African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6691

Full Length Research Paper

Growth, blood metabolites and hormones in calves fed diets with different amounts of energy and protein during the pre- or post-weaning periods

  Fernández H. T.1, Busso C. A.1,2*, Laborde H. E.1,2, Torrea M. B.1, Fernández L. M.3, López G. H.3, Delucchi F.3 and García B. N.3
  1Departament of Agronomy, National University of the South (UNS), 8000 Bahía Blanca, Argentina. 2CERZOS (CONICET), 8000 Bahía Blanca, Argentina. 3Department of Biology, Biochemistry and Pharmacy, UNS, 8000, Bahía Blanca Argentina.
Email: [email protected]

  •  Accepted: 04 March 2012
  •  Published: 03 July 2012



We investigated the effects of diets differing in energy and protein concentrations given during pre- and post-weaning on hormone and metabolite levels in association to parameters of growth. Sixteen Aberdeen Angus calves four-day-old were allocated in individual pens during 105 days in a randomized complete design. Animals consumed ad libitum various diets differing in proportion of energy and protein (A: 80% of concentrate, 20% alfalfa hay; B: 60% concentrate, 40% of alfalfa hay; C: 40% concentrate, 60% alfalfa hay, and D: 20% concentrate, 80% alfalfa hay). Also, calves consumed milk substitute up to 60-day-old day. Serum growth hormone and cortisol levels were not altered with diet changes (P > 0.05) neither during the pre- nor the post-weaning periods. Plasma insulin concentration average daily intake, glucose and thyroid hormone levels, and concentrations of ammonia nitrogen and propionic acid were greater (P < 0.01) for diets having higher than lower energy and protein levels during the post-weaning but not during the pre-weaning period. These results suggest inclusion of higher amounts of concentrate in the diet of weaned calves.


Key words: Calves, early weaning, energy, growth, hormones, metabolites, protein.