Animals with the same lactation breeding value can have different shapes of additive genetic curve, implying differences in persistency lactation. Since environmental conditions change across lactation, animals re-rank through leading to genotype by environment interaction for daily milk yield. The objectives this project is describe curve pattern estimated values and assess extent sire cow re-...

The present study investigated the effect of L-carnitine supplementation during pregnancy (125 mg/d) and lactation (250 mg/d) on milk production, litter gains and back-fat thickness in sows fed a low-energy and low-protein diet during lactation. Sows supplemented with L-carnitine produced more milk on days 11 and 18 of lactation (+18 %; P<0.05) and had higher litter gains during suckling (+20 %...

Objective: Evaluate changes in bone mineral density (BMD) during pregnancy and lactation and evaluate BMD and fracture risk in nulliand multiparous women. Design: Review article Setting: Manuscript published in PubMed from 1966. Main outcome measure: Rate of BMD changes during pregnancy and lactation and BMD and fracture incidence in nulliand multiparous women. Results: Both a pregnancy and six...

Tuberoinfundibular dopamine (TIDA) neurons are the central regulators of prolactin (PRL) secretion. Their extensive functional plasticity allows a change from low PRL secretion in the non-pregnant state to the condition of hyperprolactinemia that characterizes lactation. To allow this rise in PRL, TIDA neurons are thought to become unresponsive to PRL at lactation and functionally silenced. Her...

The changes in the activities of a number of enzymes, representing various metabolic activities, in pyridine nucleotides, in levels of deoxyriboand ribonucleic acid, and in numbers of nuclei in mammary glands removed from rats at various stages of pregnancy and lactation have been documented. The onset of lactation is accompanied by a rapid 3to 4-fold increase in numbers of nuclei and in DNA le...

Data from a survey performed from 1986 to 1990 were analyzed to assess the effects of diseases on length of productive life of 3589 Holstein cows from 47 herds, using a proportional hazard model. The probability of a cow being culled, or hazard function, was supposed to be the product of an unspecified baseline hazard function and log-linear, time-dependent explanatory variables that possibly i...

Human breast milk (BM) protein composition may be impacted by lactation stage or factors related to geographical location. The present study aimed at assessing the temporal changes of BM major proteins over lactation stages and the impact of mode of delivery on immune factors, in a large cohort of urban mothers in China. 450 BM samples, collected in three Chinese cities, covering 8 months of la...

The capacity of animals to dissipate heat may constrain sustained energy intake during lactation. We examined these constraints at peak lactation in MF1 mice that had ad libitum access to food, or that had to run a pre-set target on running wheels to obtain ad libitum access to food. The voluntary distance run decreased sharply during pregnancy and peak lactation. When lactating females were pr...

Origins of hyperlipidemia and cholestasis that occur during pregnancy were investigated by examining expression of key elements related to plasma and hepatic cholesterol metabolism during pregnancy, lactation, and post-lactation in the rat model. Among major findings were: during pregnancy, the activities of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase, acyl coenzyme A:cholesterol ac...

Osteoporosis is considered as an important public health problem especially in postmenopausal women. There are some hypotheses support the contributory effect of pregnancy and lactation on osteoporosis later in life. High calcium demand during pregnancy and lactation and low estrogenic state support those hypotheses. Numerous studies have investigated on the issue but there is no consensus abou...