Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/31/2010
Publication Date: 8/1/2010
Citation: Schieck, S.J., Johnston, L.J., Kerr, B.J., Baidoo, S.K., Shurson, G.C. 2010. Use of Crude Glycerol, a Biodiesel Co-product, in Diets for Lactating Sows. Journal of Animal Science. 88:2648-2656. Interpretive Summary: The expansion of the bio-diesel industry has resulted in a substantial increase in the availability of crude glycerin (the principal co-product of biodiesel production) to be used as a feedstuff in diet formulations. Previously we reported that the apparent metabolizable energy content of crude glycerol can be calculated relative to its composition, thereby providing an alternative energy source to swine. The current experiment demonstrated that lactating sows could be fed up to 9% crude glycerol with little to no effect on sow or litter performance. This information is important for nutritionists at universities, feed companies, and swine production facilities showing them the ability to use crude glycerol as a viable feed ingredient in diets fed to lactating sows.
Technical Abstract: An experiment was conducted to evaluate the dietary effects of crude glycerol in lactating sow diets on sow and litter performance under heat stress conditions. Mixed parity (range = 0 to 13) sows (n = 345; 253 + 24 kg BW) were assigned randomly within gestation housing location and parity to 1 of 4 dietary treatments. Treatments consisted of: a corn-soybean meal based control diet (CON) and 3, 6, or 9% glycerol. Dietary treatments were imposed on d 109 of gestation (2.25 kg/d) when sows moved into farrowing rooms. At farrowing, sows were allowed ad libitum access to feed throughout lactation. Dietary treatment tended (P = 0.08) to influence ADFI of sows (CON = 6.04 kg/d; 3% = 6.21 kg/d; 6% = 5.69 kg/d; 9% = 6.00 kg/d; PSE = 0.18). Up to 9% crude glycerol in diet had no effect on sow BW and backfat loss, wean-to-estrus interval, pre-weaning mortality of piglets, and ADG of piglets. Increasing dietary glycerol linearly reduced (P = 0.10) litter size at weaning (CON = 9.50; 3% = 9.60; 6% = 9.36; 9% = 9.39; PSE = 0.08). Daily water consumption was not affected by dietary treatment. Crude glycerol did not affect respiration rates or rectal body temperatures indicating no efficacy in reducing heat stress of sows. Plasma glycerol levels increased linearly (P < 0.05) as dietary crude glycerol increased (CON = 1.21 µM; 3% = 1.69 µM; 6% = 7.21 µM; 9% = 29.04 µM; PSE = 1.58) while plasma glucose levels were not affected. Crude protein content of sow’s milk was not affected (P = 0.16) by dietary treatment. Dry matter (P = 0.07) and crude fat (P = 0.09) content of sow’s milk tended to increase linearly (DM: CON = 17.84%; 3% = 18.43%; 6% = 18.98%; 9% = 18.48%; PSE = 0.34; crude fat: CON = 4.78%; 3% = 4.91%; 6% = 5.50%; 9% = 5.24%; PSE = 0.30) while milk ash concentration tended (P = 0.09) to decrease linearly with increasing dietary glycerol level (CON = 0.77%; 3% = 0.79%; 6% = 0.74%; 9% = 0.74%; PSE = 0.02). Increasing levels of dietary crude glycerol linearly increased (P < 0.05) lactose concentration in sow’s milk (CON = 5.16%; 3% = 5.30%; 6% = 5.43%; 9% = 5.46%; PSE = 0.10). Results from this study suggest that lactating sows fed diets containing up to 9% crude glycerol perform similar to sows fed a standard corn-soybean meal diet.