Simulation of lean lamb production systems.

Abstract

A series of simulations were performed to evaluate the effects of mature size (WMA; 60, 70, 80 and 90 kg), slaughter weight (SW; 55, 60 and 65 kg) and three diets fed to feedlot lambs. Rations included a traditional diet (C2L) or placing weaned lambs on alfalfa for either 30 (A30) or 60 (A60) d before placing them on the C2L diet (A30-C2L and A60-C2L). Two lamb pricing schemes were used in the financial analysis of the biological results: sale price based on weight with or without adjustment for carcass fat. Placing lambs on alfalfa pasture increased ownership by 22 d on average compared to C2L. As WMA and SW increased, ownership increased from 3 to 11 d. Across nutritional treatments, fat decreased by 5.8 to 9.0% as WMA increased from 60 and 90 kg. When market lambs were priced on weight, net returns per lamb were greatest for A30-C2L or A60-C2L ($2.34 and $5.21, respectively above C2L) and for greater SW ($4.77 and $7.16 greater for SW 60 and 65 kg than for SW 55). The combination WMA of 90 kg, a SW of 65 kg and nutritional treatment of A60-C2L proved most profitable. However, when sale price was discounted for excessive fat content, the combinations WMA of 60 or 70 with a SW of 65 and A60-C2L were most profitable. The rank correlation between biological efficiency (weight gain/dry matter feed consumption) and net return, when sale price was based on weight, was found to be -.51. This was because lambs slaughtered at lighter weights had high biological efficiencies but low net returns due to a negative price margin. With negative price margins but positive feeding margins, net returns are greatest for heavier, fatter lambs fed longer.

Carcass traits and meat quality of Texel lambs raised in Brachiaria pasture and feedlot systems

“…Blackburn, Snowder, and Glimp (1991) reported lower amounts of fat in the meat of exclusively pasture‐raised lambs compared to animals submitted to concentrate‐based diets, being an attractive attribute for consumers. However, the meat industry is interested in heavy carcasses of young animals with good musculature, providing good cut yield and a minimum fat layer to protect carcasses while in cold storage.…”

The effect of forage type on lamb carcass traits, meat quality and sensory traits

“…Australian lamb producers often use extensive forage-based finishing systems that include irrigated, dryland, green and senesced pasture, as well as feed supplements (Ponnampalam et al, 2014). When compared with concentrate-based systems the forage-based systems are better suited to finishing lambs because of: a lower fat content (Blackburn, Snowder, & Glimp, 1991); reduced production costs (Woodward & Fernández, 1999); better use of natural resources; and provision of meat quality that better represents consumer requirements (Grunert, Bredahl, & Brunsø, 2004). However, seasonal oscillations and climatic variability can affect forage quantity, nutritional quality and availability and as consequence, affect lambs capacity to achieve their productivity potential (Nardone, Ronchi, Lacetera, Ranieri, & Bernabucci, 2010) by exhibiting slower growth rates, lower carcass weights and potentially meat with a lower nutritional value (Winichayakul et al, 2008) compared to concentrate finished animals.…”

Idade à desmama e manejo alimentar na produção de cordeiros superprecoces

“…Esperava-se que os animais desmamados aos 34 dias obtivessem índices mais elevados de gordura de cobertura nas carcaças do que os animais que foram mantidos em pastagem. Esses resultados não concordam com o esperado por inúmeros autores (Ely et al, 1979;Crouse et al, 1981;Arnold & Meyer, 1988;Waghorn et al, 1990;Blackburn et al, 1991;Murphy et al, 1994) que relataram excessiva deposição de gordura subcutânea em cordeiros submetidos à alimentação intensiva no confinamento. Não concordaram tampouco com as conclusões de Arnold & Meyer (1988) de que cordeiros terminados à base de forragem apresentaram cortes menos gordurosos do que animais confinados.…”