The study was conducted to assess the effect of milk production, parity, stage of lactation, season and individual milk components themselves on milk urea nitrogen (MUN) concentration and other milk components of 3,219 Holstein dairy cows in Korean dairy farms. The MUN concentrations in Korean dairy cows were estimated to 16.68±5.87 mg/dl. Milk yield was negatively correlated with fat and prote...

Postpartum infertility is caused by four factors: general infertility, lack of uterine involution, short estrous cycles and anestrus. The general infertility component is common to any estrous cycle and reduces potential fertility by 20 to 30%. Incomplete uterine involution prevents fertilization during the first 20 d after calving but is not related to anestrus. Short estrous cycles prevent fe...

a study to evaluate the reproductive performance of abergelle goat was carried out at sekota district of amhara national regional state. on-farm flocks from two peasant associations were monitored for two years to collect data. data collected included identification number of doe and kid, birth / kidding date, kid birth weight, sex of kid, post partum doe weight, litter size, parity of doe. dat...

The main objective of this study was to estimate the genetic parameters for multi-trait evaluation of birth weight (BW), gestation length (GL) and calving difficulty (CD) in first-parity Iranian Holstein dairy cattle. The data included 29,950 calving records collected during 1995 to 2014 by the Animal Breeding and Improvement Center of Iran. A threshold-linear sire-maternal grandsire model was ...

Two bioeconomic computer models were used to evaluate calving seasons in combination with calf marketing strategies for a range-based cow-calf enterprise in the Northern Great Plains. Calving seasons studied were spring (SP, calving beginning March 15 and weaning October 31), spring with calf mortality increased by 5% (SP-IM), summer (SU, calving beginning May 15 and weaning December 31), summe...

(Co)variance components for stillbirth in US Holsteins were estimated under a sire-maternal grandsire threshold model using subsets of data from the national calving ease database, which includes over 6 million calving records with associated stillbirth scores. Stillbirth was coded as a binomial trait indicating whether the calf was alive 48 h postpartum. Records were selected for calves whose ...

Estimates of variances due to additive and dominance genetic effects and permanent and temporary environmental effects were obtained for ovulation and twinning rates from a composite population selected for twinning rate. Measures of ovulation rate after 11 mo of age on 2,317 heifers with a total of 19,209 measures were used. Twinning measures were on 1,522 first-parity cows, 1,311 later-parity...

The present study was planned to find out the magnitude of environmental factors affecting udder type traits in Sahiwal cattle. Fourteen were measured for each randomly selected 100 lactating cattle maintained at Livestock Research farm, NDRI, Karnal, India. data analysed by least squares methods using general linear model procedures including parity, stage lactation and season calving classifi...

Pure Holstein (HO, n=430), crosses between Swedish Red and HO (SRxHO, n=41), Montbeliarde and HO (MOxHO, n=18), and MO and SRxHO (MOxSH, n=53) were compared for milk, fat and protein yield, fat and protein percentage, somatic cell count (SCC), milking time (MT), and age at fi rst and second calving. A total of 180,933 test-day information for milk yield and MT, and 5,249 for fat and protein per...

The population of free-roaming white rhinoceroses (Ceratotherium simum) is under serious threat. Captive breeding of this species is therefore becoming more important, but this is challenging and often not successful. Obtaining reproductive reference values is a crucial aspect of improving these breeding results. In this study performed between 2008 and 2016, reproductive performance was analys...