a total of 125 russian red pied cows were genotyped for the prolactim-related gene. the prl-rsai genotypes were analysed using the polymerase chain reaction -restriction fragment length polymorphism (pcr-rflp) method. in this breed, the frequencies of alleles were as follows;  a= 0.794 and b= 0.206. the frequencies of aa, ab and bb genotypes were 0.598, 0.392 and 0.01; respectively. results sho...

some factors affecting crude protein balance (cpb), as a measure of efficiency, were studied using 2824 records of 501 lactating holstein cows. the cpb (kg d-1) was calculated as crude protein (cp) intake (kg) minus cp yield (kg). two different statistical methods including principal components (pcs) and general linear model analyses were used to study the effects of different factors. crude pr...

Fif teen lactating Holstein cows in a 3 × 3 Latin square experiment determined effects of ground newspaper in the diet. Test components of the rations were: A) 20% cottonseed hulls; B) 10% paper and 10% cottonseed hulls; C) 20% paper. All animals received 2.3 kg of long alfalfa hay daily. Proximate analysis and gross energy determinations indicated that the paper rations contained more crude fi...

In the past decade, a global demand for products from organic agriculture has increased rapidly. Milk quality is of major interest to all parties. Therefore, the objective of this study was to compare cow performance and product quality on conventional and organic diets. 72 Holstein dairy cows were allotted to one of four diets: a conventional diet (CON40), an organic diet with a low amount of ...

STATs are a family of latent transcription factors that reside in the cytoplasm of resting cells. The STAT1 transcription factor gene located on the chromosome 2 at interval 60 to 63 cM. This factor upon stimulation with INF gamma, dimerizes and translocate to the nucleus where mediates transcriptional regulation. In this study, we estimated the allele and genotype frequencies of STAT1/Pag<...

the aim followed in the present study was to investigate the effects of different metabolizable protein (mp) levels on holstein cows, milk yield and composition, and as well on concentration of plasma metabolites in the cow,s early lactation. twenty - four holstein cows(bw 580±23, dim 30±7, parity 2.4±0.5) were randomly assigned to each one of the 4 dietary treatments containing 1) 10.60% (diet...

An experiment was conducted to compare the effect of the same amount of 18:2 offered either as 18:2n-6 or as a mixture of unprotected 18:2c9t11 and 18:2t10c12 on feed intake, milk components as well as plasma and milk fatty acid profile. Fifteen cows were blocked by milk yield and milk fat percentage and within block assigned randomly to 1 of 3 treatments (n = 5). Each cow passed a 12-d adjustm...

Materials and Methods The ability of the dairy cows to increase daily energy intake depends on the net energy density of the diet. The daily Dry Matter Intake (DMI) is highly regulated by animal nutrient requirements, metabolic states, and the type and temporal absorption of fuels. Fat supplements from different sources, its form and type has different hypophagic effects [1]. Previous reports i...

Udder and teat morphology measurements were taken at approximately 7.5 hr after the a.m. milking for 131 East Friesian (EF) crossbred ewes at an average of 71 d in lactation. Additionally, milking time was recorded for each ewe during two evening and morning milkings. Average daily milk production, milking time, percentage of milk fat, percentage of milk protein, and somatic cell count were 2 L...