The objective of the study was to investigate the effects of supplementing different plant oils to the basal diet on milk yield and milk composition in mid-lactating dairy cows. Forty Chinese Holstein dairy cows averaging 120 days in milk (DIM) at the start of the experiment (body weight = 580 ± 18.2 kg; milk yield = 33.0 ± 2.00 kg/day) were used in a completely randomized block design. The ani...

in the research the genetic investigation productive and reproductive traits and changes trend the traits in years, seasons and different lactation periods and genetic evaluation cows and bulls of 785 records for milk and 665 records for fat yield and reproductive information during years 1998 to 2003 of 207 dairy cows ghezlagh farm aboureyhan campus (university of tehran) studied. the least sq...

OBJECTIVE This experiment was studied the effects of various levels of crude glycerin (CG) in dairy goat diet on daily intake, milk yield, milk composition, some physical properties and some quality changes of goat milk after sterilization. METHODS Twelve 75% Saanen dairy goats (body weight = 49±3 kg; days in milk = 60±12 d) were randomly assigned in a completely randomized design to evaluate...

Maximum likelihood methodology was used to estimate effects of both a marker gene and a linked quantitative trait locus (QTL) on quantitative traits in a segregating population. Two alleles were assumed for the QTL. In addition to the effects of genotypes at both loci on the mean of the quantitative trait, recombination frequency between the loci, frequency of the QTL alleles and the residual s...

Control of milk composition is of importance in dairy ewes because milk is mostly used for cheese making. Besides numerous factors that alter milk composition, knowledge on the effects of nutrition is useful for it concerns both yield and milk content. Furthermore, modification of nutrition is a powerful and short-term means of altering milk composition. Global effects of nutrition are to be se...

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...

The aim of this study was to examine the expression patterns of SREBP-1 gene in milk somatic cells and its association with milk fat yield during early lactation in Sarda breed sheep. A sample of 20 Sarda ewes, aged between 4 and 5 years, in their third to fourth lactation were chosen. From each ewe 28 days after lambing milk yield was measured, and a 160 ml milk sample for the RNA extraction a...

abstract             (co) variance components of milk, fat and protein yield of 11368 first lactation iranian holstein dairy cow were estimated by single trait random regression test-day models and restricted maximum likelihood (reml) method. in this study the homogeneous residual variance was assumed throughout lactation. estimated heritability for 305-day production traits ranged from 0.25 to...

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...

Results from 12 switchback field trials involving 1216 cows were combined to assess the effects of a protected B vitamin blend (BVB) upon milk yield (kg), fat percentage (%), protein %, fat yield (kg) and protein yield (kg) in primiparous and multiparous cows. Trials consisted of 3 test periods executed in the order control-test-control. No diet changes other than the inclusion of 3 grams/cow/ ...