نتایج جستجو برای: lactation duration
تعداد نتایج: 218741 فیلتر نتایج به سال:
The authors analyzed the relation between lactation history, organochlorine serum levels-in particular, 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE)-and the risk of breast cancer within a subsampe from a larger breast cancer case-control study conducted among women living in Mexico City, Mexico, between 1990 and 1995. From the origin...
Two experiments were designed to determine the effects of duration of lactation and plane of nutrition on the reproductive performance of Finn x Dorset Horn ewes mated at a hormonally induced oestrus 9 weeks after lambing. In Exp. 1, ewes were mated on 4 December or 19 March and lactation was terminated at 35 or 15 days before mating or 7 or 35 days after mating. The fertility of ewes lactating...
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...
We investigated presence and levels of DDT in 163 breast milk samples from four South African villages where, in three of them, malaria is controlled with DDT-sprayed indoors. Mean ΣDDT levels in breast milk were 18, 11, and 9.5 mg/kg mf (milk fat) from the three DDT-sprayed villages, respectively, including the highest ΣDDT level ever reported for breast milk from South Africa (140 mg/kg mf). ...
Background and aimsThe composition enzymology of human milk changes throughout the lactation period, differ for mothers who give birth prematurely compared to those deliver at full-term. Understanding from very low weight premature infants is great significance, objective this study was evaluate composition, protein profile plasmin activity delivered different gestational ages.MethodsSamples we...
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...
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