the objective of this study was to determine the optimum replacement strategy using dynamic programming for dairy herds in fars province. a dairy cow is kept several lactations for milk production in the herd. after spending several lactations, milk production gradually begins to decline, while animal health problems rises simultaneously. so one of the most important management decisions of dai...

Body condition score (BCS), energy content (EC), cumulative effective energy balance (CEEB), and blood serum concentrations of glucose, beta-hydroxybutyrate (BHBA), and nonesterified fatty acids (NEFA) were measured throughout first lactation in 497 Holstein cows raised on a large commercial farm in northern Greece. All these traits are considered to be indicators of a cow's energy balance. An ...

Superimposed on inherently high basal metabolic demands, the additional energetic requirements of reproduction can push female sea otters beyond physiological limits. Indeed, the resulting energy imbalance contributes to disproportionately high rates of mortality at the end of lactation in this species. To examine and quantify metabolic changes associated with reproduction, we measured the rest...

Abstract Most dairy cows experience negative energy balance (NEB) in early lactation because demand for milk synthesis is not met by intake. Excessive NEB may lead to metabolic disorders and impaired fertility. To optimize herd management, it useful detect lactation, but direct calculation of feasible commercial herds. Alternative methods rely on fat-to-protein ratio or concentrations non-ester...

There is limited information regarding both nitrogen (N) and energy partitioning of dairy cows grazing well–managed tropical pastures. The objective this study was to investigate the N mid–lactation on rotationally grazed elephant grass using two pre–grazing targets: 95 % or maximum canopy light interception (LI95% LIMax) during regrowth. used 26 Holstein × Jersey arranged in a randomized compl...

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 %...

BACKGROUND/AIMS The offspring and grandoffspring of female rats fed low protein diets during pregnancy and lactation, but fed nutritionally adequate diets thereafter, have been shown to exhibit altered insulin sensitivity in adulthood. The current study investigates the insulin sensitivity of the offspring and grandoffspring of female rats fed low protein diets during pregnancy, and then mainta...

BACKGROUND The quality of dairy products, raw milk in particular, depends on many factors. Low bacterial and somatic cell counts are basic determinants of the appropriate raw milk quality. The objective of the work was to assess the effect of selected factors, that is, the age of cows and their daily milk performance, on cytological quality (somatic cell count) and energy value of milk produced...

Laboratory mice (strain MF1) were used to determine whether sustainable rates of energy intake are limited during lactation. Mice raising natural-sized litters (N=71) reached an asymptote in their daily food intake between days 13 and 16 of lactation at 23.1 g x day(-1) and also between litter sizes of 9 and 15 pups (22.8 g x day(-1)). A second group of 37 females had their litter sizes manipul...