J. Anim Sci., doi: 10.2527/jas.2006-831
©Copyright, 2007, The American Society of Animal Science
Assessment of lactose level in the mid- to late-nursery phase on performance of weanling pigs
G. L. Cromwell 1*,
G. L. Allee 2,
D. C. Mahan 3
1 University of Kentucky, Lexington 40546
2 University of Missouri, Columbia 65211
3 The Ohio State University, Columbus 43210
* To whom correspondence should be addressed. E-mail: gcromwel{at}uky.edu.
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Abstract |
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An experiment involving a total of 1,320 crossbred pigs was conducted at 3 universities to assess the effects of various levels of lactose in diets during phase 3 (wk 3 and 4 post weaning) of a 4-phase starter program. Pigs were weaned at 15 to 20 d (6.2 kg initial BW) and allotted to 5 treatments. All pigs were fed a complex, phase 1 diet (20% lactose) the first wk post weaning followed by a complex, phase 2 diet (15% lactose) the second wk post weaning. Phase 3 diets containing 0, 2.5, 5.0, 7.5, or 10.0% lactose were fed for wk 3 and 4, then a common, corn-soybean meal diet was fed for an additional 1 to 2 wk (phase 4). The source of lactose was Dairylac 80, (International Ingredient Corp., St. Louis, MO), which contains 80% lactose. The phase 1, 2, and 3 diets were prepared at one site. Pigs were weighed and feed intake determined at weekly intervals. There were 8 replications at each station for a total of 24 replications per treatment with 5 or 23 pigs per pen. As expected, ADG, ADFI, and G:F were not affected (P = 0.10) during the initial 2-wk period when all pigs received the same diet. During wk 3 and 4 (phase 3) when the 5 levels of lactose were fed, ADG and ADFI increased linearly (P < 0.01) with increasing levels of lactose, but G:F was not affected (P = 0.10). Although the quadratic component was not significant, ADG and ADFI reached a numerical plateau at the 7.5% inclusion level of lactose during phase 3. Compared with pigs fed the diet without lactose, the 7.5% level of lactose resulted in 350 g of additional weight gain coupled with 420 g of additional feed consumed per pig during phase 3, and most of the additional weight gain (294 g) was maintained through the end of the 5- to 6-wk study. These results suggest that pigs respond to dietary lactose during the mid to latter phase of the nursery period and that the response was obtained under different management and facility conditions.
Key Words:
lactose, pigs, weaning
