Bacon Weight Research Articles

Effects of feeding pelleted diets without or with distillers dried grains with solubles on fresh belly characteristics, fat quality, and commercial bacon slicing yields of finishing pigs.

One hundred ninety-two pigs were blocked by age and stratified by initial BW (25.7 ± 2.3 kg) into pens (2 barrows and 2 gilts/pen), and within blocks, pens were assigned randomly to 1 of 4 treatments in a 2 × 2 factorial arrangement, with main effects of diet form (meal vs. pelleted) and distillers dried grains with solubles (DDGS) inclusion (0% vs. 30%). Pigs were slaughtered after a 91-d feeding trial, and carcasses were fabricated after a 24-h chilling period. Belly dimensions and flop distance were measured, and an adipose tissue sample from each belly was collected for fatty acid analysis. Bacon was manufactured at a commercial processing facility before being returned to the University of Illinois Meat Science Laboratory for further evaluation. Although bellies from pigs fed pelleted diets were 5.3% heavier ( < 0.01) than bellies from meal-fed pigs, belly weight as a percentage of chilled side weight ( = 0.55) and fresh belly dimensions ( ≥ 0.11) were not affected by diet form. Slab bacon weight and cooked yield were greater ( ≤ 0.01) for bellies from pellet-fed than meal-fed pigs. Despite pellet-fed pigs having a 3.1-unit greater iodine value (IV) than meal-fed pigs, there was no effect ( ≥ 0.16) of diet form on commercial bacon slicing yields. Bacon slabs from pellet-fed pigs produced more ( < 0.01) total bacon slices, but 3.1% fewer ( < 0.01) slices per kilogram than slabs from meal fed pigs. Inclusion of 30% DDGS reduced belly thickness ( < 0.001), flop distance ( < 0.001), and initial belly weight ( = 0.04) by 0.32 cm, 4.97 cm, and 2.85, respectively, and increased ( < 0.001) belly fat IV by 7.1 units compared with bellies from pigs fed 0% DDGS. Feeding 0% DDGS produced more ( < 0.01) total bacon slices than feeding 30% DDGS. Distillers dried grains with solubles inclusion had no effect on slice yields ( ≥ 0.14) or slices per kilogram ( = 0.08). Overall, bellies from pellet-fed pigs were heavier and had greater IV but did not differ in commercial slicing yields from meal-fed pigs. Feeding pigs 30% DDGS produced thinner, softer bellies with greater IV, but slicing yields were not different from bellies of pigs fed 0% DDGS. Thus, swine producers can feed pelleted diets, without or with 30% DDGS, without negatively affecting commercial bacon slicing yield.

Association between leptin gene single nucleotide polymorphisms and carcass traits in pigs

It was investigated the association between leptin gene single nucleotide polymorphisms (SNPs) T2411C and T3266G with carcass traits in F2 pigs obtained by crossing native Brazilian Piau with commercial sows composed of Landrace, Large White and Pietrain breeds. Association analyses were performed using a statistical model that included genotype, sex, and batch as fixed effects, sire and error as random effects. The T2411C SNP was associated with skinless and fatless boston shoulder weight (BSW), backfat thickness at last rib, 6.5 cm from the midline (P2), skinless and fatless picnic shoulder weight, and sirloin weight (SLW). The T3266G mutation was associated with slaughter age, bacon weight, BSW, midline backfat thickness between last and last but one lumbar vertebra, midline backfat thickness at last rib, P2 and rib weight. Phenotypic associations were also performed by combining genotypes for both SNPs. Associations with P2, carcass yield, total boston shoulder weight, and SLW were observed. The results obtained demonstrate that the SNPs analyzed have potential to be explored as markers for carcass composition in pigs.

Mapeamento de locos de características quantitativas associados à composição de carcaça, no cromossomo seis de suíno

Uma população de suínos, composta de 550 animais F2, foi produzida a partir do intercruzamento da geração F1, obtida pelo cruzamento divergente de dois machos da raça nativa brasileira Piau com 18 fêmeas comerciais. O objetivo do trabalho foi mapear locos de características quantitativas (QTL) associados a cortes de carcaça. Os animais foram genotipados para 13 marcadores microssatélites, distribuídos no cromossomo 6 de suínos. As características avaliadas foram: peso total do pernil, peso do pernil sem pele e sem capa de gordura, peso total da copa, peso da copa sem pele e sem capa de gordura, peso total da paleta, peso da paleta sem pele e sem capa de gordura, peso total do carré, peso do lombo, peso total do bacon, peso das costelas, peso total da papada, peso do filezinho e peso da banha rama. Utilizou-se o método de regressão por intervalo de mapeamento por meio do programa QTL Express. Foram encontrados indicativos de QTL para peso de pernil limpo, peso de paleta, peso de lombo e peso de filezinho. A região genômica deve ser saturada com marcadores adicionais para confirmar a presença de QTL reais.

QTL mapping for growth and carcass traits in an Iberian by Landrace pig intercross: additive, dominant and epistatic effects.

Results from a QTL experiment on growth and carcass traits in an experimental F2 cross between Iberian and Landrace pigs are reported. Phenotypic data for growth, length of carcass and muscle mass, fat deposition and carcass composition traits from 321 individuals corresponding to 58 families were recorded. Animals were genotyped for 92 markers covering the 18 porcine autosomes (SSC). The results from the genomic scan show genomewide significant QTL in SSC2 (longissimus muscle area and backfat thickness), SSC4 (length of carcass, backfat thickness, loin, shoulder and belly bacon weights) and SSC6 (longissimus muscle area, backfat thickness, loin, shoulder and belly bacon weights). Suggestive QTL were also found on SSC1, SSC5, SSC7, SSC8, SSC9, SSC13, SCC14, SSC16 and SSC17. A bidimensional genomic scan every 10 cM was performed to detect interaction between QTL. The joint action of two suggestive QTL in SSC2 and SSC17 led to a genome-wide significant effect in live weight. The results of the bidimensional genomic scan showed that the genetic architecture was mainly additive or the experimental set-up did not have enough power to detect epistatic interactions.

A repeat national survey of muscle pH values in commercial pig carcasses

Measurements of pH values at 45 min post-slaughter (pH 1) in m. longissimus were taken in a total of 5598 commercial bacon weight carcasses. pH values at 24 h post-slaughter (pH 2) were taken on a further 5598 carcasses. The overall mean pH 1 was 6.39 with 15.1% of values less than 6.0. The overall mean pH 2 was 5.64, none of the values recorded were greater than 6.5. This survey shows a small increase over the 1983 study in the incidence of potentially Pale Soft and Exudative (PSE) carcasses. It found no evidence of a Dark, Firm and Dry (DFD) problem related to high ultimate pH.

Incidence, location and interrelationships between the sites of abscesses recorded in pigs at a bacon factory in Northern Ireland.

The position and incidence of all the abscesses detected during post mortem inspection of 75,130 bacon weight pigs were recorded. Abscesses were detected at one site only in 2.87 per cent of the carcases examined, and at more than one site in 0.26 per cent of the carcases. Tail biting was the cause of the infection in 61.7 per cent of all the carcases with lesions at more than one site. In almost all cases there was a statistically significant interrelationship between the visible abscesses at different sites.

Pig slaughtering procedures: Head-to-back stunning

High voltage head-to-back electrical stunning can induce vertebral compression fractures, blood splash and poor meat quality in pigs. This experiment was designed to determine the optimum position of the rear electrode which would not only stun and kill pork and bacon weight pigs with a 1·3 A 50 Hz sinewave but would also produce a good carcass with desirable meat quality. Although there was a trend for less breaks to occur the further forward the rear electrode was positioned, there was no position which gave 100% cardiac fibrillation and an absence of breaks. The incidence of blood splash, muscle haemorrhages and the variations in meat colour were not related to electrode position and fell in the ‘normal’ range quoted by other workers. The severity and incidence of kicking after stunning was reduced the more caudal the electrode position. This was in direct contrast to the effect on compression fractures where a reduction was seen with the more rostral applications.

The effect of water-spraying bacon weight pigs in lairage on behaviour and carcase quality

Handling pigs with care before slaughter is beneficial for both animal welfare and meat quality. Water showering pigs in lalrage prior to slaughter is considered to calm pigs, improve meat quality and reduce slaughter line contamination (Logtestijn, Corstiaensen and Kruijf, 1977; Smulders, Romme, Kruijf, Eikelenboom and Corstiaensen, 1982). The objective of this experiment was to investigate whether water-spraying pigs, in the lairage of a commercial abattoir, reduced the amount of fighting and if it improved meat quality.

Nitrogen factors for pork: a reassessment

The nitrogen factor (the percentage of fat-free nitrogen in a sample) for pork was estimated from a sample of 60 carcases from four commercial abattoirs. The sample included carcases defined as pork weight (52 +/- 2 kg), bacon weight (72 +/- 4 kg) and heavy weight pigs (92 +/- 8 kg). The nitrogen factor for the lean with intermuscular fat in the whole side was 3.50 (estimated for the national average pig used for processing). Comparable figures for joints were 3.49 (leg), 3.38 [neck (collar)], 3.42 (hand), 3.66 (loin) and 3.50 (belly). These factors are similar to those published by the Analytical Methods Committee in 1986 but are based on a larger sample more representative of the current pig population in Britain. It is recommended that they now become the basis for the standard factors. As factors change significantly with the mass of carcase and fatness, it will be appropriate to revise the estimates as the average national pig population changes. Fat, moisture, ash, hydroxyproline and nitrogen contents in each joint and the side are also reported in this paper.

The influence of dietary linoleic acid on backfat firmness in bacon weight pigs

There is a growing concern in the UK meat industry over carcasses containing soft fat, which prove difficult to cut and process. This may be caused by the feeding of high levels of unsaturated fatty acids resulting in high levels in carcass fat, and hence soft fat. This trial examined the critical levels of linoleic acid affecting fat firmness.

Aujeszky's disease outbreak

Abstract Extract Madam: — In June 1986, I was called to a piggery in the West Auckland area. The piggery consists of a breeding and fattening unit. Piglets from two hundred sows are taken through to pork and bacon weight. All pigs are meal fed. The dry sows and farrowing unit are separated within the same building. The weaners and fatteners are in two separate buildings in close proximity. Boars and gilts are brought in from more than one source.

Effects of diet density and environmental temperature on performance and carcass quality of pigs fed ad libitum to bacon weight

Ad libitum feeding from hoppers offers a simple system for feeding growing pigs and maximises liveweight gain. High feed intake in the later stages of production often results in excessive backfat deposition, making it difficult to achieve optimum carcass gradings with pigs kept to bacon weight. Both nutrient density of the diet and ambient temperature may influence voluntary feed intake. This experiment investigated the extent to which these factors could be used under commercial conditions to manipulate growth rate and fat deposition of pigs on an ad libitum feeding system.

16-androstene steroids in the submaxillary salivary gland of the boar in relation to measures of boar taint in carcasses

ABSTRACTFifteen Large White boars were randomly allocated to three groups of five pigs. The boars were slaughtered over a period of time at one of three live weights: group 1 (pork weight), 63 to 68 kg (mean age 141 days), group 2 (bacon weight), 90 to 97 kg (mean age 203 days) and group 3 (heavy weight), 121 to 133 kg (mean age 268 days). Testes, bulbourethral glands, submaxillary salivary glands, blood and thoracic fat were taken from each pig and the glands weighed and steroids determined in extracts of the submaxillary glands, blood plasma and fat. Testosterone and the boar taint steroid, 5a-androstenone (5a-androst-16-en-3-one) were measured in plasma by radioimmunoassay (RIA). 3a-androstenol (5a-androst-16-en-3a-ol) and 5a-androstenone were determined separately in submaxillary glands by gas-liquid chromatography and together semi-quantitatively by a colour reaction. 5a-androstenone was also determined in submaxillary glands by RIA and in fat by enzyme-linked immunosorbent assay. Mean somatic characteristics differed significantly between the groups, but due to the wide variation in steroid concentrations between individual boars, mean differences for steroid concentrations between groups were not significant.Significant positive correlations were found in boars between bulbourethral gland weight, submaxillary gland weight, concentrations of 3a-androstenol and 5a-androstenone in the submaxillary gland and concentrations of free plasma 5a-androstenone and fat 5a-androstenone (P &lt; 0·05). The application of a simple colour reaction to detect readily extractable 16-androstene steroids (16-androstenes) in submaxillary gland tissue is discussed in relation to other methods for determining boar taint.

Backfat quality in boars and barrows at 90 kg live weight

ABSTRACTForty male commercial hybrid pigs, half castrated at 10 days of age, were used in a study to determine whether boars at bacon weight (90 kg live weight) have different fat quality from barrows. Fat quality was defined as the firmness and cohesiveness of subcutaneous fat, both properties being measured using an Instron materials testing instrument. Within each group of boars and barrows, half the pigs were fed a normal commercial diet and half a lower energy diet at a lower level of food intake. The latter diet provided relatively more energy as C18:2 (linoleic acid).Firmness of subcutaneous fat was related to fat thickness and to concentrations of the chemical components in the fat which are affected by fat thickness. The single best predictor of firmness was C18:0 (stearic acid). Cohesiveness was less closely related to fat thickness and was most associated with the concentration of C18:2.On the low energy/high C18:2 diet, all the pigs were judged to have soft fat, the difference between boars and barrows being small and explained by the difference in fat thickness. On the normal commercial diet, some barrows had particularly firm fat but they had thicker fat than any of the boars. Most (0·84) of the pigs in the experiment had P2 values (fat thickness over the m. longissimus at the last rib) between 8 and 15 mm. In this range there was no difference in firmness between boars and barrows. Cohesiveness was also similar between boars and barrows.

Immunization against 5α-androstenone in boars

The effects of specific immunization against 5α-androstenone have been examined in large, genetically homologous groups of boars reared either to bacon weight (90–95 kg live weight) or to heavy manufacturing weight (115–120 kg live weight). At the lighter weight, immunization significantly ( P < 0.05) reduced the concentration of androstenone in the adipose tissue from a mean value of 1.77 (S.E. 0.2) μg g −1 fat in untreated boars ( n=39) to 1.10 (S.E. 0.18) μg g −1 for animals ( n=19) treated with 5α-androstene-3-BSA. In contrast, boars ( n=20) treated with 5α-androstenone-11-BSA as immunogen accumulated androstenone to a level of 1.99 μg g −1 fat (S.E. 0.38). At the heavier weight, immunization reduced the accumulation of androstenone in adipose tissue from a mean value of 1.81 μg g −1 fat (S.E. 0.22) in untreated boars ( n=76) to 1.17 μg g −1 (S.E. 0.19) for animals ( n=22) treated with androstene-3-BSA as immunogen. In contrast, boars ( n=21) treated with androstenone-11-BSA as immunogen accumulated androstenone to a mean level of 1.74 μg g −1 fat (S.E. 0.46). No detrimental side-effects were observed in the immunized animals and the advantages of male-type performance and carcass composition were fully preserved.

Prediction of the weight of lean and fat yield in bacon weight carcasses. A comparison of predictors used in commercial pig carcass classification

Alternative methods of pig carcass description were compared as predictors of the weight (kg) of commercial lean yield and fat yield in 209 bacon weight carcasses. The predictors used included hot carcass weight and carcass sex in association with: the backfat measurements used in the Danish grading scheme (minimum loin, 3rd–4th lumbar and 3rd–4th last rib fat thickness); the proposed Australian system (P 2 fat thickness); fat classes published by the South Australian Livestock Marketing Study Group (1980); mid-line carcass measurements (backfat at minimum loin, mid back, maximum shoulder as well as carcass length) and visual carcass grade. There was no difference in precision between the carcass classification systems as predictors of lean yield. ( R 2 = 69·0 % and residual standard deviation = 1·5.) Precision varied between the predictors of fat yield. The predictors were ranked as follows with R 2(%) and residual standard deviation in parentheses. Danish (80·0, 0·50); Australian (70·5, 0·60); fat class (67·8, 0·64); mid-line (64·9, 0·67) and grade (58·1, 0·72).

A repeat national survey (ten years on) of muscle pH values in commercial bacon carcasses

Measurements of M. longissimus pH values at 45 min post mortem (pH 1) were taken in a total of 5383 commercial bacon weight carcasses at fourteen bacon factories and meat plants in 1980/81. Comparable pH 2 values at 24 h post mortem were taken in a further 5150 carcasses. The overall mean pH 1 was 6·38 ± 0·29 (SD) with 12·8% of values less than 6·0. The overall mean pH 2 was 5·91 ± 0·18 with 0·6% of values greater than 6·5. Relationships between pH values and carcass weight, fat thickness and length were very low (maximum r = 0·05). Comparison of the results with a similar survey conducted in 1972/73 indicated that the proportion of carcasses with pH 1 values less than 6·0 has doubled (1972/73 result was 5·7%). The proportion of carcasses with high pH 2 values changed little.

Effects of index selection at bacon weight on early growth rate and body composition in Large White pigs

ABSTRACTConsistent age differences at around 27 kg live weight have been found between control (C) and selection (S) line boars of the Large White breed in a coordinated breed improvement programme (89·8 v. 94·6 days, P&lt;001). After 10 generations of index selection on feeding ad libitum, a sample of 20 boars from the programme, 10 C and 10 S, were slaughtered at 27·6 (s.e. 0·48) kg live weight for a more comprehensive examination of this finding. Physical dissection of the carcass and whole body chemical analysis were carried out. Differences between C and S boars were apparent even at this light weight: S boars were older than C (92·7 v. 83·5 days, P&lt;0·01), contained less dissected fat (2·93 v. 3·58kg, P&lt;005) and chemical lipid (315 v. 3·59kg, P&lt;0·05), and had a higher lean proportion (0·477 v. 0·458, P&lt;0·01). There was no significant difference between lines in weight of dissected lean or whole body protein. Index selection has clearly affected early growth and body composition, which questions current assumptions underlying pig testing methods.

Inheritance of Escherichia coli K88 adhesion in pigs: identification of nonadhesive phenotypes in a commercial herd

A method for preparing fragments of brush border from the small intestinal epithelial cells of pigs was modified so that specimens as small as 3 mm X 3 mm could be used. This modification also allowed more rapid preparation and the brush borders thus prepared adhered specifically to K88+ but not K88- Escherichia coli. At slaughter 12.2 per cent of 459 bacon weight pigs from a commercial herd were of nonadherent phenotype. Litters containing only nonadherent pigs were identified. Parents of these litters and siblings intended for breeding stock replacements could be identified as probably also being of nonadherent phenotype and this was confirmed by examining biopsy samples obtained by enterotomy from the siblings.

A note on the housing of intact male and female pigs together in the same pen during the growing period to bacon weight

ABSTRACTA feeding trial was carried out, using 180 pigs, to assess the effect on performance when intact male and female pigs were housed together in the same pens from 20 to 90 kg live weight. There were no significant differences in daily feed intake, rate of growth or feed: gain ratio between pigs from mixed-sex pens and pigs from single-sex pens. Carcass measurements indicated slightly leaner carcasses for intact male pigs whether housed in separate pens or together with female pigs, while female pigs likewise had a significantly higher dressing percentage.