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Brown/beige adipocytes dissipate energy as heat. We previously showed that brown/beige adipocytes are present in white adipose tissue (WAT) of fattening cattle. The present study examined the effect of vitamin A restriction on mRNA expression of brown/beige adipocyte-related genes. In Japan, fattening cattle are conventionally fed a vitamin A-restricted diet to improve beef marbling. Twelve Japanese Black steers aged 10 mo were fed control feed (n = 6) or vitamin A-restricted feed (n = 6) for 20 mo. Subcutaneous WAT (scWAT) and mesenteric WAT (mesWAT) were collected, and mRNA expression levels of molecules related to the function of brown/beige adipocytes (Ucp1, Cidea, Dio2, Cox7a, and Cox8b) as well as transcriptional regulators related to brown/beige adipogenesis (Zfp516, Nfia, Prdm16, and Pgc-1a) were evaluated. The vitamin A restriction significantly increased or tended to increase expression levels of Cidea and Pgc-1a in scWAT, and Cidea, Dio2, and Nfia in mesWAT. Previous studies revealed that the bone morphogenetic protein (Bmp) pathway was responsible for commitment of mesenchymal stem cells to brown/beige adipocyte-lineage cells. The vitamin A restriction increased expression of Bmp7 and some Bmp receptors in WAT. The interrelationship between gene expression levels indicated that expression levels of Nfia, Prdm16, and Pgc-1a were closely related to those of genes related to the function of brown/beige adipocytes in scWAT. Also, expression levels of Nfia, Prdm16, and Pgc- 1a were highly correlated with those of Alk3 in scWAT. In summary, the present results suggest that the vitamin A restriction increases the number or activity of brown/beige adipocytes through regulatory expression of transcriptional regulators to induce brown/beige adipogenesis, especially in scWAT of fattening cattle, which may be governed by the Bmp pathway. [ABSTRACT FROM AUTHOR]

Estimates age-related changes in duodenal flow of microbial nitrogen in calves after weaning by determining endogenous excretion of purine derivatives and the ratio of excretion into urine as PD to duodenal flow of purine bases. Experimental design; Administration of acid-free milk replacer; Administration of purine bases into the abomasum.

Identifies limiting amino acids in weanling calves fed a corn and soybean meal (SBM) diet. Materials and methods used; Information on some free amino acids (AA) immediately before and after morning feeding; Results and discussion of the study.