Desempenho de cordeiros Santa Inês do nascimento ao desmame filhos de ovelhas alimentadas com diferentes níveis de energia

Abstract

The main objective of this study was to evaluate the influence of the energy levels in the diet of ewes in the last third of gestation and lactation on body measurements and weights of lambs from birth to weaning. As secondary objectives were also evaluated the effects of year of birth, sex of the lamb, type of birth and age of the ewe at lambing on the same characteristics. Forty-five Santa Inês lambs were evaluated. They were born from 40 ewes distributed randomly to three treatments: 2.0, 2.2 and 2.4 Mcal of metabolizable energy/kg of dry matter). Ewes were subjected to the experimental diets during the last third of gestation and lactation. Lambs were kept with their mothers until weaning, which occurred at 70 days. Feeding energy level did not affect traits measured on the lambs at birth. Regression analysis showed a linear increasing in all traits at weaning and in average daily gain until weaning as the energy level increased. Male lambs were heavier at birth and at weaning. All morphometric measurements performed were similar between males and females, except for thoracic perimeter at 70 days, which was higher in male lambs. Single lambs were larger and heavier than twin lambs. Lambs born from ewes of intermediate age (4 and 6 teeth) showed higher means for average daily weight gain. Among morphometric measurements, thoracic perimeter showed the best correlation to body weight at birth and at weaning. Besides the nutrition of the ewe, it is important to consider other environmental factors that affect animal's growth characteristics by acting on the expression of genetic potential.

Eficiência Produtiva De Ovelhas Com Diferentes Características Conformacionais Sob Pastejo

“…Os pesos ao nascimento de pequenos ruminantes podem ser influenciados pelo grupo genético, pelo número de cordeiros, pela nutrição da fêmea e pelo sexo (11,14,15) . Destes fatores, a alimentação é limitante, mas pode ser manipulada e o manejo das forrageiras é decisivo para os avanços corporais (16) .…”

“…Desta forma, além de as ovelhas maiores exigirem mais nutrientes do que as demais, elas provavelmente produzem mais leite, o que pode ter sido a provável razão da maior perda de escore dessa categoria. Ovelhas que parem em melhor condição corporal produzem mais leite, com maiores pesos dos cordeiros ao desmame (14) . No entanto, se a alimentação for restrita e o animal tiver de recorrer às suas reservas energéticas, podem ocorrer prejuízos na reprodução subsequente em sistemas mais intensivos de produção (21) .…”

Caracterização Fenotípica De Ovinos E Sistema De Criação Da Região Sul Do Estado Do Espírito Santo - Brasil

“…Os estudos relacionados aos cordeiros da raça Santa Inês também encontram-se voltados para aspectos zootécnicos, como o desempenho (SOUZA et al, 2011b;FERNANDES et al, 2011;CASTRO et al, 2012), qualidade física e sensorial da carne , características de carcaça (PEREIRA et al, 2010;FARIA et al, 2011) morfologia muscular (SANTELLO et al, 2010a;SANTELLO et al, 2010b), qualidade da carne (MORENO et al, 2011;ALBUQUERQUE et al, 2014) e comportamento ingestivo (OLIVEIRA et al, 2013;NEGRI et al, 2013).…”

Characteristics of the wool produced by ewes raised for meat production

“…Regarding the lower weights of younger ewes, it can be considered that the four-teethed ewes were still growing, and when the nutrition is not optimum, the development of the body structure is somehow decreased (Castro et al, 2012a). In this situation, the adult weights can also be lower.…”