Distribution of tissues in carcasses at the same proportion of total fat in Portuguese cattle breeds

Abstract

-A comparison was made of the distribution of bone, muscle, subcutaneous fat and intermuscular fat (g of tissue in the joint per kg of the respective tissue in the carcass) at the same proportion of total carcass fat for a total of 165 animals from three large (Alentejana (n = 24); Mirandesa (n = 24); Marinhoa (n = 24)), and four small, (Arouquesa (n = 24); Barrosã (n = 23); Maronesa (n = 24) and Mertolenga (n = 22)) Portuguese breeds, serially slaughtered at three different weights. The distribution of muscle was significantly different across breeds in a larger number of joints than either the distribution of bone, subcutaneous fat or intermuscular fat. However, the range of differences in each joint was narrower for muscle. So, amongst the first class joints (leg, sirloin, ribs and fore ribs), only the sirloin and the fore ribs, both with a range across breeds of only 7 g·kg -1 , were significantly different between breeds. On the contrary to subcutaneous fat, the proportions of intermuscular fat tend to decrease, particularly in the leg. As expected, the joints with homogeneous parameters were the most accurate for predicting the proportion of muscle (g·kg -1 ) in the carcass from the proportion of muscle (g·kg -1 ) in the joint. For the large breeds, the most accurate joints were the leg and the coast, with a residual s.d. of 13.91 g·kg -1 and 18.45 g·kg -1 , respectively; and for the small breeds the most accurate joints were the fore ribs and the leg, with a residual s.d. of 15.35 g·kg -1 and 17.11 g·kg -1 , respectively. The difference between the actual breed means and the means predicted using the overall equation for each of the most accurate joints were lower than ± 4 g·kg -1 for all breeds with the exception of the Barrosã with a value of -8 g·kg -1 . distribution / joints / carcasses / beef cattle Résumé -Répartition des tissus dans les carcasses de bovins de races autochtones portugaises. Une étude comparative a été menée sur la répartition des tissus osseux, musculaires, adipeux sous-cutané et adipeux intermusculaires (g de tissu dans le morceau par kg de tissu respectif dans la carcasse) pour une même proportion de gras total. Au total 165 animaux, comprenant des races de grande taille : Alentejana (n = 24), Mirandesa (n = 24), Marinhoa (n = 24), et des races de petite taille : 287 Anim. Res. 52 (2003) Arouquesa (n = 24), Barrosã (n = 23), Maronesa (n = 24) et Mertolenga (n = 23), ont été séquentiel-lement abattus à 3 poids différents. Le muscle était le tissu dont la répartition a été significativement différente entre les morceaux, mais où l'amplitude des différences entre races, pour chaque morceau, a été plus étroite. Parmi les morceaux de première catégorie, seuls l'aloyau et l'entrecôte, tous deux avec une amplitude de 7 g·kg -1 , ont été significativement différents entre les races. Comme attendu, les morceaux avec des paramètres de régression homogènes ont été les plus précis pour prédire la proportion de muscle (g·kg -1 ) dans la carcasse à partir de la proportion de muscle (...

Contrasting Cellularity and Fatty Acid Composition in Fat Depots from Alentejana and Barrosã Bovine Breeds Fed High and Low Forage Diets

“…Subcutaneous adipose tissue was sampled and its amount was determined by dissection of the leg joint. The former has been suggested to be representative of the overall bovine carcass composition, at least in these particular breeds 19 . For histometrical analyses, samples from subcutaneous and mesenteric fat depots (approximately 100 mg) were fixed by immersion in 10% neutral buffered formalin (Merck, Darmstadt, Germany) for 24 hours and processed for paraffin (Microscopy Histosec, Merck) embedding.…”

Differential mesenteric fat deposition in bovines fed on silage or concentrate is independent of glycerol membrane permeability

“…The amount of subcutaneous fat was determined by dissection of the leg joint. The former has been suggested to be representative of the overall bovine carcass composition in these particular breeds (Simõ es and Mendes, 2003). Mesenteric, omental and kidney knob and channel fat (KKCF) depots were excised and weighed.…”

Carcass fat partitioning and meat quality of Alentejana and Barrosã young bulls fed high or low maize silage diets

“…When comparing Alentejana and Barrosã breeds at the same proportion of total fat, Simões and Mendes (2003) reported no significant variations between breeds concerning the subcutaneous fat of the leg joint. According to these authors, any difference found in the subcutaneous fat of the leg would, therefore, reflect discrepancies in the carcass total fat and, consequently, in maturity.…”

“…The left half carcass was subsequently separated into commercial joints and the leg joint was dissected into the component tissues: muscle, intermuscular and subcutaneous fats, and bone. This joint has been suggested to be representative of the overall bovine carcass composition, at least, in these particular breeds (Simões & Mendes, 2003).…”