RESUMO
Muscle fiber morphometry and physicochemical characteristics were evaluated in LT muscles obtained from entire male lambs treated with zilpaterol hydrochloride (ZH, 0 and 0.15 mg/kg body weight) and/or steroidal implant (SI, with and without trenbolone acetate/estradiol). ZH and SI acted synergistically to increase LT area, type-IIb fiber cross-sectional area and soluble collagen content, likewise to decrease metmyoglobin concentration and insoluble collagen content. Ash content and ultimate pH showed a decrease due to an antagonistic effect between ZH and SI. Content of total collagen, protein, fat, moisture, oxidized lipids and water-holding capacity were unaffected by ZH and SI. Supplemental ZH, but not SI, decreased all color parameters and tended to increase shear force. Overall, the SI implantation of male lambs followed by a ZH supplementation promoted greater LT hypertrophy, without affecting protein and fat content, and physicochemical characteristics in their meat.
Assuntos
Fibras Musculares Esqueléticas/efeitos dos fármacos , Carne Vermelha/análise , Compostos de Trimetilsilil/farmacologia , Adrenérgicos/farmacologia , Animais , Cor , Estradiol/farmacologia , Masculino , Músculos Paraespinais/anatomia & histologia , Músculos Paraespinais/química , Resistência ao Cisalhamento , Carneiro Doméstico , Acetato de Trembolona/farmacologiaRESUMO
This study aimed to evaluate the effects of dietary supplementation of ferulic acid (FA) on reproductive tract weight (RTW), ovarian activity and serum concentrations of some metabolites and thyroid hormones of pre-pubertal hairbreed ewe lambs during the natural anestrous season. Twenty Dorper x Pelibuey crossbred ewe lambs (initial body weightâ¯=â¯28.5⯱â¯0.5â¯kg and ageâ¯=â¯5.0â¯mo) were fed a basal diet and assigned to two treatments (nâ¯=â¯10) under randomized complete block design: FA supplementation to dosages of 0 (control) or 300â¯mg of FA/d animal-1. Females were treated with FA during 34â¯d and then slaughtered to evaluate RTW and ovary. Blood samples were collected at days 1 and 34 to determine serum concentrations of metabolites (i.e. glucose, cholesterol, triglycerides, urea and total protein) and thyroid hormones. Final weight, dry matter intake, and serum concentrations of metabolites (except glucose) and thyroid hormones were unaltered by FA. Compared to control, FA-fed ewe lambs had lower (Pâ¯=â¯0.05) serum glucose level but higher (Pâ¯≤â¯0.05) RTW, ovarian mass, number of larger follicles and corpus luteum (CL). While percentage of ewe lambs with small follicles and number of small follicles per female did not vary, percentage of ewe lambs with large follicles and CL increased (Pâ¯=â¯0.02) with FA. In conclusion, FA supplementation improves the reproductive tract development and ovarian activity of pre-pubertal hairbreed ewe lambs during the natural anestrous season. An improvement in functionality of the glucose-insulin system could be related with this benefic effect of FA.
Assuntos
Ácidos Cumáricos/farmacologia , Dieta/veterinária , Maturidade Sexual/efeitos dos fármacos , Ovinos/crescimento & desenvolvimento , Animais , Glicemia/efeitos dos fármacos , Feminino , Folículo Ovariano/efeitos dos fármacos , Distribuição Aleatória , Estações do AnoRESUMO
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.
Assuntos
Transtornos de Estresse por Calor/veterinária , Temperatura Alta/efeitos adversos , Ovinos , Estresse Fisiológico , Animais , Glicemia/análise , Temperatura Corporal , Colesterol/sangue , Clima , Feminino , Transtornos de Estresse por Calor/sangue , Transtornos de Estresse por Calor/fisiopatologia , Umidade , Potássio/sangue , Taxa Respiratória , Estações do Ano , Ovinos/sangue , Ovinos/fisiologia , Triglicerídeos/sangue , Ureia/sangue , VentoRESUMO
Fifty-six (56) pigs were immunized against Taenia solium cysticercosis with antigens from Taenia crassiceps metacestodes, in a variety of protocols, and then challenged orally with Taenia solium proglottids or eggs. Results of immunization (expressed as individual parasite loads) ranged from significant reduction of parasite loads (host protection) to clear increase (parasite facilitation) in apparent relation to the immunogen dose, adjuvant employed and genetic background of the pigs. In all trials, however, immunized pigs harboured more damaged cysticerci than controls, indicating that immunization does induce some restrictions to parasite these are eventually overwhelmed by other parasite-promoting factors. Western blots in immunized-protected pigs indicated antigens of 242, 234, 118, 77, 55 and 45 kDa as possibly being involved in immunological protection.