PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Meat quality”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

Changes in the histochemical properties and meat quality traits of porcine muscles during the growing-finishing period as affected by feed restriction, slaughter age, or slaughter weight.

In this study, the degree of contractile and metabolic development of myofibers in porcine LM, rectus femoris (RF), and dark and light portions of the semitendinosus (STD and STL, respectively) was determined, and their impact on meat quality was compared at the same age but different BW (trial 1) or at a given BW but different age (trial 2) in 48 Swiss Large White barrows from 12 litters after the growing and finishing period. The barrows had ad libitum (A) or restricted (R, 80% of A) feed access. In trial 1, at 113 and 154 d of age, 6 barrows in treatment A (62.1 and 99.5 kg of BW, respectively) and 6 siblings in treatment R (51.0 and 86.6 kg of BW, respectively) were slaughtered. In trial 2, a similar protocol was used except that the barrows were slaughtered at 61.3 (104 or 119 d of age, respectively) or 101.3 kg of BW (145 or 167 d of age, respectively). Muscle fibers were stained and classified as slow oxidative (SO), fast oxidative-glycolytic (FOG), or fast glycolytic (FG), and fiber area and distribution were determined. At 113 and 154 d of age, R barrows had smaller (P < or = 0.04) SO fibers in the LM, STD, and STL, smaller (P < 0.01) FOG fibers in the STL, smaller (P = 0.03) FG fibers in the LM, and smaller (P < or = 0.04) overall mean area in the LM, STD, and STL. In the STL and RF, R barrows had fewer (P < or = 0.06) FG and more (P < or = 0.08) FOG fibers than A barrows at 113 and 154 d of age. Except for smaller FOG fibers in the STD of R compared with A barrows slaughtered at the same BW, the myofiber size did not differ (P > or = 0.11). However, the LM tended to have fewer (P = 0.06) SO and more (P < 0.01) FG fibers, and the STD had more (P < 0.01) FOG fibers in R barrows. Regardless of whether R barrows were slaughtered at the same age or the same BW as the A barrows, shear force values and cooking losses were greater (P < or = 0.08) in the STD and STL of R barrows. These findings revealed that myofiber hypertrophy was impaired by feed restriction in barrows compared at the same age, but differences in myofiber size vanished at the same BW. By contrast, restricted nutrient supply affected myofiber maturation depending on the age and BW, but the impact differed between muscles. The absence of changes in myofiber type distribution among the younger-lighter and older-heavier barrows indicated that myofiber maturation was already completed in the younger-lighter barrows. Although changes in meat quality traits were affected by the feeding regimen, they were not related to myofiber characteristics.

Abattoirs↗

Influence of steam-peeled potato-processing waste inclusion level in beef finishing diets: effects on digestion, feedlot performance, and meat quality.

Inclusion of potato-processing waste (PW) from the frozen potato products industry in high-grain beef cattle finishing diets was evaluated in two studies. In a randomized complete block design, 125 crossbred yearling heifers (365 +/- 0.3 kg initial BW; five pens per treatment; five heifers per pen) were used to evaluate PW level on feedlot performance and meat quality. Heifers were fed for 85 (two blocks) or 104 d (three blocks). In a digestion study, four ruminally, duodenally, and ileally cannulated Holstein steers (474.7 +/- 26.6 kg initial BW) were used in a 4 x 4 Latin square design to evaluate effects of PW level on ruminal fermentation, site of digestion, and microbial protein synthesis. The control diet for both studies contained 80% corn, 10% alfalfa hay, 5% concentrated separator by-product (CSB), and 5% supplement (DM basis). Potato waste replaced corn and separator by-product (DM basis) in the diet at 0, 10, 20, 30, and 40% in the feedlot study, and at 0, 13, 27, and 40% in the digestion study. In the feedlot study, DMI decreased (linear; P = 0.007) with increasing inclusion of PW. Increasing PW decreased ADG and feed efficiency from 0 to 30% and then increased at 40% (quadratic; P < 0.01). Calculated dietary NEg concentrations did not differ among treatments (P = 0.18). Hot carcass weight decreased as PW increased from 0 to 30% and then increased at 40% PW (cubic; P < 0.01). Fat thickness and longissimus muscle area decreased with increasing PW (linear; P < 0.05). Level of PW did not affect marbling or liver scores (P > 0.30). No difference (P > 0.20) was observed for Warner-Bratzler shear force at 0, 10, 20, and 30% PW levels; however, 40% PW resulted in lower (P = 0.05) shear force values. Taste panel scores for juiciness and flavor intensity did not differ with increasing PW (P > 0.30). Steaks from cattle fed 0% were scored less tender than 10 and 40% PW (cubic; P < 0.05). In the digestion study, DMI decreased (quadratic; P < 0.01) with increasing PW. Ruminal pH and total VFA concentration increased (linear; P < 0.05) and true N disappearance from the stomach complex and apparent total-tract N disappearance decreased with increasing level of PW (linear; P < 0.01). Starch intake and ruminal disappearance decreased with increasing level of PW (quadratic; P < 0.05). Inclusion of PW decreased feedlot performance, with little effect on carcass characteristics or meat quality. Optimal inclusion of PW in finishing diets may depend on the cost of transportation and other dietary ingredients.

Animal Feed↗

Variable abattoir conditions affect Salmonella enterica prevalence and meat quality in swine and pork.

Research suggests that abattoir holding pens pose significant Salmonella enterica risk to swine immediately preharvest. The goal of this study was to evaluate those factors related to holding that increased the prevalence of S. enterica in swine at slaughter. To accomplish this goal, we focused on holding time and flooring. Our objectives were to (1) compare Salmonella enterica prevalence among pigs held for short (15-45 min) versus long (up to 4 h) periods before slaughter; and (2) determine the impact of flooring (slatted vs. concrete) as it relates to the prevalence of S. enterica. The study consisted of seven repetitions at a large volume (11,000 head/day) Midwest abattoir. Each repetition consisted of one truck load of pigs (n = 170) sorted into one of three groups: (1) animals held for a short time (15-45 min) on solid floors (short-hold); (2) animals held for 4 +/- 0.5 h on slatted floors; and (3) animals held for 4 +/- 0.5 h on solid concrete floors. At slaughter, samples were collected from 30 pigs in each group. Cecal contents (20 mL), feces (20 g), and the ileocecal lymph node were cultured for S. enterica. Additionally, the effect of holding time on meat quality parameters (loin pH at 35 min and 6 h, color, drip loss) was evaluated for the first four replicates. The proportion of S. enterica-positive samples was highest (p < 0.05) in the cecum of pigs held on solid concrete floors (72.4%), and slightly less for pigs held on slatted floors (63.3%). Animals held for less than 45 min before slaughter demonstrated the lowest proportion of S. enterica-positive samples (52.9%). The pig prevalence, as measured by any one of the three samples being positive, was significantly different (p < 0.05) between animals held on solid floors (81%) and those animals held for 45 min or less before slaughter (69%). Meat quality, as measured by multiple parameters, was adversely affected by lack of a rest period. The mean 24-h pH was significantly lower for the short-hold group compared to the other two groups. The mean Minolta L and the drip loss were significantly higher in the short-hold group. From this and other studies, it appears that elimination of the holding process is not feasible S. enterica control option, given current U.S. harvesting systems.

Abattoirs↗

Estimated frequency of the RN- allele in Swedish Hampshire pigs and comparison of glycolytic potential, carcass composition, and technological meat quality among Swedish Hampshire, Landrace, and Yorkshire pigs.

The frequency of the dominant RN- allele (Rendement Napole) was estimated in purebred Swedish Hampshire pigs (n = 208) by using the estimated glycogen content in the longissimus muscle at slaughter (glycolytic potential; GP). Carriers (n = 177) and noncarriers (n = 31) of the RN- allele were compared with purebred Swedish Yorkshire (Y, n = 208) and Swedish Landrace (L, n = 114) pigs with respect to GP and carcass composition. Technological meat quality was compared between the RN phenotypes from the Hampshire breed and Yorkshire pigs. The distribution of GP deviated from a normal distribution in all three breeds. Hampshire pigs with GP > or = 183 micromol lactate equivalents per gram wet weight were regarded as carriers of the RN- allele (RN-/RN-, or RN-/rn+), and those constituted 85% of all Hampshire pigs evaluated, giving a frequency of .61 for the dominant allele (RN-). The RN- carriers had higher GP than noncarriers, Landrace, and Yorkshire pigs, but noncarriers and Landrace did not differ regarding GP. The two RN phenotypes did not differ in carcass composition, but the carriers were leaner than Landrace and Yorkshire, with larger proportions of meat plus bone in ham and back. Noncarriers and Yorkshire did not differ in leanness, but both these groups were leaner than Landrace. The RN- carriers had lower Napole yield (cured cooked muscle) and higher drip loss than noncarriers and Yorkshire, but in comparison with noncarriers they also had lower shear force values. In conclusion, the frequency of the RN- allele is high in purebred Swedish Hampshire. Most of the effects of the allele on technological meat quality (i.e., ultimate pH, water-holding capacity, and technological yield) found in crossbred pigs seem also to be consistent for purebred pigs. However, the RN- allele exerted less influence on meat content in purebred pigs.

Alleles↗

Investigation of two candidate genes for meat quality traits in a quantitative trait locus region on SSC6: the porcine short heterodimer partner and heart fatty acid binding protein genes.

A highly significant quantitative trait locus (QTL) on pig chromosome 6, affecting intramuscular fat (IMF), has previously been detected by our group and others. Two genes of positional and biological interest, the small heterodimer partner (SHP; NR0B2) and the heart fatty acid binding protein (FABP3; H-FABP), were investigated for meat quality traits and IMF respectively. SHP was partially sequenced (GenBank: DQ002896 and DQ002897) and mapped to the QTL region on porcine chromosome 6, affecting IMF. The map shows no recombination between SHP and FABP3, which was previously mapped to the same QTL region. Twelve single nucleotide polymorphisms were detected in the sequenced region of SHP gene. Haplotype information was used to investigate association between genetic variation and different meat quality traits. SHP haplotype combinations were found to have significant effect on connective tissue. However, further studies are needed to evaluate this possible association more effectively. The FABP3 is involved in fatty acid transport and has been studied as a candidate gene for IMF by several research groups. In our study, FABP3 genotypes were confirmed to be significantly associated with IMF in pigs. The average content of IMF in our population was 1.6%, which may indicate that the FABP3 polymorphism explains as much as 30-35% of the variation in IMF in our pig cross-population.

Animals↗

Growth performance, meat quality and activities of glycolytic enzymes in the blood and muscle tissue of calves infected with Sarcocystis cruzi.

Growth performance and the pattern of glycolytic enzymes in the blood plasma were assessed during experimental Sarcocystis cruzi infection (1 x 10(5) sporocysts per calf) in six calves; five calves served as noninfected controls. At slaughter (68 or 88 days post infection), carcass weight, dressing percentages and several parameters of meat quality (pH, color brightness, rigor, water absorbing capacity, water binding capacity) were recorded. Moreover, enzyme activities were measured in muscle homogenates. Weight gain was significantly impaired by the infection. Activities of lactate dehydrogenase (LDH) and aldolase (ALD) significantly increased in the blood plasma of the infected calves during the chronic stage of the disease, while glucose-6-phosphate dehydrogenase (G6PDH) and isocitrate dehydrogenase (ICDH) were not significantly altered. This was accompanied by a significant decrease of enzyme activities in the Musculus longissimus dorsi (LDH, ALD), in the diaphragmatic musculature (ALD, G6PDH) and in the heart (LDH, ALD). Activities of LDH, ALD, ICDH and G6PDH were visualized by enzyme histochemistry within the developing sarcosporidial cysts. However, isoenzymes of parasite origin could not be demonstrated by agar-gel electrophoresis of muscle homogenates or blood plasma. It is concluded that sarcocystiosis of even moderate severity alters the performance of calves but not meat quality. Leakage of glycolytic enzymes from the affected muscles is the probable cause of increased plasma enzyme activities. Although these enzymes are also synthesized by the parasite, the contribution of parasite-derived enzymes to the observed changes of enzyme patterns remains in question.

Animals↗

Modification of glycolyzing enzymes lowers meat quality of turkey.

This paper presents the results of a study on meat quality and protein alterations of fast glycolyzing (FG) and normal glycolyzing (NG) turkey breast muscles. In a commercial processing plant, 34 breast muscles were sampled at 20 min postmortem from a large flock: 17 samples showing the lowest pH(20min) (6.04 +/- 0.09; FG) and 17 showing average pH(20min) (6.47 +/- 0.01; NG). Over a 9-d storage period at 4 degrees C, L* values did not differ between the 2 groups. The FG group showed higher drip, thawing, and cook loss values, and lower processing yield than the NG group. Warner-Bratzler shear force values of cooked meat were higher in the FG group than in the NG group. The FG meat presented a lower protein extractability with low ionic strength buffer than the NG meat. No differences in SDS-PAGE banding patterns were detectable for the different protein extracts between the 2 groups. On the contrary, when SDS-PAGE gels were performed on basic proteins, they showed differences in banding intensity for 2 proteins: glyceraldehyde-3-phosphate dehydrogenase and aldolase A.

Animals↗

Influence of a conjugated linoleic acid mixture on growth, organ weights, carcass traits and meat quality in growing pigs.

Grain soybean meal diets, either with 2% of a conjugated linoleic acid (CLA) preparation or with 2% rapeseed oil (control), were tested in 2 x 40 pigs, Pietrain x (Landrace x Large White), each group with 20 female in the live weight range 23.5-117.0 kg and 20 male-castrated pigs in the live weight range 23.5-110.6 kg. The CLA-content of the preparation amounted to 54.0% cis/trans + trans/cis, 8.7% cis/cis and 32.7% trans/trans isomers. Daily weight gain, feed intake and feed : gain ratio were not influenced by the diets tested. The carcass lean increased significantly from 57.2% of the control group to 58.7% in the CLA group (p < 0.05). The male-castrated showed a stronger CLA effect than the female pigs - not only was the carcass lean significantly increased by 2%, but backfat thickness was significantly decreased by 2.8 mm, i.e. minus 11% (as compared with barrows of the control). The meat of CLA-fed pigs had a higher conductivity. A CLA effect on further meat quality characteristics (pH 45 min post-mortem, impedance, colour criteria, intramuscular fat, drip loss, frying loss, shear force, sensory attributes) could not be detected. There were some significant correlations between the meat quality attributes.

Adipose Tissue↗

Effects of dietary soy isoflavones on growth, carcass traits, and meat quality in growing-finishing pigs.

Two experiments were conducted to determine the effect of soy isoflavones on growth, meat quality, and carcass traits of growing-finishing pigs. In Exp. 1, 36 barrows (initial and final BW, 26 and 113 kg, respectively) were used and each treatment was replicated four times with three pigs each. The dietary treatments were 1) corn-soybean meal (C-SBM), 2) corn-soy protein concentrate (low isoflavones, C-SPC), or 3) C-SPC + isoflavones (isoflavone levels equal to those in C-SBM). Daily gain and ADFI were increased (P < 0.10) in pigs fed the C-SPC relative to pigs fed the C-SPC + isoflavone diet in the late finishing period; otherwise, growth performance was not affected (P > 0.10) by diet. Longissimus muscle area, 10th-rib fat depth, percentage muscling (National Pork Producers Council), 24-h pH and temperature, color, firmness-wetness, marbling, drip loss, and CIE L*, a*, and b* color values were not affected (P > 0.10) by diet. Dressing percentage, carcass length, weight and percentage of fat-free lean in ham and carcass, lean gain per day, lean:fat, and ham weight were increased (P < 0.10), and ham fat and percentage fat in ham and carcass were decreased (P < 0.10) in pigs fed the C-SPC + isoflavone diet compared with pigs fed the C-SPC diet. Pigs fed the C-SPC + isoflavone diet had similar (P > 0.10) carcass traits as pigs fed the C-SBM diet, except carcass length, percentage ham lean and thaw loss were greater (P < 0.10), and total ham fat was less (P < 0.10) in pigs fed the C-SPC + isoflavone diet. In Exp. 2, 60 gilts (initial and final BW, 31 and 116 kg, respectively) were used, and each treatment was replicated five times with four pigs per replicate. The treatments were 1) C-SBM, 2) C-SBM + isoflavone levels two times those in C-SBM, and 3) C-SBM + isoflavone levels five times those in C-SBM. Daily feed intake was linearly decreased (P < 0.10) in the growing phase and increased (P < 0.10) in the late finishing phases as isoflavone levels increased; otherwise, growth performance was not affected (P > 0.10) by diet. Diet did not affect (P > 0.10) carcass traits; however, CIE a* and b* color scores and drip loss were decreased (P < 0.06) as isoflavone levels increased. Soy isoflavones decreased fat and increased lean in barrows when fed within the dietary concentrations found in typical C-SBM diets but not when fed to gilts at concentrations above those present in C-SBM diets.

Animals↗

Ascorbic acid, alpha-tocopherol, and oregano supplements reduce stress-induced deterioration of chicken meat quality.

In order to ameliorate a negative effect of stress on meat quality characteristics, chickens were fed a diet supplemented with a combination of ascorbic acid (1,000 ppm) and alpha-tocopherol (200 ppm) or oregano (3%), which has a high content of antioxidants. Chickens were slaughtered by cervical dislocation in the stable (no stress) or after transport and electrical stunning at the slaughter plant (stress). Activities of antioxidative enzymes (catalase, superoxide dismutase, and glutathion peroxidase) in pectoralis major (PM), iliotibialis (IL), and liver were unaffected by supplementation. However, erythrocyte stability, which is a more complex model system for determining oxidative status, increased with ascorbic acid-alpha-tocopherol supplementation and tended to increase after oregano supplementation. In nonstressed birds, this improved antioxidative status was reflected in decreased TBA-reactive substances (TBARS) in PM and liver of ascorbic acid-alpha-tocopherol-supplemented chickens and likewise in liver from oregano-supplemented chickens compared to that of nonstressed control birds. However, postmortem temperature, pH, and water-holding capacity were not affected by supplementation. Drip loss from oregano-supplemented chickens showed increased protein oxidation in specific bands, but this did not relate to water-holding capacity or antioxidative status. When exposed to stress, the concentration of TBARS in the control animals increased in PM and IL. Ascorbic acid-alpha-tocopherol supplementation protected IL, and oregano supplementation protected PM from stress-induced increases in TBARS. This differential effect between muscles may indicate differences in protection mechanisms. In conclusion, ascorbic acid-alpha-tocopherol and oregano supplements to chickens protect against stress-induced increase in TBARS, in different muscles.

Animal Feed↗

Citrus pulp and wheat straw silage as an ingredient in lamb diets: effects on growth and carcass and meat quality.

Twenty "Merinizzata Italiana" lambs were introduced to two experimental diets. Ten animals (five males and five females, control group) received the traditional diet that is supplied by farmers in southern Italy, which comprised of oat hay ad libitum and commercial concentrate. The second group (the same number of lambs, silage group) received citrus pulp and wheat straw silage ad libitum and 70% of the commercial concentrate supplied to the control group. The animals were slaughtered after 80 days of feeding and carcass and some meat quality parameters were measured. No differences were observed for live weight between treatments, and carcass weights were similar for the two diets, but with obvious differences between sexes. Animals on silage produced carcasses with a better muscular conformation and with a lower fatness score (P<0.05). Subcutaneous fat colour was influenced by sex, being lighter in the female carcasses (P<0.05). Dissection of different anatomical parts showed a higher percentage of lean and a lower proportion of fat in silage samples compared to control ones. Ultimate pH was highly affected by sex being higher in the samples from male lambs (P<0.01), but was unaffected by diet treatment. Diet tended to affect meat shear force value which was lower in the silage samples, although, samples from all the animals were extremely tender. Meat from silage samples had a higher water content (P<0.05). Overall, in our experimental conditions, the use of citrus pulp silage seemed to be economically convenient for producing animals with substantially unmodified carcass and meat quality characteristics.

Journal Article↗

Evidence for new alleles in the protein kinase adenosine monophosphate-activated gamma(3)-subunit gene associated with low glycogen content in pig skeletal muscle and improved meat quality.

Several quantitative trait loci (QTL) affecting muscle glycogen content and related traits were mapped to pig chromosome 15 using a three-generation intercross between Berkshire x Yorkshire pigs. On the basis of the QTL location the PRKAG3 (protein kinase, AMP-activated, gamma(3)-subunit) gene was considered to be a good candidate for the observed effects. Differences in the PRKAG3 gene sequences of the founder animals of the intercross were analyzed. The RN(-) mutation previously reported was not present in the cross but three missense substitutions and a polymorphic short interspersed element (SINE) were identified. To confirm the hypothesis that at least one of these mutations was associated with differences in meat quality, >1800 animals from several unrelated commercial lines were genotyped for the candidate substitutions and an association study was performed. The results demonstrate the presence of new economically important alleles of the PRKAG3 gene affecting the glycogen content in the muscle and the resulting meat quality. Haplotype analysis was shown to resolve the effects of PRKAG3 more clearly than analysis of individual polymorphisms. Because of their prevalence in the more common commercial breeds, the potential implications for the pig industry and consumers are considerably greater than the original discovery of the RN(-) mutation. Furthermore, these results illustrate that additional alleles of genes involved in major mutations may play a significant role in quantitative trait variation.

Alleles↗

Genetic associations of prolificacy with performance, carcass, meat quality, and leg conformation traits in the Finnish Landrace and Large White pig populations.

The objective of this study was to estimate genetic associations of prolificacy traits with other traits under selection in the Finnish Landrace and Large White populations. The prolificacy traits evaluated were total number of piglets born, number of stillborn piglets, piglet mortality during suckling, age at first farrowing, and first farrowing interval. Genetic correlations were estimated with two performance traits (ADG and feed:gain ratio), with two carcass traits (lean percent and fat percent), with four meat quality traits (pH and L* values in longissimus dorsi and semimembranosus muscles), and with two leg conformation traits (overall leg action and buck-kneed forelegs). The data contained prolificacy information on 12,525 and 10,511 sows in the Finnish litter recording scheme and station testing records on 10,372 and 9,838 pigs in Landrace and Large White breeds, respectively. The genetic correlations were estimated by the restricted maximum likelihood method. The most substantial correlations were found between age at first farrowing and lean percent (0.19 in Landrace and 0.27 in Large White), and fat percent (-0.26 in Landrace and -0.18 in Large White), and between number of stillborn piglets and ADG (-0.38 in Landrace and -0.25 in Large White) and feed:gain (0.27 in Landrace and 0.12 in Large White). The correlations are indicative of the benefits of superior growth for piglets already at birth. Similarly, the correlations indicate that age at first farrowing is increasing owing to selection for carcass lean content. There was also clear favorable correlation between performance traits and piglet mortality from birth to weaning in Large White (r(g) was -0.43 between piglet mortality and ADG, and 0.42 between piglet mortality and feed:gain), but not in Landrace (corresponding correlations were 0.26 and -0.22). There was a general tendency that prolificacy traits were favorably correlated with performance traits, and unfavorably with carcass lean and fat percents, whereas there were no clear associations between prolificacy and meat quality or leg conformation. In conclusion, accuracy of estimated breeding values may be improved by accounting for genetic associations between prolificacy, carcass, and performance traits in a multitrait analysis.

Adipose Tissue↗

The effect of date fibre supplemented with an exogenous enzyme on the performance and meat quality of broiler chickens.

1. Two experiments were conducted to evaluate the use of date fibre as a partial replacement of maize as a source of energy for growing broiler chicken. In experiment 1, date fibre was given alone to determine apparent metabolisable energy (AME) and apparent ileal digestibility of amino acids and crude fibre. 2. Date fibre had lower AME content (8.7 vs 13.6 MJ/kg) and apparent ileal digestibility coefficients for dry matter (0.35 vs 0.83), crude fibre (0.20 vs 0.54) and amino acids. 3. Based on the results of experiment 1, a growth study was conducted to test the effect of exogenous enzymes on the nutritive value of date fibre (experiment 2). 4. Three date fibre contents (5, 10 and 15%) with and without enzyme supplementation were evaluated. Daily feed intake, body weight gain and feed conversion ratio were measured. At the end of experiment 2, 160 birds were randomly selected and slaughtered to evaluate carcase and meat quality traits as well as measuring ileal viscosity. 5. Substitution of maize by 10 and 15% date fibre significantly depressed AME. Enzyme supplementation did not improve crude fibre digestibility. The inclusion of date fibre in the diets except at 5% decreased average daily gains, feed intake and feed conversion ratio. 6. Addition of date fibre caused a significant increase in the weights of total digestive tract, pancreas and caecum. Addition of date fibre or the exogenous enzyme had no significant effect on carcase or meat quality characteristics. 7. Date fibre increased ileal digesta viscosity compared to the control. Addition of the exogenous enzyme decreased the viscosity of the basal diets but had no effect on the date fibre diets.8. This study indicated that date fibre can be included at levels of 5% in broiler diets without affecting performance.

Animal Feed↗

Broiler survivors of intravenous micro-particle injections: evaluation of growth, livability, meat quality, and arterial blood gas values during a cyclic heat challenge.

When broilers are exposed to high ambient temperatures, their cardiac output can increase by 20 to 50%. Previously, we developed an intravenous micro-particle injection technique to select broilers having a cardiopulmonary capacity capable of accommodating increases in cardiac output associated with fast growth and cool temperatures. In the present study, male broilers were injected at 18 to 20 d of age with cellulose micro-particles sufficient to trigger >50% mortality by 35 d of age. The survivors of micro-particle injections (cellulose survivors) and saline-injected flock mates (control group) were exposed to a moderate cyclic heat challenge (peak temperature of 35 to 37 degrees C) beginning on d 36 and continuing through d 57. We tested the hypothesis that if the cellulose survivors represent the population cohort having the most robust cardiopulmonary capacity, then during a subsequent heat challenge these survivorspotentially may perform better than their unselected flock mates. Based on data combined from two independent experiments, the cellulose survivors exhibited improved livability and body weight gain when compared with their unselected flock mates during the cyclic heat challenge. Meat quality characteristics did not differ between the groups. In a third experiment, cellulose survivors and saline-injected male broilers were reared at thermoneutral temperatures or were exposed to a cyclic heat challenge beginning on d 36. Arterial blood samples were collected from unanesthetized birds at 47 to 49 d of age and were analyzed for pH, partial pressure of CO2, bicarbonate, partial pressure of O2, and saturation of hemoglobin with O2. The blood gas values for the cellulose survivors and saline-injected broilers did not differ within a temperature regimen, regardless of whether the broilers were chronically acclimated to heat or were exposed to an acute heat challenge at the end of the experiment. The cellulose survivors did not differ in susceptibility to panting-induced respiratory alkalosis or hypoxemia when compared with their saline-injected flock mates. Overall, these observations indicate that selection for a robust cardiopulmonary capacity can confer advantages in growth and livability without affecting meat quality when broilers are exposed to a moderate heat challenge.

Animals↗

Bayesian statistical analyses for presence of single genes affecting meat quality traits in a crossed pig population.

Presence of single genes affecting meat quality traits was investigated in F2 individuals of a cross between Chinese Meishan and Western pig lines using phenotypic measurements on 11 traits. A Bayesian approach was used for inference about a mixed model of inheritance, postulating effects of polygenic background genes, action of a biallelic autosomal single gene and various nongenetic effects. Cooking loss, drip loss, two pH measurements, intramuscular fat, shearforce and back-fat thickness were traits found to be likely influenced by a single gene. In all cases, a recessive allele was found, which likely originates from the Meishan breed and is absent in the Western founder lines. By studying associations between genotypes assigned-to individuals based on phenotypic measurements for various traits, it was concluded that cooking loss, two pH measurements and possibly backfat thickness are influenced by one gene, and that a second gene influences intramuscular fat and possibly shearforce and drip loss. Statistical findings were supported by demonstrating marked differences in variances of families of fathers inferred as carriers and those inferred as noncarriers. It is concluded that further molecular genetic research effort to map single genes affecting these traits based on the same experimental data has a high probability of success.

Animals↗

Prediction of meat quality from biopsy in live pigs with different RYR1 genotypes.

To predict meat quality after slaughter, biopsy samples were taken from musculus longissimus lumborum et thoracis of live pigs at approximately 40 kg and 80 kg of weight. The obtained values from biopsies for pH1 and EC50 (electric conductivity) were compared with measurements after slaughter at a weight of approximately 110 kg. RYR1 genotypes were determined from blood samples using PCR-RFLP. Mating of Nn sows with two nn boars resulted in 72 Nn and 40 nn offspring. Significant differences between the two genotypes were found for pH1 and EC50 values for the three weights. The coefficients of correlation for the Nn genotype of the RYR1 gene between the values after slaughter and both the first and the second biopsy for pH1 and EC50 were very low (r = 0.06, r = 0.14; and r = 0.26, r = 0.26; P ? 0.05). For the nn genotype were r = -0.23, r = -0.15; and r = -0.25, r = -0.11 respectively. The values of pH1 and EC50 were highly correlated (r = -0.52 to -0.84; P < or = 0.001) both within biopsies and after slaughter.

Journal Article↗

Relationship between muscle growth and poultry meat quality.

For a number of years, poultry selection has concentrated on growth velocity in meat lines, producing improvements in growth that have not been without consequence for muscle structure, metabolism, and meat quality. Higher growth rates may induce morphological abnormalities, induce larger fiber diameters and a higher proportion of glycolytic fibers, and a lower proteolytic potential in the muscles. After death, the faster development of rigor mortis increases the likelihood of paler color and reduced water holding capacity and poorer quality of further processed products. Reduced proteolytic potential is likely to increase toughness of poultry meats.

Animals↗