Effects of inclusion of different sources of dietary energy in close up Holstein dairy cow's rations on birth weight and blood parameters of calves

Researchers believe that the addition of supplemental fat in close up period can improve the status of cows and calves. To this end,Twenty seven Holstein cows were selected by the expected date of parturition (around 30 days before calving) and randomly assigned to one of the three experimental treatments including: 1) control (with carbohydrate source), 2 rumen-protected fat (RF) and 3 roasted soybean (RS). The diets were formulated as isonitrogenous and not iso-caloric. Dry matter intake and body condition score of cows in transition period and blood parameters of cows and calves were determined at the birthday. Also, calves weight was measured at birth. Difference in calf weight, plasma glucose and triglycerides concentrations in calves were significant (P<0.05). Glucose concentration were higher in calves born from cows were fed RS diet than 2 other groups. Difference in dry matter intake, body condition score and plasma non esterified fatty acids concentration of cows between 2 and 3 groups were significant.