Multivariate approach to milk production and some physiological traits of crossbred dairy cows

Autor: Débora Andréa Evangelista Façanha, Josiel Borges Ferreira, Benito Soto-Blanco, Magda Maria Guilhermino, Jacinara Hody Gurgel Morais Leite, Kelly Mary Nery, Angela Maria de Vasconcelos, Wirton Peixoto Costa
Jazyk: English<br />Portuguese
Rok vydání: 2017
Předmět:
Zdroj: Semina: Ciências Agrárias, Vol 38, Iss 4Supl1, Pp 2851-2856 (2017)
Druh dokumentu: article
ISSN: 1676-546X
1679-0359
DOI: 10.5433/1679-0359.2017v38n4Supl1p2851
Popis: The aim of the present study was to evaluate the changes in physiological responses and serum biochemical panel in crossbred dairy cow populations kept in a hot climate environment. We used a population of 384 dairy cows of genetic groups ½Holstein × ½Guzerá (n = 105) and ¾Holstein × ¼Guzerá (n = 279) derived from the Brazilian semiarid region. The physiological responses analyzed were: respiratory rate (RR, movements/minute), rectal temperature (RT, °C), free thyroxine (T4, µg/mL) and thyroid-stimulating hormone (TSH, µUI/mL). The values of RR, RT, T4, TSH and serum levels of glucose, cholesterol, total protein, urea and creatinine were determined and correlated with milk production for 305 days, correlation lying only with TSH. Significant differences were observed just in milk production, RR and TSH comparing the genetic groups ½Holstein × ½Guzerá and ¾Holstein × ¼Guzerá. In conclusion, ¾Holstein × ¼Guzerá cows showed higher thyroid activity and milk production than ½Holstein × ½Guzerá cows, and may therefore be a better option for dairy production systems in semiarid regions.
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