An important branch of the modern global economy is food production. Our focus is milk production on dairy farms, the period in which cows produce milk (lactation) and the quantity of milk produced. Special attention will be given to the time-dependent function that describes the quantity of the milk produced over a lactation period. The respective graph is known as the lactation curve and is o...

It is not acceptable to compromise animal welfare in any system of farming. Feeding should be aimed at meeting the nutritional requirements at the various stages of production. This paper deals with the detrimental effects that organic, extensive or low input farming systems may have on the energy status in early lactation of the high potential dairy cow. Bovine ketosis is the most important di...

To investigate the relationship between feeding level during gestation and voluntary feed intake, feeding behavior, and plasma metabolite levels during lactation, 18 crossbred, primiparous sows were assigned to two dietary treatments. From d 60 of gestation until farrowing, sows were fed either a standard level of feed (SL; 1.85 kg/d) or were allowed ad libitum (AL) access to feed. During a 28-...

I t is a common observation of dairymen that the milk flow of the dairy cow rises for some time after calving and then declines steadily. In preceding papers 1 we have presented data and have offered an interpretation for the declining segment of the curve of milk secretion. Having found that after the first month of lactation the curve of milk secretion with the advance of the period of lactat...

Monthly estimates of 24-h milk yield were obtained on 160 spring-calving and 153 fall-calving crossbred cows containing various proportions (0, 1/4 or 1/2) of Brahman breeding, all bred to Limousin sires. Milk production was measured using weigh-suckle-weigh procedures. Interactions between crossbred group and season of calving were not significant. Across seasons, milk production rarely was af...

The objective of this study was to estimate the breed, heterosis, and recombination effects on different components lactation curve Girolando cattle. dataset used consisted 12,121 purebred cows Holstein (H) Gyr (G) breeds, six H×G crossbred (Girolando). model presents random herd cow, regression coefficient associated with linear effect proportion H heterosis between G [...]