RESUMEN
The relationships between rectal temperatures and physiological and cellular responses to heat stress can improve the productivity of Saanen goats in tropical environments. In this context, this study evaluated the physiological responses and gene expression of heat shock proteins (HSP60, 70, and 90) and genes related to apoptosis (Bax, Bcl-2, and p53) of Saanen goats subjected to acute heat stress. Ten health Saanen goats were exposed to solar radiation during 3 consecutive days. The expression of HSP60, HSP70, HSP90, Bax, Bcl-2, and p53 genes in blood leukocytes, rectal and superficial temperatures, respiratory frequency, cortisol, triiodothyronine, and thyroxine was measured at 06:00, 13:00, and 18:00 h. In vitro, blood leukocytes were subjected to 38 °C and 40 °C for 3 h to measure the expression of the same target genes. The temperature humidity index, measured from 12:00 to 15:00, was greater than 80 and black globe temperatures were greater at 40 °C, indicating the intensity of the solar radiation. Although the solar radiation caused acute heat stress, increased cortisol release, and the expression of HSP60 and 70 in dry Saanen goats, the increased respiratory frequency and decreased T4 and T3 restored the homeothermy of the experimental goats. In vitro, the 40 °C increased the expression of p53 (pro-apoptotic protein), Bcl-2 (anti-apoptotic protein), HSP60, HSP70, and HSP90, suggesting that these genes have protective functions. However, further studies are necessary to understand the physiological and cellular responses to heat stress.
Asunto(s)
Enfermedades de las Cabras/fisiopatología , Cabras/fisiología , Trastornos de Estrés por Calor/fisiopatología , Trastornos de Estrés por Calor/veterinaria , Animales , Temperatura Corporal , Femenino , Enfermedades de las Cabras/sangre , Enfermedades de las Cabras/genética , Trastornos de Estrés por Calor/sangre , Trastornos de Estrés por Calor/genética , Proteínas de Choque Térmico/genética , Humedad , Hidrocortisona/sangre , Leucocitos/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Temperatura , Tiroxina/sangre , Triyodotironina/sangre , Proteína p53 Supresora de Tumor/genéticaRESUMEN
In the semiarid region of Brazil, in areas with vegetation composed mainly of Poincianella pyramidalis, several cases of congenital malformation and reproductive losses were observed in goats and sheep from 2012 to 2014. To determine the teratogenic effect of P. pyramidalis, two groups of eight goats each were used. Goats from Group 1 received fresh P. pyramidalis, harvested daily, as the only roughage during the whole breeding and pregnancy period. Goats in Group 2 (control) received Cynodon dactylon (tifton) hay free choice. Ultrasound examination for pregnancy diagnosis was performed every 28 days. Four goats from Group 1 were pregnant on day 28 but not on day 56, suggesting embryonic death or abortion. Another goat from Group 1 died at day 70 of pregnancy, and the fetuses exhibited micrognathia. The other three goats bore six kids, three of which showed bone malformations in the limbs, spine, ribs, sternum, and head, including arthrogryposis, scoliosis and micrognathia. One kid also showed hypoplasia of the left pulmonary lobes. In the control group, all goats bore a total of 13 kids and none of them exhibited malformations. These results demonstrated that P. pyramidalis causes congenital malformations and other reproductive losses in goats.
Asunto(s)
Anomalías Inducidas por Medicamentos/veterinaria , Aborto Veterinario/inducido químicamente , Caesalpinia/toxicidad , Reabsorción del Feto/veterinaria , Enfermedades de las Cabras/inducido químicamente , Enfermedades de las Cabras/etiología , Intoxicación por Plantas/veterinaria , Complicaciones del Embarazo/veterinaria , Animales , Artrogriposis/inducido químicamente , Artrogriposis/veterinaria , Brasil , Cynodon , Femenino , Reabsorción del Feto/inducido químicamente , Enfermedades de las Cabras/fisiopatología , Cabras , Micrognatismo/inducido químicamente , Micrognatismo/veterinaria , Componentes Aéreos de las Plantas/toxicidad , Intoxicación por Plantas/fisiopatología , Embarazo , Complicaciones del Embarazo/fisiopatología , Escoliosis/inducido químicamente , Escoliosis/veterinariaRESUMEN
Eleven Murciano-Granadina goats in late pregnancy were separated into two groups (1) control (n=6) and (2) fasting for 72 h to induce pregnancy toxaemia (n=5). Venous blood was taken daily to determine acid-base and electrolyte parameters. Significant decreases in blood pH, bicarbonate concentration and base excess, and a significant increase in anion gap were observed after 24h of fasting. These changes were significantly correlated with non-esterified fatty acid concentration. No significant changes were observed in pCO(2), and electrolyte or lactate concentrations. Clinical signs of pregnancy toxaemia in fasted goats appeared by 72h post-fasting. These signs and the changes in acid-base balance disappeared once feed was reintroduced. Blood pH, bicarbonate concentration, base excess and anion gap could be indicators of early pregnancy toxaemia in goats.