In this study we estimated the allele and genotype frequencies of SCD1 and DGAT1 gene polymorphism. The analysis was conducted on 408 Holstein cows from five dairy herds in Isfahan province. Genotypes were identified using PCR-RFLP technique. Two genetic variants (A and V) of the SCD1 gene were observed in this experiment. The frequency of A-allele ranged from 0.49 to 0.66, while frequency of V...

A seroprevalence study of bovine immunodeficiency virus (BIV) was undertaken on 1,541 serum samples from Holstein cattle from 23 herds, located in different geographical regions of Poland. The analysis was performed using ELISA, with recombinant Gag protein of BIV as antigen. The average BIV prevalence was 4.9% in individual cattle, while the percentage of herds harboring at least one seroposit...

: Irish dairy herd fertility has been declining since the 1980s. The extent, nature and causes of this decline in fertility and the current status of Irish dairy herd fertility were described. An increase in calving interval of approximately one day per year has been recorded. The principal components of this trend have been an increased incidence of postpartum endocrinopathies, reduced express...

Milk and serum samples from 35 dairy herds in 17 states were evaluated for cow- and herd-level Mycobacterium avium subspecies paratuberculosis (MAP) antibody test agreement. Evaluation of 6,349 samples suggested moderate agreement between milk and serum enzyme-linked immunosorbent assay (ELISA) results, with a kappa value of 0.50. Cow-level sensitivity (Se) for 18 dairy operations with 1,921 an...

This study aimed to investigate the effect of interaction between total (SCC) and differential somatic cell count (DSCC) on milk yield, composition coagulation traits from individual dairy cows. A 159 224 test-day records (daily traits) have been collected during a period 14 months 12 849 Holstein-Friesian 9275 Simmental cows farmed in 223 herds. The was highly significant for almost all evalua...

The objective of this study was to evaluate the effect of temperature-humidity index (THI) on the milk coagulation properties of Holstein-Friesian dairy cattle from northeast part of Italy. A total of 592 individual milk samples from six dairy herds were evaluated. The milk coagulation properties traits analysed were milk rennet coagulation time and curd firmness, as well as the fat, protein, a...

Milk performance (protein and fat content) and milk fatty acids (FA) profile of dairy cows under supplementation with two sources of concentrate, oilseeds (C, cottonseed) at two levels, low (5kg DM/cow/day) and high (7 kg DM/cow/day), and cereal grains (B, barley) at high rate (7 kg DM/cow/day), were studied in three herds (n=36) of spring calving Holstein-Friesian dairy cows (200 days in milk)...

To describe proportion and pattern of culling in commercial dairy herds of Khorasan Razavi Province, this survey was carried out from 21st March 2008 to 20th March 2009 in 15 industrialized dairy herds. For each culled cow data related to parity at culling, last calving to culling interval and primary reason for culling were recorded. Annual herd exit rate was 20.9%. Out of a total of 652 culle...