The mammary gland is a relatively unique tissue in that it may undergo repeated cyclic phases of development, functional differentiation and regression. The carryover of mammary tissue from one lactation cycle to the next can vary considerably among sows, particularly considering the number of glands that they may have and the range of litter sizes. When a sow farrows, she has a set number of p...

Serum estradiol (E2) and progesterone (P4) levels were measured by chemiluminescence immunoassay (CLIA) during consecutive reproductive states in Mongolian gerbils. The results show that E2 and P4 levels throughout the estrous cycle in Mongolian gerbils peaked at proestrus and estrus, respectively. During gestation in primiparous and multiparous gerbils, E2 levels reached a small peak on day 6 ...

We measured the plasma levels of amino acids at various reproductive stages in female rats, including the estrous cycle, pregnancy and lactation, and compared the resulting amino acid profiles using two- or three-dimensional figures. These figures revealed that the amino acid profiles of pregnant and lactating dams differed considerably from those during the estrous cycle or in male rats. The p...

The cow mammary transcriptome was explored at -30, -15, 1, 15, 30, 60, 120, 240, and 300 d relative to parturition. A total of 6,382 differentially expressed genes (DEG) at a false discovery rate ≤ 0.001 were found throughout lactation. The greatest number of DEG (>3,500 DEG) was observed at 60 and 120 d vs. -30 d with the largest change between consecutive time points observed at -15 vs. 1 d a...

The transition period for dairy cows, which refers to the time from 3 weeks before through 3 weeks after calving, is now recognized as the most critical phase of the lactation cycle (Drackley , 1999) . Nutrition and management during this period essentially determine the profitability of th e cow for the remainder of the lactation . A problem-filled transition gets cows off to a poor start to l...

Eighteen crossbred goats were selected from the Institute’s goat herd to determine the changes in hormones, blood metabolites and yield and composition of milk during lactation. The blood and milk samples were collected from each goat in a heparinized vacutainer tubes at fortnightly interval for a period of 150 days. In milk samples, fat, protein and lactose contents were estimated while in blo...

OBJECTIVES The goal of this article was to evaluate the association between flaxseed intake during lactation and its effects on the reproductive indexes in female offspring at infancy, puberty and adult age. MATERIAL AND METHODS Two groups were evaluated, an experimental group (FG, n=24) which consumed a flaxseed based diet and a control group (CG, n=26) which had access to a casein based die...

We evaluated 2 strains of mice for their utility in the investigation of nutritional and molecular regulatory mechanisms of lactation. The lactational performance and milk composition were characterized for an inbred mouse strain, inbred Quackenbush Swiss line 5 (QSi5) selected persistently for fecundity, and a nonselected strain, CBA. The milk yield assessed by changes in BW in response to suc...

The hierarchy of selenium (Se) requirements for growing rats ranges from <0.01 to 0.1 microg Se/g diet, depending on the choice of Se status parameter. To further evaluate the efficacy of molecular biology markers to determine Se requirements in later periods of the life cycle, which are less amenable to traditional approaches, we studied pregnant and lactating rats. Female weanling rats were f...

repeat breeding (rb) is a syndrome and several factors have been identified as its causes. luteal insufficiency is a known cause of embryonic mortality. the aim of this study was to assess the effect of two periods of p4 therapy on the second service and also their effects on the first plus the second service conception rates (cr) of repeat breeder dairy cows. cows included in the study were in...