Use of cold carcass weight and fat depth measurements to predict carcass composition of Rasa Aragonesa lambs

Abstract

A total of 22 measurements of fat depth, taken along the 13th rib, 5-6th lumbar vertebra, 3-4th sacrum vertebra, and the 2nd, 2-3rd, 3rd, 3-4th, 4th. 4-5th stemebra of the breast bone, were taken on intact carcasses with a sharpened steel rule, and related to the carcass composition of 18 Rasa Aragonesa lambs. The objective was to study the accuracy of these different measurements for predicting carcass composition and possible value, in the process of carcass grading or classification of 'Temasco' Aragdn lambs. Cold carcass weight (CCW) accounted for 74% and 40% of the total variation of muscle weight and total carcass fat weight, respectively. The addition of 4 cm fat depth over the 13th rib from the left side accounted for a further 13% of muscle weight, and the addition of 4 cm fat depth over the 5-6th lumbar vertebra from the right side accounted for a further 29% of the variation of total carcass fat weight. Regarding different fat depots, CCW accounted for 49% and 31% of the total variation of the intermuscular fat and kidney and pelvic fat, respectively.However, CCW alone only accounted for 21% (NS) of the total variation of subcutaneous fat weight, but the addition of 4 cm fat depth over the 13th rib from the right side or the addition of 4 cm fat depth over the 5-6th lumbar vertebra from the right side accounted for a further 47% of the subcutaneous fat variation. A comparison of the residual standard deviations (RSD) of the two measurements indicated that the fat depth over the 5-6th lumbar vertebra was more accurate for predicting subcutaneous fat. The highest precision, after CCW, for predicting intermuscular fat, was fat depth over the 13th rib from the left side, which accounted for a further 18% of total variation of this fat depot. Prediction of carcass composition was improved by the addition of fat depth measurements, assisting in the commercial classification of 'Temasco' Aragdn lambs. ResumeUn total de 22 mesures d'kpaisseur du gras, &al&es sur la 13kme cate, entre la Sbme et la 6bme vertkbre lombaire, 3&me et &me vertsbre du sacrum et 2&me, 2bme-3sme, 3&me, 3&me-&me, @me, &me-5&me stemkbres du sternum, ont Cti effect&es par calibrage, sur des carcasses entikres et intactes et ont &C rapporties B la composition de la carcasse de 18 agneaux de race Rasa Aragonesa, en ayant comme objectif principal I'etude exacte des diffkrentes mesures d'ipaisseur du gras comme &mehts de prCdiction de la composition de la carcasse, ainsi que lint&Et de I'inclure dans un schCma de classification commerciale du Temasco de Arag6n. De& et al./ Smdl Ruminmt Resrurch 20 (1996) [267][268][269][270][271][272][273][274] Le poids de la carcasse froide (PCF) explique 74 et 40% de la variation totale du poids du muscle et du gras total de la carcasse respectivement. L'addition de la mesure de i'epaisseur du gras prise sur le cott? gauche de la carcasse a 4 cm de la 13eme coti augmente de 13% la precision de I'estimation de poids du muscle et l'addition de la mesure de l'epaisseur du gras prise sur le cot6 droi...

Estimation of light lamb carcass composition by in vivo real-time ultrasonography at four anatomical locations1

“…Although the very thin subcutaneous fat layer of light lambs used in the present study limited the potential of ultrasound to provide accurate measurements (Teixeira et al, 2006), it is probably the narrow range of BW that was responsible for these results. This would be in accordance with the results of Delfa et al (1995Delfa et al ( , 1996a, who used in vivo and carcass ultrasound on the same kinds of animals, with carcasses weighing between 8.5 and 11.5 kg. Delfa et al (2007) used lambs slaughtered at 22.4 kg, with a SD of 0.96, but despite the narrower range of BW than was considered in our study, these authors achieved R 2 of 0.70, 0.81, and 0.51 for muscle, subcutaneous fat, and bone, respectively.…”

“…These measurements were made at 2 and 4 cm from the nearest end of the LM to the backbone (Delfa et al, 1996a), and at 1/3 of the LM width (Delfa et al, 2007; Figure 1). With the probe parallel (Figure 2) to the dorsal midline, the following were also measured: LM depth (US_MDP); skin thickness + subcutaneous fat thickness + interfaces (US_FDP); subcutaneous fat thickness + interfaces (US_FDGIP); subcutaneous fat thickness (US_FDGP); and skin thickness (US_SKP) at 1/3 of the total length of the transverse apophysis from the dorsal midline (Delfa, 2004).…”

“…For ultrasound measurements at 3-4L, Junkuszew and Ringdorfer (2005) reported R 2 of 0.67, 0.62, and 0.58 for muscle, fat, and bone, respectively. Delfa et al (1991Delfa et al ( , 1996a and Stanford et al (1995) concluded that lumbar fat thickness measurements assessed ultrasonically in live animals were the best predictors of total carcass muscle.…”

The influence of strain and age on some egg quality parameters of commercial laying hens

“…Raji et al (2009) reported that the relationship between live body measurement for estimation of carcass component in vivo depends on the correlation between them, these observation was noticed here with higher correlation existing between body weight and carcass components (.906, .950 and .786) with carcass weight , breast weight and thigh weight respectively. Several authors, (Sehested 1986;Teixeira et al, 2006;Wood and Maefie, 1980;Delfa et al, 1996) observed that multiple regression models developed to predict lean meat weight are dominated by live weight or carcass weight . In the present findings, prediction of both the carcass weight and breast weight seems to have been mainly influenced singly by the body weight 82 and 90.2%…”

Effect of feeding system on growth and carcass characteristics of Churra Tensina light lambs

“…Kidney and pelvic fats from the two halves were removed and weighed to obtain the contents of kidney knob and channel fat (KKCF). The subcutaneous fat thickness (C) was measured with a calliper at 4 cm from the spinal column on the level of 13th rib (Delfa et al, 1996).…”