calving records from april 1996 to december 2005 comprising 31863 calving events of 1173 dairy cows in a large commercial dairy herd were used to evaluate the effects of heat stress, using temperature-humidity index (thi) on milk yield and composition and reproductive performance of holstein dairy cows under humid climatic conditions of rasht in iran. thi values were grouped into six groups: 30...

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...

in this research, 272977 test day records collected from 659 herds during years 2001 to 2011 by the iranian animal breeding center were used. in the first section the ability of different models to predict daily milk yield from alternative milk recording was tested. the result showed that a complex model including noon milking time plus the effect of lactation curve of ali and schaeffer functio...

The objective of this work was to estimate genetic parameters for the Italian population of river buffaloes. Lactation records (10,663) for milk, fat, protein and mozzarella cheese production of river buffalo cows were analyzed by fitting a multiple trait animal model using restricted maximum likelihood. The number of cows with records was 3873 with 6842 animals in the relationship matrix. mozz...

The effect of carcass weight, age at slaughter and sex on some chemical components was evaluated in twenty-two Boutsiko lambs (twelve females and ten males). Chemical composition of meat was expressed as percentage of fat, protein, collagen and moisture content. Measures of the four chemical components were taken by carcass cuts included shoulder, leg, racks, kidney, rear flank, breast ribs and...

The objective of this study was to analyze the association of somatic cell score (SCS) with milk, fat and protein yields across parities. Records of production traits and somatic cell counts (SCC) from first, second and third parity that were collected by the Animal Breeding Center of Iran from 1993 to 2010 were used.All animals were grouped into six classes according to SCC and production trai...

Persistency of lactation is the ability of a cow to continue producing milk at a high level after the peak of her lactation. Differences in persistency, if not properly accounted for, reduce accuracy of genetic evaluation when incomplete records are used. Persistency has also direct economic value. Reduction of feed, health and reproductive costs are the major factors which favour more persiste...

introduction: expansion of the area of oilseed crops such as soybean is one of the policies of iranian agricultural policy makers as iran is one of the major oilseed importers in the world. however, the area of this crop in kermanshah province is negligible, but it could be cultivated in most parts of this province. the quantity and quality of the produced grain could be affected by environment...