The objective of this study was to estimate genetic effects for the muscle hypertrophy mutation (mh) of the myostatin gene for conventional milk production traits and for milk fatty acid composition in dual-purpose Belgian Blue dairy cows. For the present study, only cows from a single herd, in which genotype frequencies were as balanced as possible (0.266 for +/+, 0.523 for mh/+, and 0.211 for...

Two experiments were conducted to determine whether exposure to a photoperiod of artificial long days in autumn increased milk yield in subtropical goats milked once (Exp. I) or twice daily (Exp. II). In Exp. I, starting at d 10 of lactation, 1 group of does was kept under naturally decreasing photoperiod (DD1X; n = 8), whereas the other group was submitted to an artificial photoperiod of long ...

In dairy cows, increased milking frequency (IMF) during early lactation stimulates an increase in milk yield that partially persists through the remainder of lactation. However, the effects of IMF on lactation performance and udder health of primiparous heifers have not been clearly established. The objective of this study was to determine the effects of IMF during early lactation on milk yield...

A total of 6604 test-day records belonging to 1651 lactations of 784 Egyptian Zaraibi goats were used to generate and evaluate several simplified milk yield recording plans based on the yield of a single monthly milking, adjusted or unadjusted for interval between milkings and for production level. Loss of precision associated with simplified designs was evaluated by comparing estimated lactati...

A 2-yr study investigated effects of different levels of concentrate supplementation on milk production, composition, and lactation curves in pastured dairy goats. For both years, 44 Alpine goats (Capra hircus; 55 +/- 11 kg body weight) were randomly allocated to 4 groups. Animals were supplemented with 0.66 (treatments A and B), 0.33 (treatment C), or 0 kg of concentrate (treatment D) per kg o...

The present experiment aimed to evaluate the effect of HMBi on the production performance and metabolism in dairy cows. Thirty multiparous Holstein dairy cows under similar conditions were randomly assigned to three dietary treatments; i) Control, a basal diet; ii) T1, a basal diet plus HMBi (0 g prepartum and 18 g postpartum); and iii) T2, a basal diet plus HMBi (10 g prepartum and 18 g postpa...

Aflatoxin M1 (AFM1) residues in milk are regulated in many parts of the world and can cost dairy farmers significantly due to lost milk sales. Additionally, due to the carcinogenicity of this compound contaminated milk can be a major public health concern. Thirty-four lactating dairy cows were utilised to investigate the relationship between somatic cell counts (SCC), milk yield and conversion ...

The aim of the present study was to investigate the relation between different indices of milk yield andbody condition score (BCS) with the commencement of the luteal activity (C-LA) during the postpartumperiod in high producing dairy cows. Seventy-one multiparous healthy (free of detectable reproductivedisorders) Holstein dairy cows (mean peak milk yield = 56.7 ± 7.4 kg) were used in the prese...

The effect of reducing the frequency of offi cial milk recording and the number of recorded samples per test-day on the accuracy of predicting daily yield and cumulative 305-day yield was investigated. A control data set consisting of 58 210 primiparous cows with milk test-day records every 4 weeks was used to investigate the infl uence of reduced milk recording frequencies. The accuracy of pre...

This study investigated the effect of Rumex Sc (commercial product which includes of Saccharomyces cervisiae, saponin and essential oils) on rumen fermentation, blood glucose, urea, milk yield and milk composition. Animals were offered a basal diet containing alfalfa hay (15.5%), corn silage (24%), beet pulp (7%) and concentrate (53.5%). Additionally, Rumex Sc was included in the experimental d...