390,263) in this study were much higher than those in previous studies [ 15 , 16 ], and using the accurate, deep, and wide pedigree information in this study brought a tight genetic connectedness among individuals. These could compensate for the lower number of records per cow and contribute to a more reliable estimation of additive genetic variance ( ) using the additive relationship matrix in random regression analysis in this study.…”

“…Recently, Setiaji and Oikawa (2019) estimated the genetic correlation of the CI between first and second parities to be 0.969 with the CI between second and third parities and 0.943 with the CI between third and fourth parities, and the genetic correlation of the CI between second and third parities to be 0.988 with the CI between third and fourth parities, using records of 2078 Japanese Black cows in Okinawa prefecture, the southernmost prefecture of Japan [ 31 ]. Using the random regression model, Panetto et al (2012) reported genetic correlations between ages of cows to be <0.8 for the CI of a Guzerat dairy subpopulation in Brazil [ 16 ]. Possible reasons for the difference among the studies might be the mating pattern (artificial insemination vs. natural mating) and the selection process.…”

“…Gutierrez (2010) [ 15 ] analyzed 1852 records for days open (DO) for 766 Holstein dairy cows from 20 to 90 months of age using pedigree information on 1644 individuals and a random regression model that used up to first-order Legendre polynomials based on calving age as sub-models, and reported that the genetic correlation between ages was 0.99. On the other hand, Panetto et al (2012) [ 16 ] estimated lower genetic correlations from random regression analysis of 4409 CI records obtained from 1114 Guzerat dairy cows from 26 to 150 months of age with up to third-order Legendre polynomials based on calving age. The validity of fitting a repeatability model to CI records of Japanese Black cows should be investigated also.…”