title: Effects of seasonal ambient heat stress (spring vs. summer) on physiological and metabolic variables in hair sheep located in an arid region.
abstract: Twenty Dorper × Pelibuey primiparous ewes were used to evaluate effects of seasonal ambient heat stress (i.e., spring vs. summer) on physiological and metabolic responses under production conditions in an arid region. Ten ewes experiencing summer heat stress (i.e., temperature = 34.8 ± 4.6 °C; THI = 81.6 ± 3.2 units) and 10 under spring thermoneutral conditions (temperature = 24.2 ± 5.4 °C; THI = 68.0 ± 4.8 units) were corralled together to measure rectal temperature, respiratory frequency, and skin temperatures at 0600, 1200, 1800, and 2400 h on four occasions over 40 days. Blood metabolite and electrolyte concentrations were also measured at 0600 and 1800 hours. Data were analyzed with a completely randomized design using repeated measurements in time. Rectal and skin temperatures, as well as respiratory frequency, were higher (P < 0.01) in summer than spring at all measured days. Blood serum glucose, cholesterol, triglycerides, and chlorine concentrations were lower (P < 0.01) in summer than spring at 0800 and 1800 hours. In contrast, summer heat stress increased (P < 0.01) blood urea and potassium concentrations at 0800 and 1800 hours. Compared with spring thermoneutral conditions, summer heat stress affected the physiological and metabolic status of hair breed ewes in an arid region, which included blood metabolite and electrolyte adjustments to efficiently cope with summer heat stress.
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, 21705, Mexicali, B.C., Mexico.
authors.forename: U
authors.initials: U
authors.lastname: Macías-Cruz
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, 21705, Mexicali, B.C., Mexico.
authors.forename: M A
authors.initials: MA
authors.lastname: López-Baca
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, 21705, Mexicali, B.C., Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Vicente
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, 21705, Mexicali, B.C., Mexico.
authors.forename: A
authors.initials: A
authors.lastname: Mejía
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, 21705, Mexicali, B.C., Mexico.
authors.forename: F D
authors.initials: FD
authors.lastname: Álvarez
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, 21705, Mexicali, B.C., Mexico.
authors.forename: A
authors.initials: A
authors.lastname: Correa-Calderón
authors.affiliation: Unidad Regional Universitaria de Zonas Áridas, Universidad Autónoma Chapingo, 35230, Durango, Mexico.
authors.forename: C A
authors.initials: CA
authors.lastname: Meza-Herrera
authors.affiliation: Departamento de Nutrición Animal, Universidad Autónoma Agraria "Antonio Narro", 25315, Coahuila, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Mellado
authors.affiliation: Facultad de Agronomía, Universidad Autónoma de Sinaloa, 80000, Culiacán de Rosales, Sinaloa, Mexico.
authors.forename: J E
authors.initials: JE
authors.lastname: Guerra-Liera
authors.affiliation: Instituto de Ciencias Agrícolas, Universidad Autónoma de Baja California, 21705, Mexicali, B.C., Mexico. lar62@hotmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Avendaño-Reyes
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001831:Body Temperature; D002784:Cholesterol / Q000097:blood; D002980:Climate; D005260:Female; D018882:Heat Stress Disorders / Q000097:blood / Q000503:physiopathology / Q000662:veterinary*; D006358:Hot Temperature / Q000009:adverse effects*; D006813:Humidity; D011188:Potassium / Q000097:blood; D056152:Respiratory Rate; D012621:Seasons; D012756:Sheep / Q000097:blood / Q000502:physiology; D013312:Stress, Physiological; D014280:Triglycerides / Q000097:blood; D014508:Urea / Q000097:blood; D014919:Wind
chemical_list: D001786:Blood Glucose; D014280:Triglycerides; D014508:Urea; D002784:Cholesterol; D011188:Potassium
keywords: Body temperature; Circadian rhythms; Glucose; Hair breed; Heat tolerance