Live weight and metabolic hormone profile in steers moved in drives

• Main Authors: Marcella Cândia D'Oliveira, Maria Inês Lenz Souza, Camila Celeste Brandão Ferreira Ítavo, Ruy Alberto Caetano Corrêa Filho, Maria da Graça Morais, João Alberto Negrão, Gumercindo Loriano Franco
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Zootecnia 2014-10-01
• Series: Revista Brasileira de Zootecnia
• Subjects: compensatory gain; metabolism; post-driving; transportation
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982014001000551&lng=en&tlng=en

The objective was to determine the effects of driving on the growth of steers during 55 days of moving by drive and 84 days after the arrival. Twenty-five steers were randomly chosen from a herd of 1,000 Nellore cattle, which were evaluated in two periods: the driving period, in which animals were moved a distance of 700 km on foot for 55 d; and the post-driving period, which lasted 84 d. Serum samples were obtained for hormone dosing (T3, T4, cortisol, and IGF-I) by radioimmunoassay using commercial kits. The data was collected at different time points during the experiment. No changes in live weight were observed between days 0 and 55. During the post-driving period, on the 28th, 56th, and 84th d, the average weights were 226.10 kg, 224.28 kg, and 242.6 kg, respectively; differences in weight were observed on the 84th d when compared with the 56th d. There were no changes in insulin and T3 levels in either periods; the lowest T4concentration was observed during the driving period. The serum T4concentration increased after 56 d of post-driving, and it was greater than the concentrations detected on the other days. The highest levels of cortisol were identified after 28 d of post-driving. An increase in IGF-I concentration was observed after 56 and 84 d of post-driving. Moving cattle by driving does not alter the weight of the animals and weight gain occurs during the post-driving period due to an increase in the T4 and IGF-I levels.