Weight and age at puberty and their correlations with morphometric measurements in crossbred breed Suffolk ewe lambs

Abstract

-The objective of this study was to identify and to correlate parameters that characterize puberty and estimate the age and weight of Suffolk ewe lambs in Mato Grosso do Sul. This study was carried out with twenty-two Suffolk ewe lambs for 256 days. Blood samples were collected from the jugular vein and centrifugated and the plasma were stored at -20°C until analysis of progesterone (P 4 ) concentration by radioimmunoassay (RIA). The morphometric measurements included: head length and width, body length, elbow height, chest perimeter, back-sternal diameter, croup length, width and height, cannon bone perimeter and shoulder and hip width, using a tape. The animals became pubertal when the plasma progesterone concentration was >1.0 ng/mL, at 34.1 ± 5.2 kg and 39.5 ± 8.5 weeks of age. Meanwhile, the lambs that did not reach puberty (37.7 ± 11.4 weeks of age) were lighter. The morphometric measurements has medium to low correlations with age and weight at puberty.Key Words: chest perimeter, progesterone, radioimmnunoassay, sheep Peso e idade à puberdade e suas correlações com medidas morfométricas em cordeiras mestiças SuffolkRESUMO -Os objetivos neste trabalho foram identificar e correlacionar parâmetros que caracterizem a puberdade e estimar a idade e o peso à puberdade de cordeiras mestiças Suffolk. Amostras de sangue de 22 borregas foram coletadas e centrifugadas e o plasma armazenado a -20 ºC para posterior análise das concentrações de progesterona (P 4 ) por meio de radioimunoensaio. As medidas morfométricas aferidas foram: comprimento e largura da cabeça; comprimento do corpo; altura de cernelha; perímetro torácico; diâmetro dorso-esternal; comprimento, altura e largura de garupa; perímetro de canela; e largura entre ísquios e ílios, utilizando-se fita métrica. Definiu-se como início da puberdade quando os animais apresentaram concentração plasmática de P 4 >1,0 ng/mL, o que ocorreu aos 34,1 ± 5,2 kg de peso vivo e 39,5 ± 8,5 semanas de idade.Entretanto, as cordeiras que não atingiram a puberdade (37,7 ± 11,4 semanas de idade) apresentaram peso menor. As medidas morfométricas apresentam médias e baixas correlações com idade e peso à puberdade.

<b>Productive and reproductive parameters in high and low growing Syrian Awassi lambs

“…Average age at the onset of puberty was 359.5 ± 90.2 days, ranging 271-573 days for the FG group and 394.9 ± 90.4 days ranging 328-577 for the WG group, with no difference between them. The overall average of age for both groups was 377.2 ± 90.4 days, which is higher than 145.6 days in Sudanese Desert ewe lambs, 276.5 days in crossed ewe lambs in Brazil (Ferra et al, 2010), 280 days Awassi ewe lambs in Jordan (Kridli et al, 2006), 257 days in Rahmani ewe lambs (Khalifa et al, 2013), 300 days in Finnish Landrace x Rahmani ewe lambs in Egypt (El-Gohary et al, 2011) and 330 days in Merino d'Arles ewe lambs in France (Abella, Cognie, Thimonier, Seck, & Blanc, 2005). All female lambs were naturally mated, therefore, mating rate was 100%, while 14 (an abortion case occurred after 3 months of pregnancy for unknown reason) and 15 females lambed in FG and WG, respectively, consequently, lambing rate was 93.3 and 100%, respectively.…”

“…Progesterone levels exceeding 3.18 nmol L -1 for the first time, were indicative of the onset of puberty (Ferra et al, 2010).…”

“…Blood progesterone concentrations have been extensively used in the studies of animal reproduction to determine the onset of puberty in female sheep such as Suffolk in Brazil (Ferra et al, 2010) Ramboullet and Suffolk in the USA. Progesterone concentrations have been also used during the oestrous cycle (Jarquin, Roldan, Zarco, Berruecos, & Valencia, 2014), during pregnancy (Alwan, Amin, & Ibrahim, 2010), in early diagnosis of pregnancy (Adama, Chiezy, Ajanusi, & Lawal, 2013), and other reproductive parameters (GrazulBilska et al, 2014) in female sheep.…”

Application of multivariate principal component analysis to morphological characterization of indigenous goats in Southern Nigeria

“…Body size and shape are important traits in meat animals. The characterization of local genetic resources depends on the knowledge of the variation of morphological traits, which have played a very fundamental role in classification of livestock based on size and shape (Ferra et al, 2010;Agga et al, 2010;Leng et al, 2010;Yakubu et al, 2010a and b). Based on body conformation, meat production can better be estimated than other production properties making body measurements important selection criteria (Bene et al, 2007).…”

Morphometric Characterization of Indigenous Goats in East Gojjam Zone, Amhara Region, Ethiopia

“…According to CSA (2017), the number of goats reported in the country isestimated to be about 30.2 million, of which about 70.61% are females and 29.39% are males. Phenotypic characteristics are important in breed identification local genetic resources as it depends on the knowledge of the variation of morphological traits, which play very fundamental role in classification of livestock based on size and shape (Ferra et al, 2010;Agga et.al., 2010;Leng et al, 2010).…”