Physicochemical characteristics of meat from pantaneiro lambs slaughtered with different of subcutaneous fat thicknesses

Abstract

Twenty-four lambs of the pantaneiro genetic group were used in a completely randomized design with eight replicates, slaughtered with subcutaneous fat thicknesses (SFT) of 2.0, 3.0 and 4.0 mm, which was evaluated by ultrasound in the longissimus dorsi muscle to measure the effect of the SFT on the physicochemical properties of the meat. The animals received water ad libitum throughout the experimental period and were fed a complete, pelleted ration formulated to provide an average daily gain of 0.300 kg -1 . As the lambs reached the predetermined SFT in the fortnightly evaluation by ultrasound, they were slaughtered the day after the measurements, regardless of weight. The pH values for 0h00 (6.58) and 24h00 (5.50) and cooking loss (23.99%) did not differ between treatments. Regarding the meat color, lambs slaughtered with 2.0 mm and 3.0 mm SFT had meat with greater lightness and the meat from those with 3.0 and 4.0 mm SFT showed higher values for the intensity of red and yellow. Lambs slaughtered with 4.0 mm SFT (1.43 kgf) had more tender meat than those slaughtered with a SFT of 2.0 mm. Lambs slaughtered with 4.0 mm SFT had the greatest sarcomere length (1.47 µm). The crude protein (21.15%) and moisture (72.38%) contents in the 2.0 mm treatment were higher than those in the 4.0 mm treatment. The total lipids (4.84%) in the meat from 4.0 mm SFT animals were higher than those in the meat from 2.0 mm SFT lambs. Slaughtering lambs with 3.0 mm of fat thickness in the loin is recommended, as these animals comprise a larger number of favorable characteristics with regard to the meat chemical composition, softness, and color.

Evaluator effect on the ultrasound measurement of subcutaneous fat deposition and loin eye area from weaning to slaughter lambs

“…Images were captured using two types of ultrasound equipment: One of the brand Aloka (SSD-500v Aloka Co., Ltd, Mitakashi, Tokyo, Japan), with a linear probe of 13 cm, with 3.5 MHz frequency and the support of acoustic coupling "standoff," and another of the brand Pie Medical (410477 Falco 100 rev A, California Prop 65 Warning, US) with a multifrequency transducer (6 and 8 MHz), using B mode, with a linear probe and 8.0 MHz frequency. To perform the measurements, lambs were manually immobilized, and with the aid of a comb, the wool was separated in the measuring areas and mucilage was applied for the best transducer coupling to the skin [12]. All the measurements were performed by the same technician, on the left side, between 12 th and 13 th ribs, 4 cm from the spine median line.…”