There are many potential applications of transgenic methodologies for developing new and improved strains of livestock. One practical application of transgenic technology in pig production is to improve milk production or composition. The first week after parturition is the period of greatest loss for pig producers, with highest morbidity and mortality attributed to malnutrition and scours. Des...

The ability of mathematical models to represent the lactation process varies according with their structure and database characteristics. aim current study was evaluated goodness fit empirical mechanistic applied dairy sheep curves different shapes. A total 4,494 weekly test day records were analyzed. All lactations individually fitted using two (Wood Wilmink) (Dijkstra, Pollott) models. Dijkst...

The effect of cow genetic merit on the performance of spring calving Holstein Friesian dairy cows in first, second and third lactation was investigated. The study contained 96 first lactation animals in 1995, 96 second lactation animals in 1996, and 72 third lactation animals in 1997. Half of the animals were of high genetic merit (HG) and half of medium genetic merit (MG) for milk production. ...

the base of this review is to consider the relevant role that animal factors (potential milk yield, body weight, body condition score, state of lactation, parity and fertility) play on milk performance (considering the energy balance and the rumen function across the full lactation curve of animals) and milk quality (milk protein content, milk fat content, milk lactose content, vitamins, minera...

Low protein intake during lactation has been demonstrated to increase the loss of body protein and to reduce the reproductive performance of female pigs. The objectives of the current experiment were 1) to determine whether protein (lysine) restriction alters levels of somatotropic hormones, insulin, follicle-stimulating hormone, and leptin around weaning, and 2) to evaluate the relationships b...