Loin Backfat Research Articles

The Potential Role of MYOM1 and ATGL Genes in Pig Production Improvement

Abstract In the present study, two missense variants within ATGL (rs331307082) and MYOM1 (rs326001585) genes were tested for their potential usage as genetic markers related to pig production traits. The genotyping was performed on 519 pigs representing 990 synthetic sire line. The association analysis indicated that ATGL gene affected the panel of fattening parameters (test daily gain, age at slaughter), meatiness traits (meat percentage in the carcasses; the weight of loin, ham and primary cuts, and loin eye area), and meat quality characteristics (water exudation). In turn, MYOM1 polymorphism was related to loin weight, the weight of primary cuts and weight of loin backfat. Pigs with AA genotype were characterized by significantly higher loin and primary cut weights compared to opposite homozygotes GG (P<0.05). The observed differences were 2.29 kg and 1.2 kg, respectively. Moreover, despite higher meatiness, AA animals together with AG were characterized by lower weight of loin backfat (P<0.05) and average backfat thickness (P<0.1) compared to GG pigs. The MYOM1 polymorphism did not affect pork quality traits. The results allowed us to propose the new genetic markers which may be used in pig selection to obtain appropriate meatiness and fatness level in carcasses without decreasing meat quality.

Non-destructive evaluation of carcass and ham traits and meat quality assessment applied to early and late immunocastrated Iberian pigs

Castration is a common practice in Iberian pigs due to their advanced age and high weight at slaughter. Immunocastration (IC) is an alternative to surgical castration that influences carcass and cut fatness. These traits need to be evaluated in vivo and postmortem. The aims of the present work were (a) to determine the relationship between ham composition measured with computed tomography (CT) and in vivo ultrasound (US) and carcass fat thickness measurements, (b) to apply these technologies to early (EIP) and late (LIP) immunocastrated Iberian pigs in order to evaluate carcass fatness and ham tissue composition and (c) to assess meat quality on these animals and to find the relationships between meat quality traits (namely, intramuscular fat (IMF)) and fat depot thicknesses. For this purpose, 20 purebred Iberian pigs were immunocastrated with three doses of Improvac ®, at either 4.5, 5.5 and 9 or 11, 12 and 14 months of age (EIP or LIP; respectively; n = 10 each) and slaughtered at 17 months of age. Fat depots were evaluated in vivo by US, in carcass with a ruler and in hams by CT. Carcass and cut yields, loin meat quality and loin acceptability by consumers were determined. Also, IMF was determined in the loin and three muscles of the ham. Carcass weight was 14.9 kg heavier in EIP vs LIP, and loin backfat thickness (US- and ruler-measured) was also greater in EIP. Similarly, CT-evaluated ham bone and fat contents were greater and smaller for EIP vs LIP, respectively. Loin and ham IMF were also greater in EIP, but the other meat quality parameters were similar. The acceptability of meat by consumers was high and it did not differ between IC protocols. Correlations between several fat depots measured with the different technologies were high. In conclusion, all these technologies allowed fat depot measurements, which were highly correlated despite being obtained at different anatomical locations.

Ácidos graxos da gordura de cobertura do contrafilé de bovinos Nelore e Canchim terminados em confinamento e alimentados com diferentes níveis de concentrado nas dietas

The objective was to evaluate fatty acids composition of the back fat in loin meat (Longissimus muscle) from Nellore and Canchim young bulls. The animals were finished at feedlot and received sugar cane diets with two concentrate levels (40 and 60% of dry matter). The concentrates were formulated with sunflower grains, corn, soybean meal, dry sugar cane yeast, urea and mineral mixture. The experimental design was a completely randomized design with a 2x2 factorial arrangement (genetic group x concentrate level), and the results were submitted to the variance analysis and means compared by Tukey test at 5% probability, when the interaction was significant. The loin backfat of Nellore bulls had higher concentration of conjugated linoleic acids than Canchim bulls (0.86 and 0.59%, respectively). On the other hand, the loin back fat of Canchim bulls had higher concentrations of estearic (17.07%) and linoleic acids (2.40%) and polyunsaturated fatty acids than Nellore bulls, that showed values of 13.47 and 1.44, respectively. The Nellore and Canchim loin back fat presents significant amounts of beneficial fatty acids to human health. Levels of 40 and 60% of concentrate in the diet did not alter the fatty acids composition of loin backfat.

Association of body weight, loinlongissimus dorsiand backfat with body condition score in dry and lactating Holstein dairy cows

AbstractThe lactation cycle of the dairy cow induces large changes in body fat and protein pools, which can be monitored through loin backfat (BF) and longissimus dorsi (LD) measurements. Data from two experiments (exp) using Holstein-Friesian dairy cows (no. = 40 and 32 respectively) were used to study the association of body weight (BW), BF and LD depth with body condition score (BCS) for the last 6 weeks of the dry period (DP) and the first 8 weeks of lactation. Loin and tail BCS were manually assessed (0 to 5 scale) and BF and LD depth were measured by ultrasound at the fifth lumbar process. The BCS data ranged from 1.3 to 3.0 units in the DP, and from about 1.1 to 3.1 units during early lactation in both experiments. Data were analysed by two models: BW, LD or BF = exp + period (DP or lactation) + BCS + interactions + cow + error (model 1); and BCS = exp + period + LD + BF + LD2+ BF2+ exp × LD + exp × BF + exp × LD2+ exp BF2+ period × LD + period × BF + period × LD2+ period × BF2BF2+ cow + error (model 2).A first-order autoregressive (AR(1)) covariance structure was employed for the error terms to account for the correlation among repeated measures within cow. Regressions of BW and LD on BCS (model 1) found pre- to post-calving differences (P< 0.001) in intercept for BW and LD, and slope coefficients of 35 (DP) and 21 (lactation) kg BW, and 5.8 mm LD per BCS unit. Regression of BF on BCS (model 1) showed an exp × period interaction (P< 0.001), with 0.4 mm BF (exp 1;P< 0.05) and 2.0 mm BF (exp 2;P< 0.001) per BCS unit. Regression of BCS on LD and BF (model 2) showed intercepts not equal to 0 (P< 0.06), and differences (P< 0.001) between DP and lactation; BCS increased (P< 0.001) by 0.027 units per mm BF and 0.05 units per mm LD, but LD had a quadratic term −0.0004 (P= 0.02). It is concluded that at BCS lower than 3, LD contributes to BCS following a quadratic function, whereas BF causes BCS to increase linearly. Each unit of BCS equated to about 35 and 20 kg BW for DP and lactation periods respectively, to 5.8 mm LD, and to between 0.4 and 2.0 mm BF.

The phospholipids of pig adipose tissue

1. 1. The phospholipids of pig adipose tissue (loin back fat) have been isolated and the amount and fatty acid composition of each determined. 2. 2. The positional distribution of fatty acids in the phosphatidyl choline, the major component (61% of the total phospholipid), was determined after hydrolysis with phospholipase A 2. 3. 3. Diglyceride acetates were prepared from the phosphatidyl choline and separated into simpler molecular species by silver nitrate chromatography and by high temperature gas-liquid chromatography. The results differ markedly from those reported for the phosphatidyl choline from other pig tissues.

The prediction of lean percentage of pigs of bacon weight from carcass measurements

1. Carcass measurement and dissection data from 250 pigs reared at the stations of the National Pig Progeny Testing Board have been analysed to study the value of the carcass measurements in predicting the percentage lean in the carcass.2. Differences between sexes in the carcass characteristics were generally larger than those between breeds. Gilts had a higher percentage of lean meat than the hogs, with larger eye muscle dimensions and smaller measurements of backfat thickness.3. For pigs of the same breed and sex, the best predictions of leanness possible without cutting the carcass were derived from measurements of shoulder and minimum loin backfat (see Figure 1). Mid-backfat measurements improved the accuracy of prediction, but length and depth of carcass did not. The residual standard error in percentage lean at constant shoulder and minimum loin backfat was 2·66% of side weight overall but this was reduced to 2·28% by adjustments for breed and sex.4. Measurements made after cutting the carcass at the last rib gave more accurate predictions of percentage lean than did the split carcass measurements. The residual standard error in percentage lean at constant B, C and K (see Figure 2) was 1·97 % of side weight overall, reduced to 1·88 % by adjustments for breed and sex.5. The implications of these relationships in carcass grading and carcass evaluation generally are discussed.