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1.
The aim of the present investigation was to study the development of the reproductive organs in boars fed restrictively and fed ad libitum. A total of 120 boars were purchased by the experimental station at 20 kg live weight. Three groups of 4 litter mates were selected after each of 10 A.I. boars (7 Swedish Landrace and 3 Swedish Yorkshire). The dams were unselected sows from pigletproducing herds. Two boar pigs from each litter were allocated at random among 2 treatment groups. One group ( = N) was fed restrictively and the other group (=A) ad libitum. The boars were slaughtered at 90 kg or at 120 kg live weight. The reproductive organs were removed at slaughter and examined.The ad libitum fed boars were about 2 weeks younger at slaughter than those fed restrictively (16.5 and 13.7 days respectively for the 2 weight classes). The weights of the testes were somewhat higher for ad libitum fed than for restrictively fed boars. Out of 94 examined pairs of testes, epididymides, seminal vesicles and bulbo-urethral glands, the left was heavier than the right in 68%, 62%, 48%, and 36%, respectively. Fewer (4/23) ad libitum fed than restrictively fed boars (9/26) had reached puberty at 90 kg live weight. Age at puberty thus seems to be less variable than body size in boars.  相似文献   

2.
A trial was conducted in 1983 and repeated in 1984 to measure effects of restricted feed intake and realimentation on weights of organs and on carcass and noncarcass composition. A total of one hundred six weaned lambs from two breeds (Timahdit and D'man) and a breed cross (Ile de France x D'man) were used in both years. Lambs were allotted to one of six feed intake regimens: HH (ad libitum access to feed from 21 to 30 kg); HM (ad libitum access to feed from 21 to 26 kg then 70% ad libitum to 30 kg); MH (70% ad libitum from 21 to 26 kg then ad libitum to 30 kg); MM (70% ad libitum from 21 to 30 kg); LH (restricted to lose weight from 21 to 17 kg then ad libitum to 30 kg); and LM (restricted to lose weight from 21 to 17 kg then 70% ad libitum to 30 kg). Weights of visceral organs and mesenteric and kidney fat showed dramatic responses to alteration of feed allowances. After recovery from 20% live weight loss, weight of liver equaled or exceeded that of both the ad libitum and 70% refed lambs. Mesenteric and kidney fat did not. Refeeding was accompanied by an increase in water (P less than .05) and a decrease in fat (P less than .01) of both carcass and noncarcass components. These results indicate that weight loss of lambs incurred during feed shortage was largely in internal organ weights, and that these lambs can recover these losses during realimentation and undergo compensatory growth with better feed efficiency and lean carcasses.  相似文献   

3.
Peri- and postpubertal boars accumulate substances (e.g., androstenone and skatole) in their fatty tissue that are responsible for boar taint in pork. The objective of this study was to assess the efficacy of a GnRH vaccine, Improvac, in eliminating boar taint. Three hundred male (200 intact boars, 100 barrows) crossbred (Large White x Landrace) pigs were used in a 2 x 3 factorially arranged experiment. The respective factors were sex group (barrows, boars treated with placebo, or boars treated with Improvac) and slaughter age (23 or 26 wk). Vaccines were administered 8 and 4 wk before slaughter. All Improvac-treated pigs exhibited anti-GnRH titers. Testes and bulbo-urethral gland weights in treated pigs were reduced by approximately 50% (P < 0.001) and serum testosterone levels were below 2 ng/mL in the majority of treated boars (94 and 92% across both age groups at 2 and 4 wk, respectively). Boar taint, as assessed by the concentration of androstenone and skatole in s.c. fat, was suppressed to low or undetectable levels in 100% of Improvac-treated boars. No Improvac-treated pigs had significant concentrations of either androstenone (> 1.0 microg/g) or skatole (> 0.20 microg/g). In contrast, 49.5% of placebo-treated controls had significant androstenone and 10.8% had significant skatole levels, resulting in 10% of the control boars with high concentrations of both compounds. The mean concentrations of taint compounds in the Improvac-treated pigs were not significantly different from those in barrows. Improvac-treated boars grew more rapidly (P = 0.051 and < 0.001 for pigs slaughtered at 23 and 26 wk of age, respectively) than control boars over the 4 wk after the secondary vaccination, possibly because of reduced sexual and aggressive activities. Compared with barrows, Improvac-treated boars were leaner and had superior feed conversion efficiency. The vaccine was well tolerated by the pigs, and no observable site reactions could be detected at the time of slaughter. Vaccination of boars with Improvac allows production of heavy boars with improved meat quality through prevention and control of boar taint.  相似文献   

4.
Seventy-two crossbred (Large White X Landrace) pigs were used in a 3 X 7 factorial experiment to investigate the response of two strains of boars (strains A and B) and of castrated male pigs (strain B) to seven levels of intake of a single diet (ranging from 5.3 Mcal digestible energy [DE]/d to ad libitum) between 45 and 90 kg live weight. All aspects of growth performance and body composition were affected to different degrees by both strain and sex. At all levels of energy intake strain A boars grew faster, had a lower feed to gain ratio and contained less fat and more water in the empty body than strain B boars, which in turn exhibited faster live weight gain and more efficient and leaner growth than castrated males. The magnitude of the differences in growth performance between strain A and strain B boars and castrates increased with increased energy intake above 7.88 Mcal DE/d, and these differences were associated with concomitant strain differences in their respective capacity for protein growth and in the relationship between energy intake and protein deposition. For strain A boars the rate of protein deposition increased linearly from 92 to 188 g/d with increased energy intake from 5.3 Mcal DE/d to ad libitum. For strain B boars and castrates the rate of protein deposition increased linearly with increased energy intake up to 7.88 Mcal DE/d, but thereafter it remained constant at 128 and 85 g/d, respectively. For castrates protein deposition was depressed (P less than .01) when the diet was offered ad libitum. Strain A boars had a higher energy requirement for maintenance (3.55 Mcal DE/d) than strain B boars (2.77 Mcal DE/d) or castrates (2.60 Mcal DE/d). Strain A boars also contained less protein and more water in the fat free empty body than the other two pig types.  相似文献   

5.
This study aimed to describe the association between incidence of boar taint and pubertal changes in gonadal hormones, size of reproductive organs and aggressive behaviour in entire male pigs. In total, 111 entire male pigs were included in the study. Sampling was performed first at 90 kg live weight (LW) and, then, at 115 kg LW. Variables measured were skatole and androstenone levels in plasma and fat, testosterone and oestrone sulphate in plasma, free oestrone in fat, weight of testes and length of bulbourethral glands. Aggressive interactions between pigs were registered when a limited amount of feed was provided to the pigs prior to routine feeding. The number of initiated interactions (attacks) and the difference between number of initiated and received interactions (relative attacks) were calculated for each pig. Multivariate analysis revealed that gonadal hormones and reproductive organ size influenced prevalence of boar taint, accounting for 30% of the variation in skatole levels in fat and for 37% of the variation in androstenone levels in fat. These relations were independent of aggression levels in entire male pigs. Skatole levels were influenced by the levels of oestrone sulphate in plasma and free oestrone in fat, but not levels of plasma testosterone. Pigs with testes weight below 565 g and a bulbourethral gland length <90 mm did not produce high amounts of skatole; therefore, these values can be used as a threshold level to detect pig carcasses with low skatole levels. High androstenone levels could not be predicted by measuring reproductive organ sizes. More research is required to develop a rapid and accurate method for the analysis of carcasses of entire male pigs.  相似文献   

6.
Two hundred ninety-eight Rambouillet ewe and wether lambs approximately 9 mo old from Texas were allotted to pens (29 to 30 lambs/pen). Two replicate pens were fed each of five diets. Two methods of restricting energy intake were evaluated: altering nutrient density (55% vs 72.5% vs 90% concentrate levels) and restricting intake of the 90% concentrate pelleted diet (92.5% or 85% ad libitum intake). Daily gains were highest with the 72.5% concentrate level and feed efficiency was poorest with the 55% concentrate diet fed ad libitum. Altering nutrient density did not reduce energy intake because lambs compensated by increasing feed intake at the lower nutrient densities. Actual feed intake was 89.5% of ad libitum for the 92.5% of ad libitum intake level and 84% of ad libitum at the 85% of ad libitum intake level due to refusal to consume some fines from the 90% concentrate diet. Feed refusal was greatest for lambs with ad libitum access to feed. Average daily gain was depressed by 8% at the 85% intake level. However, feed efficiency was improved (P less than .01) by 20% when intake was restricted to 92.5% of the ad libitum intake level. Differences in carcass traits were small, but consistent; carcass fat content was reduced slightly by restricting feed intake at constant slaughter weight.  相似文献   

7.
早期数量限饲对肉仔鸡生长性能和胴体特性的影响   总被引：1，自引：0，他引：1  
石宝明  单安山  镡龙 《中国家禽》2006,28(13):16-18
试验研究了早期数量限饲对肉仔鸡生长性能和胴体品质的影响。200只8日龄艾维茵肉仔鸡被随机分成4组,每组五个重复,每重复10只鸡。对照组基础饲粮根据NRC营养水平配制,试验组肉仔鸡从8日龄开始喂料量分别为对照组的90%、80%和70%,限饲1周后各组恢复自由采食。试验结果表明:在第2周,限饲各组肉仔鸡的体重和日增重分别显著低于对照组(P<0.05);在第3周,限饲90%组完成补偿生长,体重与对照组差异不显著(P>0.05);在第4周,限饲80%和70%组完成补偿生长,体重与对照组差异不显著(P>0.05);5、6、7周及2～7周各组在体重、日增重、日采食量和饲料转化率等方面都无显著差异(P>0.05)。早期数量限饲对肉仔鸡胴体特性没有显著影响(P>0.05)。  相似文献   

8.
An experiment was carried out with young male New Zealand White (NZW) rabbits to establish live body weight changes, body measurements, body composition and sexual maturity as a function of feeding intensity. Animals in Group 1 ('AL', n = 10) were fed ad libitum, while those in Group 2 ('RS', n = 10) received restricted feeding corresponding to 70% of the ad libitum level. The starting liveweights were practically the same (0.907 +/- 0.146 and 0.911 +/- 0.147 kg in Group AL and Group RS, respectively). The feeding trial lasted from 6 to 22 weeks of age. The average body weight was significantly higher in Group AL from 7 to 22 weeks of age. At 22 weeks of age the body weight of RS rabbits was 85.64% of the weight of AL animals (3.22 +/- 0.52 kg and 3.76 +/- 0.33 kg, respectively). Average body weights of RS males at 8, 9, 11, 19 and 21 weeks of age were similar to those of ad libitum fed (AL) animals at 7, 8, 10, 15 and 16 weeks of age, respectively. The growth of bucks fed restricted tended to be allometric. The most significant difference was found at 16 and 18 weeks of age, while the lowest difference occurred at 6, 12, 15 and 19 weeks of age. It can be stated that low-intensity feeding up to slaughtering weight causes backwardness in rear cannon length and this backwardness remains also after the 15th week, which is well over the optimal slaughtering age. Based on the present data, the 70% restricted feeding cannot be recommended either for the future breeding bucks or for broiler males reared for slaughter. To determine the major chemical components of the body, rabbits were euthanised. Original dry matter and crude fat content of the body significantly (P < 0.05) decreased under restricted feeding (41.42%; 32.48% and 16.73%; 7.35%) while the percentage of protein within the dry matter increased (49.6%; 65.0%) and fat decreased (40.17%; 22.1%) significantly. Libido unambiguously decreases as a consequence of feed deprivation. The most conspicuous difference was found in the level of blood testosterone. Although a few RS bucks produced semen but only much later than the rabbits fed ad libitum. On the other hand, there was no difference in the motility of spermatozoa and ejaculate volume in comparison with AL animals. There was no relationship between the body fat content and the reproductive status of bucks in the present trial.  相似文献   

9.
Differences in total carcass bone, muscle and fat, and linear measurements of the tibia and radius were evaluated in barrows at 105 kg and boars at 105, 118, 132 and 145 kg live body weight. The carcasses of five replicates were physically separated into skin, bone and soft tissues, and the linear measurements of the tibia and radius were obtained on seven replicates. At live weight of 105 kg, boars did not differ significantly in fat-free muscle, but they had 33.2% less fat, 11% greater bone weight and 14% greater skin weight than barrows. At 145 kg, boars had total carcass fat weight comparable with 105-kg barrows. Fat-free muscle, bone and skin weight of boars increased at linear rates of .41, .083 and .104 kg/kg of body weight increase from 105 to 145 kg, respectively. At 105 kg, density and length of the tibia and radius did not differ between boars and barrows. The tibia of boars were heavier than those of barrows at 105 kg, resulting in a greater ratio of tibia weight to length (indirect measure of bone thickness). As boars increased in live weight from 105 to 145 kg, total weight and length of the tibia and radius increased linearly. The ratio of weight to length of the tibia and radius increased during this 40-kg weight gain, indicating that weight of both bones increased at a greater rate than length. These results indicate that boars and barrows have the same weight of total carcass fat when boars are 40 kg heavier than the barrows. The greater bone weight of boar carcasses compared with barrows is due to greater bone thickness.  相似文献   

10.
本研究通过饲养试验与屠宰试验来探讨限饲对绒山羊生产性能和屠宰性能的影响。将20只育成羊随机分成4组,即分别为自由采食组(AL)及自由采食组采食量的90%(IR90%)、80%(IR80%)和70%(IR70%)。正式试验期为90 d。结果表明:AL的日增重比IR90%组I、R80%组显著高出91.21%和194.92%(P<0.05),但IR90%和IR80%之间无显著差异(P>0.05),另外IR70%组的日增重为-6.3 g/d。宰前活体重、空体重、胴体重和屠宰率随着营养水平的降低有所减少(P<0.05)。随着营养水平的降低,肾周脂肪、系网膜脂肪占空体重的比例显著减少(P<0.05)。随着限饲强度的增加,日增重逐渐下降,体内脂肪沉积也随之减少。综合分析显示,绒山羊的限饲的阈值为IR80%。  相似文献   

11.
Forty-five pigs with an average initial live weight of 60 kg were used to investigate the effects of daily exogenous porcine pituitary growth hormone administration at two dose levels (pGH; 0, excipient buffer injected, and 100 micrograms.kg-1.d-1) for a 31-d period on the performance and body composition of boars, gilts and barrows allowed to consume feed ad libitum. Excipient boars consumed less feed, exhibited faster and more efficient growth (P less than .01) and produced less fat and more protein and water (P less than .01) in the empty body compared with excipient barrows, which in turn contained more fat and less water (P less than .05) in the empty body than did excipient gilts. These differences were largely eliminated by pGH administration, which induced differential effects in growth performance and body composition in boars, gilts and barrows. Growth hormone administration improved growth rate by 13, 22 and 16% and feed conversion efficiency by 19, 34 and 32% in boars, gilts and barrows, respectively. The reduction of body fat content (g/kg) elicited by pGH was 22, 36 and 33% for boars, gilts and barrows, respectively, with a corresponding increase (P less than .01) of body protein and water content. The magnitude of the pGH responses was greatest for gilts and barrows compared with boars, negating intrinsic sex-effect differences in growth performance and body composition of pigs. Pigs used in this study and treated with pGH exhibited a rate of protein deposition (approximately 225 g/d) far greater than previously reported, and as such redefine the genetic capacity for lean tissue growth by the pig.  相似文献   

12.
Fattening of young boars in practice does not develop because of the occurrence of boar odour. In this paper a survey is given of the experiments in this field in The Netherlands. A consumer test involving 720 families divided into four groups judging cutlets or belly cuts from boars or gilts revealed that only a low percentage of the consumers were able to recognize boar odour. It should be taken into account that the boars used in this test had a strong boar odour. Besides that an expert panel considered smoked sausages acceptable in which meat and fat from boars with a strong boar odour was mixed up to a certain extent: up till 25% if consumed cold and between 6 and 12% if consumed warm. The incidence of boar taint as ascertained by meat inspection services in about 2 200 boars was very low: about 6% had a slight odour and only about 1% had a strong odour. Unexpected was the finding that there was no difference in frequency between the boars below and beyond 80 kg carcass weight.In spite of these findings the few consumers sensitive to boar odour should be protected. Pilot experiments with the use of a handsealer in the slaughterline are encouraging, so that boar carcasses with a strong odour may be selected already in the slaughterline.Based on the results of the fattening experiments in The Netherlands the economical advantage of fattening boars over hogs has been calculated. With 10.5 million slaughter pigs in 1972 the profit should have been about 75 million guilders.It is stated that sufficient evidence seems to be available to convince the authorities that removal of statutory bars to fattening uncastrated males should be considered at international and national levels.  相似文献   

13.
Wheat infected naturally with Fusarium, contaminated mainly with deoxynivalenol (DON) (16.6 mg DON/kg), was added to a total constant wheat content of 400 g/kg diet. To distinguish between differences in feed intake and specific effects of the DON contaminated diet, control and DON contaminated feed was administered for 11 weeks under ad libitum and restrictive feeding conditions to 48 pigs of both sexes, which were randomly divided into four groups (n = 12 per group). Feed intake was 2.90 kg/day, live weight gain 987 g/day and feed to gain ratio 2.77 kg/kg for the ad libitum fed control group. The group fed DON contaminated wheat ad libitum significantly consumed 15% less feed and gained 13% less live weight, while the feed to gain ratio was unaffected. Moreover, it was concluded that the lower growth performance by DON contaminated feed resulted mainly from the lower voluntary feed intake, because there were no differences in live weight gain between the groups with the restrictive feeding regimen. On the contrary, metabolizable energy, nitrogen retention digestibility of organic matter, crude protein, crude fat and crude fibre were significantly increased by 3, 10, 3, 6, 9 and 20% in the DON group respectively. Animals fed DON contaminated diets needed more time to consume the restrictive ration than the control group. For example in the first hour after feeding 85% of the control pigs had consumed all feed, but only 39% of the DON group had. There were only few differences in haematological and serum parameters, which were characterized by a high variation between individuals. DON and IgA concentrations in serum were significantly influenced by DON exposure.  相似文献   

14.
The effects of feeding level on body weight (BW), lifetime growth rate, backfat thickness (BF), fatness (BF/BW) and ovulation rate at first (puberty) and second estrus were examined in 145 gilts. From 47.2 kg until puberty, gilts were fed 2.0 kg/d (L) or had ad libitum access to feed (H). From puberty to second estrus, the feed allowance of one-half of the L gilts was increased to 2.8 kg/d. Flush-feeding only normalized ovulation rate (OR) to that observed in gilts with ad libitum access to feed. At puberty, a quadratic negative relationship between lifetime growth rate and age indicated that age at puberty was minimum at a growth rate of less than or equal to .60 kg/d. Thereafter, age at puberty became independent of, or possibly positively related to, lifetime growth rate. Gilts with higher lifetime growth rate also were heavier and fatter at puberty. It was concluded that puberty may have been attained when a certain BF or fatness was achieved, because growth rate of restricted-fed gilts and quickly growing gilts with ad libitum access to feed may have been associated with reduced fat deposition. Hence, maximizing growth rate in replacement gilts does not hasten the attainment of puberty. Growth rate may be manipulated by feed restriction, in order to attain a target BW at boar stimulation (approximately 90 kg), which would coincide with a minimum age (approximately 155 d) and BW at puberty (approximately 97 kg). Nutritional flushing during the first estrous cycle then could be used to normalize OR at mating at second estrus of gilts that were restricted-fed when prepubertal.  相似文献   

15.
Two trials were conducted to evaluate intake restriction, energy, and protein source on the performance and carcass merit of heifers limit-fed corn gluten feed. Trial 1 crossbred heifers (n = 140) were allotted to ad libitum wet corn gluten feed (WCGF)-hay, ad libitum WCGF-corn, WCGF-corn continuously limit-fed to achieve a gain of 1.1 kg/d or WCGF-corn fed in the following sequence: 70% of ad libitum for 20 d, ad libitum for 20 d, and 2 d common intake during the 84-d growing period. One-half of these restricted-refed heifers received a rumen-undegraded protein supplement, and the other half received a rumen degraded protein supplement. Heifers were fed a common finishing diet ad libitum subsequent to the growing period. Heifers offered ad libitum WCGF-hay and WCGF-corn were slaughtered at a common compositional fat end point. Heifers limit-fed WCGF-corn were slaughtered at the same time as heifers offered ad libitum WCGF-corn, regardless of subcutaneous fat cover. Limit-feeding WCGF-corn diets to growing heifers reduced ADG (P < or = 0.01) but did not compromise feed efficiency. Method of intake restriction, continuous or ad libitum-interrupted, and supplemental protein source did not affect combined growing-finishing performance. However, when fed for a common length of time, the average of the limit-fed heifers had lighter carcass weights (P < or = 0.01) and lower (P = 0.04) marbling scores. Heifers offered ad libitum WCGF-hay gained slower (P < or = 0.01) and less efficiently (P < or = 0.01) than heifers offered WCGF-corn. Trial 2 crossbred heifers (n = 222) were allotted to dry corn gluten feed (DCGF)-corn ad libitum or restricted to 80% of ad libitum for 42, 84, or 126 d; or ad libitum corn silage or DCGF-corn silage at 80% of ad libitum for 84 d. Feed efficiency (P = 0.07) and ADG (P = 0.08) tended to behave quadratically, being poorer for heifers limit-fed for 126 d during the growing period. Heifers limit-fed DCGF-corn gained more efficiently (P = 0.05) than heifers grown on ad libitum corn silage. Limit-feeding CGF-corn to growing beef heifers can be used to achieve moderate rates of gain without compromising feed efficiency. However, limit-feeding during the growing period may result in lighter weight carcasses with lower quality grades if not fed to the same fat end point as heifers grown with free access to concentrate.  相似文献   

16.
Three groups of six pigs each (live weight at the beginning of the experiment 20 kg) were given a cereal ration with 8% rape seed meal. Group I did not receive a J supplement and was fed ad libitum. The rations of groups II and III were supplemented with 1 mg J/kg feed. The feed intake of group II was limited to the amount consumed by group I (pair fed); group III received the feed ad libitum. The daily weight gains of the 3 groups were 327, 377 and 613 g, feed expenditure 3.79, 3.68 and 3.47 kg/kg gain. In an N balance experiment carried out with 3 animals each from groups I and II, 41.4% of the N taken in group I and 43.8% in group II were retained (p greater than 0.05). Liver, intestinal fat and leaf were heavier in group I (p less than 0.01), the protein content of the empty body, the bones and bristles significantly lower than in group II. Protein retention in group II was 14% higher than in group I. In case of iodine deficiency protein retention is lower, energy retention, however, is largely unchanged.  相似文献   

17.
Twenty-six 6-week old female New Zealand White rabbits were divided into two groups: ad libitum (AL) and 70% restricted (RS) feeding. At the beginning of the experiment the liveweights were practically the same: 0.99 +/- 0.08 vs. 1.01 +/- 0.08 kg in group AL and RS, respectively. At 18 weeks of age the body weight of Group RS rabbits was 84.7% (3.14 +/- 0.24 kg) of the group AL (3.71 +/- 0.31 kg). The apparent digestibility of crude protein was significantly (p < 0.001) higher in Group RS than in Group AL (76.5 +/- 1.4 vs. 73.0 +/- 2.7%). The daily water consumption was significantly (p < 0.05) higher (3.5 ml/g DM intake) in Group RS as compared to Group AL (1.9 ml/g DM). Since the average body weight in Group RS at 18 weeks was the same as that of Group AL at 14 weeks of age (3.14 kg), the comparison of the live body measures and indices was based on these ages. Animals fed ad libitum or restricted show no differences at the defined age in most live body measurements except in heart girth and rump width, which were significantly (p < 0.05) shorter in Group AL than in Group RS (29.3 +/- 0.8, 5.7 +/- 0.5 and 30.7 +/- 1.0, 6.2 +/- 0.3 cm, respectively). Body capacity was significantly (p < 0.05) smaller in Group AL, as the head capacity-body capacity proportion was significantly (p < 0.05) higher in Group AL than in Group RS (1653.1 +/- 134.5, 22.0 +/- 2.5 and 1913.7 +/- 168.7, 17.7 +/- 1.9, respectively). Due to restricted feeding the growth of the head proved to be less intensive than that of the body at the same body weight. The body in these does tended to be wider. Since the head in comparison to length or capacity of the body was smaller in does fed 70% of ad libitum, it could be concluded that the development of body parts of restricted-fed does was unequal (allometric growth). The effect of feed restriction reflected in lower dry matter and fat, and a higher ash and protein content both in total body and in dry matter composition of rabbits at 18 weeks of age. Restricted feeding delayed sexual maturity (69 vs. 92% of rabbits) with later starting ovarian activity, weaker ovarian responsiveness, and a smaller number of tertiary follicles on the ovarian surface.  相似文献   

18.
为了研究长白山野猪与杜洛克猪杂交1代猪肌内脂肪代谢酶激素敏感脂酶（hormone-sensitive lipase,HSL）和苹果酸脱氢酶（malate dehydrogenase,MDH）活性的发育性变化规律及其对肌内脂肪沉积的影响,试验以5个体重组（20、35、50、70和90 kg）的长白山野猪与杜洛克猪的杂交1代猪（简称野杜F1代猪,各40头,公、母各半）为研究对象,研究了肌肉组织中脂肪代谢酶活性的发育性变化规律与肌内脂肪含量和肌肉嫩度的关系。结果表明,在生长期随着体重的增加,肌肉组织中HSL和MDH的活性差异显著（P<0.05）,野杜F1代猪HSL活性均高于莱芜黑猪的活性（90 kg除外）,且在35 kg时,野杜F1代猪和莱芜黑猪差异极显著（P<0.01）;肌肉组织中的MDH活性变化,野杜F1代猪呈先升后降的趋势,活性最高点在70 kg;在90 kg时野杜F1代猪中MDH活性极显著低于莱芜黑猪（P<0.01）。不同体重阶段,肌肉嫩度差异显著（P<0.05）,且随着体重的增加而呈不断升高的趋势。相关分析结果表明,野杜F1代猪90 kg时肌肉组织中MDH活性与肌内脂肪含量呈极显著正相关（r=0.97,P<0.01）,HSL和MDH的活性与肌肉嫩度呈显著正相关（P<0.05）。研究结果提示,肌肉组织中的HSL和MDH对肌内脂肪的沉积量有一定的影响,可以通过控制其活性调节肌内脂肪的含量,且肌内脂肪的沉积量与肌肉嫩度有一定的联系。  相似文献   

19.
Groups of each 10 boars, weight range 20-60 kg, were fed ad libitum the following 4 rations of similar protein: energy ratio: Ration I (control), Ration II (+ 2% soyaoil ), Ration III (+ 2% soyaoil + 5% lard), Ration IV (+ 7% lard). When the animals reached 60 kg body weight each group was halved. One half had free access to the above rations, while the other half were fed ad libitum on the control ration. At body weights of 50 and 100 kg the concentrations of urea, insulin, glucose and cholesterol were measured, in addition the fatty acid composition of the backfat. At the end of the experiment (100 kg) the content of fat in the carcass was calculated by determining the specific gravidity of the carcass. There was little difference in the intake of metabolizable energy (ME) of the different groups of animals at both body weight ranges as a result of the reduction in feed intake of the fat supplemented diets on account of the higher ME-content. There were little differences in the glucose and urea concentrations in the blood of the animals fed the different rations. The highest cholesterol and the lowest insulin levels were measured in groups III and IV, when 5 and 7% lard was added, respectively. The animals, continuously fed Rations III and IV over the whole period of experiment, had a significantly higher fat content (p less than 0,05) than the control animals. There was a very marked influence of the fatty acid intake on the fatty acid pattern of the backfat. Following the change of feed to the control ration at 60 kg body weight, the linoleic acid content of the animals in Groups III and IV was significantly reduced (p less than 0,001) from 15.7 to 11.2%. However this was higher than the 7.3% linoleic acid measured on the animals continuously fed the control ration.  相似文献   

20.
A total of 315 crossbred females (gilts) ranging in weight from 14 to 68 kg was split between pole-type and a closed piggery (cold and moderate environments, respectively One third of the pigs in each piggery was fed a growing ration ad libitum, the remaining pigs were restrictively fed 80% of the amount consumed by the first group. Data on ultrasonic backfat probe, estimated market index, and age were taken on the pigs at 90 kg live weight. Results indicated that the effect of environmental temperature was very small on backfat thickness and carcass index, but was significant on age. The pigs fed ad libitum had 10.2% thicker backfat, were 4 points inferior in index, but were 13 days younger at 90 kg (P < 0.01) than those restrictively fed. When the gilts exhibited their first oestrus after 90 kg live weight, half of the pigs restrictively fed were flushed by feeding them ad libitum for one oestrus cycle. All gilts were bred at the second oestrus. The gilts raised in a cold environment were 4 kg lighter, farrowed litters 0.2 larger and 0.5 kg heavier than those raised in the moderate environment. Gilts restrictively fed, then flushed gained 3 kg on flushing and farrowed litters averaging 10.7 pigs, 0.2 and 0.8 pigs larger than those of the gilts fed ad libitum and not flushed respectively. Significant differences between crosses were observed in all the traits studied except gestation length and litter size. There was little effect on the different traits of the initial weight at which the gilts were exposed to the treatment.  相似文献   

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