Respuestas metabólicas de cabras lecheras en condiciones de estrés térmico al inicio de la lactación

• S. Hamzaoui ^[1] ; A.A.K. Salama ^[1] ; G. Caja ^[1] ; E. Albanell ^[1] ; X. Such ^[1]
  1. [1] Universitat Autònoma de Barcelona

     Universitat Autònoma de Barcelona

     Barcelona, España

     
• Localización: XVI Jornadas sobre Producción Animal: 19 y 20 de mayo de 2015, Zaragoza / Javier Álvarez Rodríguez (aut.), Begoña Panea Doblado (aut.), Jorge Hugo Calvo Lacosta (aut.), Mireia Blanco Alibés (aut.), José Alfonso Abecia Martínez (aut.), Daniel Villalba Mata (aut.), María Ángeles Latorre Górriz (aut.), Vol. 1, 2015, ISBN 978-84-606-7969-1, págs. 230-232
• Idioma: español
• Títulos paralelos:
  • Metabolic responses of dairy goats exposed to heat stress conditions
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• Resumen

  • The fact that goats under heat stress have lower feed intake without body fat reserves mobilization might indicate metabolic adaptations under high ambient temperatures. The objective was to evaluate the metabolic responses of heat-stressed dairy goats to hormonal challenges and glucose tolerance test. Eight multiparous Murciano-Granadina dairy goats (43.3 ± 1.6 kg BW; 2.00 ± 0.04 L/d; 81 ± 3 DIM) were kept in metabolic cages and randomly assigned to 2 climatic treatments differing in the value of temperature humidity index (THI). Treatments were:1) thermal neutral (TN; 15 to 20°C, 40 to 45% humidity, THI = 59 to 65), and 2) heat stress (HS, 12 h/d at 37°C and 40%, and 12 h/d at 30°C and 40%, THI = 86 and 77, respectively). Goats were kept under these conditions for 5 weeks. Jugular silicon catheters were fitted, and insulin challenge, epinephrine challenge, and glucose tolerance test were done on different days during week 4. The insulin (4.6 μg/kg BW), epinephrine (2 μg/kg BW) and glucose (0.25 g/kg BW) solutions were administrated via the jugular catheter. Blood samples were collected at í30, í20, í10, 0, 5, 10, 20, 30, 45, 60, 90, and 120 min relative to the administration for analysis of plasma insulin, NEFA, and glucose concentrations. Goats in both groups had similar blood NEFA after insulin injection, but NEFA values were greater (P < 0.05) in TN than HS goats after epinephrine administration. The HS goats secreted lower (P < 0.05) amounts of insulin than TN goats in response to the glucose tolerance test. In conclusion, body lipid tissue of HS goats became more resistant to lipolysis, making them unable to mobilize body fat reserves despite the negative energy balance.