The objective of the current study was to evaluate the effect of bovine somatotropin (bST) on milk yield and composition of Holstein cows in early and very early lactations. Twenty-two lactating Holstein cows averaging 62 days in milk (DIM:25-115), 28.5 kg/d milk, a body condition score (BCS) of 2.87, and 648.2 kg of body weight (BW), were assigned to one of the four treatments in a completely ...

Aim: The present research work was carried to study the estrus response and conception rate in lactating Ongole cows consequence to double injection of prostaglandin. Material and Methods: Estrus synchronization was performed by double injection of PGF2α (Lutalyse, 5ml/cow) in purposively selected 22 lactating Ongole cows. The 1st injection was administered on 60 days post partum (day 0) follow...

The current study was performed to clarify the effects of GHRH treatment on milk production and plasma hormones and metabolites in lactating Japanese Black cows (a beef breed) under negative energy balance (EB). Ten multiparous lactating beef cows were offered a normal-energy diet daily (110% of ME requirements for maintenance and lactation) until 5 d in milk (DIM) to standardize the cows befor...

One critical determinant of fertility is the establishment and maintenance of pregnancy after insemination or embryo transfer. Pregnancy success is low in lactating dairy cows. Reduced fertility of the dairy female is only expressed in the lactational state but the magnitude of depression of fertility is not related to milk yield. Pregnancy failure occurs throughout gestation with the greatest ...

Female fertility is essential to any beef breeding program. However, little genetic gain has been made due long generation intervals and low levels of phenotyping. Days calving (DC) a trait that may provide lead an increased weaning rate. Genetic parameters correlations were estimated compared for DC across multiple joinings (first, second third+) lactation status (lactating non-lactating) trop...

More than a decade of observations of dairy operations in Hawai‘i suggested that there were more black cows in the local dairy herds than white cows. Hence, the objective of the study was to investigate if hair coat color affected productive life of Holstein cows in the sub-tropics. Two large herds within 2,000 meters of each other in the Waianae Coast district were used. Lactating cows were cl...

Premature disposal of female calves before reaching milch herd and undesirable disposal of lactating cows are the major constraints in achieving larger herd size. During the early lactations, younger cows are supposed to give higher milk yield and undesirable disposal of early calvers, thereby, greatly hampers profitability of a dairy farm. Knowledge of the incidence of disposal along with reas...

The objective of this study was to compare utilization of red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) by lactating dairy cows. Red clover and alfalfa were harvested and conserved as silage at two maturities in 2 consecutive yr. Each year, diets containing experimental forages and supplemental grain were fed to 16 multiparous Holstein cows in early lactation in a replicat...

One strategy for improving fertility in cattle is mid-cycle administration of GnRH to increase progesterone secretion and delay luteolysis. This strategy might be especially useful during hot weather because heat stress increases uterine prostaglandin release and reduces development of the elongating embryo. A series of experiments was conducted to test the efficacy of GnRH for increasing ferti...

This study was conducted to test the effects of feeding supplemental Bulgarian nutritive additive OVOCAP® administrated per os, on blood lipid profile in lactating cows. Twelve lactating American Brown cows (BW = 695 ± 28 kg; at the beginning of the lactation) were separated to two treatments for 1,5 year. Cows were fed typical diets during the winter (corn silage, meadow hay, straw, wheat bran...