The effects of fat supplementation and weaning system on commercial milk yield and milk composition were determined on 129 East Friesian crossbred ewes. Prior to lambing, ewes were randomly assigned to one of two weaning systems. The DY1 system involved weaning of ewes from their lambs within 24 to 36 hr post-partum and then twice-daily machine milking. In the MIX system, ewes had access to the...

The effects of kappa-casein (kappa-CN) and beta-lactoglobulin (beta-LG) loci on milk production traits (milk, fat, protein, and lactose yield, fat, protein, and lactose content) and reproductive performance (gestation length, calving interval, age at first and second calving, number of services per conception) was estimated for 278 Holstein cows in the first 2 lactations. Genotypes of kappa-CN ...

Results from 4 switchback field trials involving 608 cows were combined to assess the effects of a protected B vitamin blend (BVB) vs 10 mg of unprotected biotin upon milk yield (kg), fat %, protein %, fat yield (kg) and protein yield (kg) in primiparous and multiparous cows. Trials consisted of 3 DHIA periods executed in the order control-test-control. Cows from 45 to 300 days in milk (DIM) at...

The experiment was carried out on lactating Holstein Friesian cows with the objectives of evaluating the effect of stage of age, pregnancy, lactation, parity and on yield, and components (fat, protein, solid not fat and lactose) and pH of milk. Milk samples were directly collected from the teat and immediately analysed using milk. The result showed that lactation stage and pregnancy significant...

Maternal lineage effects on milk yield traits, considered indicative of cytoplasmic inheritance, were evaluated with animal models. Cattle were from a selection experiment begun in 1968. Maternal pedigrees were traced to the first female member in the Holstein-Friesian Herdbook; purchased cows entering the herd, considered foundation females, were assigned to maternal lineage groups. All models...

Sixteen Holstein cows in midlactation were used in a 4 × 4 Latin square design to determine the effect of replacing alfalfa neutral detergent fiber (NDF), with NDF from a combination of whole linted cottonseed, dried distillers grains, and wheat middlings. The four diets were a basal control diet that was low in forage and fiber [(5.9 g of corn silage NDF and 6.1 g of alfalfa NDF/100 g of dry m...

382 yak cows were examined for milk yield, fat, protein and lactose contents. Six polymorphic loci, alphas1-CN, kappa-CN, beta-CN, beta-Lg, alpha-La and MUC-1, were scored by PAGE electrophoresis for each individual. The values of milk yield, fat, protein and lactose content were 247.13 kg, 5.81%, 5.18% and 4.93%, respectively. Based on the 6 polymorphism loci, the average heterozygosity of the...