For an evaluation of the effects of heat stress during pregnancy on calf birth weight and postpartum maternal milk yield, 21 cows and 10 heifers were assigned to shade (S; n = 16) or no shade (NS; n = 15) treatments during the last trimester of pregnancy in June 1978. At parturition, all cows were removed from treatment and uniformly managed in the milking herd. At 4-d intervals from d 199 of p...

This study was conducted to determine the chemical composition and nutritive value of sunflower residues silage (SRS) and effects of its substitution with alfalfa hay and corn silage on lactation performance, feed intake, nutrient digestibility and some blood parameters of Mohabadi dairy goats. Four experimental diets were formulated to gradually replace alfalfa hay and corn silage with SRS as ...

To determine whether insulin exerts an effect on milk fat yield through the direct regulation of milk fat synthesis in the mammary gland, the hyperinsulinemic-euglycemic clamp procedure was performed in lactating goats in the present study. The effects of the hyperinsulinemic-euglycemic clamp on milk yield, milk composition, milk fatty acid yield and the expression levels of mRNAs of milk fat s...

Developing machine learning and soft computing techniques has provided many opportunities for researchers to establish new analytical methods in different areas of science. The objective of this study is to investigate the potential of two types of intelligent learning methods, artificial neural networks and neuro-fuzzy systems, in order to estimate breeding values (EBV) of Iranian dairy cattle...

introduction: lactation yield and persistency are two economic important traits in dairy cow. the production level of a dairy cow is determined by a joint effect of genetic and environmental factors.the main factors determining the total amount of milk production are milk yield at the peak of lactation and persistency as well as length of lactation period. persistency are defined as a extent to...

The objective of this study was to investigate effects of rumen-protected γ-aminobutyric acid (GABA) on dry matter intake, milk performance, and serum metabolites in Chinese Holstein lactating cows. Thirty-nine multiparous cows were blocked based on days in milk (60 ± 6.3 d; mean ± SD) and milk production (30.9 ± 4.17 kg; mean ± SD), and were randomly assigned to 1 of 4 treatments, with rumen-p...

Dairy cattle breeding programs have been based in the selection for traits related to milk production. In this research a data set of 63 herds of East Azerbaijan province Holstein cattle, collected during 2002-2013 by the Iranian Animal Breeding Center was used to estimate the repeatability and heritability of three traits of economic importance. Genetic parameters for first three lactations of...

The present paper was aimed at assessing the benefit of strategic anthelmintic treatments on milk production in four commercial dairy sheep farms in Southern Italy whose animals were naturally infected by gastrointestinal (GI) strongyles and Dicrocoelium dendriticum. The scheme was based on two treatments timed in relationship to parturition, i.e. the first with moxidectin in the periparturient...

Milk yield and pre-weaning calf performance of spring-calving Charolais (C) and Beef × Holstein-Friesian (BF) cows was compared over 3 experiments. Cows were individually offered a restricted allowance of grass silage pre partum in Experiments 1 and 2 and ad libitum silage in Experiment 3. In all three experiments cows received silage to appetite for the first 34 (s.d. 16.2) days of lactation. ...