n-6 Polyunsaturated fatty acids in the feeding of late gestation hair ewes: the effects on thermoregulation, growth, and metabolism of heat-stressed growing lambs.

Autor: Macías-Cruz U; Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Valle de Mexicali, Baja California, 21705, México., Vicente-Pérez R; Departamento de Producción Agrícola CUCSUR, Universidad de Guadalajara, Autlán de Navarro, Jalisco, 48900, México., Correa-Calderon A; Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Valle de Mexicali, Baja California, 21705, México., Mellado M; Departamento de Nutrición Animal, Universidad Autónoma Agraria Antonio Narro, Saltillo, Coahuila, 25315, México., Meza-Herrera CA; Unidad Regional Universitaria de Zonas Áridas, Universidad Autónoma Chapingo, Bermejillo, Durango, 35230, México., Arechiga CF; Unidad Académica de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Zacatecas, Calera, Zacatecas, 98500, México., Avendaño-Reyes L; Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, Valle de Mexicali, Baja California, 21705, México. lar62@hotmail.com.
Jazyk: angličtina
Zdroj: International journal of biometeorology [Int J Biometeorol] 2021 Dec; Vol. 65 (12), pp. 2077-2086. Date of Electronic Publication: 2021 Jul 06.
DOI: 10.1007/s00484-021-02165-2
Abstrakt: The objective was to determine the effects of feeding soybean oil (SBO), an ingredient rich in n-6 polyunsaturated fatty acids (PUFA), to late gestation hair ewes on physiological responses, feedlot performance, and serum metabolite and electrolyte concentrations of their growing ewe lambs under outdoor heat stress conditions. Twenty-four Dorper × Pelibuey ewe lambs weaned (body weight = 21.5 ± 0.2 kg, age= 2 months, and multiple birth) born from ewes fed 0, 30, or 60 mg of SBO/kg dry matter (DM) during late gestation were selected (n = 8/treatment) to conduct a 30-day feeding trial during the summer season of a desert region (temperature = 34 °C and temperature-humidity index = 35 units). While rectal temperature was unaffected in any daytime, respiratory rate in the afternoon quadratically increased (P = 0.05) as the SBO levels increased from 0 to 60 mg/kg DM in the maternal diet. Final weight, average daily gain, and feed efficiency linearly increased (P = 0.04) with increasing levels of SBO. Body surface temperatures and serum concentration of glucose, cholesterol, triglyceride, total protein, urea, sodium, potassium, and chlorine did not vary by the SBO inclusion in the maternal diet. In conclusion, feeding late gestation hair ewes with source rich in n-6 PUFA appears to be an effective maternal nutritional strategy to improve post-weaning growth without compromising the thermoregulatory ability of their growing offspring under a heat stress environment.
(© 2021. ISB.)
Databáze: MEDLINE
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