Belly Weight Research Articles

Pig carcass quality in relation to carcass lean meat proportion

The objective of the study was to quantify differences in the carcass composition of pig carcasses with different lean meat proportions. Totally 132 carcasses with lean meat proportions ranging from 45 to 65% were analysed. The average lean meat proportion in the analysed set of carcasses was 55.38% (s = 4.319). The carcasses were classified into the groups according to their lean meat proportion (R, 45.0 to 49.9%; U, 50.0 to 54.9%; E, 55.0 to 59.9%; S, more than 60.0%). Carcasses from each group were cut into primal cuts and the main cuts (leg, loin, shoulder and belly with bones) were further separated into different tissues. Carcass value was markedly enhanced by the increasing carcass lean meat proportion. Average leg percentages in the groups R, U, E and S were 17.88% (s = 0.918), 19.32% (s = 0.889), 20.88% (s = 0.817) and 21.88% (s = 0.827), respectively. Average proportions of fat over leg expressed as percentages of leg weight in these groups were 5.82% (s = 0.402), 4.87% (s = 0.556), 4.05% (s = 0.479) and 3.21% (s = 0.321), respectively. Lean meat proportions of leg weight were improved from 84.93% (s = 1.136) in the group R to 88.12% (s = 0.986) in the group S. The most distinct differences were found in lean proportions of belly weight. The observed averages in the group R and S were 43.90% (s = 2.729) and 62.10% (s = 2.219), respectively. Actually, in carcasses with a high classification score the belly can be considered as a cut with the predominant muscle tissue. The results of the study proved the efficiency of carcass evaluation based on the lean meat proportion. Such a method can significantly contribute to the overall improvement of pig production.  

Drip loss of case-ready meat and of premium cuts and their associations with earlier measured sample drip loss, meat quality and carcass traits in pigs

Drip loss of 374 samples taken from porcine M. longissimus dorsi and M. semimembranosus was measured by using the “bag method” (BM), EZ-DripLoss (EZ-DL) from premium cuts (PC) and in retail tray (case-ready meat; CRM). This provided a comparison between these methods and their relationships to other meat quality and carcass traits. Samples were prepared at 24 h post-mortem (pm) and were measured 24 and 48 h after preparation (at 48 and 72 h pm) using the BM and after 48 h (at 72 h pm) with the EZ-DL and PC. Drip loss of meat kept in retail trays was measured after 7 days (CRM 7) and daily within a week (CRM 1–7). Average drip loss was 1.80% and 3.10% using the BM after 24 and 48 h, respectively. EZ-DL and CRM 7 showed higher drip losses of 4.71% and 4.00%. Daily loss of CRM 1–7 showed a concavely shaped curve and increased from 1.57% to 5.64% after 7 days. High correlations were obtained between drip loss of CRM 7 and BM ( r = 0.88) or the EZ-DL ( r = 0.91). The development of drip loss in case-ready meat fitted by linear-quadratic regression ( y = 0.439 + 1.245 x − 0.072 x 2) showed that high drip loss measured earlier by bag and EZ-DripLoss methods was highly associated with a high intercept ( r = 0.63–0.72), a high linear increase ( r = 0.77–0.81), but larger decrease in increments ( r = −0.82 to −0.86) during weekly stored meat in retail trays as supplied at consumer level. Because the positive linear regression coefficient was substantially higher than the negative quadratic regression coefficient, the development of drip loss is mainly dependent on the initial drip loss. Therefore, animals with high drip loss within 72 h post-mortem also showed undesirable high drip loss curves over the entire retail period. Relationships between drip loss and other meat quality traits were similar for BM, EZ-DL and CRM 7. Of these the correlation between pH 24 and drip loss was highest with r = −0.54, −0.49 and −0.47 for BM, EZ-DL and CRMH 7, respectively. Interestingly, a correlation of r = −0.35 between blood pH value and CRML 7 was obtained. Carcass traits such as loin, ham, shoulder, belly weight or loin eye area showed only marginal correlations to drip loss. In conclusion, EZ-DL was the most appropriate method to predict drip loss of case-ready meat in retail trays and its development during a 7 day storage period.

June Riot

June Riot J.C. Dickey-Chasins (bio) Greenwood, Oklahoma June 1, 1921 The belly weight won't let me sleep. That, and the heat and the smoke. Ned was up before dawn and I was still awake, wanting this baby out. My husband slipped out like he always does, not putting on his boots until he's outside. Considerate. Some women here complain about their men, say they give coloreds a bad name with their whoring and gambling. But Ned was never like that, never even a stray glance, not once the whole time I been with child. I attribute it to the Lord. The smoke wafts in. I ease from the bed. Last night some of the uppity niggers marched out of Greenwood into Tulsa. Carrying guns. Went to prevent a lynching, is what Missus Charles next door said. Ned shook his head, kept saying, "They's fools," but I don't know. A black boy bumped a white girl in an elevator. She says he raped her. Next thing you know, the whites are at the courthouse ready to kill the boy. If I had a dollar for every time some white woman said she was raped by our men, I'd be living in a fine house up north. Living in town and still on straw ticking. Don't seem right. But the coloreds get straw and the whites get mattresses. That's the difference between Greenwood and Tulsa right there—straw and mattresses. Oh, there's no profit in such thoughts. I push up from the nightstand and make my way into the kitchen. My back aches and my ankles feel like they'll explode. Ned's left half the coffee and a surprise: a slice of white bread slathered in molasses. I heat up the coffee and nibble at the bread. I'm not hungry—no space down there. The baby barely shifts now, an enormous, washpan-sized lump. I slide back, trying to get comfortable on the hard, flat-bottomed chair. That smoke smell again. I expect they set another house on fire, the white boys with their torches and guns, those white hoods. Ned says the good Negroes—like us—have nothing to fear. No use trying to sit. I stand. Upright the baby settles down. It's a kicker, has been for months. Ned so wants it to be a boy. Lord knows he deserves it [End Page 61] after two stillborn babies. And I want this child, please dear God, I do. Just one healthy baby for me and Ned. There's shouting outside. I lean out the window. The air is hot and still, dank from the night. The noise seems to come from the northwest—up on Greenwood Street maybe? That's where all the businesses are. A fire, most likely. Explains the smoke. I hesitate, listening. Doesn't sound like a fire, exactly. I turn and go to the counter. Best clean up the dishes now, when I've got my strength. Seems like afternoons I just want to rest and sleep. I feel a shift inside, a settling. Is it today? I don't trust my body, not after the last baby. So certain it would come out screaming, and then Betty Lou shaking her head, saying, "He's strangled is all." God's will. A child not meant to be. His judgment is heavy but always just. I glance at the wind-up clock on the windowsill. Ned's been working a good hour at the stable. Mister Shockley is one of the good whites, Ned says, willing to treat you right if you give him respect. Ned says these young niggers have gotten used to making folding money and wearing fancy clothes, as if they were better than us. Ned says these niggers don't respect their elders, and I expect that's right. But it's not my place to say, anyhow. I move into the sitting room. The house has three rooms and no hallway—each space just runs into the other. Cozy is what Ned says. Elbows touching when both of us is here. With the baby, I don't know. A...

비육돈 생산단계에 따른 도체 및 부분육 생산 특성

본 연구는 수출규격돈 생산과 고품질 돈육 생산에 필요한 기초자료를 제시하고자 도체 및 부분육 생산 특성을 조사한 것으로 도체중량에서는 듀록종이 원종, <TEX>$F_1$</TEX>종 및 비육돈에 비하여 적었다(p<0.05). 거래정육중량은 요크셔종과 <TEX>$F_1$</TEX>종이 다른 원종과 비육돈에 비하여 높은 반면 듀록종이 가장 낮았다(p<0.05). 도체길이는 랜드레이스와 <TEX>$F_1$</TEX>종이 다른 원종 및 비육돈에 비하여 길게 나타났고(p<0.05), 도체폭은 <TEX>$F_1$</TEX>종이 다른 순종 및 비육돈 보다 넓었다. 도체후도는 <TEX>$F_1$</TEX>종과 비육돈이 원종에 비하여 유의적으로 두꺼운 것으로 나타났다(p<0.05). 안심과 등심의 생산량은 랜드레이스와 요크셔 및 <TEX>$F_1$</TEX>종이 듀록 및 비육돈에 비하여 높게 나타났고 듀록이 가장 적었다(p<0.05). 목심 생산량은 요크셔와 <TEX>$F_1$</TEX>종이 다른 순종 및 비육돈에 비하여 높게 생산되었고(p<0.05), 듀록과 랜드레이스종이 가장 낮았다. 삼겹살 생산량은 듀록종이 낮았으며, 뒷다리는 요크셔와 <TEX>$F_1$</TEX>종이 다른 순종과 비육돈에 비하여 높게 생산되었고, 앞다리는 요크셔종이 생산량이 많았다(p<0.05). 일본 수출 기준에 따른 등심 합격율은 전체적으로 대단히 낮았고, 안심 합격률은 랜드레이스종이 100%로 가장 높았다. 앞다리와 뒷다리 합격률은 요크셔종이 각각 90.91%, 87.88%로 가장 높았다. 이상의 결과를 종합하면 비육돈의 부분육 및 수출규격육 생산이 미흡하므로 이를 만족시킬 수 있는 순종의 도입과 교배체계의 확립이 필요할 것으로 사료된다. The characteristics of carcass and meat yields of fattening pigs by production steps were investigated with Landrace (LL, n=41), Yorkshire (YY, n=33), and Duroc (DD, n=30), <TEX>$F_1$</TEX> (LY, n=25), the Crossbred of LYD (n=48). Duroc had more weight loss in carcasses weight than that of the other breed(p<0.05). Yorkshire and <TEX>$F_1$</TEX> had higher production weight in retail cut than that of the other pure or crossbred. Carcass from Landrace and <TEX>$F_1$</TEX> were significantly longer in length than the other breed(p<0.05). <TEX>$F_1$</TEX> produced wider carcass than the other breed. Carcass thickness at aitch bone was higher for <TEX>$F_1$</TEX> and Crossbred than the other breed(p<0.05). Landrace, Yorkshire and <TEX>$F_1$</TEX> produced more loin and tenderloin in weight than the other breed (p<0.05). Yorkshire and <TEX>$F_1$</TEX> produced more picnic shoulder when compared to the other breed. The hind legs produced from Yorkshire and <TEX>$F_1$</TEX> were higher in weight and the fore legs produced from the Crossbred were higher in weight. Duroc produced the lowest weight of belly among the breeds. The acceptance level of loin were extremely low for all breed. Landrace had the highest acceptance level for tenderloin. Yorkshire had the highest acceptance level for picnic shoulder and ham when evaluated by export standard of Japan. In conclusion, The introduction of pure breed and establishment of mating steps are necessary to produce highly accepted pork with high acceptance in carcass and meat yields.

Conjugated Linoleic Acid in Combination with Supplemental Dietary Fat Alters Pork Fat Quality

Interest in fortification of human foods, including pork, with conjugated linoleic acid (CLA) is growing and may provide benefits as a neutraceutical based on research evaluating CLA as an anticarcinogen, immune modulator, antiatherogenic agent and a body composition modulator. This study evaluated the combined effects of dietary CLA and supplemental fat source on growth, fatty acid composition and belly quality of lean genotype gilts (n = 144). Pigs (49.3 kg) were randomly assigned to six diets (3 x 2 factorial) varying in supplemental fat (none, 4 g/100 g yellow grease or 4 g/100 g tallow) and linoleic acid [1 g/100 g corn oil (CO) or 1 g/100 g CLA (CLA-60)] for 47 d. Both the cis-9, trans-11 and the trans-10, cis-12 isomers of CLA were increased in belly and longissimus fat depots from pigs fed CLA, and that increase was up to 92% greater when CLA was fed with 4 g/100 g supplemental fat (fat source x linoleic acid interaction, P < 0.05). Pigs fed CLA had a greater concentration of 18:0 and less 18:1 cis-9 (P < 0.01) in various fat depots, suggesting a reduction in Delta(9) desaturase activity. The iodine value of belly fat from pigs consuming tallow and CLA combined was reduced to 62.0 from an initial value of 70.4. CLA supplementation also increased belly weights (P < 0.05). CLA did not affect longissimus muscle area, backfat depth and the percentage of fat-free lean (P > 0.10), but it increased the subjective intramuscular fat score by 18.8% (P < 0.01). In conclusion, CLA enrichment of pork products may be enhanced when combined with additional supplemental dietary fat, and together with tallow can be used to increase the saturated fatty acid content of pork.

Influence of obesity gene in quantitative traits of swine

Genotype data of 477 animals of several swine races (Landrace - LD, Large White - LW, Pietrain - PI, LWXLDXPI, Piau, Monteiro, and unknown race) were obtained to determine the allele frequency of the obesity gene. Genotype data of 174 crossbred swine (LWXLDXPI) were also obtained, in order to assess its correlation with carcass evaluation data (lean meat percentage, backfat thickness at P2, loin eye area, adjacent fat area, total fat and meat). Finally, genotype data of 96 pure swine (Landrace, Large White and Pietrain) were collected, to establish its relation with meat quality (drip loss, meat color, texture analysis and intramuscular fat) and carcass evaluation data (lean meat percentage; ham, loin, shoulder and belly weights; and backfat thickness at P2). This work also aimed associating EPDs (expected progeny differences) for litter size, daily weight gain and backfat thickness with genotype data of 49 Large White males and 54 Landrace females. Genotyping was done on animal blood by PCR-RFLP, based on Stratil et al. (1997). Statistical analysis was done by using SAS software for variance analysis between genotypes and data for each cited class. For purebred animals, a mixed model was used, with sire within race as random effect. The allelic frequencies of alleles T and C were, respectively: 0.8142; 0.1857 (Landrace); 0.9125; 0.0875 (Large White); 0.9433; 0.0566 (Pietrain); 0.8333; 0.1666 (LWXLDXPI); 0.2500; 0.7500 (Piau); 0.8750; 0.1250 (Monteiro), and 0.8870; 0.1130 (unknown race). Since the highest allele C frequency occurred in Piau, we suggest that this allele could be associated with fat accumulation. In the Landrace race, a study was done separating the frequencies of 2 generations (great-grandfather and grandfather), and the differences confirmed by a Chi-square test, a higher frequency of allele C having been found in the grandparental generation. This suggests that this allele could be eliminated by selection from the great-grandparental generation, when the male grandparent is replaced by the great-grandparental generation. The obesity gene did not influence any of the carcass evaluation data from crossbred animals. In pure swine, where the only genotypes were TT and TC, it greatly influenced shoulder weight and meat texture, with the highest average in heterozygotes (shoulder: 4.07 vs. 3.93; texture: 2.62 vs. 1.82), suggesting better carcass quality and worse meat quality than in homozygotes. The obesity gene did not influence any trait in the expected progeny difference (EPD) study.

Correlated response to selection for litter size in pigs: II. Carcass, meat, and fat quality traits.

Data on a pig line selected for litter size (H) and a control line (C) were used to estimate the correlated responses to litter size in carcass, meat, and fat quality traits. The differences between the genetic means of animals from line H and line C were used to estimate correlated responses. No differences were found between the two lines in carcass measurements except backfat depth, which was higher (P < 0.05) in line H (0.69 +/- 0.28 mm). This led to a decrease (P < 0.05) in predicted carcass lean content (-6.0 +/- 2.7 g/kg). Differences in joint weight distribution between lines were primarily due to belly weight, which was higher (P < 0.05) in line H (6.3 +/- 1.2 g/kg). There were no important changes in meat quality traits. Chemical composition of semimembranosus muscle (SM) and subcutaneous backfat (SB) differed between lines only for DM in SB, which was higher (P < 0.05) in line H (15.1 +/- 7.1 mg/g), and for the fatty acid composition of intramuscular fat. The fatty acid profile in line H showed a lower (P < 0.01) proportion of polyunsaturated fatty acids (-14.7 +/- 4.8 mg/g FA), particularly with regard to the content of linoleic acid (-12.5 +/- 3.9 mg/g FA). It is concluded that selection for litter size reduced the lean content in the carcass but the proportion of high-priced cuts and meat quality traits were not affected. However, selection may lead to changes in the composition of intramuscular fat lipids towards a lower content of polyunsaturated fatty acids. The observed correlated effects can be interpreted assuming that selected pigs are more mature at the same weight, though the underlying genetic and physiologic processes that cause them are unknown. The results of this experiment indicate that the metabolic pathways taking part in fat metabolism should be considered first.

Genetische Fundierung von AutoFOM-Merkmalen

Abstract. Title of the paper: Genetic foundation of AutoFOM-traits Since the beginning of the year 2000 the payment System of pig carcasses in some slaughter houses in northwest Germany is based on the recordings of the fully automated carcass Classification system AutoFOM. Besides legal information 'estimated lean meat percentage' relative exact details of the weights of important valuable cuts are available. Genetic parameters of the AutoFOM lean carcass cut information, ham-, chop-, Shoulder- and belly weights as well as lean meat percentage of the belly cut were estimated. Using the field data of the pig breeding organisations BHZP (n = 2224) and SNW (n = 3601) the estimated heritabilties of these carcass cuts vary between 0.13 and 0.27 (BHZP) and 0.13 and 0.31 (SNW), respectively. The estimated heritabilities of the AutoFOM carcass traits of station-tested pigs were more pronounced for the dam lines German Landrace and Large White (n = 1693) and Piétrain Al-boars mated to Fl sows (n = 1053). The estimates ranged from 0.27 to 0.59 (dam lines) and 0.05 to 0.40 (Pi Al-boars), respectively. Using the records of Station tested purebred Pietrain pigs (n = 1693) the heritabilities of the AutoFOM carcass cuts did not exceed 0.10. The genetic correlation between the different AutoFOM carcass traits exceed the absolute value of 0.8. In a similar way, the genetic correlation between the "estimated lean meat percentage" used in the test Station and the AutoFOM carcass traits were close to unity. We concluded that AutoFOM traits of slaughter pigs provide a useful information for the selection of Al-boars. Moreover, with regard to the Station testing of dam lines AutoFOM carcass informations derived from AutoFOM are a useful supplementation. Because of the low heritability, only a marginal additional benefit could be expected for the genetic ranking of Pi-boars using AutoFOM carcass cut records of purebred Station tested progenies.

Identification of quantitative trait loci affecting carcass composition in swine: II. Muscling and wholesale product yield traits.

A genomic scan was conducted on 540 reciprocal backcross Meishan x White composite pigs for hot carcass weight (HCWT); loin eye area (LOIN); carcass length (CRCL); belly weight (BELLY); and weight of trimmed ham, loin, picnic, and Boston butt adjusted to a constant live (TWPLWT) or carcass (TWPCWT) weight. Genetic markers spanned the entire porcine linkage map and were spaced at approximately 20-cM intervals. Grandparental breed of origin for all chromosomal segments was determined using multipoint linkage procedures, and a least squares regression analysis was conducted. Nominal P-values were converted to a genome-wide level of significance to adjust for the number of tests actually conducted. Seven associations were significant at the genome-wide level relating to chromosomes 1 (SSC 1), 7 (SSC 7), and X (SSC X). The SSC 1 region affected LOIN, TWPLWT, and TWPCWT; SSC 7 affected HWCT and CRCL; and SSC X affected TWPLWT and TWPCWT. Twelve associations relating to seven chromosomal regions (including SSC 1 and X) presented suggestive evidence for quantitative trait loci (QTL), and many of these regions are likely to contain QTL. Chromosomes 8 and 14 had two and three traits with suggestive evidence for QTL, respectively. Many pleiotropic effects were detected for regions on SSC 1, 7, 14, and X in this study and a companion study looking for fat deposition QTL in the same population. In addition, SSC 4 was nearly significant for CRCL in the same region identified as affecting backfat in a wild boar x Large White population. These results expand our knowledge of the inheritance of quantitative traits and are directly relevant to composite populations containing Meishan germplasm.

Growth, body composition, and endocrine responses to chronic administration of insulin-like growth factor I and(or) porcine growth hormone in pigs.

The actions of IGF-I, alone and in combination with porcine growth hormone (pGH), on growth and circulating endocrines and metabolites important in growth were investigated in peripubertal-age Meishan barrows. Pigs were assigned to four treatments: control, buffer; IGF-I, 33 microg rhIGF-I/kg BW injected twice daily; pGH, 33 microg rpGH/kg BW injected once daily; and IGF-I+pGH, 33 microg rhIGF-I/kg BW injected twice daily plus 33 microg rpGH/kg BW injected once daily. Treatments were administered for 28 d. Feed intake, BW, and backfat were recorded and blood samples were collected weekly. At slaughter, organ and primal cut weights were recorded. Offal and half the carcass were ground for chemical analysis. Serum concentrations of IGF-I on d 7, 14, 21, and 28 in the IGF-I, pGH, and IGF-I+pGH groups were increased 60, 107, and 131%, respectively, compared with those of the control group. Administration of pGH increased gain 43%, feed efficiency 60%, carcass protein accretion 88%, and trimmed lean cuts 16%, whereas IGF-I administration increased gain 22%, carcass protein accretion 33%, and trimmed lean cuts 5%. There was little difference in responses to administration of IGF-I+pGH and pGH alone except that coadministration of IGF-I with pGH reduced the ability of pGH to suppress backfat gain (P < .02). Even though administration of IGF-I resulted in a 60% increase in chronic nadir serum concentrations of IGF-I, only a few growth and carcass measures were changed when compared with control pigs. These included increased (P < .05) weight of body, leaf fat, kidneys, and belly. The actions of pGH on growth of pigs were not mimicked, and some were countermanded by administration of IGF-I at a dose that produces significantly increased serum concentrations of IGF-I.

Maintenance feeding of 100 kg pigs: effect on carcass lean and fat yield and on gastrointestinal organ size

AbstractThe study was conducted to test the hypotheses that sustained restriction of food to maintain constant body weight of market-ready pigs, hereafter terminal maintenance (TM), would (1) decrease the size of gastrointestinal and other visceral organs, (2) increase dressing proportion, and (3) increase lean and decrease fat content and improve the lean: fat ratio of carcass. Forty-eight crossbred castrated male pigs (initial body weight, 23·5 kg) were randomly assigned to eight treatment groups (six pigs per group; one pig per pen). Three comparison groups were included. Thead libitumcontrol group (AL) was slaughtered at the target weight, 105 kg. One group was continuously restricted (CR) to 0·8 of the intake by AL and slaughtered at the target weight. The terminally restricted (TR) group was given food ad libitum to 1·1 times the target weight; then food was restricted to effect weight loss to the target weight before slaughter. Five TM groups were given food ad libitum to the target weight; then TM was administered for various periods (7, 14, 21, 28 and 42 days) before slaughter. CR either had no effect or caused enlargement of visceral organs compared with AL. TR caused reduction of viscera, especially of abdominal-digestive organs. TM caused reduction of most viscera organs (0·001 &amp;lt;P&amp;lt; 0·05). Regression analyses indicated that most abdominal organs were reduced 50 to 70 g/kg per 10 days of terminal maintenance. TM and TR also increased carcass weight (P&amp;lt; 0·05). Catabolism associated with reduction of viscera organs may provide nitrogenous substrates to support the continued lean accretion observed during terminal maintenance. The reduced viscera and increased carcass weight combined resulted in increased dressing proportion (P= 0·06). Regression analyses (weightv.TM-days) showed that lean mass increased (71 g/day;P&amp;lt; 0·05) and fat mass decreased (−52 g/day;P&amp;lt; 0·01). Weight of bone and belly did not change. Differential lean gain, lean gain minus fat gain, during TM occurred at a rate of about 120 g/day.

Correlated responses in reproductive and carcass traits to selection for 200-day weight in Landrace pigs.

Correlated responses in reproductive and carcass traits from a line of Landrace pigs selected for increased 200-d weight along with a randomly selected control line were studied in 195 litters (109 select, 86 control) and 285 pigs (132 select, 153 control). Reproductive and maternal traits studied included litter sizes born, born alive, and alive at 21 d and litter weights at birth and at 21 d. Carcass traits studied were carcass length, longissimus area, average backfat thickness, 10th-rib backfat thickness, specific gravity, weights of closely trimmed ham, loin, and shoulder, belly weight, subjective scoring of the longissimus muscle for color and marbling, estimated percentage of muscle, and lean growth. Total weighted cumulative selection differential for 200-d weight over six generations was 88.7 kg. The realized heritability for 200-d weight was .26 +/- .08, and the change in 200-d weight was 4.2 +/- 1.3 kg per generation. None of the regression coefficients for reproductive traits differed significantly from zero. Ham weight, belly weight, marbling score, and lean growth increased by .069 +/- .027 kg, .051 +/- .020 kg, .045 +/- .012 points, and .0042 +/- .0007 kg/d, respectively, per generation. Specific gravity decreased by -.00063 +/- .00023 per generation in response to the selection for 200-d weight. The increase in lean growth in the select line was the result of an increased growth rate and not from an improvement in percentage of lean in carcasses from pigs from the select line.

Correlated responses in reproductive and carcass traits to selection for 200-day weight in Duroc swine.

Correlated responses in reproductive and carcass traits from a line of Duroc pigs selected for increased 200-d weight along with a randomly selected control line were studied in 189 litters (116 select, 73 control) and 191 pigs (106 select, 85 control), respectively. Reproductive and maternal traits studied included litter sizes born, born alive, and alive at 21 d and litter weight at birth and at 21 d. Carcass traits studied were carcass length, longissimus muscle area, average backfat thickness, 10th rib backfat thickness, specific gravity, weights of closely trimmed ham, loin, and shoulder, belly weight, subjective scoring of the longissimus muscle for color and marbling, estimated percentage of muscle and lean gain per day. Total weighted cumulative selection differential for 200-d weight was 81.7 kg. The realized heritability for 200-d weight was .18 +/- .08, and the change in 200-d weight was 2.5 +/- 1.2 kg per generation. The regression coefficient of litter size born on generation was -.29 +/- .12 (P less than .10) pigs per generation. None of the other regression coefficients for the reproductive traits differed from zero. Average backfat thickness, 10th rib backfat thickness, and belly weight increased by .093 +/- .016 cm, .122 +/- .029 cm, and .089 +/- .040 kg, respectively, per generation. Specific gravity, ham weight, shoulder weight, color score, and percentage of muscle decreased -.00086 +/- .00024, -.165 +/- .013 kg, -.104 +/- .011 kg, -.035 +/- .015 points, and -.47 +/- .12%, respectively, per generation in response to the selection.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlated responses in reproductive and carcass traits to selection for 70-day weight in Landrace swine.

Correlated responses in reproductive and carcass traits were studied in 181 litters and 218 pigs from a line of Landrace pigs selected six generations for increased weight at 70 d of age and a contemporaneous, randomly selected control line. The reproductive and maternal traits studied included litter sizes born, born alive, and alive at 21 d and litter weight at birth and at 21 d. Carcass traits studied were carcass length, longissimus muscle area, average backfat thickness, 10th-rib backfat thickness, specific gravity, weights of closely trimmed ham, loin, and shoulder, belly weight, subjective scoring of the longissimus muscle for color and marbling, estimated percentage of muscle, and lean gain per day. Total weighted cumulative selection differential for 70-d weight was 30.2 kg. The realized heritability for 70-d weight was .13 +/- .06, and the change in 70-d weight was .65 +/- .29 kg per generation. The regression coefficient of litter size at 21 d on generation was .24 +/- .10 (P less than .10) pigs per generation. None of the other regression coefficients for the reproductive traits differed from zero. Carcass length, specific gravity, and ham weight decreased (P less than .10) -.075 +/- .036 cm, -.00054 +/- .00027, and -.102 +/- .048 kg, respectively, per generation. Color score and lean gain per day increased .046 +/- .021 points and .0032 +/- .0013 kg/d, respectively, each generation in response to the selection.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of a potent analog of human growth hormone-releasing factor on carcass composition and quality of crossbred market pigs.

The effect of a human growth hormone-releasing factor (hGRF) analog ([desamino-Tyr1, D-Ala2, Ala15] hGRF(1-29)NH2) on the carcass composition of crossbred barrows was evaluated. pH, color and collagen content were measured on 74 animals distributed among the following five treatments started at about 50 kg BW: T1, control saline three times daily (TID); T2, hGRF analog (1.66 micrograms/kg, TID); T3, hGRF analog (3.33 micrograms/kg, TID); T4, hGRF analog (6.66 micrograms/kg, TID) and T5, hGRF analog (10 micrograms/kg, once daily). Animals were slaughtered at approximately 106 kg BW giving an average of 55 d on test. Carcass composition was determined on eight animals from T1 and eight animals from T4. The left side of each carcass was divided into four untrimmed commercial cuts: ham, loin, shoulder and belly, which then were dissected into muscle, separable fat, bone and skin. Ham, loin and belly weights were not affected by GRF treatment, but shoulder weight was increased (P less than .05; 10.11 vs 11.15 kg, SE = .21). There was an increase (P less than .0.05) in muscle content of all the cuts considered and a concomitant decrease (P less than .05) in fat content. The analog increased muscle weight by 16% and decreased fat weight by 25% in the pooled tissues of the shoulder, ham and loin. Overall, hGRF analog increased skin and bone weights by 39% and 19%, respectively. Chemical analysis demonstrated that the hGRF analog increased overall protein accretion in the carcass by 10.5% and decreased crude fat by 28.7%.(ABSTRACT TRUNCATED AT 250 WORDS)

CRITERIA OF BELLY BACON DESIRABILITY. I. FAT–LEAN RATIO OF THE PORK BELLY IN RELATION TO BACKFAT, CARCASS WEIGHT AND SPECIFIC GRAVITY

Belly composition in relation to specific gravity of the cured belly and weight and backfat measurements of the carcass was evaluated on a sample of 730 carcasses. Substantial sex differences were observed with boars (n = 109) having 4.5% less fat in the belly than gilts (n = 379) and gilts 2.7% less fat than castrates (n = 242). Percent fat of belly increased in a linear fashion with increasing backfat thickness with the change consistent for each sex across the carcass weight range (56–90 kg). In regression analysis of the total population, backfat explained 46.1% of the total variance in percent fat of the belly, weight after backfat 0.5% and specific gravity after weight 36.1%. Inclusion of sex in the regression equation increased the proportion of variance explained by 0.4% (from 82.7 to 83.1). Carcass weight, backfat thickness, and percent fat in the belly were directly related to belly weight expressed as a proportion of carcass weight and inversely related to percent curing shrink.

The association between face cover and the productivity of Merino ewes in twelve NSW flocks

The association between the face cover and productivity of more than 3000 Merino ewes has been examined in 12 flocks located in the major sheep producing areas of New South Wales. Each flock was divided into Open (scores 1 and 2), Moderate (scores 3 and 4), and Muffled (scores 5 and 6) groups. A significant negative association between face cover and reproductive performance was apparent in two flocks that contained appreciable numbers of muffled-faced ewes. A similar trend was apparent in another Muffled flock, but in one other Muffled flock and four Open flocks, there was no evidence of such an association. The results from the remaining four flocks were not considered, due to the possibility that the results were confounded by face cover scoring after joining. In one Muffled flock, the body weights of weaner lambs were negatively correlated with their dams' face cover. A relationship between face cover score and total greasy fleece weight, corrected for previous reproductive performance, was absent from most flocks and negative in two, despite evidence of a positive correlation with belly weight. There was a trend to inferior fleeces of finer trade count in Moderate and Muffled groups of several flocks. Excess face cover was found to be an undesirable attribute in Merino flocks. Its importance was greatest in flocks containing appreciable numbers of muffled-faced ewes

THE GROWTH OF TENDON AFTER DENERVATION OR EXCISION OF ITS MUSCLE.

The weight and girth of a muscle belly denervated in the three-week-old rabbit eventually grows to about 30%, its total collagen content to almost 300% and the thickness of its tendon to approximately 75% of those of the controls. There is, as occurs during normal growth, the same increase from 0.7 to 1.25 in the ratio of the thickness of the tendon of peroneus brevis to that of tibialis anterior. If a muscle is completely excised at three weeks, its tendon, which is subjected only to passive tensions during movement, grows to as much as 85% of the girth of its control. If, however, such passive tensions are eliminated as far as is possible, the isolated tendon may grow no more in thickness.