Postmating Feeding Level Effects on Conception Rate and Embryonic Survival in Gilts

Dietary Supplementation with 0.8% L-Arginine between Days 0 and 25 of Gestation Reduces Litter Size in Gilts

“…However, our studies indicate that the period of gestation in which L-arginine is supplemented to gilts is critical, because 0.8% L-arginine was detrimental to embryonic survival between d 0 and 25. This phenomenon is consistent with previous reports indicating that a high plane of feeding between d 0 and 10 of gestation, but not d 11-20, decreased embryonic survival and progesterone levels at d 30 in pigs (14). Similarly, embryonic survival on d 28 was greater in gilts fed 1.8 kg of a diet daily between d 0 and 15 after mating compared with 2.5-kg diet/d (27).…”

“…Previous researchers concluded that the adverse effects of increased feed intake (e.g. augmenting total feed intake from 2 to 4 kg/d) on embryonic survival resulted from increased intake of dietary energy (13)(14)(15). In our study, total intake of feed and metabolizable energy (2.0 kg/d and 26 MJ/d, respectively; currently recommended by NRC) did not differ among the treatment groups.…”

“…These unexpected findings are novel and important, because they question the long-standing view that augmenting total daily feed intake of gilts (e.g. from 2 to 4 kg/d and, therefore, doubling arginine intake) reduces embryonic/fetal survival due to increased intake of dietary energy (13)(14)(15).…”

The effect of level of diet intake after mating on the serum concentration of thyroxine, triiodothyronine, growth hormone, insulin and glucose, and embryonic survival in the gilt

“…This research has focused on why embryos die and on the development of management procedures to minimize deaths. Previous research showed that high levels of diet intake after mating are detrimental to embryo survival in gilts (Dyck and Strain 1983). More recent research, using crossbed gilts with a greater growth potential, found no effect of the same level of dietary intake on embryo survival (Dyck 1991).…”

“…The observation that short-term dietary restriction may increase embryo survival (Dyck and Strain 1983) suggests that metabolic hormones may be directly involved in the establishment of pregnancy and in embryonic survival.…”