Effect of nutrition on embryonal mortality in gilts: association with progesterone.
The effect of the timing of nutritional changes during the immediate period after mating on early embryonal survival and of progesterone as a potential mediator of such changes was studied. A total of 82 gilts were initially fed 2.5 kg.gilt-1.d-1 for one estrous cycle before they were inseminated at 16 and 24 h after the onset of estrus (d 0) using fresh, pooled semen. After AI, gilts were randomly allocated to one of the three feeding regimens, normal NRC allowance of 1.5 x maintenance per day from d 1 (Group N1) or d 3 (Group N3) or an allowance of 2 x maintenance from d 1 (Group H1). All gilts were fed on an individual basis. Single blood samples were collected 72 h after first detection of standing estrus. From d 15 onward, all gilts were fed 1.8 kg/d until they were slaughtered on d 28 +/- 3. Total and viable empryonal survival were affected by dietary treatment (P = .044 and .027, respectively), and viable embryonal survival in group N1 was greater than in group H1 (84.7 +/- 4.5 vs 64.5 +/- 7.6%; P < .05). Plasma progesterone was greater in group N1 than in groups N3 and H1 (10.5 +/- 1.0 vs 3.7 +/- .8 and 4.5 +/- .7 ng/mL, respectively; P < .05). The timing of the change in feed allowance after mating is therefore crucial for demonstrating effects of nutrition on embryonal survival in gilts, and progesterone may mediate these effects.
Jindal
R
R
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada.
Cosgrove
J R
JR
Aherne
F X
FX
Foxcroft
G R
GR
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004435:Eating / Q000502:physiology; D005260:Female; D005313:Fetal Death / Q000503:physiopathology / Q000662:veterinary*; D010060:Ovulation / Q000502:physiology; D011374:Progesterone / Q000097:blood / Q000502:physiology*; D011897:Random Allocation; D013552:Swine / Q000196:embryology* / Q000502:physiology*; D013553:Swine Diseases / Q000503:physiopathology; D015430:Weight Gain / Q000502:physiology
D011374:Progesterone