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...

We first sought to clarify the effects of discounted rate, survival rate, and lactation persistency as a component trait of the selection index on net merit, defined as the first five lactation milks and herd life (HL) weighted by 1 and 0.389 (currently used in Japan), respectively, in units of genetic standard deviation. Survival rate increased the relative economic importance of later lactati...

Nutrition has a significant effect on reproduction and lactation in Ruminant. Supply of require nutrient of dairy cows and ewes in early lactation is the main challenges that will be considered, since in most cases the animals facing negative energy balance after calving and the beginning of the period of lactation. Negative energy balance may sometimes result in reduced livestock production an...

Random regression models (RRM) are used for genetic estimations of milk traits in dairy cows. RRM utilize data on traits that are repeated during the time, such as milk trait, which allows of the evaluation of the test day production information. In this study, to estimate genetic parameters for milk production trait, test day records (TDR) were collected from the first lactation of Holstein co...

Nutrition has a significant effect on reproduction and lactation in Ruminant. Supply of require nutrient of dairy cows and ewes in early lactation is the main challenges that will be considered, since in most cases the animals facing negative energy balance after calving and the beginning of the period of lactation. Negative energy balance may sometimes result in reduced livestock production an...

The study aimed to determine factors affecting the dry period length and effect of dry days on milk yield, milk composition and lactation length in the next lactation of dairy cows. Data used for analysis included 7264 lactation records collected from 2012 to 2016 on 4737 Holstein cows raised in 152 herds. The statistical model used to determine the factors influencing the dry period length sho...

Records for daily feed intake during lactation were available for 774 sows with 2,234 litters farrowing from May 2002 to November 2006. Genetic parameters were estimated for whole-oflactation feed intake and feed intake averaged over 5-day periods during lactation. Estimates of heritabilities and the permanent environment of the sow were 0.16±0.05 and 0.18±0.04 for total lactation feed intake a...

The Ural type of the domestic black-and-white breed is characterized by high productivity and good suitability for use in conditions industrial milk technology. During its breeding, purebred bulls-producers Holstein both foreign breeding continues. As a result conducted research, it was found that cows changes significantly with age. Milk yield 305 days lactation increases from 1 to 3 lactation...

Mice raised on a coconut oil (CO)-containing diet for 6 wk prior to the addition of conjugated linoleic acid (CLA) are more sensitive to CLAinduced body fat loss than mice raised on a soy oil (SO)-containing diet. Coconut oil is deficient in essential fatty acids. However the addition of linoleic acid to a CO-containing diet did not alter the enhanced sensitivity to CLA. The objective of this s...

in surrogate pregnancies genetic parents have little opportunity for early bonding with their infants either prenatally (in utero) or during the immediate postnatal period. procedures commonly used to induce lactation include both pharmacologic and nonpharmacologic methods often in combination. studies reporting induced lactation are sparse due to the rarity of augmented lactation. here we repo...