Autoria: CAMPOLINA, J. P.; COELHO, S. G.; BELLI, A. L.; NEVES, L. F. M.; MACHADO, F. S.; PEREIRA, L. G. R.; TOMICH, T. R.; CARVALHO, W. A.; DAIBERT, R. M. P.; REIS, D. R. de L.; COSTA, S. F.; VOORSLUYS, A. L.; JACOB, D. V.; CAMPOS, M. M.

Resumo: The objective of this study was to evaluate blood cells and metabolites, insulin-like growth factor-1 (IGF-1), digestibility, internal organs weight and histology, gene expression, and spleen cell proliferation of pre-weaned bull calves supplemented with a blend of essential oils in milk replacer (MR). Sixteen newborn Holstein?×?Gyr crossbred dairy bull calves, with body weight at birth of 33.3?±?3.7 kg, were housed in individual sand bedded pens, blocked by genetic composition, and randomly assigned to 1 of 2 treatments in a randomized complete block design: Control (CON, n?=?8) and blend of essential oils supplementation (BEO, n?=?8, 1 g/day/calf, Apex Calf, Adisseo, China). The commercial blend was composed by plant extracts derived from anise, cinnamon, garlic, rosemary, and thyme. Animals were fed 5 L of MR/day reconstituted at 15% (dry matter basis), divided into two equal meals. Water and starter were provided ad libitum. ß-hydroxybutyrate, urea, and glucose were evaluated weekly, IGF-1 was evaluated biweekly, and total blood cell count was performed every four weeks until the end of the trial at eight weeks of age. Feed samples were collected three times a week and polled for weekly analysis. Apparent total nutrient digestibility was determined from d 56 to 60 of age. On d 60?±?1, animals were euthanized for organ weight, histology, spleen cell proliferation, and intestinal gene expression analysis. Data were analyzed independently using linear mixed models using the REML method in the nlme package in R for continuous outcomes. A non-parametric test was used for ordered categorical outcomes using the Artools package in R. There were no differences between groups for blood evaluations, digestibility, gene expression, and a spleen cell proliferation assay. However, BEO calves presented a heavier pancreas, heavier intestines, bigger ileum villi, and higher cecum butyrate levels (P?

Ano de publicação: 2023

Tipo de publicação: Artigo de periódico

Unidade: Embrapa Gado de Leite

Palavras-chave: Bezerro Leiteiro, Célula Sangüínea, Células do baço, Digestibilidade, Expressão gênica, Fator de Crescimento, Gado Leiteiro, Metabólito, Peso