Title: Lysozyme as an alternative to antibiotics improves growth performance and tumor necrosis factor-a levels during an indirect immune challenge Authors
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: January 22, 2014
Publication Date: March 1, 2014
Citation: Oliver, W.T., Wells, J., Maxwell, C.V. 2014. Lysozyme as an alternative to antibiotics improves growth performance and tumor necrosis factor-a levels during an indirect immune challenge [abstract]. Journal of Animal Science 92(Supplement 2):50. Technical Abstract: Lysozyme is a 1,4-ß-N-acetylmuramidase that has antimicrobial properties. The objective of this study was to determine the effect of lysozyme and antibiotics on growth performance and immune response during an indirect disease challenge. Two replicates of 720 pigs each were weaned from the sow at 24 d of age, blocked by litter and gender, and then randomly assigned to one of 24 pens in either a nursery room that had been fully disinfected or a nursery room left unclean since the previous group of pigs. Within a room, pigs were randomly assigned to either control diets (C; 2 phase nursery regime), control diets + antibiotics (A; chlorotetracycline/Denegard), or control diets + lysozyme (L; 500 mg/kg diet). Pig weights and feed disappearance were measured and blood was collected on d 0, 14, and 28 of treatment. A group of 20 pigs were killed at 24 d of age for initial body composition analysis and 10 pigs of median weight were killed per diet room combination for body composition analysis after 28 d of treatment. A and L fed pigs grew at a faster rate for the 28 d study (318±14, 320±15, vs. 288±15 g/d, respectively; P<0.05), regardless of immune status (P<0.05). The indirect immune challenge did not alter growth performance from d 0 to 14 of treatment, but decreased ADG from d 14 to 28 of the study (415±15 vs. 445±13; P<0.05). Feed intake was not altered by the immune challenge (P>0.61) or dietary treatments (P>0.10), but feed efficiency was worsened by the indirect immune challenge (P<0.05) and improved by both A and L diets (P<0.01). The immune challenge did not alter body composition (P>0.68), but both A and L decreased, as a proportion, the amount of whole-body lipid (P<0.01). However, diet did not affect whole body protein composition (P=0.19). Interleukin-6 was not altered by dietary treatment (P>0.14) or immune status (P>0.51) at the initiation of treatment and was undetectable on d 14 and 28. However, TNFa was increased in the immune challenged pigs (166±8 vs. 135±7 pg/mL; P<0.01). TNFa was similar at d 0 of treatment, but lower in both A and L fed pigs on d 14 (P<0.01) and 28 (P<0.01) of treatment. Thus, lysozyme or antibiotics improve pig performance during an indirect immune challenge.