Onset of reproductive activity of white and natural colored corriedale ewe lambs

Abstract

Article historyThe objective of this study was to estimate differences in growth, plasma progesterone (P4) and age at puberty between white and natural colored Corriedale ewe lambs. Thirty ewe lambs with average age of 12 months were randomly allocated to genetic groups: white (WC, n = 15) and natural colored (NC, n = 15). Ewes were maintained under extensive grazing conditions on natural pasture, and herbage mass was estimated over a 28-day experimental period. Morphometric measurements (front and hind height, body length, thoracic perimeter, rump length and width, wool fiber length), body condition score (CC) and weight were taken at 28-day intervals. There was no effect of genetic group on body weight, average daily gain and morphometric measurements (P > 0.05). The WC ewe lambs had longer fiber length (P < 0.05). Plasma P4 was similar between genotypes (P > 0.05); however, it increased above 1ng ml -1 in NC from January onward and in WC from March onwards. Estrus was detected at the same time in both groups. The results of this study indicate that both genetic groups have similar growth patterns and ovarian activities.

Corriedale Naturalmente Colorido – Histórico, características raciais e a origem das cores

“…Embora haja inexistência de informações exatas sobre o número de exemplares de cada raça ovina no Brasil, estima-se que o Corriedale seja a mais numerosa entre as lanadas criadas no território nacional (Mendonça et al, 2014;Feijó et al, 2017), assim como nos países vizinhos da Argentina (Almirón; Norberto-Macarrein & Hugo- Paredes, 2003;McRae, 2018), do Chile (Farías et al, 2010) e do Uruguai (Vage et al, 2003;Peraza et al, 2013), e de ampla participação no Peru (Tron, 2019). Research, Society and Development, v. 9, n. 10, e899108397, 2020 (CC BY 4. (Fleet & Stafford, 1989;Osório et al, 2016;ARCO, 2019;Tron, 2019), e pela adaptabilidade a variados climas e espécies forrageiras em condições extensivas de criação (Tron, 2019).…”