Evaluation of Duroc- vs. Pietrain-sired pigs for growth and composition

Accurate evaluations of growth and composition traits enable better management decisions regarding genetic merit, feeding, and marketing. Sires from Duroc and Pietrain populations were used to produce crossbred pigs, which were evaluated for growth and composition traits. All parents were normal for the ryanodine receptor gene. Boars from each breed were mated to either Yorkshire or F1 Yorkshire-Landrace females with 307 offspring evaluated from birth through 26 wk of age. No significant differences between sire breeds were seen for pig BW from birth through 10 wk of age. Body weight, 10th rib backfat (BF10), last rib backfat (LRF), and loin muscle area (LMA) were serially measured at 10, 13, 16, 19, 22, 24, and 26 wk of age. At 26 wk of age, Duroc-sired progeny were heavier (143.4 vs. 132.7 kg, P < 0.001), had more BF10 (27.1 vs. 23.7 mm, P < 0.001) and LRF (21.2 vs. 19.2 mm, P < 0.001), but had similar LMA (46.4 vs. 47.1 cm2) compared with Pietrain-sired progeny. Mean feed efficiency did not differ between breed of sire in any period of the study. Duroc progeny had a greater ADG (980.1 vs. 892.3 g/d, P < 0.001) from 10 to 26 wk of age than Pietrain-sired pigs. Composition traits of fat-free total lean (FFTOLN), total fat tissue (TOFAT), empty body protein (EBPRO), and empty body lipid (EBLIPID) were calculated. Random regression animal models with polynomial regression on week on-test were fitted to BW, BF10, LRF, LMA, FFTOLN, TOFAT, EBPRO, and EBLIPID from 10 to 26 wk of age. Duroc-sired barrows tended to grow faster but with more fat tissue, and Pietrain-sired gilts were slower growing but leaner, whereas Duroc-sired gilts and Pietrain-sired barrows were intermediate for growth and backfat measures. Serial heritability estimates generally increased from 10 to 26 wk of age with ranges as follows: BW (0.05 to 0.39), BF10 (0.13 to 0.76), LRF (0.11 to 0.79), LMA (0.05 to 0.73), FFTOLN (0.07 to 0.16), TOFAT (0.19 to 0.45), EBPRO (0.02 to 0.55), and EBLIPID (0.12 to 0.60). Pigs sired by Duroc and Pietrain boars had similar lean tissue growth but achieved it through different mechanisms.     

生长育肥猪胴体品质和肉质演变规律的研究

以长×荣杂交猪为对象 ,研究营养水平和性别对生长育肥猪胴体品质和肉质演变规律的影响。设高低两个营养水平 ,分别为 2 0、35、5 0、80、10 0kg进行屠宰试验 ,测定了公母猪肌肉水分、肌间脂肪、失水率、肉色、肌纤维面积、胶原蛋白、次黄嘌呤随体重的变化规律。试验结果证明 ,2 0～5 0kg阶段 ,高低水平组间水分、失水率、肌间脂肪差异不显著 (P >0 .0 5 ) ,5 0～ 10 0kg阶段出现分化 ,到 10 0kg屠宰时 ,高低水平组水分、失水率差异显著 (P <0 .0 5 ) ;肌间脂肪差异极显著 (P <0 .0 1) ;肌纤维面积生长规律呈“S”型 ,35～ 5 0kg时生长速度最大 ,5 0～ 80kg时下降 ,80～ 10 0kg又上升 ;胶原蛋白、次黄嘌呤随体重增加而升高 ,到 80kg时含量趋于稳定 ,高低水平间无显著差异(P >0 .0 5 ) ;全期高低水平间肉色差异不显著 (P >0 .0 5 ) ;性别对肌间内脂肪和失水率影响较大 ,10 0kg时 ,失水率公母间差异极显著 (P <0 .0 1) ,肌间脂肪差异显著 (P <0 .0 5 )。     

胆囊收缩素主动免疫对猪生产性能、胴体品质及肉质的影响

为了研究胆囊收缩素(CCK-8)主动免疫对猪生产性能、胴体品质、肉质的影响,将12头体重为23.2±0.3kg的长荣猪随机分为2个处理,试验组和对照组,每个处理3个重复,每个重复2头猪,其中试验组猪注射CCK-8 人血清白蛋白(HSA),对照组猪则只注射HSA,测定猪的日采食量、日增重、料重比、屠宰率、胴体斜长、背膘厚、眼肌面积、pH、肉色评分、大理石纹、失水率、肌间脂肪等指标。试验期78d。整个试验期,与对照组相比,试验组的日增重低5.53%(P>0.05),日采食量高0.6%,料重比高6.64%(P>0.05),这表明,500μgCCK-8主动免疫有降低猪整个试验期生产性能的趋势,CCK-8免疫对猪胴体品质和肉质无显著影响,但对肉质有改善的趋势。     

甜菜碱和B族维生素对商品猪生长性能及同体肉品质影响

许多研究表明,甜菜碱可以促进肥育猪生长,改善饲料利用率,降低背膘厚,减少胴体脂肪沉积,增大眼肌面积和提高瘦肉率。日粮中添加B族维生素,可     

The influences of weaning age and weight on carcass traits and meat quality of pigs

The purpose of this study was to establish the effects of weaning age and weight on pigs, and their interaction with carcass traits and meat quality. A total of 468 piglets were obtained from 57 sows and four boars and grouped by age at weaning (D21, 18–24 days; D28, 25–32 days). Each weaning group was subdivided into three weight groups (L, M and H) according to weaning weight. The D28 group had heavier carcass weight, redness and yellowness, but had lower marbling scores and less drip loss than the D21 group (P < 0.05). The pigs with a light weight at weaning had higher carcass weights and lower yellowness than did pigs with a medium or heavy weight at weaning (P < 0.05). Weaning age was found to have a negative correlation with drip loss, while weaning weight was negatively correlated with carcass weight and drip loss (P < 0.05). We concluded that carcass and meat quality traits in pigs were significantly related to their age and weight at weaning. Therefore, we find that piglet weaning age and weight are no less important than post‐weaning growth performance and behavior, with regard to carcass traits and meat quality.     

Performance,carcass and technological meat quality of pigs in indoor and outdoor production systems

Abstract

This study aimed to compare different production systems, i.e., the combined effect of outdoor and indoor rearing of pigs and organic diets fed ad libitum or restrictively. Furthermore, the suitability of two breed crosses for outdoor rearing was studied. The effects on performance, carcass and technological quality traits were investigated. During two years, 240 pigs of Duroc x Large White (D*LW) and Swedish Landrace x Large White (L*LW) were allocated to three production systems: 1) Pigs kept outdoors, fed an organic diluted diet (20% alfalfa roughage) ad libitum; 2) Pigs kept outdoors, strategically fed a diluted organic diet up to a live weight of approximately 80 kg and thereafter an undiluted organic diet ad libitum; 3) Pigs kept indoors, fed an undiluted organic diet restrictively. For outdoor pigs, strategic feeding increased daily weight gain and backfat thickness, compared with feeding a diluted diet throughout (p≤0.01). L*LW pigs in both outdoor systems grew slower than in the indoor system (p≤0.001), whereas for D*LW pigs only outdoor pigs fed the diluted diet had a slower growth rate. Outdoor pigs had lower dressing percentage than indoor pigs. Glycogen content and L* values in M. longissimus dorsi were higher, whereas b* values were lower in meat from pigs in the indoor system. D*LW pigs had higher water-holding capacity (lower drip, thawing and cooking losses), lower shear force and higher intramuscular fat content compared with L*LW pigs.     

Effects of Sarcocystis miescheriana infection on carcass weight and meat quality of halothane-tested fattening pigs

Ten halothane-positive pigs (Group A) and ten halothane-negative pigs (Group C) were each infected per os by 50 000 sporocysts of Sarcocystis miescheriana when they had reached a mean body weight of 36 kg. Twelve halothene-positive pigs (Group B) and ten halothane-negative pigs (Group D) served as non-infected controls. Thirteen weeks p.i. (post infection), the pigs were slaughtered and the carcass weights and the number of cystozoites in several muscles were determined. In addition, 11 parameters of meat quality were measured in Musculus longissimus dorsi (M.l.d.) and Musculus semimembranosus (M.s.): pH and temperature 30 min and 24 h p.m. (post mortem), electrical conductance 45 min, 60 min and 24 h p.m., colour brightness (FOP) and rigor values 30 min and 24 h p.m. Additionally, the AMP, ADP, ATP and lactate contents were determined in samples from the M.l.d. The mean carcass weights of the infected pigs (A: 79.9 ± 6.9 kg; C: 76.3 ± 11.6 kg) were lower than those of the pigs of the non-infected groups (B: 85.7 ± 8.0 kg; D: 87.5 ± 7.0 kg). The pH values at 24 h p.m. were significantly higher in the M.l.d. of infected pigs than in M.l.d. of non-infected pigs. Electrical conductance in the M.s. at 45 min p.m. was significantly higher in the halothane-negative infected pigs, but at 24 h p.m., the mean values of electrical conductance in the M.s. of the pigs of both infected groups were significantly lower than in the control groups. FOP values at 30 min p.m. were raised in the M.l.d. of the halothene-negative infected pigs, but at 24 h p.m., differences between infected and non-infected pigs could no longer be found. Mean rigor values were higher in the pigs of the infected groups at 24 h p.m., but the difference from the non-infected groups was not statistically significant. AMP was reduced only in the meat of halothane-positive infected pigs, while lactate was reduced in both infected groups. Using conventional methods for the determination of meat quality, the hypothesis of impaired meat quality in Sarcocytis-infected pigs could not be confirmed. The meat quality parameters investigated were, in part, better in infected pigs than in non-infected controls.     

Effect of age at slaughter on carcass traits and meat quality of Italian heavy pigs

Barrows and gilts (n = 128) from four breed crosses were used to investigate the effect of age at slaughter on carcass traits, proteolytic enzyme activity, and meat and fat quality. Pigs were blocked by breed cross into four blocks, and within blocks, one pen (eight barrows and eight gilts) was assigned randomly to be slaughtered at either 8 or 10 mo of age. Pigs were fed a corn-barley-soybean meal finisher diet from 104 +/- 2.5 d of age (37.7 +/- 0.33 kg BW) to the appropriate slaughter age. Carcasses from older (10 mo) pigs had lower (P < 0.01) muscularity indexes and lean cut yields than those of younger (8 mo) pigs, but dressing percentage and longissimus muscle area increased (P < 0.01) with age. Older pigs produced a redder (P < 0.01) and darker (P < 0.05) semimembranosus, with lower (P < 0.01) ultimate pH and cathepsin B and B + L activities, as well as higher (P < 0.01) aminopeptidase hydrolyzing activity than younger pigs. Moreover, the longissimus muscle of pigs slaughtered at 10 mo of age had lower (P < 0.01) drip and cooking loss percentages than that from pigs slaughtered at 8 mo of age. Ham subcutaneous fat from 10-mo-old pigs had greater (P < 0.05) percentages of oleic acid and lower (P < 0.01) proportions of moisture, linoleic, and linolenic acids than subcutaneous fat from pigs slaughtered at 8 mo of age. Results from this study indicate that fresh hams from pigs slaughtered at 10 mo of age would be more suitable for the production of high-quality, Italian, dry-cured hams.     

Relationship between perilipin genes polymorphisms and growth,carcass and meat quality traits in pigs

The perilipins (PLIN) belong to a family of structural proteins that play a role regulating intracellular lipid storage and mobilization. Here, PLIN1 and PLIN2 have been evaluated as candidate genes for growth, carcass and meat quality traits in pigs. A sample of 607 Duroc pigs were genotyped for two single‐nucleotide polymorphisms, one in intron 2 of the PLIN1 gene (JN860199:g.173G>A) and the other at the 3′ untranslated region of the PLIN2 gene (GU461317:g.98G>A). Using a Bayesian approach, we have been able to find evidence of additive, dominant and epistatic associations of the PLIN1 and PLIN2 polymorphisms with early growth rate and carcass length. However, the major effects were produced by the dominant A allele at the PLIN2 polymorphism, which also affected the carcass lean weight. Thus, pigs carrying an additional copy of the A allele at the g.98G>A PLIN2 polymorphism had a probability of at least 98% of producing carcasses with heavier lean weight (+0.41 kg) and ham weight (+0.10 kg). The results obtained indicate that the PLIN2 polymorphism could be a useful marker for lean growth. In particular, it may help to reduce the undesired negative correlated response in lean weight to selection for increased intramuscular fat content, a common scenario in some Duroc lines involved in the production of high quality pork products.     

Economic values for meat quality traits in pigs.

The aim for this study was to derive economic values for meat quality traits. Meat quality experts from 10 slaughter and retail companies in Switzerland were asked to give an interview in which they indicated their willingness to pay different prices for carcasses from different quality classes. Economic values for the seven meat quality traits color (L*), drip loss, intramuscular fat content, iodine value, pH1 (45 min after slaughtering), pH2 (24 to 30 h after slaughtering), and proportion of premium cuts were derived from the answers. For each trait, a weighted mean of these economic values was calculated using the number of pigs slaughtered by a company per year as a weighting factor. Population mean and standard deviation of the investigated traits were taken from station test results of Swiss Large White pigs (intramuscular fat content, iodine value, pH1, pH2, and proportion of premium cuts) and from the literature (color and drip loss). Weighted means (range among companies) of economic values per slaughter pig on the basis of one phenotypic standard deviation of the trait in Swiss Francs (SFr.) were -22.92 (0 to -62.46) for color, -10.27 (0 to -43.64) for drip loss, 10.84 (0 to 29.43) for intramuscular fat content, -29.90 (-15.54 to -43.58) for iodine value, 11.50 (.67 to 19.79) for pH1, 0 (0) for pH2, and 10.92 (-2.30 to 33.67) for proportion of premium cuts.     

Comparisons of carcass traits,meat quality,and serum metabolome between Shaziling and Yorkshire pigs

This study aims to compare the meat quality of Shaziling and Yorkshire pigs and to find the potential indicator in serum for superior meat quality. Six Shaziling and Yorkshire pigs at 30, 60, 90, 150, 210, and300 d of age were selected to examine carcass traits, meat quality, and serum metabolome. The results showed that the body weight, carcass length, and loin eye area of Shaziling pigs at 150, 210, and 300 d of age were significantly lower than those of Yorkshire pigs (P <0.05). Shaziling ...     

Evaluation of recombinant porcine somatotropin on growth performance, carcass characteristics, meat quality, and muscle biochemical properties of Belgian Landrace pigs.

The dose related effects of recombinant porcine somatotropin (rpST) on growth, carcass characteristics, muscle properties, and meat quality were investigated in lean Belgian Landrace finishing pigs. Ninety-six pigs (48 barrows and 48 gilts) were injected daily with either vehicle, 1.5, 3, or 6 mg of rpST from 60 to 97.5 kg live weight. Each treatment group consisted of six pens of four pigs each (two of each sex). Pigs were given ad libitum access to a high-protein (20.4% CP) cereal-based diet. Administration of rpST increased (P less than .05) growth rate (16.3 to 25.4%) and improved (P less than .05) feed efficiency (16.9 to 29.4%). Feed consumption was reduced (12%; P less than .05) only in the 6 mg of rpST group. Liver, kidney, and heart weights were increased (P less than .05) in the 3 and 6 mg of rpST groups. Although the Belgian Landrace pigs are bred for superior carcass quality, rpST further improved (P less than .05) carcass composition at all dose levels as evidenced by a reduction (10 to 50%) in a number of subcutaneous fat depth measurements, an increase (10 to 20%) in longissimus muscle area, and an improvement in the lean cut:fat cut ratio. Rate of pH decline in the gluteus and longissimus muscles was similar, but rapid, in all groups (pH after 30 min = 5.74 to 5.94); the ultimate (24 or 72 h) pH was .15 to .2 pH units higher (P less than .05) in the pigs that received the 3 and 6 mg of rpST doses.(ABSTRACT TRUNCATED AT 250 WORDS)     

营养水平对鲁农2号生长猪屠宰性能和肉品质的影响

试验选用108头鲁农2号生长猪(49.58±1.49)kg,随机区组,分为3个处理组,每处理4个重复,每重复(圈)9头猪,在保持日粮消化能/粗蛋白质比例不变的情况下,分为高、中、低3个营养水平组,研究日粮不同消化能和粗蛋白质水平对鲁农2号生长猪屠宰性能和肉品质的影响。试验分50～80 kg和80～100 kg两个体重阶段饲养,当试验猪平均体重达到100 kg时进行屠宰,测定屠宰性能和肉品质。结果表明:3个处理组的背膘厚、眼肌面积、后腿重、后腿比例、脂肪率、屠宰率和瘦肉率均差异不显著(P>0.05);除大理石纹外,3个处理组的肉品质差异也不显著(P>0.05)。这预示着低能量和粗蛋白质日粮饲喂鲁农2号生长猪可以获得与高能量粗蛋白质日粮相近的屠宰性能和肉品质。     

The effects of halothane sensitivity on carcass composition and meat quality in HAL-1843-normal pigs

Objectives of this study were to determine the incidence of halothane sensitivity in pigs that are homozygous normal at the ryanodine receptor nucleotide 1843 (HAL-1843-normal) and the relationships between halothane sensitivity and carcass composition or meat quality. In Exp. 1, piglets (Lines A, B, C, and D; n = 168, 170, 168, and 169, respectively) were obtained from mating a HAL-1843-normal sire line to four HAL-1843-normal dam lines. In Exp. 2, piglets from Lines A and B (n = 87 and 90, respectively) were included with piglets (Lines E, F, G, and H; n = 94, 92, 89, and 89, respectively) obtained from mating four HAL-1843-normal sire lines to a single HAL-1843-normal dam line. Pigs were subjected to 3% halothane at approximately 9 wk of age. In Exp. 1, limb rigidity, blotching of the skin, and muscle tremors were visually assessed, and based on these criteria, halothane sensitivity (HS) was observed in 48% of the pigs. To better characterize this response, a scoring system was developed and used in Exp. 2. Using this system, 25, 42, and 33% of the pigs in E and 40, 33, and 27% of the pigs in Line G were categorized as HS-low (HS-L), HS-intermediate (HS-I), and HS-high (HS-H), respectively. In Lines F and H, 13 and 18% of the pigs were HS-I, and 0 and 2% were HS-H, respectively. No consistent effects due to HS were observed in carcass composition or meat quality; however, when a subset of pigs from Exp. 2 were subjected to more extensive handling and transportation before slaughter, ultimate pH was lower and drip loss was higher in LM from HS-H compared with HS-L pigs (P < 0.05; n = 71). These results demonstrate that some pigs are sensitive to halothane anesthesia even in the absence of the known HAL-1843 polymorphism. Additionally, halothane sensitivity may be associated with inferior pork quality under adverse antemortem conditions.     

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。     

烟台黑猪不同杂交组合猪肥育性能、胴体品质及肉质研究

研究测定了烟台黑猪与鲁育杜洛克、鲁育大约克和长白猪杂交商品猪的生长肥育性能、胴体品质及肉质。结果表明,大约克×烟黑组合日增重最高为717.37 g,料重比最低为2.97,与杜洛克×烟黑、长白×烟黑和烟黑×烟黑相比,日增重分别提高7.93%（P〉0.05）、16.22%（P〈0.05）和21.31%（P〈0.01）,料重比分别降低11.08%、3.88%、21.43%。4个组合的胴体性能及肉品质差异显著。其中,屠宰率以杜洛克×烟黑最高,比大约克×烟黑提高11.69%（P〈0.05）;眼肌面积也以杜洛克×烟黑最大,比烟黑×烟黑提高31.33%（P〈0.05）;瘦肉率以大约克×烟黑最高为60.24%,比烟黑×烟黑提高22.09%（P〈0.01）;大理石纹评分以烟黑×烟黑最高,其次是杜洛克×烟黑,分别比大约克×烟黑、长白×烟黑提高10.67%（P〉0.05）、38.02%（P〈0.05）和9.15%（P〉0.05）、36.12%（P〈0.05）;pH1以大约克×烟黑最高为6.66,其次是烟黑×烟黑组合为6.29,分别比杜洛克×烟黑、长白×烟黑提高14.63%（P〈0.01）、17.25%（P〈0.01）和8.26%（P〈0.01）、10.74%（P〈0.01）;失水率以杜洛克×烟黑最低,比长白×烟黑降低51.49%（P〈0.05）。4个组合的背最长肌氨基酸总量、鲜味氨基酸含量和必需氨基酸含量都以烟黑×烟黑组合最高,分别比大约克×烟黑和长白×烟黑提高10.07%（P〈0.01）和6.17%（P〈0.05）、9.55%（P〈0.01）和6.17%（P〈0.05）、11.18%（P〈0.01）和6.79%（P〈0.05）。背最长肌棕榈酸含量以杜洛克×烟黑最高,比大约克×烟黑提高10.59%（P〈0.05）;硬脂酸也以杜洛克×烟黑最高,分别比大约克×烟黑、长白×烟黑和烟黑×烟黑提高18.62%（P〈0.01）、20.5%（P〈0.01）和20.20%（P〈0.01）;油酸以烟黑×烟黑最高,比杜洛克×烟黑提高11.96%（P〈0.05）。     

The effect of the Halothane and Rendement Napole genes on carcass and meat quality characteristics of pigs

The objective of this study was to determine the effects of the Halothane (N) and Rendement Napole (RN) genes on carcass and meat quality characteristics in pigs. Halothane and RN carrier (Nn/RN- rn+) Hampshire boars (n = 4) were mated to dams that were homozygous for the normal allele of both genes (NN/rn+ rn+) to produce progeny of four genotypes: 1, NN/rn+ rn+ (n = 31); 2, Nn/rn+ rn+ (n = 27); 3, NN/RN- rn+) (n = 30); and 4, Nn/RN- rn+ (n = 23). A DNA test was used to determine Halothane genotype, and longissimus glycolytic potential was used to predict the RN genotype. Pigs were reared under standard conditions to approximately 120 kg live weight and slaughtered at a commercial plant, and carcass characteristics and meat quality were evaluated. Halothane carriers (Nn/ _ _), in comparison to Halothane normal (NN/_ _) pigs, had shorter carcasses, lower longissimus ultimate pH, higher Minolta L* and b* values, and greater drip loss. Rendement Napole gene carriers (_ _/RN- rn+) had higher L* and b* values and drip and cooking loss and lower longissimus ultimate pH than homozygous recessive animals (_ _/rn+ rn+). There were Halothane x RN genotype interactions (P < 0.05) for subjective color, firmness, and marbling scores, and for shear force. Animals that were normal for both genes (NN/rn+ rn+) had the highest subjective scores for color (2.60, 1.88, 1.85, and 1.95, SE = 0.181, P < 0.05), firmness (2.53, 2.03, 2.10, and 1.89, SE = 0.182, P < 0 .05), and marbling (2.11, 1.44, 1.53, and 1.55, SE = 0.153, P < 0 .05) for genotypes 1, 2, 3, and 4, respectively, suggesting darker, firmer muscle with a higher level of marbling for this genotype. Shear force was highest for Nn/rn+ rn+ animals (3.83, 4.41, 3.79, and 3.70, respectively, SE = 0.172, P < 0.05). Gilts had less s.c. backfat thickness, greater longissimus muscle area, and lower subjective marbling scores than barrows. There was no effect (P > 0.05) of gender on other meat quality traits. This study illustrates the negative effects of the Halothane and RN genes on fresh pork quality and suggests that in combination the detrimental effects of the two genes are additive for ultimate pH, objective color, and water-holding capacity.     

Dietary mulberry leaf powder affects growth performance,carcass traits and meat quality in finishing pigs

This study was conducted to evaluate the effect of mulberry leaves as an alternative source of protein on growth performance, carcass traits and meat quality in finishing pigs. A total of 180 Xiangcun Black pigs were randomly assigned to five treatment groups with six pens of six pigs per pen. The pigs were provided with a basal diet or a diet contained 3%, 6%, 9% or 12% of mulberry leaf powder during a 50‐day experiment period. The results showed that dietary mulberry leaf powder had no negative effect on growth performance in Xiangcun Black pigs, except in the 12% mulberry group, where final body weight and average daily gain decreased (p < .05) and feed to gain ratio of the pigs increased (p < .05). Dietary mulberry inclusion decreased (quadratic, p < .05) the back fat thickness, fibre mean cross‐sectional area (CSA) in the longissimus dorsi (LD) muscle and mRNA expression levels of myosin heavy chain (MyHC) IIb in LD and biceps femoris (BF) muscles, while increased (linear or quadratic, p < .05) the plasma concentration of albumin, levels of crude protein (CP), inosine monophosphate (IMP) and several amino acids in muscle tissues. When compared with the other groups, the 9% mulberry diet increased (p < .05) loin‐eye area and contents of CP and IMP in muscles, while decreased (p < .05) plasma activity of cholinesterase and concentrations of uric acid and urea. The 6% mulberry diet had the lowest fibre mean CSA and shear force and increased total fibre number of the LD muscle, when compared with the other groups. These results suggest that including mulberry in the diet at <12% is an effective feed crop to improve meat quality and the chemical composition of muscle without negatively affecting growth performance.     

苏淮猪高肌内脂系的生长、胴体和肉质性能测定

为了培育更优良肉质的苏淮猪新品系,跟踪苏淮猪高肌内脂系的选育进展,本试验对苏淮猪与苏淮猪高肌内脂系(暂命名为苏淮猪B22系)进行了饲养和屠宰试验比较。结果表明:在生产性能方面,苏淮猪B22系日增重(g)极显著低于苏淮猪(399.88±13.11)vs(453.95±13.71),(P0.01);在胴体性状方面,苏淮猪B22系的平均背膘厚(mm)(29.25±1.33)vs(24.45±1.64),(P0.05)和第6-7肋背膘厚(mm)(29.49±2.02)vs(23.55±4.30),大于苏淮猪(P0.05),而眼肌面积(cm2)小于苏淮猪(33.50±2.39)vs(37.83±1.37),P0.05;但在肉质性状方面,苏淮猪B22系的肉色红度a值(9.53±0.79)vs(7.07±0.74),P0.05;失水率(35.45±0.72)%vs(39.17±1.39)%,P0.05和肌内脂含量(4.29±0.45)%vs(2.76±0.35)%,P0.05,均优于苏淮猪。总之,苏淮猪高肌内脂B22系具有更优良的肉质性状。     

非淀粉多糖酶对生长育肥猪生长性能、胴体性状和肉品质的影响

本研究主要通过生长育肥猪的饲养试验,观察日粮中添加非淀粉多糖酶(Non-Starch Polysaccharide Enzyme,NSP酶)对生长育肥猪生长性能、胴体性状和肉品质的影响。试验选择体质量约为40kg的杜长大三元杂交猪48头,公母各半。本试验随机分为2个处理,每个处理3个重复,每个重复8头猪,对照组饲喂基础日粮,NSP酶组饲喂基础日粮+0.6%NSP酶。结果表明:(1)生长性能方面,NSP酶组的平均日增重和平均日采食量均显著高于对照组(P<0.05),分别提高了9.8%和4.7%;NSP酶组的料重比显著低于对照组(P<0.05),降低了5.0%;(2)在胴体性状和背最长肌化学组成方面,NSP酶组眼肌面积比对照组显著提高(P<0.05),提高了9.8%;与对照组相比,滴水损失和剪切力2个指标分别降低了2.0%和14.6%,但在统计学上未达到显著水平(P>0.05)。结果显示,基础饲粮中添加NSP酶能有效提高生长育肥猪生长性能,并在一定程度上改善肉品质。