INTERACTION OF DIET COMPOSITION AND A REDUCED NOCTURNAL TEMPERATURE REGIMEN IN WEANLING PIGS

A three-trial experiment using 3- to 4-wk-old newly weaned pigs was co nducted to evaluate the possible interaction between 16-h reduced noct urnal temperature regimen (RNT16) and a lowered nursery diet lysine re gimen on weaned pig and subsequent growing-finishing performance. Nurs ery temperature treatments were 1) a control temperature (CT) regimen of 30 degrees C constant air temperature lowered 2 C degrees/wk and 2) a regimen beginning 1 wk after weaning in which the temperature from 1600 to 0800 was lowered 6C degrees from CT. Within each temperature t reatment, all pigs were offered a diet containing 1.20% lysine for the 1st wk after weaning followed by 1.20 or 1.10% lysine to 10.5 kg and 1.00 or .90% lysine to 20 kg. There was no interaction of temperature regimen and diet on overall nursery performance. The RNT16 pigs had im proved (P = .1) ADG (.351 vs .342 kg/d) with no difference (P > .1) in ADFI (.693 vs .680 kg/d) or G:F (.508 vs .506) compared with CT. Pigs fed the lower lysine sequence had poorer (P < .0001) ADG (.333 vs .36 0 kg/d) and G:F (.487 vs .527) than controls. There was also no effect (P > .1) of RNT16 vs CT on subsequent performance to slaughter weight for ADG (.770 vs .755 kg/d) or G:F (.309 vs .311). There was also no effect (P > .1) of a lowered nursery lysine sequence compared to contr ol on growing-finishing ADG (.768 vs .757 kg/d) or G:F (.312 vs .309). These results suggest that the weaned pig is more tolerant of an exte nded reduced nocturnal temperature regimen than previously thought and that reduced nursery performance due to nutrient insufficiency may no t affect growing-finishing performance.