Impact of shearing on body weight and serum total proteins in ewes | Impacto del esquilado sobre el peso corporal de las ovejas y sus proteínas séricas totales

Spanish; Castilian. El objetivo del presente estudio fue evaluar la influencia del esquilado de ovejas durante la temporada de verano sobre la evolución del peso corporal y las proteínas séricas totales. Cuarenta ovejas del Valle del Belice (Sicilia, Italia), clínicamente sanas y bien alimentadas, se dividieron en dos grupos de 20 individuos cada uno. Veinte ovejas se dejaron sin esquilar como grupo control (Grupo A) y 20 ovejas fueron esquiladas (Grupo B). Todos los animales fueron pesados por la mañana antes de la corta utilizando una balanza mecánica y las medidas se repitieron para cada individuo de los Grupos A y B 1, 7, 15, 30, 45, 60, 75 y 90 días después del esquileo. Durante los días de experimentación se registraron las condiciones climáticas y se calculó el índice de temperatura-humedad. Se obtuvieron sueros en los que se evaluó la concentración de proteínas totales. Se utilizaron análisis ANOVA, seguidos del test de Bonferroni, para determinar diferencias significativas entre los dos grupos para el peso corporal y las proteínas totales. No hubo un efecto significativo del esquilado y del tiempo transcurrido sobre el peso corporal, pero sí hubo un efecto significativo del esquilado sobre las proteínas totales. Esto confirma que el esquilado induce respuestas de adaptación en el organismo. Tanto las ovejas esquiladas como las que no se esquilaron estuvieron sometidas a estrés por calor, pero la sensibilidad de los dos grupos a este estrés es diferente.

English. The aim of the present study was to evaluate the influence of shearing ewes during summer season on the evolution of body weight and serum total proteins. Forty Valle del Belice (Sicily, Italy) ewes, clinically healthy and well-fed, were divided into two groups of 20 subjects each. Twenty ewes were let unshorn as a control group (Group A) and 20 ewes were shorn (Group B). All animals were weighed using a mechanical balance in the morning before shearing and the measurements were repeated for each subject of Groups A and B after shearing (1 day) and after 7, 15, 30, 45, 60, 75 and 90 days from the shearing. In experimental days climatic conditions were recorded and temperature humidity index was calculated. Blood samples were collected by means of a jugular venipuncture and were centrifuged; and the obtained sera were separated to assess serum concentration of total proteins. Two-way repeated measures analysis of variance (ANOVA), followed by the Bonferroni's test, was used to determine significant differences between two groups for body weight and total proteins. ANOVA did not show a significant effect of shearing and of time on body weight but showed a statistical significant effect of shearing and of time on total proteins. These confirm that shearing induces adaptive responses in the organism. Both shorn and unshorn ewes are subject to heat stress, but it is evident a different sensitivity to heat stress in shorn ewes in comparison with unshorn ewes.