EFFECT OF FAT SOURCE IN RECEIVING DIETS AND REDUCED NOCTURNAL TEMPERATURES ON COMMINGLED FEEDER PIG PERFORMANCE

Three experiments using 864 crossbred feeder pigs were conducted to de termine the effects of fat sources and a feed flavor in 3-wk receiving diets and a reduced nocturnal temperature regimen on commingled feede r pig performance. In Exp. 1, there was no response to a feed flavor o n overall ADG or ADFI. Commingled pigs offered receiving diets contain ing 5% blended vegetable oil (5B) or 5% tallow (5T) did not differ in overall ADG (.61, .63 vs .61 kg/d) and gain:feed (.315, .307, .310) co mpared with pigs offered corn-soy diets. In Exp. 2, pigs offered corn- soy receiving diets containing 0, 2, 4, or 6% (C2, 2B, 4B or 6B) of a blended vegetable oil had a cubic (P < .075) response for overall ADG (.67, .68, .66, and .69 kg/d) and linear(P < .075) response for gain:f eed (.309,.307, .316, and .317). Four percent tallow (4T), compared wi th 4B and 4% soybean oil (4SO), improved (P < .1) overall ADFI (2.24 v s 2.10 + 2.14 kg/d) with no effect on overall ADG. In Exp. 3, 4B compa red with 4T and 4% yellow grease (4YG) resulted in a slower (P < .01) overall ADG(.63 vs .68 + .65 kg/d) with no difference in ADFI or gain: feed. When pooled across Exp. 2 and 3, there was no effect of a reduce d nocturnal temperature (RNT) regimen imposed beginning 1 wk after arr ival vs a constant temperature control regimen on overall ADG (.65 vs .67 kg/d) and gain:feed (.303 vs .304). When pooled across Exp. 2 and 3, pigs fed 4T had a better (P < .0005) overall ADG than pigs fed 4B ( .68 vs .65 kg/d). These results suggest a differential response on ove rall performance due to fat sources in commingled feeder pig diets. Th e results do not support the use of the feed flavor tested or RNT to s timulate performance.