Pelibuey and Suffolk sheep were compared as to their capacity to regulate body temperature under environmental hyperthermia by measuring their differences in cellular response to heat stress (HS). In a first experiment, seven Pelibuey and seven Suffolk ewes were kept in a climatic chamber for 6 h daily during 10 days (temperatures within the 18 to 39.5 °C range). As chamber temperature rose, sheep rectal temperature increased in both groups, but to a lesser extent in Pelibuey (0.3 °C) than in Suffolk sheep (0.7 °C) (P < 0.05). In a second experiment, cellular viability was assessed using cultured blood mononuclear cells from 15 Pelibuey and 15 Suffolk sheep. They were incubated at 37 °C for 24 h (control) or 43 °C for 6 h followed by 18 h at 37 °C (HS). In a third experiment, another blood mononuclear cells culture from eight Pelibuey and eight Suffolk sheep was kept at 37 °C for 15 h; these were subsequently cultured for 6 h at 37 °C (controls) or 43 °C (HS). Next, HSP-70 concentration was determined. HS reduced the percentage of viable cells to a greater extent in Suffolk [37 °C (73.7 %) vs. 43 °C (61.9 %); P < 0.05] than in Pelibuey sheep [37 °C (74.9 %) vs. 43 °C (66.7 %); P > 0.05]. HS significantly increased HSP-70 average concentrations for both breeds at 43 °C. A significant effect was observed for the breed by temperature interaction (P < 0.05) caused by a greater difference between Pelibuey and Suffolk at 43 °C (2.85 vs. 0.53 ng/mL, respectively; P < 0.05) than at 37 °C (0.05 vs. 0.03 ng/mL, respectively; P > 0.05). In conclusion, Pelibuey sheep show more effective body temperature regulation under conditions of environmental hyperthermia. Also, cell viability after HS was higher in Pelibuey than in Suffolk, an effect that could be mediated by an HSP-70-related mechanism.
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http://dx.doi.org/10.1007/s11250-013-0416-1 | DOI Listing |
Trop Anim Health Prod
November 2013
Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, D.F., 04510, Mexico.
Pelibuey and Suffolk sheep were compared as to their capacity to regulate body temperature under environmental hyperthermia by measuring their differences in cellular response to heat stress (HS). In a first experiment, seven Pelibuey and seven Suffolk ewes were kept in a climatic chamber for 6 h daily during 10 days (temperatures within the 18 to 39.5 °C range).
View Article and Find Full Text PDFJ Anim Sci
December 2012
Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Campus El Cerrillo 50090, Toluca, Estado de México, México.
This study was conducted to estimate the effects of sire breed (Charollais, Dorper, Dorset, Hampshire, and Suffolk) and genetic group of the dam [local whiteface (Criolla), grade Hampshire, grade Suffolk, F(1) Dorper × Pelibuey, Australian composite, hair sheep (Barbados Blackbelly or Pelibuey), Dorset, Hampshire and Suffolk] on birth weight, survival rate from birth to weaning, and weaning weight adjusted to 65 d of age. Data were recorded from 2004 to 2006 on crossbreed lambs obtained by artificial insemination from 114 flocks in Central Mexico. High (above the mean) or low (below the mean) environmental categories were assigned to each record from flock-year-season effects solutions obtained in fixed-effects linear model analyses.
View Article and Find Full Text PDFAnim Reprod Sci
November 2007
Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, México 04510, DF, México.
Under photoperiod regulated conditions, some Pelibuey ewes appear to express estrous cycles continuously throughout the year. Ovulatory activity of Suffolk ewes has not being determined at 19 degrees N. The aim of the present study was to describe the annual reproductive cycle of Pelibuey and Suffolk ewes under natural conditions at 19 degrees N.
View Article and Find Full Text PDFMeat Sci
May 2005
Laboratorio de Ciencia de la Carne, Secretaria de Producción Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad 3000, Del. Coyoacán, Ciudad Universitaria, México, DF 04510, Mexico.
Fifty nine lambs: Pelibuey (P), Suffolk×Pelibuey (SP) and Rambouillet×Pelibuey (RP), were used to evaluate the effect of crossbreeding on carcass characteristics and composition. Following carcass evaluation, muscle, bone, subcutaneous, seam, internal, total fat and other tissues were dissected. Carcass dressing percentage was similar across the three genotypes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!