Effect of winter season and feeding techniques on the growth performance and blood expression profile of the stress-, inflammation-, and cellular integrity-associated genes in Bos taurus and Bos indicus breeds

We determined the effects of the winter season (cold stress), from October to March 2023, on the growth performance and expression profile of the blood chemo-cytokines and tight junction proteins in two cattle breeds [ Bos indicus (Brahman) vs. Bos taurus (Angus)] reared under two feeding techniques or treatments: traditional with growth-promoting technology (GPT) (TRT treatment) vs. natural without GPT (NAT treatment) ( n = 50 steers/breed per treatment) in Colorado State, USA. The body weight (BW), the average daily BW gain (ADG), the dry matter (DM) feed intake (DMI), and the feed efficiency (FE; kilograms gain/kilogram DMI) were monitored. Total RNA was extracted from blood at the end of each month and subjected to reverse transcription and real-time quantitative PCR to measure the relative expression of target genes using the 2 −ΔΔCt method. There were no significant period-by-breed-by-feeding technique (P × B × T) interactions for BW, ADG, and FE. When the factors were analyzed separately, the data showed a significant increase of BW for both breeds during the study period. However, Angus cattle had higher BW, ADG, and FE compared with their Brahman counterparts. These differences were associated with higher feed intake ( p < 0.0001) in Angus versus Brahman. The blood expression levels of heat shock protein 90 ( Hsp90 ), interleukin 6 ( IL6 ), chemokines ( Ccl4 , Cxcl12 , and Xcl1 ), and chemokine receptor ( Cxcr2 ) were significantly upregulated in November, which coincided with the lower environmental temperature. The abundance of occludin ( Ocln ) mRNAs peaked in January after an initial increase from October, followed by a downward trend through March. Brahman cattle exhibited a significant higher expression of Hsp90 , Ccl4 , and Xcl1 compared with their Angus counterparts. The TRT treatment significantly downregulated the expression of the Cxcr2 gene compared with the NAT feeding technique. Together, to the best of our knowledge, this is the first study showing a differential expression of Hsp90 and chemokines between a cold-resilient (Angus) and a cold-sensitive (Brahman) cattle. This work provides novel opportunities and offers new avenues for the identification of molecular signatures for marker-assisted selection.