Development of organs and tissues in lambs raised on Spanish mountain grassland

• Autor(a) principal: Álvarez-Rodríguez, Javier
• Data de Publicação: 2009
• Outros Autores: Sanz, Albina, Joy, Margalida, Carrasco, Salomé, Ripoll, Guillermo, Teixeira, Alfredo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/4892
• topic: Sheep; Carcass; Non-carcass; Tissues; Fat depots; Allometric growth

The present study was conducted to establish the pattern of body development in grass-raised Churra Tensina lambs. Forty-nine single male lambs were slaughtered at three body-weight intervals, according to the commercial categories of suckling (11.191.0kg), light (22.190.8 kg) and heavy lamb (32.092.9 kg). Non-carcass and carcass components were recorded and the half left carcasses were completely dissected. Lambs showed a low growth rate of main organs in relation to empty body weight (BW) (PB0.01). Skin fleece and liver accompanied the rest of mass growth (P 0.05). The allometric coefficients of forestomachs and large intestine were higher than that of the small intestine (PB0.05). Joints related to locomotion had early development (PB0.01), whereas those belonging to the trunk grew at faster rates than did carcass weight (PB0.01). The fatty tissues had increased growth coefficients (PB0.01), whereas bone and lean coefficients decreased (PB0.01) with increasing carcass weight. Intermuscular fat attained greater growth rates in lambs slaughtered at light BW than in heavy lambs (PB0.01). However, the former group displayed lower relative growth of pelvic-renal, subcutaneous and abdominal fat than the latter (PB0.01). This trait might reflect improved investment of dietary energy towards deposition of adipose tissue through the increased digestive tract capacity. L’e´tude devait pre´ciser comment se de´veloppe le corps des agneaux Churra Tensina engraisse´s a` l’herbe. Quarante-neuf agneaux maˆ les ont e´ te´ abattus a` trois poids corporels diffe´rents selon les cate´gories commerciales d’agnelet (11,191,0kg), d’agneau le´ger (22,19 0,8 kg) et d’agneau lourd (32,092,9 kg). Les auteurs ont consigne´ les parties de la carcasse et les autres parties puis entie`rement disse´que´ le coˆ te´ gauche de la carcasse. Les principaux organes des agneaux croissent lentement comparativement au poids de la carcasse vide (PB0,01). La peau et la laine ainsi que le foie suivent le reste de l’accroissement ponde´ ral (P 0,05). Les coefficients allome´triques du secteur gastrique ante´rieur et du gros intestin sont plus e´leve´ s que ceux de l’intestin greˆ le (PB0,05). Les articulations associe´es a` la locomotion se de´veloppent haˆ tivement (PB0,01) alors que celles du tronc croissent plus vite que le poids de la carcasse (PB0,01). Les tissus adipeux se caracte´ risent par un coefficient de croissance plus e´leve´ (PB0,01), tandis que les coefficients des os et de la viande maigre diminuent (PB0,01) a` mesure que le poids de la carcasse augmente. Le taux de croissance de la graisse intermusculaire est plus e´leve´ chez les agneaux le´gers que chez les agneaux lourds (PB0,01). Cependant, les sujets du premier groupe re´ve`lent une plus faible croissance relative de la matie`re grasse pelvique-re´nale, sous-cutane´e et abdominale que ceux du second groupe (PB0,01). Cette caracte´ristique pourrait traduire une meilleure utilisation de l’e´nergie des aliments pour le de´poˆt de tissu adipeux graˆ ce a` une capacite´ supe´rieure du tube digestif.