The PPARg2 gene is a key regulator of both proliferation and preadipocyte differentiation in mammals. Herein its ge- notype and allele frequencies were analyzed using PCR-SSCP in eight pig breeds (N = 416). Two kinds of polymorphisms of the PPARg2 gene were detected, including a previously reported shift SNP A177G (Met59Val) in exon 1 and a novel silent mutation G876A in exon 5. The results revealed that European pig breeds carry a higher al- lele A frequency at the A177G locus and a fixed GG genotype at the G876A locus. Allele A at the G876A locus was only found in Jinhua pigs. The association between haplotype (A177G/G876A) and carcass and meatquality traits was analyzed in a Pietrain x Jinhua F2 population (N = 248). The PPARg2 gene was found to be significantly associ- ated with backfat thickness at the shoulder (p < 0.05), 6-7 th
Molecular markers permit the early estimation about a future phenotypic variation, and it is not necessary that the individual reaches the adult age to obtain information on its phenotypic performance. Another advantage concerns the traits whose phenotypic values can only be obtained after slaughtering the animals. The use of the data from molecular markers can provide information on a certain carcass composition or meatquality traits, for example, without having to slaughter the animal.
Malek et al. (2001 a,b) reported several QTL for body composition and meatquality in the distal arm of SSC5 in the Berkshire and Yorkshire population that was used in this study. The analysis of the Berkshire and Yorkshire F2 population showed evidence of associations of PPARA with meatquality traits (average drip loss, loin eye area, cholesterol, hormel loin Hunter and average lactate). Bossé et al. (2003) associated PPARA with reduced adiposity and oxidation of fatty acid that can relate with cholesterol index. Thus, PPARA is an interesting candidate gene for meatquality in swine (Table 3). But many significances can be decreased because a low frequency of the allele 11 (0.17) in the population of study. More studies need be made in others populations.
This study evaluated the effects of intramuscular alpha-tocopherol (vitamin E) supplementation on meatquality characteristics of Santa Inês and Dorper crossbreed lambs. All animals were feed with a high concentrated diet in feedlot. Eight days before slaughter, the animals were distributed into four blocks according to weight gain. At the seventh and fourth days before slaughter, they were intramuscularly treated with 0, 10 or 20 IU of DL-alpha-tocopherol per kg of metabolic body weight. At slaughter they had 138 days of age and 43.6 kg of live weight, in average. Carcasses were stored for 24 hours under refrigeration at 2°C. Longissimus thoracis muscle pH (pH24h) and color (lightness, yellowness and redness) were analyzed and its samples were collected for evaluation of shear force (SF), cooking loss (WLC), fatty acid composition (FA) and thiobarbituric acid reactive substances after one (TBARS1m) and after five months (TBARS5m) of freezing. Linearity deviation effect was observed for lightness (L*; P=0.0042) and yellowness (b*; P=0.0082). Intramuscular administration of 10 or 20 IU of alpha-tocopherol/kg of metabolic weight did not influence the conservation of fatty acid in the carcasses, but benefit L* and b* values.
After the determination of the carcass and yield cuts, breast (pectoralis major) meat samples were removed from carcasses approximately 20 min after slaughter, placed in labeled plastic bags, sealed, chilled in ice bath, and stored at 4 °C for 24 hours, after which they were analyzed for following meatquality traits: pH, color, water-holding capacity, cooking loss and shear force.
According to Savenije et al. (2002), the natural time p erio d f o r ch icken b reast m u scle t o h alt en erg y consumption is 6 h. The muscle can maintain its internal energy balance for up to 2h postmortem through other means than glycolysis. Betw een 4 and 6h postmortem, rigor m ort is set s in, af t er w hich deboning can be perf orm ed w it h no risk of cold shrinking. Energy consumption in the muscle is not limited by the amount o f availab le g lyco g en , b u t rat h er b y p H an d b y availability of Adenosine Tri-Phosphate. Glycogenolysis continues after the glycolysis has stopped. It w as show n that feed w ithdraw al and transport quickly exhausts the main energy supplies of chickens (Savenije et al., 2002). Energy exhaustion compromises the w elfare of t h e an im als, an d m ak es t h em p ro g ressively less capable of coping w it h f urt her st ressors. Cat ching, crating, and transport are stressful stimuli, but it w as f ound t hat energy availabilit y is not com prom ised during the short periods of time. Also, neither feed deprivation nor transport under good conditions for short periods of time significantly affected meatquality.
indicus cross breeds are commonly raised for beef in the tropical areas of Brazil, with the common husbandry practice of growing entire bulls until late castration at approximately 18 to 24 months of age to capture the growth advantages of entire animals, and then slaughter at 30 to 36 months of age (Silva et al., 2003). This practice is also commonly conducted in other Latin American countries where Bos indicus cross breeds are raised provides improved meat and carcass quality. How- ever, late neutering of bulls has several recognized problems. Set-back due to stress associated with late castration procedures has been recog- nized as important (Bretschneider, 2005), which has been further studied in Brazil (Carvalho, Silva, & Hoe, 2011; Silva et al., 2003). An additional complication following surgical castration in tropical regions is the high risk of infestation of the wound with the New World screw- worm ﬂy, Cochliomyia hominivorax, which requires expensive preventa- tive and therapeutic treatment (Muniz et al., 1995). Therefore the recent trend is to revert back to raising entire bulls to increase yield and eliminate productive cost associated with surgical castration com- plications at the expense of carcass and meatquality.
The phenotypic data was obtained from the Pig Breeding Farm of the Department of Animal Science, Universidade Federal de Viçosa (UFV), MG, Brazil. A three-generation resource population was created and managed as described by Band et al., 2005a, Band et al., 2005b. Briefly, two local breed Piau grandsires were crossed with 18 grand dams from a commercial line composed of Large White, Landrace and Pietrain breeds, to produce the F1 generation from which 11 F1 sires and 54 F1 dams were selected. These F1 individuals were crossed to produce the F2 population, of which 345 animals were phenotyped for several meatquality and carcass traits.
measure the meatquality and carcass for a total of 13 slaughters. The broilers were submitted to a minimum of 10 h of feed withdrawal prior to slaughter and were held in transportation crates. The transportation of the broilers to the processing plant occurred during the night and lasted about 6 h and they were allowed to rest about 2 h before slaughtering. The processing plant was semi-industrial. The voltage used for electric shock in the stunning of the broilers was 40 V, at 60 Hz and an average of 45 mA per bird, for 9 s. Processing speed was carried out to allow adequate time to perform all measurements. The bleeding of the broilers lasted 3 min. Prior to feather removal, the broil- ers were immersed in water at 57 ºC for 2 min. After eviscera- tion, the carcasses were chilled at 0-4 ºC within water and ice before stored at 0-2 ºC for 24 h and then deboned. Meatquality data from the sib test flock were all measured in the Pectoralis major muscle and collected as follows.
From May 2005 to March 2006, each flock of approximately 200 broilers at 44d of age was transported to the Experimental Processing Plant (Pirassununga, São Paulo, Brazil), to measure the meatquality and carcass for a total of 13 dates of slaughter. The birds were submitted to a minimum of 10h of feed withdrawal prior to slaughter and were held in transportation crates. The transportation of the broilers to the processing plant occurred during the night and lasted about 6h and they were allowed to rest about 2h before slaughtering. The processing plant was semi- industrial. The voltage used for electric shock in the stunning of the birds was 40V, at 60Hz and an average of 45mA per bird, for 9 seconds. Processing speed was carried out to allow adequate time to perform all measurements. The bleeding of the birds lasted 3 minutes. Prior to feather removal, the birds were immersed in water at 57ºC for 2 minutes. After evisceration, the carcasses were chilled at 0-4ºC within water and ice before stored at 0-2ºC for 24h and then deboned. Meatquality data from the sib test flock were all measured in the Pectoralis major muscle and collected as follows:
The purpose was to evaluate the effects of gender and of different genotypes of chickens on the physicochemical parameters and centesimal composition, related to the quality of meat. The design was completely randomized arranged in 5x2 factorial scheme, five genotypes (Índio Gigante - IG; New Hampshire - NHS; Gigante Negra de Jersey - GNJ; poultry from the crossing between the IG and NHS breeds - IG x NHS; and between the IG and GNJ breeds - IG x GNJ) and two genders, with five repetitions and each one represented by three poultry, totaling 150 animals, slaughtered at 105 days. The parameters evaluated on the breast and thigh were: centesimal composition (moisture, ether extract - EE, protein and ash), ultimate pH, color (L*- luminosity, a*- redness, b* -yellowness, C* - chroma index and h* - hue angle), weight loss by cooking (WLC) and shear force (SF). The IG genotype had the highest average of ultimate pH of the breast (6.03). The NHS and IG x NHS genotypes showed, respectively, higher average of L * (58.93) and a* (1.92) of the breast. The IG, IG x NHS and IG x GNJ showed the highest values of b* of the breast (12.53, 13.37 and 12.69, respectively). The IG poultry showed high average of SF of the breast and thigh (4.79 and 5.01kgf, respectively). The IG x NHS and IG x GNJ genotypes showed the lowest ultimate pH values of the thigh (6.13 and 6.02, respectively). The IG x GNJ genotype showed a high average of b* of the thigh (14.94) and the NHS had a high average of WCL (24.65%). The females showed higher averages of EE on the breast and ash on the thigh (1.03 and 1.11%, respectively). The IG x NHS and IG x GNJ poultry showed higher averages of EE of the breast (1.21 and 1.38 %, respectively). The poultry of IG breed and those from the crossing with NHS and GNJ presented meatquality characteristics more desirable by the consumer in relation to physicochemical parameters and centesimal composition, while genders showed no influence on these aspects.
This study aimed at evaluating the effect of different fasting periods and water spray during lairage on the quality of chicken meat. A number of 300 male Ross broilers were reared up to 42 days of age, and submitted to four pre-slaughter fasting periods (4, 8, 12, and 16 hours) and sprayed with water or not during lairage. Deboned breast meat was submitted to the following analysis: pH, color, drip loss, water retention capacity, cooking loss, and shear force. There was a significant effect (p≤0.05) of fasting period on meat luminosity was significantly different, with the highest value obtained for 4-hour fasting, whereas no difference was found among the other fasting periods. Meat pH values were different among fasting periods when birds received water spray, with birds fasted for 4, 8, and 12 hours of fasting presenting lower meat pH values (5.87, 5.87, and 6.04, respectively). The interaction between fasting period and water spray influenced meat drip loss and cooking loss, with birds fasted for 16h and not receiving water spray presenting higher drip loss (4.88) and higher cooking loss (28.24) as compared to the other birds. Fasting period affects meatquality, and very short periods (4h) impair meatquality.
The present work evaluated the effect of different probiotics on carcass and meatquality of broilers. One thousand and fifty male Cobb chicks were distributed at one day of age in a randomized design with 3 x 2 + 1 factorial arrangement (3 probiotics, 2 levels of probiotics in drinking water and 1 negative control group), using 5 replications with 30 birds. Carcass yield was higher (p<0.05) in control birds. Nevertheless, the groups fed with probiotics showed higher (p<0.01) leg yield at 45 days of age. There was a significant decrease in color (lightness) and increase in pH of breast muscle 5 hours after slaughter in the probiotics treated birds. In the sensory analysis, meat flavor and general aspect 72 hours after slaughter were better when probiotics were added in both water and diet. There were no differences in water holding capacity, cooking loss and shearing force among different probiotics or between them and the control. Thus, meatquality was better when probiotics were fed in the water and diet instead of only in the diet. Nevertheless, carcass and meatquality showed no alteration when the control group was compared to birds fed with probiotics, except for leg yield improvement in the latter.
In order to shorten ripening time, electric stimulation is applied not only for pork and beef carcasses, but also for poultry („Rapid Rigor“). There are different ways of cooling for beef and pork (fast/shock cooling, ultra chilling, fog cooling). Niewiarowicz et al. (1979) investigated the pH-value of the surface of the plain breast skin prior to slaughtering (a.m.) for PSE and DFD meat. PSE meat has to be expected when pH 0 -values range from 6.5 to 6.6 (standard meat composi- tion 6.6:6.9, DFD-condition 7.0:7.1). A correlation (0.73) could be found for pH 0 and pH 1 . For pork, measurements 15 min p.m. would be 5.4 to 5.8 for PSE, 5.8 to 6.3 for standard meatquality and 6.0/>6.3 for DFD (Scheme 1).
proi les analysis. Texture is a very important quality parameter. Hardness assessment using the Texture proi le Analysis (TPA) revealed no statistical signii cant between Zn supplemented groups and control group. Zn treatment groups were tenderer than control group. Kohmaraie (1990) reported that the infu- sion of ZnCl 2 toughens meat. Furthermore, dietary Zn sources (Zn oxide, Zn polysaccharide complex, Zn proteinate; 10 mg Zn per kg) did not inl uence the meatquality parameters colour, drip loss and instrumental tenderness (Kessler et al., 2003). h e pH value of leg muscle 24 h and 48 h post mortem did not dif er between treatments. h e pH value 48 h post mortem showed an increasing trend in all groups. h e colour of group ZnCh seems to be darker than of other groups. h e group ZnL had less red colour (lower a* value) than control group and Zn oxide and Zn chelate groups. But the dif erences were not statistically signii - cant (P > 0.05). It has been suggested that organic and inorganic forms of zinc are metabolized dif erently following absorption. Of the inorganic forms of the mineral, the sulfate form seems to be the most available. Organic sources tend to have equal or greater availability than sulfate forms (Wedekind et al., 1992).
The overall sensory quality (appearance, texture and smell) of all samples of raw meat from DY, DYWB and WB was evaluated. A scoring range of 1.00 to 5.00 was used, with the possibility of assigning half- and quarter-points. For each selected quality cha- racteristic the coefficient of importance (CI) was determined, which was used for the correction (multi- plication) of given ratings. The coefficients were chosen according to the importance of effect of individual characteristics on the overall quality, and balanced so that their sum was 20. Addition of individual scores gave us a complex indicator that represented the o e all se so ualit a d as e p essed as pe e - tage of the a i u possi le ualit . Dividing that value by the sum of the coefficients obtained by weighted importance mean score, which also repre- sented the overall sensory quality of raw meat samples D Y, DYWB and WB. Rating: 1.00 – very pronounced errors, 2.00 – pronounced errors, 3.00 – noticeable deviations, 4.00 –5.00 and slight differences – fully meets the requirements for quality. In evaluation of sensory characteristics of raw meatquality DY, DYWB and WB , 20 experienced tasters were involved [19,20].
Rabbits are very sensitive to heat stress because they have difficulty eliminating excess body heat. The objective of the current study was to evaluate the effects of heat stress on slaughter weight, dressing percentage and carcass and meatquality traits of rabbits from two genetic groups. Ninety-six weaned rabbits were used: half were from the Botucatu genetic group and half were crossbreds between New Zealand White sires and Botucatu does. They were assigned to a completely randomized design in a 2 3 3 factorial arrangement (two genetic groups and three ambient temperatures: 188C, 258C and 308C) and kept under controlled conditions in three environmental chambers from 5 to 10 weeks of age. Slaughter took place at 10 weeks, on 2 consecutive days. Meatquality measurements were made in the longissimus muscle. Actual average ambient temperature and relative humidity in the three chambers were 18.48C and 63.9%, 24.48C and 80.2% and 29.68C and 75.9%, respectively. Purebred rabbits were heavier at slaughter and had heavier commercial and reference carcasses than crossbreds at 308C; however, no differences between genetic groups for these traits were found at lower temperatures. No genetic group 3 ambient temperature interaction was detected for any other carcass or meatquality traits. The percentages of distal parts of legs, skin and carcass forepart were higher in crossbred rabbits, indicating a lower degree of maturity at slaughter in this group. The percentage of thoracic viscera was higher in the purebreds. Lightness of the longissimus muscle was higher in the purebreds, whereas redness was higher in the crossbreds. Slaughter, commercial and reference carcass weights and the percentages of thoracic viscera, liver and kidneys were negatively related with ambient temperature. Commercial and reference carcass yields, and the percentage of distal parts of legs, on the other hand, had a positive linear relationship with ambient temperature. Meat redness and yellowness diminished as ambient temperature increased, whereas cooking loss was linearly elevated with ambient temperature. Meat color traits revealed paler meat in the purebreds, but no differences in instrumental texture properties and water-holding capacity between genetic groups. Purebred rabbits were less susceptible to heat stress than the crossbreds. Heat stress resulted in lower slaughter and carcass weights and proportional reductions of organ weights, which contributed to a higher carcass yield. Moreover, it exerted a small, but negative, effect on meatquality traits.
Physico-chemical parameters of analysed porkers was typical for normal meat (Koćwin-Podsiadła, 2004a) except intamuscular fat content, which level was 1.1 % lower than that achieved by Florowski, et al. (2006). Duroc fatteners are considered as meatquality model which is used widely in breeding programs in majority of European countries ( Koćwin-Podsiadła, et al., 1998b), although its usage should not be higher than 25 – 50 % on the grounds of above-mentioned high intramuscular fat content (5 – 8 %) in Longissimus dorsi. On the other hand, the ivestigations of Wood, et al. (1994, 1996) have proved that Danish population of Duroc was characterised by noticeably lower level of this trait, i.e. 2,5-3 % in LD, that is however still higher than value achieved in this paper.
There was no effect (p > 0.05) of the supplementation of vitamins D and E on animal performance and carcass characteristics (Table 2). Likewise, no effect of the genetic group (p > 0.05) was observed on animal performance and carcass characteristics, except for dressing percentage (p < 0.05), and the contents of total lipids and vitamins D and E in LM, in which NEL bulls presented higher dressing with greater contents of lipids and vitamins D and E (Table 2). It is well documented (PACHECO et al., 2012) that NEL bulls present increased dressing percentage, since they are characterized by lighter leather, head, and gastrointestinal tract than Bos taurus breeds. Similarly, as NEL breed is considered smaller than CAC, NEL bulls may have started depositing fat earlier, which could explain the greater lipid content in the meat (MENEZES et al., 2005). Moreover, the concentration of the active vitamin D (1.25(OH) 2 D) in the plasma and in different tissues