Abstract #T89

# T89
Evaluation of passive transfer of calves receiving maternal colostrum or colostrum replacer.
A. P. Silva1, A. F. Toledo*1, A. M. Cezar1, M. Poczynek1, M. G. Coelho1, M. D. Silva1, M. Campos2, C. M. M. Bittar1, 1Department of Animal Sciences, College of Agriculture Luiz de Queiroz (ESALQ), University of Sao Paulo, Piracicaba, SP, Brazil, 2Department of Clinical Research, The Saskatoon Colostrum Company Ltd, Saskatoon, Canada.

Failure of passive immunity transfer (FPIT) remains a major problem in dairy production. Therefore, commercially available colostrum replacers have emerged to mitigate this deficiency. Literature suggests that consumption of levels of Ig, beyond that needed to prevent FPIT, may improve calf health and performance. Fifty calves were blocked according to sex, birth weight and date of birth and were distributed among different colostrum feeding protocols: 2MC: 2L of maternal colostrum (MC); 4MC: 4L of MC; 2MC1CR: 2L of MC + one dose of colostrum replacer SCCL (100g IgG) all given at birth; 2CR: 2 doses of colostrum replacer (CR) SCCL (200 g IgG) given at birth; 3CR: 2 doses of CR SCCL (200 g IgG) given at birth + one dose of CR SCCL (100 g IgG) given between 6 and 8 h after birth. Calves received starter (24,6% of CP; 5,22% of CF; 13,89% of NDF and 46,57% of NFC as-fed) and water free-choice and were fed 6L/d of milk replacer (22,44% of CP, 16,2% of CF and 14% of solids) until 56d of age. The apparent efficiency absorption (AEA) was calculated using the following equation: AEA IgG (g) = {[serum IgG g/L 24h − serum IgG g/L birth] × birth weight kg × 0.09}/IgG intake (g), where: 0.09 = plasma volume of 9% of BW at birth. Protocols affected Ig intake and AEA (P < 0.01), but did not influence serum IgG or total serum protein at 48h (P > 0.05). Increasing Ig intake with higher volumes of MC or CR decreased AEA. There were no differences on performance or health among the different colostrum feeding protocols. The ADG (kg) was also not affected colostrum protocols (2MC = 0.29; 4MC = 0.24; 2Mc1CR = 0.25; 2CR = 0.25 and 3CR = 0.21; P > 0.05). However, calves from all protocols had low ADG, which can be explained by the milk replacer composition and the history of Cryptosporidium infection in the herd. The CR fed in the study may be an alternative to MC. However, while all treatments resulted in excellent levels of passive transfer the potential benefits of increasing the amounts of colostrum (>200 g IgG) with either MC or CR were not perceived in this short-term study.

Key Words: health, IgG, newborn