Background: Presynchronization could enhance fertility in timed breeding programs. The best presynchronization method has to justify biological requirements and to provide practical and economic advantages. OBJECTIVES: Present study investigated the effectiveness of presynchronization with equine chorionic gonadotropin (eCG) before ovsynch (eCG-ovsynch) compared to conventional presynch-ovsynch...

retrospective data from sebele dairy farm were analysed for reproductive performance of friesian/holstein cows. three hundred records from 1989 to 1995 were used. the herd was zero grazed and the data was analysed for age at first calving (afc), calf birth weights (bw), calving interval (ci), days open (do), calving rate (cr), reproductive wastage (rw) and calving difficulty (cd); dystocia, aft...

the aim of this study was using bayesian approach via gibbs sampling (gs) for estimating genetic parameters of production, reproduction and health traits in iranian holstein cows. data consisted of 320666 first- lactation records of holstein cows from 7696 sires and 260302 dams collected by the animal breeding center of iran from year 1991 to 2010. (co) variance components were estimated using ...

For lactating dairy cows, we need management tools, that are "clean, green and ethical", cost-effective and easy to use. Specific tools are needed for artificial insemination (AI) after oestrus detection within a few months of calving, and for managing the complex nutritional requirements of cows between successive calvings. Assessment of energy deficit by measurement of body condition score (B...

The objective of this study was to investigate the association of polymorphisms at the STAT5A and FGF2 gene loci with fertility, lactation milk yield and lameness in dairy cattle. Five hundred and eighteen primiparous Holstein cows were included in the study. Several reproductive traits were considered including conception rate (0/1) at first insemination, conception rate (0/1) in a 305-day lac...

The aim of presented study was to compare the effect of intrauterine ozone and rifaximine treatment in cows with subclinical endometritis. The study was conducted on 53 Simmental cows with subclinical endometritis, which was diagnosed by ultrasonographic examination. According to results, interval between treatment to pregnancy (46.4±6.2 vs. 40.0±6.0), interval from calving to pregnancy (129.4±...

This study was performed to estimate the effect of age at first calving and first two calving intervals on productive life and life time profit in Korean Holsteins. Reproduction data of Korean Holsteins born from 1998 to 2004 and lactation data from 276,573 cows with birth and last dry date that calved between 2000 and 2010 were used for the analysis. Lifetime profit increased with the days of ...

Whether to select for longer life in the herd or shorter calving interval depends on the genetic and phenotypic relationships among herd life, amount of milk in first lactation, and calving interval. Herd life and average calving intmwal are essentially phenotypically uncorrelated. The phenotypic and genetic correlations of herd life and milk in first lactation ranged from .19 to .25 and from ....

This study had the objective of determining the fertility and calving ease of small holder indigenous cattle herds inseminated with imported semen from proven sires. Sixty one indigenous cows of different breed origin (Bunaji, Sokoto Gudali and Rahaji) were selected from different herds across Jigawa state-Nigeria, and were used for this study. The selected dams were inseminated with semen from...