Abstract
This study aimed to evaluate the effects of feeding avian-derived polyclonal antibody preparation (PAP; CAMAS, Inc.) against Streptococcus bovis, Fusobacterium necrophorum, and lipopolysaccharides (40, 35, and 25% of the preparation, respectively) on growth performance of beef cattle during the backgrounding phase. From d 0 to 56, Angus crossbreed heifers (n = 80; 360 ± 60 kg of BW; 470 ± 26 d of age) and steers (n = 20; 386 ± 65 kg of BW; 465 ± 30 d of age) were blocked by BW and randomly assigned to 1 of 16 concrete-floored pens (108 m2), equipped with 2 GrowSafe (GrowSafe Systems Ltd., Airdrie, Alberta, Canada) feed bunks each. Animals received a common ad libitum diet (76% TDN, 15.9% CP, DM basis) with the addition of 1 (PAP1), 3 (PAP3), or 0 g (CON) of PAP per d. Feed intake was recorded daily and BW were obtained on d -1, 0, 14, 28, 42, 55, and 56, to assess changes in BW, ADG, DMI, and G:F. Based upon orthogonal contrasts (CON vs. PAP1, and PAP1 vs. PAP3), BW and ADG on d 14, and DMI from 0 to 28, and 0 to 42 were greater for PAP1 vs. CON (P ≤ 0.03), whereas PAP3 animals were intermediate (P ≥ 0.20). No differences in final BW, DMI, and ADG from d 0 to 56 were detected among treatments (P ≥ 0.22). In conclusion, feeding 1g of polyclonal antibody preparations against Streptococcus bovis, Fusobacterium necrophorum, and lipopolysaccharides in a backgrounding diet, improved growth performance in the first 14 d of feeding suggesting that feeding these PAP for longer than 14 d may not be necessary. The effects on subsequent feedlot performance when using PAP should be evaluated in future studies
Effects of dry or wet conditions during the preweaning phase on subsequent feedlot performance and carcass composition of beef cattle