The influence of different copper and zinc contents in rations on blood serum concentrations in dependence on feeding (Groups A and B) and lactation (Lactation 1 and 2) was tested in a feeding trial with 60 German Holstein cows. All animals received a diet based on maize and grass silage ad libitum. 30 cows received a concentrate supplemented with copper and zinc as recommended (Group A), where...

Inheritance of economic traits was studied in Nili-Ravi dairy buffaloes through analysis of data comprising 5037 records of daughters of 79 sires. Data were collected from three large-sized state dairy farms. Heritability, genetic and phenotypic correlations of some indicator traits on important production and reproduction traits were worked out. Based upon analysis of records for first lactati...

Several studies have suggested that lactation performance may be programmed by the number of fetuses during pregnancy, whereas other studies indicate that processes during lactation are more important. As gestation litter size and litter size in lactation are usually strongly correlated, separating the roles of pregnancy and lactation in lactation performance is difficult. To break this link, w...

Abstract. The purpose of the research is to study age retirement cows from herd, depending on various genetic and paratypical factors. Methods. was carried out according data a black-and-white breed dairy herd Chelyabinsk region. studied animals different ages were divided into groups relative live weight at first fruitful insemination, mothers bulls-producers Holstein lines. paper analyzes for...

determination of milk yield potential using an accurate method is essential for assessing nutritional requirements, evaluation of genetic potential, lamb growth and survival, management decisions and improving performance traits of sheep flocks. exogenous oxytocin injection is applied to estimate milk secretion rate in sheep. oxytocin is a neurohormone produced in the hypothalamo-neurohypophysi...

Partial budget analysis is an effective production tool to evaluate economic implications of proposed changes to pig production systems. We describe a partial-budgeting tool that estimates the effects of lactation space and lactation-space management on net revenue in a multi-site production system. A partial-budgeting worksheet is linked to an economic model that couples production-system-spec...

BACKGROUND Research suggests that estrogenic endocrine-disrupting chemicals interfere with lactation. OBJECTIVES (1) to determine if estrogenic persistent organic pollutants (POPs) are associated with shortened lactation duration; (2) to determine whether previous breastfeeding history biases associations. METHODS AND RESULTS We measured selected organochlorines and polychlorinated biphenyl...

Ten multiparous crossbred goats, ®ve each of alpine beetal (AB) and saanen beetal (SB) were selected from the National Dairy Research Institute goat herd immediately after parturition. These were managed as per the practices followed in the institute's goatherd. Blood and milk samples were collected at biweekly intervals from day 14 post-kidding for 22 weeks (154 days). Somatic cell count, elec...

A genome wide association study was conducted using estimated breeding value (EBV) for milk production traits from 1st to 4th lactation. Significant single nucleotide polymorphism (SNP) markers were selected for each trait and the differences were compared by lactation. DNA samples were taken from 456 animals with EBV which are Holstein proven bulls whose semen is being sold or the daughters of...

The objective of this study was to examine the effect of compensatory growth nutritional regimen on mammary gland growth and lactation. One hundred twenty-two Sprague Dawley female rats (35 days of age) were randomly assigned to either a control or a stair-step compensatory nutrition (SSCN) feeding regimen or an alternating 2-2-3-3-week schedule beginning with 40% energy restriction for 2 weeks...