In the present study, records on 22872 first-parity Holsteins collected from 131 herds by the Animal Breeding and Improvement Center of Iran from 1995 to 2014 were considered to estimate genetic and phenotypic relationships between calving difficulty (CD) and the lactation curve traits, including initial milk yield (Ap), ascending (Bp) and descending (Cp) slope of the lactation curves, peak mil...

Multivariate factor analysis and principal component analysis were used to decompose the correlation matrix of test-day milk yields of 48,374 lactations of 21,721 Italian Simmental cows. Two common latent factors related to level of production in early lactation and lactation persistency, and 2 principal components associated with the whole lactation yield and persistency were obtained. Factor ...

Cows (n = 21), dried off for a minimum of 45 days, and nulliparous heifers (n = 26), at ages > 18 months old, were placed on a 12-day Lactation Induction (LI) protocol. One group of animals (including both cows and heifers) received 3-minute mammary gland stimulation, along with the LI protocol. Another group, again including both cows and heifers, received no stimulation. Only the LI protocol ...

a data file containing 607662 (317608) milk (open days) records belonging 294417 (177838) holstein cows that were calved from 1983 to 2008 was used. the bivariate repeatability model was used for data analyzing so that herd, calving year, calving month, days in milk (only for milk trait) and calving age for each parity, were assumed as fixed effects and additive genetics and permanent environme...

Milk would be contaminated with Aflatoxin M1 (AFM1) if it was obtained from lactating animal which fed with feedstuffs containing Aflatoxin B1 (AFB1). AFM1 is classified as group 2B, possibly carcinogenic to humans and exposure to AFM1 through milk consumption is a public concern. The purpose of this study was to determine the AFM1 exposure through liquid milk consumption for adult consumers in...

Milk would be contaminated with Aflatoxin M1 (AFM1) if it was obtained from lactating animal which fed with feedstuffs containing Aflatoxin B1 (AFB1). AFM1 is classified as group 2B, possibly carcinogenic to humans and exposure to AFM1 through milk consumption is a public concern. The purpose of this study was to determine the AFM1 exposure through liquid milk consumption for adult consumers in...

In the present work, covariance components for milk yield and disease liability were estimated with bivariate random regression test-day sire models using a Bayesian approach and implemented via the Gibbs sampler. The data consist of 8075 first-parity Danish Holstein (DH) cows, from 1259 sires, performing in 57 herds from 1992 to 1997. Treatments associated with five different type of diseases ...

the present study was conducted to estimate genetic parameters and genetic, environmental and phenotypic trends of milk production traits in holstein cattle of hamedan province. in this study 11986 305-d records of first three parities of hamedan province holstein cattle, which were gathered during 1990-2011, were used. variance-covariance components and breeding values were estimated using ani...

This study was accomplished with the objective to determine parameters of lactation curves in Beetal goats using Wood’s model. Therefore, milk yield data from 127 Beetal goats maintained at five different government farms were recorded from post-kidding to drying off of does. Wood model parameters were estimated using non-linear regression and individual curves were fitted. The characteristics/...