PSI-5 - Changes in the expression of MyD88, TRAF6, NFKB1, and NFKB1a on digestive tracts of 0 to 42 days-old calves from the tropics of Mexico

During the first and second weeks of life, calves are extremely susceptible to enteric diseases, their digestive tract is developing and their thermoregulation is not adequate; these being some factors that can contribute to the lack of their weight gain (Hulbert & Moisá, 2016). In addition, they have a reduced capacity to generate an innate and adaptive immune response, in other words, they are still not immunocompetent (Costa et al., 2017; Hulbert & Moisá, 2016), since they are born with all the essential immune components but many of them are not functional until calves are at least 2 to 4 weeks old (Chase et al., 2008). With the aim to identify the development of the innate immune response through the expression of MyD88, TRAF6, NFKB1, and NFKB1a mRNA, in different ages and regions of the digestive tract, qPCR tests were held. Twelve Zebu crossbred calves of 0, 7, 28, and 42 days of age were sampled (three animals of each age). Tissue samples included: rumen, duodenum, and ileum. Gene expression was determined by quantitative PCR (qPCR). Changes in the expression of TRAF6, NFKB1 and NFKB1a mRNA were different in rumen and ileum (P < 0.05) at day 28 of age. MYD88 mRNA expression was different only in ileum (P < 0.05). MyD88, TRAF6, NFKB1, and NFKB1a mRNA expression of rumen tended to decrease and in the case of ileum to increase with age; however, this was until day 28 and not in the first week of life, as mentioned by some other authors.