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 [...]

The objective of this study was to determine the effects of feeding an increased amount of extruded flaxseed with high proportions of n-3 fatty acids (FA) to transition dairy cows on performance, energy balance, and FA composition in plasma, adipose tissue, and milk fat. Multiparous Israeli-Holstein dry cows (n = 44) at 256 d of pregnancy were assigned to 2 treatments: (1) control cows were fed...

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)...

This study was carried out to evaluate the effects of replacing alfalfa hay with ensiled mixed tomato and apple pomace (EMTAP) on ruminal fermentation and apparent digestibility of diets. Six multiparous Holstein dairy cows in mid lactation were used in 3×3 Latin square design and fed alfalfa hay plus concentrate mixture with three levels replacement with EMTAP (0, 15, 30%) during 63 days. Resu...

A joint sire and cow evaluation for selected type traits has been carried out for the Canadian Holstein population using an individual animal model accounting for all known relationships. Only first lactation, first classification linear records were utilized. Linear scores for final class/final score (combined), feet and legs, mammary system, and stature were analyzed. The model of analysis in...

Sixty-five chromosomal preparations from bisected bovine embryos were examined and 43 embryos (66.2%) with metaphase plates were observed; however, only 25 embryos (38.5%) were sexed. Fifteen of the bisected embryos sexed by chromosomal analysis were transferred to each of the 15 recipients, and 5 recipients became pregnant. Female calves were born on December 28, 1985, August 2, 1986 and July ...

The stress of high milk production, along with increasing herd size and changes in facilities and management, has made fertility one of the main focuses of genetic improvement today. In the US, the reduction in calving rate to first service and the impact of this decrease in fertility on the Holstein breed, mainly in the last 20 years, is of major concern [27]. Figure 1 shows the clear trend fo...

Utilizing pasture-based systems may increase cow comfort during late gestation and calving as it lacks the constraints of confinement housing. The objective of this study was to quantify lying behavior and activity of Holstein dairy cows housed on pasture during the 6 d before calving. Sixteen Holstein dairy cows were moved to pasture 3 weeks before their projected calving date. Data loggers we...

The modern dairy cow has been selected over generations for high milk production, with many successful dairy operations averaging over 13,500 kg of milk per lactation cycle per cow. This amount of nutrient output in the form of milk components puts a tremendous amount of pressure on the metabolism of the dairy cow, especially during early lactation. In fact, it is common to all mammals, includi...