Inflammatory genes expression and calf responses to different dietary grains (steam flaked corn vs steam-rolled barley) and protein sources (pelleted soybean meal vs pelleted canola meal)

This study aimed to investigate the effects of grains, and protein sources in the starter diet on daily gain, pro- and anti-inflammatory genes expression, ruminal volatile fatty acid (VFA) concentration, and blood metabolites in the dairy calves. Forty Holstein calves were randomly assigned to treatments in a 2 x 2 factorial arrangement with the factors of grain source (steam-flaked corn, CG vs. steam-rolled barley, BG) and pelleted protein source (soybean meal, SBM vs. canola meal, CM). The daily gain of calves who fed with SBM was higher than those fed with CM. Total VFA concentration in the rumen of calves fed with CG was greater than BG at day 35 (p < 0.05), and calves receiving SBM had higher total VFA concentration than calves fed with CM. The relative expression of tumor necrosis factor-alpha and interleukin-1 beta genes were significantly decreased in the calves fed with BG and CM compared to calves fed with CG and SBM. Calves receiving the starter diet based on BG had the highest (p < 0.05) gene expression of interferon-gamma. Feeding calves with SBM is recommended because it resulted in a greater daily gain than CM. Complete replacement of SBM with CM, and CG with BG is not recommended in dairy calves.