|Vallet, Jeffrey - Jeff|
Submitted to: Reproduction, Fertility and Development
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/21/2000
Publication Date: N/A
Citation: ASHWORTH, C.J., BEATTIE, L., ANTIPATIS, C., VALLET, J.L. EFFECTS OF PRE- AND POST-MATING FEED INTAKE ON BLASTOCYST SIZE, SECRETORY FUNCTION AND GLUCOSE METABOLISM IN MEISHAN GILTS. REPRODUCTION, FERTILITY AND DEVELOPMENT. 11-323-327. 1999. Interpretive Summary: Manipulating the nutrition of sows around the time of mating has been demonstrated to effect embryo survival during later pregnancy, but the mechanism is not known. In this experiment, gilts were fed either a diet that met their nutritional requirements or was three times their nutritional requirements (a diet previously shown to improve embryo survival) during the estrous cycle preceding mating. Then, after mating, half the animals in each group were switched to the other diet, while the other half remained on the original diet. Embryos were recovered on day 12 and each embryo was evaluated for size, estrogen production, production of a protein involved in vitamin A metabolism, and two measures of metabolic rate. Results indicated that a diet exceeding requirements during the premating period increased the number of cells per embryo, decreased the variation in size of embryos within a litter, and increased embryo metabolism. These results suggest that a diet exceeding requirements during the premating period may improve embryo survival by enhancing embryo development, making the development more uniform and increasing embryo metabolism during early pregnancy.
Technical Abstract: This experiment was designed to determine the effects of a nutritional regime, known to increase embryo survival, on blastocyst development and function. Day 12 blastocysts were recovered from Meishan gilts allocated in a 2x2 factorial design to receive either a high or a maintenance diet before or after mating (n = 4-6 gilts per group). The post-mating diet had no effect on individual blastocyst size, cell number, secretion of oestradiol-17beta or retinol binding protein, glucose metabolism or on the within-litter variability in these measures. Blastocysts recovered from gilts consuming the high pre-mating diet had more cells (13.51 v. 13.006 log cells; SED = 0.23; P = 0.05), greater production of carbon dioxide from glucose (2.19 v. 1.23 log pmol-1 blastocyst-1 3 h-1, SED = 0.42; P = 0.05) and a lower within-litter standard deviation in blastocyst surface area (0.66 v. 1.18 log mm2, SED = 0.24; P = 0.04) compared with gilts fed the maintenance pre-mating diet. Collectively, these data suggest that a nutritional strategy that increases embryo survival is also associated with an increase in individual blastocyst cell number and reduced within-litter variability in blastocyst size.