Effect of live weight and dietary supplement of raw potato starch on the levels of skatole, androstenone, testosterone and oestrone sulphate in entire male pigs

This study evaluated the effect of supplement of raw potato starch (RPS) on the levels of skatole, androstenone, testosterone and oestrone sulphate in plasma from entire male pigs. The study also evaluated relationships between plasma levels of skatole and testicular steroids at three different live weights (LW) of approximately 90, 100 and 115 kg. A total of 111 entire male pigs of a crossbred (Yorkshire dams×Swedish Landrace sires) were used. Animals were raised either in mixed pens, with females and males, or single-sex pens. Each pen contained seven or nine pigs. The most fast-growing three pigs from the pens with nine pigs were slaughtered when they reached 90 kg LW, and the remaining pigs were slaughtered at 115 kg LW. All pigs were fed the same commercial diet until the average pen weight reached 100 kg. Then, 33 out of 80 remaining pigs received RPS, 0.6 kg per pig and day, for 2 weeks prior to slaughter. Blood samples were taken from the pigs at three occasions: first, the day prior to first slaughter occasion, low-weight group; second, the day prior to change in diet, middle-weight group; and third, the day prior to second slaughter occasion, high-weight group. Plasma was analysed for the levels of skatole, androstenone, testosterone and oestrone sulphate. Fat samples were taken at slaughter and analysed for the levels of skatole and androstenone. The levels of skatole and testicular steroids in plasma were significantly higher in entire male pigs from the high-weight group fed no RPS compared to those from low- and middle-weight groups. The levels of the investigated compounds did not differ between low- and middle-weight groups (P>0.1). The diet with RPS induced a decline in skatole levels in plasma and fat (P<0.001), but not plasma levels of testicular steroids and fat levels of androstenone (P>0.05). Skatole levels were positively correlated to testosterone and oestrone sulphate levels in the middle- and high-weight pigs fed no RPS as well as to testosterone in the low-weight group. In the high-weight group fed RPS, skatole levels were not correlated to any of the analysed compounds. Approximately 26% of the entire male pigs (11 out of 43) from the high-weight group fed no RPS produced skatole levels in fat above 0.20 μg/g, whereas the pigs from the low- and high-weight group fed RPS did not produce skatole levels above 0.20 μg/g in fat. Androstenone levels in fat were high in all groups. In total 47% (52 out of 111) pigs expressed androstenone levels above the rejection levels in fat of 1.0 μg/g and 88% (98 out of 111) had androstenone levels above 0.5 μg/g. It was concluded that a lower slaughter weight and the supplement of raw potato starch to the diet could be used to reduce skatole levels in entire male pigs. Androstenone levels in fat, however, could not be reduced by either a lower weight at slaughter or dietary manipulation.     

Effects of different rearing systems on growth performance,carcass traits,meat quality and serum biochemical parameters of Chaohu ducks

This study was conducted using a total of 360 22‐day‐old Chaohu ducks to evaluate the effect of rearing system on growth performance, carcass traits, meat quality and serum parameters of male and female Chaohu ducks. The birds were divided and raised in separate pens according to sex and rearing system, with three replicate pens of 30 male or 30 female ducks per pen for each rearing system. The rearing systems consisted of a floor rearing system (FRS) and a net rearing system (NRS). Results showed that ducks raised in NRS had better growth performance, whereas, ducks raised in FRS exhibited better carcass traits and meat color, and lower intramuscular fat. For the serum parameters, NRS significantly decreased high‐density lipoprotein cholesterol content, and enhanced total protein and triacylglycerol contents. Male ducks had lower abdominal fat percentage, and higher growth performance and shear force, but there were no other significant differences between sexes. No rearing system × sex interaction was observed in the present study, revealing that rearing system had the same effect on both sexes. In conclusion, NRS was beneficial to the growth performance of Chaohu ducks, whereas this system had some negative effects on carcass traits, meat quality and serum profiles.     

Carcass and meat quality traits of the Chato Murciano pig slaughtered at different weights

In order to evaluate the effect of slaughter weight and rearing system on the Chato Murciano pig carcass and meat quality traits, a total of 71 castrated male pigs were used. Forty-one pigs were reared in an outdoor system, divided in one heavy group (CHOHW) with an average live weight of 132.05 kg, and a second group with lower weights (CHOLW, 115.7 kg average). Simultaneously, 30 pigs were reared indoors and divided into one heavy group (CHIHW) with an average live weight of 144.3 kg, and a second group with lower weights (CHILW, 117.6 kg average).Heavier pigs showed higher values for several carcass parameters (hot carcass weight, carcass length, maximum perimeter of the ham, hand length, leg length, ham length, wrist perimeter) and meat cuts, higher Dorsal Fat Thickness (DFT) and Intramuscular Fat (IMF) levels, but no difference was found in the hot carcass yields (HCY). Differences in the colour parameters and several minerals (Ca, Mg, K and Na) were also due to the different slaughter weights. The rearing system had an influence on the HCY (it is higher in the outdoor system), on many carcass parameters, on meat the ultimate pH (it is higher for animals reared indoors) and on colour (this is variable). It also affected the levels of many minerals with the levels of Mg, P and K being higher for animals reared outdoors, whereas the Fe, Cu and Zn content were higher in the animals reared indoors. DFT and IMF levels were not influenced by the rearing system.     

Effects of Sex,Feed and Pre-slaughter Routines on Technological Meat Quality in Carriers and Non-carriers of the RN − allele

The aim of this project was to study the effects of feeding system (dry or wet feeding with whey), dietary lysine level and pre-slaughter routines on technological meat quality in entire male, female and castrated male pigs, which were carriers or non-carriers of the RN ^? allele. The feeding system only affected the yield of processed meat, resulting in lower Napole yield (87.5% vs 89.4%) for meat of whey fed pigs. Further, lower dietary lysine levels resulted in higher drip loss of the meat compared with high dietary levels (5.3% vs 4.8%). Mixing of unfamiliar pigs prior to slaughter led to meat with lower internal reflectance values (28.3 vs 32.2) and glucose+G-6-P concentrations of the meat juice (46.3 vs 49.7 μmol/ml) compared with pen-wise slaughtering. In comparison with non-carriers, RN ^? carriers had significantly lower ultimate pH, shear force values and water-holding capacity. Mixing of non-carrier pigs prior to slaughter gave higher Napole yield compared with those handled pen-wise. Females had lower ultimate pH and higher Napole yield compared with entire males.     

The capacity of inspection on farm and at the abattoir to predict post-mortem outcomes in slaughter pigs: A study at animal level

The aim of this study was to investigate associations between ear, tail, and skin lesions, hernias, bursitis, and rectal prolapses at the abattoir and meat inspection outcomes in slaughter pigs, including carcass condemnations and trimmings, carcass weight, and carcass quality. This was an observational study whereby pigs were managed according to routine practices in a single abattoir. Data were collected from 1816 pigs. The relationship between animal-based welfare and post-mortem outcomes was analyzed using generalized mixed models (Proc Glimmix). Our findings showed that tail lesions were associated with entire carcass condemnations and trimmings (P < 0.001), a reduction in carcass weight (P < 0.05), and a potential to impair carcass quality by reducing muscle pH (P < 0.05), especially in carcasses from male pigs (P < 0.05). Additionally, hernias were associated with viscera condemnation (P < 0.05) and a reduction in carcass weight (P  < 0.05). Therefore, our findings confirm that ante-mortem inspection could be useful to predict post-mortem outcomes in the same pigs, especially in cases of tail lesions and hernia, which might trigger attention of the veterinary inspector in charge of the post-mortem inspection.     

Aggressive and sexual behaviour of growing and finishing pigs reared in groups,without castration

Abstract

Aggressive and sexual behaviour in entire males and females were studied on 408 pigs. The sum of aggressive interactions in the pen during routine feeding (ALP) was lowest in single-sex pens with females. ALP was higher at 132 than at 155 days. High ALP correlated with high average growth rate. Aggressive interactions in a competition test (IA) increased after slaughter of the three fastest-growing pigs in a pen (at 155 days), although the slaughtered pigs had initiated the most IA earlier (at 132 days). Entire male pigs displayed more sexual behaviour (mounting) than females. In 15% of entire males and 6% of females there were health problems specifically involving lameness or injured legs or feet. Five entire males and one female were euthanized in response to lameness or leg fracture. The rearing of entire male pigs may cause welfare problems, given their higher levels of aggression and sexual behaviour.     

Effects of the rearing system on the quality traits of the carcass, meat and fat of the Chato Murciano pig

To evaluate the performance of the Spanish autochthonous pig breed Chato Murciano under different rearing conditions, a total of 30 castrated male pigs were used. Eighteen pigs were reared in an outdoor system, and sent to slaughter with an average age of 210 days and live weight (LW) of 124.41 kg; and 12 pigs were reared in an indoor system, and slaughtered with 119.58 kg of LW and 236 days old. The pigs reared outdoors showed a better growing rate and final live weight in relation to age, as well as higher hot and cold carcass yields, and superior weights for the most valuable meat cuts, but their morphometric parameters were similar to those of the pigs reared indoors. The rearing system did not affect many of the meat quality traits (intramuscular fat (IMF) content, pH, color, tenderness and cooking loss), but drip losses were higher in the outdoor group. The levels of IMF found in this study in both rearing systems (2.65–3.19%) were notably lower than those from previous studies, probably due to differences in the diet used. The rearing system affected the mineral and fatty acid (FA) composition. The distribution of fatty acids in both groups, with a low Polyunsaturated Fatty Acid (PUFA) content, can be expected to produce good quality processed products.     

Production Results and Technological Meat Quality for Pigs in Indoor and Outdoor Rearing Systems

The objective of the study was to compare production results and technological meat quality for pigs born outdoors and reared indoors or outdoors during the summer period. A total of 279 pigs was reared in a large pen on deep litter, or outdoors. Daily weight gain and lean meat percentage were higher for pigs outdoors than indoors during year one (864 vs. 841g; 56.9 vs. 55.9%), but were similar for year two (859 vs. 844g; 55.9 vs. 55.6%). Outdoor pigs grew faster when fed ad libitum, but slower during the second phase when restricted, with inferior feed conversion. Most technological meat quality traits (surface and internal reflectance, marbling, pH_BF, filter paper wetness, cooking loss and maximal Warner-Bratzler shear force) were similar between rearing systems, whereas pH_LD was higher indoors. Total work of Warner-Bratzler shear force was lower in outdoor reared pigs. Maternal sire breed (Duroc or Landrace) and sex (castrate or gilt) did not notably affect meat quality traits. RN genotype had a stronger impact on meat quality than rearing system. It can be concluded from the similarities in production results and meat quality in both systems, that both indoor and outdoor rearing are good alternatives for summer rearing of pigs.     

Effect of dietary zinc proteinate supplementation on growth performance, and skin and meat quality of male and female broiler chicks

1. An experiment was conducted to evaluate the effect of dietary zinc proteinate (ZP) supplementation on growth performance and on skin and meat quality of male and female broiler chicks.

2. A total of 240 1-d-old male and 240 1-d-old female broiler chicks were randomly distributed into 24 floor pens (12 replicate pens/sex; 20 birds/pen) and were given either 0 (Control diet) or 40?mg/kg ZP (ZP 40), resulting in a 2?×?2 factorial arrangement of treatments.

3. The growth performance of male and female broiler chicks was not affected by the ZP supplementation, but the males showed significantly higher growth performance than did females.

4. ZP supplementation increased the total thickness of skin in both sexes, and males had thicker skin than females. It also increased the collagen content of skin, but not that of meat. Males had higher skin collagen contents than did females, but no sex difference was found in the meat collagen contents.

5. ZP supplementation did not affect the shear force values of skin and meat; however, males had higher shear force values of back skin than females. ZP supplementation increased the zinc contents of thigh meat and plasma in both sexes. Males had higher zinc contents in back skin than females.

6. It is concluded that dietary ZP supplementation could increase the skin quality of broiler chicks in both sexes, particularly in female broilers, without any effect on growth performance. Male broilers have better growth performance and skin quality than females.     

不同屠宰体重商品猪胴体性能、肉品质及相关关系研究

测定了体重70～140 kg阶段120头商品猪的胴体品质和肉质特性,分析了商品猪胴体性能、肉质性状随体重的变化规律及相关程度,为确定适宜上市屠宰体重提供依据。结果表明:70～100 kg体重阶段,随体重增大,平均背膘厚、眼肌面积、皮脂率、肉色和大理石纹显著升高,后腿比例、瘦肉率、骨骼率、L和b值显著降低。胴体和肉质性状间相关程度有强有弱,相关系数有正有负。相同性状间有较强的正相关,相反性状间有较强的负相关。在70～140 kg阶段,胴体重、胴体直长、胴体斜长、眼肌面积、平均背膘厚、瘦肉率、皮脂率、骨骼率、肉色和L值与体重之间呈显著的回归关系,其他指标与体重间的线性相关不显著。     

Carcass quality in certified organic production compared with conventional livestock production

By studying carcass quality, expressed as affection, pathological findings, slaughter-weight and evaluation, a picture of an animal's health and potential as high quality food is achieved. This study compares the carcass quality in Swedish certified organic meat production with that of conventional meat production slaughtered during 1997. The study involves 3.9 million pigs, about 570,000 cattle and 190,000 sheep, all reared conventionally and 3483 pigs 4949 cattle and 4997 sheep reared according to organic standards. Pathological and additional findings are registered by meat inspectors from the Swedish National Food Administration at the post-mortem inspection. There was a significant difference at the post-mortem inspection of growing-fattening pigs; 28% of conventionally and 17% of the organically reared pigs had one or more registered lesion. The carcass evaluation of swine shows a higher meat percentage in conventional swine production. The total rate of registered abnormalities in cattle was systems around 28% from organic and 27% from conventionally reared herds. Carcass evaluation of cattle from organic herds gave higher classification in the EUROP system, whereas the fat content was lower than that of conventionally reared cattle. Sheep, reared both organically and conventionally, showed a lower rate of registered abnormalities than swine and cattle.     

Dietary integration with oregano (Origanum vulgare L.) essential oil improves growth rate and oxidative status in outdoor‐reared,but not indoor‐reared,pigs

The effects of a diet supplemented with oregano essential oil on performance, oxidative status, pork quality traits and sensorial properties were evaluated. In two studies, 72 pigs in indoor or outdoor conditions were assigned to either a control diet or an identical diet supplemented with 0.2% oregano essential oil. Pigs reared outdoor showed lower live weight, average daily gain and average gain:feed ratio compared to indoor pigs. The oregano supplementation improved the growth performance of the outdoor‐ but not the indoor‐reared animals. The serum oxidative status was influenced by the diet. A higher oxidative stability was observed in the oregano‐supplemented groups. As for the rearing conditions, the data suggest that after an initial adapting period, the free‐range farming systems could be better tolerated by pigs. Meat derived from pigs reared outdoor showed higher pH and a* values. Lightness was influenced by both the diet and the rearing conditions. The control group reared indoor showed shear force values higher than both supplemented groups, while no differences were detected with the control group reared outdoor. In the consumer test performed under blind conditions, the oregano groups achieved higher consistency scores compared with the control. Under informed conditions, the meat derived from the oregano‐supplemented pigs reared outdoor received the highest scores for consistency and overall liking regardless of the rearing system. The same result for the overall liking score was obtained in the expectation test. The data obtained showed that dietary oregano essential oil can be effective in reducing performance losses due to the outdoor‐rearing system, increasing the oxidative status of the animal and oxidative stability of the meat, without modifying the meat quality traits and improving consumer perceptions of the meat quality.     

Meat quality of fully or partly outdoor reared pigs in organic production

Abstract

Outdoor production on pasture is considered an option in organic pig production. The aim of the present trial was to study the influence of feeding strategies combining outdoor and indoor rearing on pig meat quality. The experiment was carried out with 245 pigs in 5 replicates, and commenced following weaning at day 52. Five treatments were compared: 1) pigs fed ad libitum and reared indoors with access to an outdoor concrete area (In-A); 2) pigs fed restrictively on pasture until 40 kg body weight and then kept indoors with access to an outdoor concrete area and fed ad libitum until slaughter (In-40A); 3) pigs fed restrictively on pasture until 80 kg body weight and then kept indoors with access to an outdoor concrete area and fed ad libitum until slaughter (In-80A); 4) pigs reared on pasture and fed restrictively during the whole period of growth (Out-R); and 5) pigs reared on pasture and fed ad libitum during the whole period of growth (Out-A). All pigs had free access to roughage (clover-grass silage/fresh clover grass). Restrictive feeding in the weight range from weaning to 40 kg body weight (In-40A) resulted in a reduced daily gain; however, following transfer to indoor facilities and ad libitum feeding these pigs compensated in growth and the overall daily gain did not differ from the In-A control pigs. Pigs fed restrictively from weaning to 80 kg body weight were unable to compensate completely following transfer to indoor facilities. Out-R pigs had the lowest overall daily gain, while In-A pigs and Out-A pigs had similar daily gain. Meat quality assessments were performed on longissimus dorsi (LD) samples from a subsample of 100 pigs (2 castrates and 2 female pigs from each treatment in each replicate). Compared to meat from either ad libitum treatments (In-A and Out-A), meat from Out-R and In-80A pigs was less red due to a lower pigmentation, and had a higher ratio of polyunsaturated:saturated fatty acids. In addition, Out-R female pigs had numerically (6–10 Newton) higher shear force than In-A and Out-A. Treatments did not affect the concentration of α-tocopherol of meat. Introducing a finishing period with free access to concentrates following 40 kg body weight until slaughter prevented the deterioration in meat quality. However, a finishing period following 80 kg body weight was not sufficient. In conclusion, ad libitum feeding in the organic production system gave superior meat quality compared to a restrictive feeding strategy. However, including a finishing period indoors with ad libitum feeding of concentrates may prevent the detrimental effect of restrictive feeding on meat quality.     

Growth performance, carcass characteristics, meat quality, and tissue histology of growing pigs fed crude glycerin-supplemented diets

The effects of dietary crude glycerin on growth performance, carcass characteristics, meat quality indices, and tissue histology in growing pigs were determined in a 138-d feeding trial. Crude glycerin utilized in the trial contained 84.51% glycerin, 11.95% water, 2.91% sodium chloride, and 0.32% methanol. Eight days postweaning, 96 pigs (48 barrows and 48 gilts, average BW of 7.9 +/- 0.4 kg) were allotted to 24 pens (4 pigs/pen), with sex and BW balanced at the start of the experiment. Dietary treatments were 0, 5, and 10% crude glycerin inclusion in corn-soybean meal-based diets and were randomly assigned to pens. Diets were offered ad libitum in meal form and formulated to be equal in ME, sodium, chloride, and Lys, with other AA balanced on an ideal AA basis. Pigs and feeders were weighed every other week to determine ADG, ADFI, and G:F. At the end of the trial, all pigs were scanned using real-time ultrasound and subsequently slaughtered at a commercial abattoir. Blood samples were collected pretransport and at the time of slaughter for plasma metabolite analysis. In addition, kidney, liver, and eye tissues were collected for subsequent examination for lesions characteristic of methanol toxicity. After an overnight chilling of the carcass, loins were removed for meat quality, sensory evaluation, and fatty acid profile analysis. Pig growth, feed intake, and G:F were not affected by dietary treatment. Dietary treatment did not affect 10th-rib backfat, LM area, percent fat free lean, meat quality, or sensory evaluation. Loin ultimate pH was increased (P = 0.06) in pigs fed the 5 and 10% crude glycerin compared with pigs fed no crude glycerin (5.65 and 5.65 versus 5.57, respectively). Fatty acid profile of the LM was slightly changed by diet with the LM from pigs fed 10% crude glycerin having less linoleic acid (P < 0.01) and more eicosapentaenoic acid (P = 0.02) than pigs fed the 0 or 5% crude glycerin diets. Dietary treatment did not affect blood metabolites or frequency of lesions in the examined tissues. This experiment demonstrated that pigs can be fed up to 10% crude glycerin with no effect on pig performance, carcass composition, meat quality, or lesion scores.     

德氏乳杆菌对育肥猪胴体性状及肉品质的影响

本试验旨在研究无抗生素饲粮中添加德氏乳杆菌对育肥猪胴体性状、肉品质及背最长肌营养成分的影响。试验选用健康、平均体重为(65.34±3.64)kg的"杜×(长×大)"育肥猪120头,随机分为2个组,每组6个重复,每个重复10头猪(公母各占1/2)。对照组饲喂无抗生素基础饲粮,试验组饲喂在无抗生素基础饲粮中添加0.1%德氏乳杆菌的饲粮。试验期42 d。结果表明:2组育肥猪的胴体性状差异不显著(P0.05);与对照组相比,试验组育肥猪的脾重率和胰重率显著升高(P0.05);宰后45 min时2组育肥猪的肉品质差异不显著(P0.05),宰后24 h时,与对照组相比,试验组育肥猪肉的黄度显著升高(P0.05),剪切力显著降低(P0.05);与对照组相比,试验组育肥猪背最长肌中甘氨酸、丙氨酸和风味氨基酸含量显著升高(P0.05),葵酸和棕榈酸含量显著降低(P0.05),棕榈油酸、亚油酸和多不饱和脂肪酸含量显著升高(P0.05)。结果提示,无抗生素饲粮中添加0.1%德氏乳杆菌对育肥猪的胴体性状、肉品质及肉中营养成分具有一定改善作用。     

Effect of gender on slaughter and carcass traits in Anatolian water buffalo

This study determined the effect of gender on slaughter and carcass traits in Anatolian water buffalos reared under free range conditions in Turkey. Sixteen four-years-old Anatolian water buffalo were divided into two groups of eight males in one group and eight females in the other. The slaughter and carcass traits, carcass measurement, amount of worthy meat from each animal and phenotypic correlations among some carcass traits were determined. Chilling loss, slaughter weight and hot and cold carcass weights were 5.27%, 496.44 kg, 234.60 kg and 222.16 kg, respectively in males and 5.43%, 515.34 kg, 236.08 kg and 223.00 kg, respectively for females (P > 0.05). The ratio of skin and four leg weights (P < 0.05) and skin, head and the legs weights to the live-weight (P < 0.01) were found significantly higher in males than in female buffalos. In addition, from worthy meat, short loin was higher in males compared to females (P < 0.05). In this study, it is concluded that, generally carcass yield and amount of worthy meat in carcass tends to be higher in male water buffalo compared to females.     

北京油鸡肥育试验及产肉性能测定

通过对北京油鸡进行肥育试验，进一步展示了北京油鸡的生长速度和饲料利用率。结果表明：北京油鸡９０日龄体重，公鸡为１．５８千克，母鸡为１．２１千克，公、母鸡平均为１．３９千克。对２００余只鸡进行屠宰试验、产肉性能测定，测出北京油鸡９０日龄平均屠宰率，公鸡为７１．８６％，母鸡为７０．４０％；公鸡胸肉率为１０．５３％，母鸡胸肉率为１０．６９％；公鸡腿率为２３．１９％，母鸡腿率为２０．９８％。     

Effect of withdrawing feed from swine on meat quality and prevalence of Salmonella colonization at slaughter

OBJECTIVE: To determine whether withholding feed from pigs prior to slaughter had any effects on meat quality, percentage of pigs with Salmonella spp in cecal contents during slaughter, or percentage of pigs with lacerations of the gastrointestinal tract during slaughter. DESIGN: Split-plot design. ANIMALS: 873 pigs. PROCEDURES: At the finishing barn, pigs were assigned to 30 pens. Feed withdrawal times were assigned to pens at random, and pigs in each pen were marketed in 3 groups. The first marketing group consisted of the 10 heaviest pigs in each pen, the second consisted of the next 10 heaviest pigs, and the third consisted of all remaining pigs. RESULTS: Withdrawing feed improved the redness score assigned to the meat but did not have any other significant effects on carcass composition or meat quality. The percentage of pigs with Salmonella spp in the cecal contents decreased from the first (73%) to the second (64%) to the third (52%) marketing group. However, isolation of Salmonella spp from cecal contents was not associated with feed withdrawal time or with pen prevalence of Salmonella shedding during the 2 months prior to slaughter. Feed withdrawal time and marketing group did not have any significant effects on overall prevalence of gastrointestinal tract lacerations. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that withdrawal of feed from pigs prior to slaughter does not increase the prevalence of Salmonella colonization or the risk of carcass contamination associated with gastrointestinal tract lacerations during slaughter but only slightly enhances meat quality.     

Free-range rearing of pigs during the winter: adaptations in muscle fiber characteristics and effects on adipose tissue composition and meat quality traits

This research aimed to determine whether outdoor free-range rearing during the winter (average ambient temperature of 5 degrees C) vs. indoor housing (22 degrees C) affects meat quality, muscle metabolic traits, and muscle fiber characteristics. Forty Large White gilts and barrows were blocked by weight within each gender (20 per gender) and allotted randomly into two groups of pigs, with one reared indoors (IN) in individual pens (2.6 m2) and the other reared outdoors (OUT) from December to March in a 0.92-ha pasture. Both groups had free access to the same grower-finisher diet from 23 to 105 kg. At slaughter, adipose (backfat [BF] and omental fat [OF]) and muscle tissues (longissimus muscle [LM], rectus femoris [RF], and semitendinosus [ST]) were obtained from the right side of each carcass. Muscle fibers were stained and classified on the basis of stain reaction as slow-oxidative (SO), fast oxidative-glycolytic (FOG), and fast glycolytic (FG); fiber area and distribution were determined. Also assessed were carcass characteristics, initial and ultimate pH, L*a*b* values, drip loss percent, glycolytic potential (GP), and intramuscular lipid content, as well as the fatty acid profile of each muscle and adipose tissue. The OUT pigs had lower (P < 0.05) ADG and leaner (P < 0.05) carcasses than IN pigs. Rearing environment did not (P > 0.63) affect the intramuscular lipid content of the ST, but intramuscular lipid content was lower (P < 0.01) in the LM and tended to be higher (P = 0.06) in the RF of OUT than in those of IN pigs. In the BF outer layer of the OUT pigs, the higher PUFA content was compensated by both a lower (P < 0.01) saturated and monounsaturated fatty acid (MUFA) content, whereas in the OF, LM, and dark portion of the ST, only the percentage of MUFA was decreased (P < 0.01). In all tissues of the OUT pigs, the linolenic acid content was higher (P < 0.01) and the n-6:n-3 ratio was lower (P < 0.01). The GP of all muscles was higher (P < 0.01), and the ultimate pH of the RF and ST was lower (P < 0.01), in OUT compared with IN pigs. Lightness (L*) values were lower (P < 0.01) in the LM. Percentages of drip loss were higher (P < 0.05) in the LM and light portion of the ST of OUT than in those of IN pigs. The LM and RF of OUT pigs had more (P < 0.01) FOG and fewer (P < 0.01) FG fibers than muscles of IN pigs. Results suggest that rearing pigs outdoors increases aerobic capacity of glycolytic muscles but has little concomitant influence on meat quality traits.     

肌糖原含量与猪生产性能、胴体品质及肉质性状间的关系

试验比较2个不同基因型猪肌糖原含量、生长性能、胴体品质和肉质的差异,并分析肌糖原含量与生长性能、胴体品质及肉质之间的相关关系。将7头纯种汉普夏阉公猪体重为(19.48±1.1)kg和6头长撒公猪体重为(20.5±1.5)kg在相同条件下进行单圈饲养,到体重达100kg左右时屠宰,并测定肌糖原、胴体品质和肉质。结果表明:汉普夏猪比长撒猪有较高的日增重(P>0.05),较高的肌糖原含量(P<0.05);长撒猪有较高的背膘厚(P<0.01),较低的屠宰率(P<0.05)、眼肌面积和瘦肉率(P<0.01);汉普夏猪有较低的pH2(P<0.05)、剪切力(P<0.05)和b值(P<0.01),但滴水损失和失水率(P<0.05)高于长撒猪。相关分析结果表明:肌糖原含量与眼肌面积和瘦肉率呈正相关,与剪切力、滴水损失、平均日增重、b值、pH1和pH2呈负相关,而与平均日增重、屠宰率和胴体长相关性不大。这表明肌糖原含量是影响猪胴体品质和肉质的一个重要因素。