The objective of present study was to derive the economic values for number of inseminations to conception, calving interval, milk yield and stillbirth, using economic data of 10 Iranian Holstein herds. The economic values were derived by using the profit function methods and differentiating a profit equation with respect to the traits of interest. The cow fertility costs herd amortization or r...

Predicted summer production losses were made for Holstein cows in three widely separated locations in the United States where field investigations of air conditioning for dairy barns have been completed. These losses, based on a functional relationship developed from Missouri Climatic Laboratory data and local climatological data, were compared to the measured losses at each location. Correlati...

Differences in feed intake and production efficiency in lactating Holstein-Friesian (HF), Jersey (JE), and JE × HF (F(1)) dairy cows have been reported. The liver-gut axis is important in the regulation of energy homeostasis, appetite behaviour, and production efficiency. The objectives of this study were to determine: 1) the effect of dairy cow genotype on the expression profiles of genes invo...

Grazing livestock contributes to pasture nitrogen (N) through urine and faeces N losses in pasture-based systems are recognized as an important consideration for sustainable land management. Knowing the frequency quantity of excreta produced dairy production could be useful informing best management practice. The aim this experiment was determine whether data from tail-mounted accelerometers us...

Conventional dairy farming practices usually involve early separation of calves from their dams. Cow-calf contact (CCC) systems may offer an alternative rearing solution that allows for the expression natural behaviours, such as suckling and bonding. However, literature exploring effects CCC on lying behaviours lactating cows is limited. Thus, aims this study were to assess: (1) with without ac...

The present study was designed to assess progesterone profiles at the secreted (caudal vena cava) and circulating levels (jugular vein) and luteinizing hormone (LH) secretion pattern in lactating and non-lactating cows with reference to feeding. Four lactating and four non-lactating cycling Holstein cows were examined. Blood samples were collected simultaneously from the caudal vena cava (via a...

Abstract Data used in these studies were part of another project described by Parsons et al. (2021). These evaluated heifer post-weaning intake classification on performance measurements two-, five- and eight-year-old lactating or non-lactating Angus females. We analyzed production data 57 pregnant, (Study 1) 54 lactating, non-pregnant 2) Heifer was calculated over 80 test days following weanin...

genetic and non-genetic correlations of the average somatic cell score (scs) at different stages oflactation (100, 150, 200, 305 and 365 days in milk) with lactation performance were estimated based on thefirst lactation records of iranian holstein calving during 2000 to 2009. (co) variance components wereestimated using derivative-free reml based on multiple traits animal models. the estimated...

Service-sire conception rate (SCR), a phenotypic fertility evaluation based on conventional (nonsexed) inseminations from parities 1 through 5, was implemented for the United States in August 2008. The SCR model contains the categorical fixed effects of parity for lactations 1 to 5; state-year-month of insemination group; 6 standardized milk yield groups; service number for inseminations 1 to 7...