Leptin and leptin receptor genes are considered as production traits markers in dairy or beef cattle. The aim of this study was to verify the associations of polymorphisms in bovine LEP and LEPR genes with production and reproduction traits in Slovak Spotted and Pinzgau cows. Long-life production was evaluated: milk, protein, and fat yield and reproduction traits: age at first calving, calving ...

correlation between breeding value of crude milk (cm) and energy-corrected milk (ecm) was studied based on a total of 774,013 test day records belongs to 88,456 first-parity holsteins dairy cattle calving during 1997-2009 in 165 herds (from six provinces). genetic analysis of the traits was carried out by a fixed regression test day model. in the model, effects of herd, calving year, production...

Purebred Holstein-Friesian cows are the main exotic breed used for milk production on large, medium, and small farms in Kenya. A study was undertaken on seven large-scale farms to investigate the genetic trends for milk production and fertility traits between 1986 and 1997 and the genetic relationships between the traits. This involved 3,185 records from 1,614 cows, the daughters of 253 sires. ...

Test day (TD) records of milk production traits (milk yield, fat, and protein percentages) of 534 Italian buffalo cows were analyzed with a mixed linear model in order to estimate lactation curves pertaining to different ages at calving and different seasons of calving. Milk yield lactation curves of younger animals were lower than those of older animals until 20 wk from parturition. No effect ...

In order to estimate genetic parameters for production traits and reproductive performance, 115 465 records of production traits and 90 942 records of reproductive performance from Iranian Holstein cows that were collected during 1980 to 2004 at Animal Breeding Center of Iran, were used. The estimations were performed using Restricted Maximum Likelihood method (REML) under an animal model by DF...

Heat stress (HT) and photoperiod affect milk production and immune status of dairy cows. The objective was to evaluate the effects of HT abatement prepartum under controlled photoperiod on hepatic metabolic gene expression and cellular immune function of periparturient Holstein cows (n=21). Cows were dried off 46 d before expected calving date and assigned to treatments by mature equivalent mil...

The periparturient period of a dairy cow is associated with increased incidence and/or severity of certain infectious diseases, including mastitis. It is believed that the heightened physiological demands of calving and initiation of milk production contribute to a state of immunosuppression during this period. Previous studies have indicated that neutrophil production of reactive oxygen specie...

Objective: The cows that don’t have access to sufficient energy in their ration can get sickness. Milk production has a high priority in metabolism of dairy cows so lactating cows are more prone to get sick This can ruin all the benefits of higher milk yield because of the higher prevalence of the disorders. Methods: Data for this research had gathered from a herd with 1600 Holstein cattle in E...

The aim of this research was to estimate the influence of environmental factors, such as air temperature and milk production, on reproduction traits of primiparous Polish Holstein-Friesian cows. The following reproduction traits were considered: interval from calving to first insemination, interval from first to last insemination, interval from calving to conception, number of inseminations per...

Objective: The cows that don’t have access to sufficient energy in their ration can get sickness. Milk production has a high priority in metabolism of dairy cows so lactating cows are more prone to get sick This can ruin all the benefits of higher milk yield because of the higher prevalence of the disorders. Methods: Data for this research had gathered from a herd with 1600 Holstein cattle in E...