The Effect of two Levels of Energy Intake on Reproductive Phenomena in Duroc Jersey Gilts

Growth and development of offspring following supplementation of sow diets with oil during early to mid gestation

“…The general consensus in the literature is that maintaining gilts on a high plane of nutrition during early pregnancy increases embryo mortality (Self et al, 1955;Haines et al, 1959;Ettiene et al, 1983;Kirkwood and Thacker, 1988), but the effect does not seem to apply to multiparous sows (Heap et al, 1967;Toplis et al, 1983). In the present study, no negative effects were observed to result from an increased plane of nutrition during early pregnancy.…”

“…In the early stages, this involves providing conditions that maximise embryo survival, leading to larger litter sizes. It is well established that a high plane of nutrition in gilts results in increased embryo mortality (Self et al, 1955;Gossett and Sorenson, 1959;Haines et al, 1959;Sorenson et al, 1961;Ettiene et al, 1983), but no such effect has been observed in sows (Heap et al, 1967;Toplis et al, 1983), which is in part due to the difference in the metabolic state of gilts compared with mature animals.…”

Ovulation Rate and Weight of the Reproductive Organs of Yorkshire and Lacombe Swine

“…Robertson et al (195r) and warnick-et al (1951) obseNed anincrease in ovulation rate from the first to second estrus following puberty. Increasing the level of feed consumption (warnick et a:1., l95r; Schultz et aI., 1966) or energy content (Rigor et at., 1963) prior to estrus results in a greater ovulation rate, while limiting feed (Haines et al, 1959) or energy (Gosset and sorensen, 1959) reduces the owlation rate. Flushing, by a single feeding, after estrus is detected, increases the ovulation rate at that estrus (I-odge and Hardy, 1968).…”

Luteal function and embryonic survival in swine

“…In two trials, embryonic death of 68 percent and 47 percent was observed in full-fed gilts compared with 43 percent and 20 percent for corresponding limited-fed animals. On a full-feeding program, Haines _et al (1959) reported 22.1 percent embryonic death at 25 days compared with 11,6 percent under limited feeding.…”

“…Several groups of workers have demonstrated that continu ous unlimited feeding or a high plane of nutrition increased the ovulation rate but also increased the embryonic death up to 25 days (Self et al, 1955;Haines et al,., 1959). The high feed levels investigated in this study had no adverse effect on embryonic survival.…”