Test-day milk yield and somatic cell count data over extended lactation (lactation to 540-600 days) were analysed considering part lactations as different traits and fitting random regression (RR) models. Data on Australian Jersey and Holstein Friesian (HF) were used to demonstrate the shape of the lactation curve and data on HF were used for genetic study. Test-day data from about 100 000 cows...

A replicated randomized block trial was conducted to determine the response of Holstein cows rotationally grazing annual ryegrass-Crimson clover pasture to supplemental concentrate. Within each of 2 yr, 16 Holstein cows were assigned to one of four blocks by energy-corrected milk yield, days in milk, and parity. Treatments included one of four levels of concentrate based on the following grain ...

The present study investigated the effects of supplementing soybean oil (SBO) and sunflower oil (SFO) on the performance of early lactating Awassi ewes, growth of their sucking lambs and on the concentration of total fatty acids in milk and blood of suckling lambs. One hundred and twenty five ewes were randomly assigned into five equal sized treatment groups involved; a control total mixed rati...

Objective: The cows that don’t have access to sufficient energy in their ration can get sickness. Milk production has a high priority in metabolism of dairy cows so lactating cows are more prone to get sick This can ruin all the benefits of higher milk yield because of the higher prevalence of the disorders. Methods: Data for this research had gathered from a herd with 1600 Holstein cattle in E...

The aims of this study were to evaluate the energy consumption and its modeling in industrial milk production units using data envelopment analysis (DEA) approach and sensitivity analysis. Data were collected from 44 industrial milk production units in Guilan province of Iran with face to face questionnaire method during 2012-2013. Inputs included animal feed, fossil fuels, electricity, machine...

the genetic parameters for milk production and milk fat traits for first to third parities were estimated using single, multi trait and repeatability models. the genetic parameters for test day milk records were also estimated using random regression model. the test day records and 305 day milk records of 17055 cows from 10 herds collected between years 1996-2007 in khorasan razavi province wer...

Objective: The cows that don’t have access to sufficient energy in their ration can get sickness. Milk production has a high priority in metabolism of dairy cows so lactating cows are more prone to get sick This can ruin all the benefits of higher milk yield because of the higher prevalence of the disorders. Methods: Data for this research had gathered from a herd with 1600 Holstein cattle in E...

In dairy cows, milk yield increases rapidly after parturition until a peak at around wk 6 of lactation. However, the description of the shape of the lactation curve is commonly based on weekly average milk yields. For a more detailed analysis of the milk production curve from the very beginning of lactation including the colostral period and the effect of colostrum yield on further lactational ...

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...