Received: 7 March, 2014 Accepted: 21 May, 2014 Published: 20 July, 2014 The data consisted of 37118 TD milk record of 5851 primiparous Holstein cows of Tunisia. Herd-years of calving means for milk production traits were clustered in three levels using the CLUSTER procedure in SAS software. Production levels included low, medium and high levels. Genotype by environment interaction were investig...

introduction genetic evaluation and estimation of breeding value are one of the most fundamental elements of breeding programmes for genetic improvement. recently, genomic selection has become an efficient method to approach this aim. the accuracy of estimated genomic breeding value is the most important factor in genomic selection. different studies have been performed addressing the factors a...

random regression models (rrm) have become common for the analysis of longitudinal data or repeated records on individual over time. the goal of this paper was to explore the use of random regression models with orthogonal / legendre polynomials (rrl) to analyze new repeated measures called clutch size (cs) as a meristic trait for iranian native fowl. legendre polynomial functions of increasing...

This study assessed the extent of reproductive losses and associated genetic parameters in dairy cattle, using in-line milk progesterone records for 14 Swedish herds collected by DeLaval's Herd Navigator. A total 330,071 samples were linked to 10,219 inseminations (AI) from 5,238 lactations 1,457 Red 1,847 Holstein cows. Pregnancy loss traits defined as early embryonic (1–24 d after AI), late (...

background: the osteopontin (opn) is a highly phosphorylated glycoprotein in numbers of bovine tissues and milk. opn has been reported to be associated with milk production in cattle.objective: the genotype and allelic frequencies for opn and its association with milk production will be evaluated in iranian holstein bulls.  materials and methods: bulls dna (100) was isolated. oligo was used for...