Year: 2024
Type: article
Abstract: This study evaluated the effects of plane of nutrition in neonatal calves on growth, development of the somatotropic axis and mode of action of IGF-I.Eight Holstein bull calves (3-4 days old) were fed either a low (LM, average 0 .63kg DM/d) or high (HM, average 1 .15kg DM/d) level of a 30 % crude protein milk replacer until slaughtered at 41-42 days old.Compared to LM calves, calves on the HM diet had heavier (P<0.01)body, carcass and semitendinosus muscle weights at slaughter.At three weeks of age, plasma insulin-like growth factor I (IGF-I) concentrations rose more rapidly in HM calves and were significantly higher at three, four and six weeks of age compared to LM calves.IGF-I mRNA levels were higher (P<0.01) in liver, and lower (P<0.01) in longissimus dorsi muscle in HM calves compared to LM calves.Growth hormone and IGF-I receptor mRNA levels in liver and muscle were not affected by plane of nutrition.Increasing intake of a high-protein milk replacer in suckling calves improved growth rate in the preweaning period.The higher plane of nutrition promoted a shift towards an endocrine mode of IGF-I action and a decline in the autocrine/paracrine IGF-I control of muscle growth.
Authors: 松﨑, 正敏, 神谷, 充, クレイグ, ダロック, 折戸, 秀樹, 常石, 英作
Language: English
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W7146428202