data related to holstein dairy cattle from 1987 to 2004 were obtained from animal breeding center of iran to estimate the genetic and phenotypic trends. variance components and genetic parameters of the first lactation records were estimated using restricted maximum likelihood method and aireml algorithm through matvec program. animal breeding values were predicted through multiple-trait animal...

The objective of this study was to evaluate production response and more specifically percentage and yield of fat in milk from dairy cows fed distillers grains with added solubles (DGS). It was hypothesized that the oil present in DGS would decrease milk fat yield. Four dietary treatments consisted of dried DGS replacing soybean meal and soybean hulls. The DGS inclusion rates as a percentage of...

Bovine lactoferrin (LTF) is a member of the transferrin family of iron-binding proteins. This protein is present in a wide variety of biological fluids and shows important physiological functions in body. In this study, 404 blood samples were collected from Holstein dairy farms in Iran. A 301 bp fragment of intron 6 in bovine LTF gene was amplified and the animals were genotyped using polymeras...

this research was conducted to assess the effect of substituting corn for barley grain in diet on performance and reproductive characteristics of early lactating, holstein dairy cattle. a number of fifteen cows in their second lactation (26±11 dim) with 36.7±5.6 kg milk/d were investigated for 75 day (15 day for adaptation and 60 day for sampling) in a completely randomized design. the iso-ener...

The present study was designed to investigate the effect of mastitis on various components including fat percentage, protein, total solids, solid not fat, pH, specific gravity and lactose content in milk cross-bred (Holstein Friesian × Cholistani) Sahiwal cattle. A 376 samples (excluding blind nonfunctional teats) from 100 cows (50 50 sahiwal) were collected aseptically. Animals different ages,...

The aim of this study was to evaluate the effects of balancing low protein diets for methionine and lysine on performance of early lactation Holstein cows under hot environmental temperature. Twenty one multiparous Holstein cows in early lactation were allocated to three experimental rations including, 1) High protein ration with 17.5% CP, 2) Medium protein ration with 16% CP and 12 g/d rumen p...

Eighteen multiparous early lactation Holstein cows were assigned to a replicated 3 × 3 Latin square with 28-d periods to evaluate milk protein production potential when corn silage (CS) or small grain silage (SGS) was added to diets based on alfalfa silage (AS). Treatments consisted of all AS, a mixture of AS and CS, or a mixture of AS and SGS. Treatment diets were isonitrogenous, isofibrous, a...

the aim of this study was to evaluate the effects of balancing low protein diets for methionine and lysine on performance of early lactation holstein cows under hot environmental temperature. twenty one multiparous holstein cows in early lactation were allocated to three experimental rations including, 1) high protein ration with 17.5% cp, 2) medium protein ration with 16% cp and 12 g/d rumen p...

in order to examine the effect of degradability rates of different starch sources on performance of holstein dairy cows in their early lactation, twenty multiparous lactating holstein cows (586±33.7 bw; 48.15±9.32 dim) were made use of in a randomized complete block design of four treatments during the 65 days of the experimental period. cows were fed the following diets: 1) 100% barley, 2) 67%...

prophet of pou1f1 (prop1) plays direct or indirect important roles in the morphogenesis of pituitary gonadotropes as well as lactotropes, somatotropes and caudomedial thyrotropes. it also controls the expression of growth hormone, prolactin and thyrotropin subunits through regulatory pit1 factor. these hormones have important influences on production traits in most animal species including the ...