This 3-year study evaluated the effect ofglycerin supplementation on ewe reproductive efficiency,blood glucose and insulin concentrations. Mature Polypayand Rambouillet ewes (n = 225) were orally dosed withglycerin following estrus synchronization at rates of 0, 50,100, 200 or 300 g/hd. In year 3 an additional 16 ewes weresupplemented (SUP) with 0.57 kg of range cake for 21 daysprior to breeding. Blood samples were collected (n = 25ewes) for 10 hours post drenching. Blood was analyzed forinsulin and glucose concentrations. Ewes were exposed torams for 35 days. Pregnancy was determined byultrasonography evaluation. Number of lambs born per eweexposed was not different (P > 0.10) between treatments(TRT) in year 1 and 2. Pregnancy rates were not different(P = 0.55) by TRT in year 3. In yr 1, a TRT x timeinteraction (P < 0.01) for insulin (ng•ml-1) concentrationswas observed, with 200 g glycerin having lower insulinthan 100 g glycerin. In yr 1, glucose exhibited a TRT x timeinteraction (P < 0.01); 50 g glycerin had lower glucose(mg•dl-1) than 0 g glycerin and 200 g glycerin having lowerlevels than 100 g glycerin. Glucose concentrationsexhibited a quadratic response with a peak at hr 1 andreturned to baseline by hr 7. In yr 2, insulin peaked at hr 4and declined to hr 10. Glucose was higher (P < 0.05) for200 and 300 g glycerin than 0, 50 and 100 g glycerin in yr2. Glucose exhibited a quadratic response (P < 0.01) with apeak at hr 2. Glucose increased linearly in year 3, (P < 0.01;135.8, 176.44, 163.12, 175.12, 195.63, and 161.44 mg•dl-1for 0, 50, 100, 200, 300 g of glycerin and SUP,respectively). Glucose had a quadratic response (P < 0.01);glucose peaked at hr 1 and return to baseline by hr 7. In yr3, insulin had a treatment by time interaction (P < 0.05);insulin peaked at hr 2, 50 and 100 g glycerin returned tobaseline by hr 7; however, 200 and 300 g glycerin did not.Insulin (P < 0.01) increased with increasing levels ofglycerin. Glycerin changed blood glucose and insulinconcentrations; however, it did not influence reproductiveperformance.
Walker, J.A.; Perry, G.A.; Salverson, R.; Nester, P.; Schauer, C.; Held, J.; and Olson, K., "Evaluating Glycerin Supplementation on Reproductive Performance of Sheep" (2011). Animal Science Faculty Publications. 15.