Effects of Increasing Standardized Ileal Digestible Lysine during Gestation on Growth and Reproductive Performance of Gilts and Sows Under Commercial Conditions

A study was conducted on a commercial sow farm to evaluate the effects of increasing dietary standardized ileal digestible (SID) Lys in gestation on sow growth and piglet birth weight. A total of 971 females (498 gilts, 138 parity 2 and 335 parity 3+ sows; Camborough, PIC, Hendersonville, TN) were group-housed (approximately 275 females/pen) and individually fed with electronic sow feeders (ESF). Scales were located in the alleyway after the feeding stations returning into the pen. Females were moved from the breeding stall to pens on d 4 of gestation and were allotted to 1 of 4 dietary treatments on d 5. Dietary treatments included increasing SID Lys (11, 13.5, 16, and 18.5 g/d). High and low dietary Lys treatments were achieved by changing the amounts of corn and soybean meal and intermediate treatments were created by different blends of each via ESF. Gilts and sows received 2.1 and 2.3 kg/d (5.3 and 5.7 Mcal NE/d) of feed throughout the entire study. Initial BW and backfat were obtained on d 5 of gestation while final BW and backfat were obtained on d 112 of gestation. Individual piglet BW was obtained within 12 h of birth on litters from 928 females. Data was divided into 3 parity groups: 1, 2, and 3+ and analyzed using the GLIMMIX procedure of SAS. There was no evidence for a treatment×parity group interaction for any of the response variables. Final BW at d 112 of gestation increased (linear, P<0.001) as SID Lys increased, but there was no evidence for differences in final backfat. On average, females gained 2.7 mm of backfat throughout gestation. Average total born was 15.6 and average piglet BW was 1.28 kg with no evidence for differences among treatment groups. In conclusion, these results appear to suggest that females gained lean tissue because final BW increased with increasing SID Lys, but final backfat did not change. Increasing SID Lys during gestation did not affect pig birthweight in this study.

	g/d SID Lys					Probability, P <
	11.0	13.5	16.0	18.5	SEM	Linear	Quadratic
Initial BW, kg	187.3	185.8	187.2	187.0	1.92	0.777	0.304
Final BW, kg	232.9	233.4	236.8	239.1	0.76	<0.001	0.205
Initial backfat, mm	14.7	14.7	14.8	14.8	0.26	0.650	0.824
Final backfat, mm	17.3	17.5	17.5	17.5	0.25	0.612	0.657
Total born, n	15.5	15.7	15.5	15.6	0.209	0.993	0.858
Piglet BW, kg	1.28	1.27	1.29	1.28	0.014	0.574	0.972