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1.
Seventy-two Rambouillet ewes were fed one of two different levels of energy and protein during gestation to determine the effects of maternal undernutrition on growth and development in their offspring. Levels of energy and protein for the two groups of ewes were: 70% of National Research Council (NRC) requirements 30 d prior to breeding and the first 100 d of gestation and then alfalfa hay fed at 70% of the average consumed by group 2, and 100% of NRC requirements 30 d prior to breeding and throughout gestation. Dissection data from the leg and muscle characteristics were recorded for each lamb. Neither dissected muscle and fat percentages nor proximate analyses of dissected muscles was influenced by ewe undernutrition during early pregnancy. However, the reduced conception rate, increased embryonic/fetal mortality, decreased birth weights and increased lamb mortality resulted in a severe reduction in kilograms of lamb per ewe bred. Feeding ewes 70% of NRC requirements during gestation resulted in lambs with heavier semitendinosus muscle weights, larger muscle fiber diameters and shorter sarcomere lengths than in lambs from adequately fed ewes. No influence of ewe diet, birth type or sex was observed for proportions of muscle fiber type (beta R, alpha R or alpha W). Therefore, low level feeding of ewes during early gestation had no detrimental effects on the carcass or muscle fiber characteristics of their lambs at slaughter.  相似文献   

2.
Changes in muscle growth, calpastatin activity, and tenderness of three muscles were assessed in 20 callipyge and 20 normal wether lambs slaughtered at live weights (LW) of 7, 20, 36, 52, and 69 kg. At 24 h postmortem, the longissimus (LM), semimembranosus (SM), and supraspinatus (SS) muscles were removed and weighed and samples were obtained for calpastatin activity (CA; 24 h) and Warner-Bratzler shear force (WBS; aged 6 d). For muscle weights and calpastatin activity, the weight group x muscle x phenotype interaction was significant (P < 0.05). Muscle weights were similar (P > 0.05) between phenotypes for all three muscles at 7 kg LW. At 20 kg LW, the LM and SM muscles from the callipyge lambs were heavier (P < 0.05) than those from normal lambs; however, the SS did not differ (P > 0.05) between phenotypes at 7, 20, or 52 kg. From 20 to 69 kg LW, the LM and SM weights were 42 and 49% heavier (P < 0.05) for callipyge than for normal lambs. Calpastatin activity of the callipyge LM was greater (P < 0.05) than that of normal LM at 36, 52, and 69 kg. In the callipyge LM, CA was similar (P > 0.05) at 20, 36, and 52 kg LW and did not differ (P > 0.05) from 7-kg or 69-kg values. Calpastatin activity declined (P < 0.05) across the growth curve for the SM and SS, but values were higher (P < 0.05) in the SM in callipyge than in normal lambs. Shear force values of the LM were lower (P < 0.05) for normal lambs at 36, 52, and 69 kg LW than for callipyge lambs. In the SM and SS, WBS values decreased (P < 0.05) across the growth curve, but values were higher (P < 0.05) for callipyge lambs in the SM only. These data indicate that the selective muscular hypertrophy of the callipyge phenotype develops during the postnatal growth period between 7 and 20 kg LW (19 and 100 d of age). Longissimus and semimembranosus muscles in the callipyge lambs were over 40% heavier from 20 to 69 kg LW; however, they also had higher levels of calpastatin activity and Warner-Bratzler shear force during this time period, indicating the need for postmortem tenderization treatments to improve palatability.  相似文献   

3.
Cimaterol-induced muscle hypertrophy and altered endocrine status in lambs   总被引：5，自引：0，他引：5  
The objectives of this study were 1) to determine how cellular growth of skeletal muscle is altered by the repartitioning agent cimaterol and 2) to determine if cimaterol alters endocrine status in association with its repartitioning effects. Thirty Dorset wether lambs were randomly assigned to a pre-treatment baseline group or received 0 or 10 ppm cimaterol in a complete, mixed, high-concentrate diet for 7 or 12 wk. Weights of biceps femoris (BF), semimembranosus (SM) and semitendinosus (ST) muscles were 32.8, 27.1 and 31.5% greater, respectively, in treated lambs at 7 wk, and were 22 to 24% greater at 12 wk. Longissimus (LD) cross-sectional area was 26 and 32% greater at these treatment intervals. Percent type I fibers declined significantly over the course of the experiment in ST, SM and LD, and cimaterol caused a small but significant reduction in percent type I fibers in the ST at 7 and 12 wk. Muscles from lambs fed cimaterol contained 50 and 75% more fibers that exhibited negative staining for phosphorylase activity. Mean cross-sectional area of type I and type II fibers in the combined portions of the ST were 30.4 and 29.3% greater, respectively, in cimaterol-fed lambs after 12 wk, while type I and type II fiber areas in the longissimus were only 13 and 15% greater, respectively. Cimaterol-induced hypertrophy of the ST resulted in both protein and RNA content being 30 to 35% greater (P less than .01) at 7 and 12 wk, while DNA concentration was 22% less (P less than .01) at 7 wk. DNA concentration returned to normal by 12 wk. These results indicate that cimaterol elicits a rapid increase in muscle RNA and protein accretion without concurrent incorporation of satellite cell nuclei. Plasma insulin and insulin-like growth factor-1 (IGF-1) concentrations were 55 and 34% lower, respectively, in cimaterol-fed lambs. Plasma somatotropin concentration and area under the curve were 2.3 times greater (P less than .01) in lambs fed cimaterol for 6 wk, while plasma cortisol, prolactin and glucose concentration were unaffected at 6 or 12 wk. The significant changes in endocrine status may be important in the mechanism(s) of cimaterol in altering muscle accretion.  相似文献   

4.
Booroola Merino (BM) and Finnsheep (FS) rams were mated to FS and crossbred (CO) ewes to compare their effects on the productivity of their mates and the performance of their progeny. Effects of breed of ram and the interaction of breed of ram X breed of ewe were no significant for fertility, total number born, number born alive, litter birth weight, or number of lambs weaned by the ewe or in the nursery. Birth weights of FS- and BM-sired lambs were equal, but FS-sired lambs were heavier at weaning and 147 d of age. Compared with BM-sired lambs, survival from birth to weaning of dam-reared lambs was greater for FS-sired lambs produced by CO dams than for FS-sired lambs produced by FS dams. At a constant live weight, FS-sired lambs had a heavier carcass with less external fat thickness than BM-sired lambs. Percentage of ewe lambs reaching puberty was lowest and age at puberty was highest for the BM X CO cross; relatively small differences existed between the other three genotypes for these traits. Ewe lambs sired by BM had a greater ovulation rate than FS-sired ewe lambs. Embryo mortality was greater in BM X CO ewe lambs than in ewe lambs of the other three genotypes; the difference was larger for ewes with three ovulations than for ewes with two ovulations. The net result was that BM X CO ewe lambs averaged slightly fewer lambs born than FS X CO ewes. The BM X FS ewe lambs had larger litters than the FS ewes due to a substantially higher ovulation rate and only a slightly lower overall embryo survival rate. With the exception of ovulation rate and litter size, FS rams produced lambs with a more desirable level of performance than did BM rams.  相似文献   

5.
Two trials examined genetic and environmental influences on muscle fiber type proportions. Trial 1 compared Polypay and Coopworth x Polypay male lambs either left intact or castrated early, mid or late in growth. Trial 2 compared Hampshire-sired lambs (females, early castrate wethers and late castrate wethers) from Suffolk x Coopworth dams and whiteface x Coopworth dams. Half the lambs in each trial were raised from weaning to 52 kg slaughter weight in drylot; the other half were reared to 41 kg on pasture before being finished in drylot. Analysis of longissimus tissue samples revealed no significant differences among rams, wethers and ewes in proportions of muscle fiber types. Early castration increased the proportion of alpha red fibers in Trial 1 (P less than .01) but not in Trial 2. Polypay lambs had a higher proportion of beta red fibers (P less than .05) than the Coopworth x Polypay lambs, but no differences were seen between the genotypes of Trial 2. Single-born lambs in Trial 1 had a 6% higher proportion of alpha white fibers (P less than .05) than twin-born lambs; however, this difference was not detected in Trial 2. Drylot lambs had a higher proportion of beta red fibers than pasture-reared lambs, the difference being 5% (P less than .01) in Trial 2. Muscle fiber type proportions were not found to be related to growth rate and carcass fatness, and no evidence of differential fiber transformation was found in this trial.  相似文献   

6.
To determine effects of clenbuterol (CB) on muscle protein turnover and growth hormone (GH) secretion, 16 crossbred wether lambs (14.4 kg) were randomized into two groups designated to receive daily oral boluses of gelatin capsules containing corn starch with either 0 (control, CTL) or 1.87 mg/kg body weight CB for either 14 (n = 8) or 28 d (n = 8). This calculates to be approximately 40 mg CB/kg diet. Lambs had ad libitum access to a 16% crude protein corn-soy diet and feed consumption (FC) was measured. After 14 and 28 d, lambs were slaughtered and semitendinosus (ST), longissimus (LD) and brachialis (BR) muscles were exercised, weighed and analyzed for protein (TP) content. For 6 h prior to slaughter of 28-d lambs, 2.5 microCi L-[U-14C]tyrosine/kg was infused intravenously, blood was sampled and plasma was analyzed for specific radioactivity of tyrosine. Plasma GH concentrations were assessed by radioimmunoassay. No differences due to treatment were found in FC, rate of gain or GH concentrations. Semitendinosus and BR weights of control lambs at 14 d did not differ between treatments. At 28 d, ST and BR weights of control lambs (58.8 and 18.5 g, respectively) were less (P less than .10) than those of lambs treated with CB (74.3 and 23.1 g, respectively). The TP per ST and BR at 28 d for control lambs was 71.5 and 85.1% (P less than .10) that of muscles of lambs treated with CB. Fractional protein synthesis rates (FSR) of the BR (9.4 vs 6.1%/d) and total protein synthesized in ST muscle per day (1.4 vs .8 g) were elevated (P less than .10) in lambs treated with CB compared to controls. These data suggest that the increased fractional accretion rate observed in lambs treated with CB for 28 d was caused by increased FSR.  相似文献   

7.
Thirty two barrows were used in a 2 x 3 factorial arrangement to evaluate the effects of porcine somatotropin (pST) administration (USDA-pGH-B1; 0 and 100 micrograms.kg BW-1.d-1) and feed intake (FI; ad libitum [A], 1.64 [R1:80% of A] and 1.38 [R2:60% of A] kg/d) on longissimus (LM) muscle fiber characteristics of pigs growing from 25 to 55 kg live weight. The administration of pST resulted in an increase (P less than .05) in muscle fiber size (all three fiber types) and shear-force (17.1%). The percentage of muscle fiber types was not affected by pST treatment. Feeding of the diet at restricted levels (R1 and R2) resulted in smaller (P less than .05) beta R and alpha W fibers compared with feeding ad libitum. Pigs with ad libitum access to their diet had fewer alpha R fibers and more alpha W fibers in the LM compared with those fed at R1 and R2 levels. Restricted feed intake (R1 and R2) resulted in lower (P less than .05) shear-force values compared with ad libitum feeding. The present study indicates that pST administration of young barrows results in an increase in muscle hypertrophy. Restricted FI reduces both transformation from alpha R to alpha W fibers and muscle fiber hypertrophy.  相似文献   

8.
The characteristic myopathic features revealed by histological observations included strong proliferation of connective and fatty tissue, perivascular infiltrations and necrosis of muscle fibers with phagocytosis to the lesser extent. In the myopathic muscle, as well as in giant fibers, histochemical techniques showed a reduction in succinate dehydrogenase and lactate dehydrogenase activity in type beta R (slow-twitch, oxidative) and alpha R (fast-twitch, oxidative and glycolytic). Magnesium-activated adenosine triphosphatase reaction ranged from diffuse to negative in beta R, alpha R and alpha W (fast-twitch, glycolytic) fiber types. Diffuse reaction for acid phosphatase and total loss of glycogen content were observed. The micrographs of the myopathic muscle indicated enlarged mitochondria with atrophy or complete destruction of cristae. Many myofibrils were hypercontracted. Giant fibers possessed mitochondria enlarged to an even greater extent and many of the myofibrils had loss of continuity, were narrow, depleted and were also hypercontracted. Significant differences between myopathic and normal groups were found in number of beta R fibers (lower in the myopathic group), number of alpha R fibers and percent of alpha R and alpha W fibers (higher in the myopathic group). Differences (P less than .01) existed between meat pH1 value in the myopathic group (mean value of 5.95) and the normal group (mean value of 6.29). Meat from the myopathic group of pigs also had a lower (P less than .01) pH24 value and reduced water-holding capacity (P less than .01) relative to the meat of the normal pigs. The lack of difference of fattening and slaughter traits between the groups suggested that the White Zlotnicka pigs is of particular value because it is possible to improve the production traits without increasing the incidence of these syndromes within the breed. Negative correlations (P less than .05) between number of giant fibers and percent of alpha W fibers, and between percent of giant fibers and percent of alpha W fibers indicate that alpha W fibers can undergo degeneration and be transformed into giant fibers. Therefore, it it suggested that giant fibers should be treated as muscular, pathological results of past stresses and not as an additional type of normal muscle cells.  相似文献   

9.
Targhee x Hampshire lambs (average BW 23 +/- 1 kg) were used in two experiments to determine the effects of finishing on concentrate with an anabolic implant or forage grazing after concentrate feeding on growth, organ and viscera weights, and carcass tissue accretion. In Exp. 1 and 2 lambs were penned by sex and assigned for slaughter at initial (23 kg), intermediate (37 kg), or end BW (ewes, 47.7; wethers 50.4 kg). From 23 to 37 kg BW, lambs were fed all-concentrate diets in drylot (DL) or grazed on alfalfa (ALF). Experiment 1 was a 2 x 2 factorial with 28 lambs; factors were wether vs ewe lambs and unimplanted vs DL implanted with trenbolone acetate-estradiol benzoate. There were no differences in organ and viscera weights due to implant status. However, ADG (P < .03) and lean gain (P < .02) were greater for implanted than for unimplanted wethers (507 vs 357 g and 1,314 vs 656 g, respectively). Ewes did not respond to the implant. Fat accretion was not affected by implantation. Experiment 2 was a 2 x 3 factorial with 42 lambs; factors were wether vs ewe lambs and drylot during growing and finishing phases (DL-DL) vs drylot during growing and alfalfa grazing during finishing (DL-ALF) vs alfalfa grazing during growing and finishing phases (ALF-ALF). In Exp. 2, ADG of DL-DL lambs was greater (P < .01) than ADG of DL-ALF or ALF-ALF lambs. Lambs on ALF-ALF had smaller (P < .05) livers and rumen/reticulum weights but heavier (P < .04) kidney, omasum, small and large intestine, and cecum weights than those on DL. In Exp. 2, DL-ALF and ALF-ALF lambs had overall hindsaddle lean gain equal to those on DL-DL with less mesenteric fat and 100 g less separable fat. Finishing lambs on alfalfa reduced fat accretion without decreasing lean accretion, whereas trenbolone acetate implants for lambs fed concentrate increased BW gain and lean accretion without affecting fat accretion.  相似文献   

10.
Carcass data from more than 4,400 Southdown x Romney ewe and wether lambs collected over a 16-yr period were analyzed for the effects of sex, rearing status, and growth rate. Ewe lambs grew more slowly than wethers and had .78 kg less carcass weight at the same age. The carcass weight advantage for wethers was nearly all caused by heavier fat-free weight. Based on fat depths, the fat on ewe lambs was distributed in more anterior and ventral parts of the carcass relative to wether lambs. Lambs reared as twins had 1.73 kg less carcass weight and correspondingly reduced carcass measurements compared with lambs reared as singles. Sex and rearing status interacted for some traits. However, in no case was a significant sex difference reversed in single- and twin-related lambs. Growth rate effects were determined by regressing average change in carcass measurements on average carcass weight gain over a 5-wk period. When carcass weight remained constant over a 5-wk period, fat weight increased by .12 kg, fat-free weight and muscle measurements decreased, and bone lengths increased. For each kilogram of increase in 5-wk carcass weight gain, the marginal increase in fat weight was .41 kg and that of fat-free weight was .59 kg. At the average 5-wk carcass weight gain of 1.4 kg, fat and fat-free gains were As carcass weight gain increased above 1.4 kg, fat-free gain exceeded fat gain.  相似文献   

11.
Twenty-four barrows were used to investigate the effects of exogenous porcine somatotropin (pST) administration (0 and 100 micrograms.kg-1.d-1) between 30 and 60 kg on longissimus muscle morphology and meat tenderness of pigs grown to 90 kg. Administration of pST was by daily i.m. injection. Pigs were fed a fortified diet in restricted amounts between 30 and 60 kg and had ad libitum access to this diet from 60 to 90 kg. Excipient pigs had fewer alpha R fibers and more alpha W fibers than pST-treated pigs (P less than .05). Administration of pST increased (P less than .05) muscle fiber area for all three fiber types at both the 60 kg (34%) and 90 kg (29%) slaughter weights. Furthermore, pST administration increased shear-force (30% at 60 kg; 19% at 90 kg) of the longissimus muscle, indicating that pST administration reduced meat tenderness. All the pST-treated pigs exhibited the "giant fiber syndrome" and a high proportion (62%) of pST-treated pigs exhibited pale, soft, exudative muscle. Whether the giant fiber anomaly resulted from increased muscle protein accretion rate or fiber degeneration is unknown. Results indicated that the stimulatory effects of pST on muscle growth are sustained following cessation of hormone treatment. However, the incidence of pale, soft, exudative muscle in 62% of the pST-treated pigs indicates that pST potentially has undesirable side effects.  相似文献   

12.
Salbutamol (2.7 ppm) fed to pigs between weaning and slaughter increased ADG (5%), dressing percentage (2%) and cross-sectional area of the longissimus (LD) muscle (14%). In fatter, White-line-sired pigs, but not in leaner, Meat-line-sired animals, it reduced backfat thickness (25%). Liver weight and glycogen concentration also were decreased. In neither genotype were there effects of Salbutamol on pH45, drip loss or reflectance value of the LD, but ultimate pH was elevated in semimembranosus (SM), adductor (AD) and supraspinatus (SS) muscles, resulting in reduced color saturation values. Total muscle heme pigment concentrations were reduced by 10 (SS) to 19% (LD and SM) and the intramuscular fat concentration of the AD, but not the LD, was reduced by 21%. Treated pigs had LD and SM muscles that when measured instrumentally were 15 and 8% tougher, respectively, after cooking, but the texture of the SS was not significantly altered by treatment. Salbutamol increased plasma lactate and creatine phosphokinase (CPK) concentrations. Compared with White-line-sired animals, Meat-line-sired pigs had a higher dressing percentage (2%) and LD muscles with larger cross-sectional area (13%). They also had higher circulating CPK levels.  相似文献   

13.
Ten crossbred (Suffolk X Rambouillet) whether lambs were randomly assigned to receive 0 or 10 ppm cimaterol (CIM) in a completely mixed high-concentrate diet for 8 wk. Total weight gain and feed efficiency were improved 29% (P less than .05) and 14%, respectively, in the CIM-fed group. CIM also improved (P less than .01) dressing percent by 4.9 percentage points and improved yield grade by one grade. CIM increased longissimus muscle (LD) area 38% (P less than .01) and the yield of four lean cuts 28% (P less than .01). No difference was found in the proportion of type I (slow-contracting, oxidative) and type II (fast-contracting, mixed glycolytic/oxidative) fibers in LD and semitendinosus (ST) muscles between control and CIM groups, indicating no change in fiber type. The cross-sectional area of type II fibers in LD and ST muscles of the CIM group was 2,081 and 1,951 micron 2 as compared with 1,391 and 1,296 micron2 of the control group, respectively. The increase was approximately 50% (P less than .01). No difference was found in cross-sectional area of type I fibers, indicating that the increase of muscle mass was due to hypertrophy of type II fibers only. DNA concentration (micrograms/g wet muscle or microgram/g protein) of CIM muscle was much lower (P less than .01) than that of control muscle, suggesting that the protein accretion in muscle was accomplished without additional incorporation of nuclei from satellite cells.  相似文献   

14.
为了研究3种营养水平(A1-0.7×NRC、A2-0.8×NRC、A3-0.9×NRC)全混合日粮对舍饲羔羊生产性能、养分表观消化率和屠宰性状的影响,本试验选择48只南非肉用美利奴×甘肃高山细毛羊杂交一代羔羊,随机分为3个处理组,进行为期60 d的育肥试验。结果显示,在全混合日粮饲喂技术下,饲喂A2、A3营养水平日粮组的羔羊全期平均日增重极显著高于A1营养水平组(P<0.01),A2和A3营养水平组差异不显著(P>0.05),公羔全期平均日增重极显著高于母羔(P<0.01);A因子对钙、总磷、中性洗涤纤维、酸性洗涤纤维消化率均有极显著影响(P<0.01),性别仅对钙、总磷消化率有极显著影响(P<0.01),但营养水平与性别没有显著交互作用(P>0.05);营养水平对育肥羔羊的屠宰性能没有显著影响(P>0.05),但杂种羔羊的屠宰率、熟肉率、眼肌面积等高于甘肃高山细毛羊。以上结果表明采用0.8×NRC营养水平全混合日粮育肥南非肉用美利奴×甘肃高山细毛羊杂交一代羔羊较为适宜,在同一营养水平下,公羔生长性能优于母羔。  相似文献   

15.
There is a need to improve the lean tissue content of ruminant animals destined for meat production. Muscle fiber number is set during fetal development. The effect of undernutrition of pregnant ewes on subsequent muscle fiber characteristics of their offspring was investigated. The trial involved 32 pregnant ewes carrying twins. The ewes were allocated randomly to one of four groups: three different treatment groups (n = 8) and a control group (n = 8). The diet of the treatment groups was dropped to 50% of their daily requirement to support the ewe and allow for conceptus growth for varying periods before being returned to 100% of their daily requirement until term. Group d 30-70 ewes were fed 100% of their daily requirement until d 30, the diet was then decreased to 50% until d 70; it was then returned to 100% of their daily requirement until term. Group d 55-95 ewes were similarly restricted from d 55 through 95, and Group d 85-115 ewes were restricted from d 85 through 115. The control group was fed 100% of their daily requirement to support the ewe and allow for conceptus growth throughout gestation. After parturition, the lactating ewes were fed a normal commercial diet. On d 14 (after parturition), the lambs were slaughtered and the LM, semitendinosus (ST), and vastus lateralis (VL) were dissected and snap frozen. The immunochemical determination of myosin heavy-chain slow (MHC-slow) and myosin heavy-chain fast (MHC-fast) proteins was measured by immunoprobing of Western blots. The number of fast and slow fibers and the diameter of these fibers also were measured in each muscle sample by histochemical techniques. Decreased maternal nutrition before fiber formation (d 30 through 70) was observed to change the muscle characteristics of the newborn lambs. These lambs had significantly fewer fast fibers (P < 0.001) and significantly more slow fibers (P < 0.001) in both the LM and VL compared with the other groups. Maternal nutrient restriction at the other periods had no effect on the number of muscle fibers in the newborn lambs; however, a decrease (LM, P < 0.05; VL, P < 0.01; ST, P = 0.08) in muscle weight was observed in the lambs born to the ewes restricted between d 85 and 115 of gestation compared with the other groups. This study has shown that decreased maternal diet before muscle fiber formation will alter the muscle fiber development in the fetus.  相似文献   

16.
Targhee x Hampshire lambs (average BW 24 +/- 1 kg) were used to determine the effect of finishing on concentrate or by grazing ryegrass forage on slaughter weights of 52 kg (N) or 77 kg (H) on tissue accretion and lamb wholesale cutout. When fed to similar slaughter weights, the wholesale cuts of concentrate-fed lambs were heavier (P < 0.05) than the same cuts from forage-fed lambs; however, when expressed as a percentage of side weight, carcasses of forage-fed lambs had a higher (P < 0.001) percentage of leg than concentrate-fed lambs. Increasing slaughter weight from 52 to 77 kg resulted in a 1-kg increase in loin weight for lambs finished on concentrate and a 0.60-kg increase for lambs finished on forage (diet x slaughter weight, P < 0.03); however, the increased loin weight for lambs finished on concentrate was due largely to increased fat deposition. For lambs slaughtered at 77 kg, those finished on forage had more lean mass in the leg, loin, rack, and shoulder than those finished on concentrate, but lean mass in these cuts did not differ between diets for lambs slaughtered at 52 kg (diet x slaughter weight, P < 0.01). At the normal slaughter weight (52 kg), concentrate-fed lambs had 50% more dissectible fat than forage-fed lambs, whereas at the heavy slaughter weight, a 79% greater amount of dissectible fat was observed for concentrate- vs. forage-fed lambs (diet x slaughter weight, P < 0.001). Lean and fat accretion rates were higher (P < 0.001) for concentrate-fed lambs than for forage-fed lambs. The lean-to-fat ratio of forage-fed lambs was higher (P < 0.001) than that of concentrate-fed lambs; however, forage finishing decreased accretion rates of all tissues compared with concentrate feeding, and these differences between forage and concentrate feeding were magnified at heavier slaughter weights.  相似文献   

17.
This study investigated effects of birth weight and postnatal nutrition on growth and development of skeletal muscles in neonatal lambs. Low (L; mean +/- SD 2.289 +/- .341 kg, n = 28) and high (H; 4.840 +/- .446 kg, n = 20) birth weight male Suffolk x (Finnsheep x Dorset) lambs were individually reared on a liquid diet to grow rapidly (ad libitum fed, ADG 337 g, n = 20) or slowly (ADG 150 g, n = 20) from birth to live weights (LW) up to approximately 20 kg. At birth, weight of semitendinosus (ST) muscle in L lambs was 43% that in H lambs; aggregate weights of ST and seven other dissected muscles were similarly reduced. In ST muscle of L lambs, mass of DNA, RNA, and protein were also significantly reduced to levels 67, 60, and 34%, respectively, of those in H lambs. However, myofiber numbers of ST, tibialis caudalis, or soleus muscles did not differ between the L and H birth weight lambs and did not change during postnatal growth. During postnatal rearing, daily accretion rate of dissected muscle was lower in L than in H lambs. Accretion of muscle per kilogram of gain in empty body weight (EBW) was reduced in the slowly grown L lambs compared with their H counterparts, although the difference was less pronounced between the rapidly grown L and H lambs. Throughout the postnatal growth period, ST muscle of L lambs contained less DNA with a higher protein:DNA ratio at any given muscle weight than that of H lambs. Slowly grown lambs had heavier muscles at any given EBW than rapidly grown lambs. Content of DNA and protein:DNA ratio in ST muscle were unaffected by postnatal nutrition, but RNA content and RNA:DNA were greater and protein:RNA was lower at any given muscle weight in rapidly grown lambs. Results suggest that myofiber number in fetal sheep muscles is established before the presumed, negative effects of inadequate fetal nutrient supply on skeletal muscle growth and development become apparent. However, proliferation of myonuclei may be influenced by fetal nutrition in late pregnancy. Reduced myonuclei number in severely growth-retarded newborn lambs may limit the capacity for postnatal growth of skeletal muscles.  相似文献   

18.

Background

Selenium is part of the antioxidant defence system in animals and humans. The available selenium concentration in soil is low in many regions of the world. The purpose of this study was to evaluate the effect of organic versus inorganic selenium supplementation on selenium status of ewes, their lambs, and slaughter lambs.

Methods

Ewes on four organic farms were allocated five or six to 18 pens. The ewes were given either 20 mg/kg inorganic selenium as sodium selenite or organic selenium as selenized nonviable yeast supplementation for the two last months of pregnancy. Stipulated selenium concentrations in the rations were below 0.40 mg/kg dry matter. In addition 20 male lambs were given supplements from November until they were slaughtered in March. Silage, hay, concentrates, and individual ewe blood samples were taken before and after the mineral supplementation period, and blood samples were taken from the newborn lambs. Blood samples from ewes and lambs in the same pens were pooled. Muscle samples were taken from slaughter lambs in March. Selenium concentrations were determined by atomic absorption spectrometry with a hydride generator system. In the ANOVA model, selenium concentration was the continuous response variable, and selenium source and farm were the nominal effect variables. Two-sample t-test was used to compare selenium concentrations in muscle samples from the slaughtered lambs that received either organic or inorganic selenium supplements.

Results

In all ewe pens the whole blood selenium concentrations increased during the experimental period. In addition, ewe pens that received organic selenium had significantly higher whole blood selenium concentrations (mean 0.28 μg/g) than ewe pens that received inorganic selenium (mean 0.24 μg/g). Most prominent, however, was the difference in their lambs; whole blood mean selenium concentration in lambs from mothers that received organic selenium (mean 0.27 μg/g) was 30% higher than in lambs from mothers that received inorganic selenium (mean 0.21 μg/g). Slaughter lambs that received organic selenium had 50% higher meat selenium concentrations (mean 0.12 mg/kg wet weight) than lambs that received inorganic selenium (mean 0.08 mg/kg wet weight).

Conclusion

Organic selenium supplementation gave higher selenium concentration in ewe and newborn lamb blood and slaughter lamb meat than inorganic selenium supplementation.  相似文献   

19.
This study utilized maternal undernutrition from early to midgestation in the ewe to determine the impact(s) of intrauterine growth restriction on postpartum growth of male offspring and the potential mechanisms involved. Multiparous ewes were fed 50% (nutrient-restricted) or 100% (control-fed) of their nutrient requirements (NRC, 1985) between d 28 and 78 of gestation, and then all ewes were fed 100% of the NRC requirements from d 79 through lambing. Male lambs born to nutrient-restricted (n = 9) and control-fed (n = 9) ewes exhibited similar BW (5.8 vs. 6.0 +/- 0.3 kg) and crown-rump lengths (53.8 vs. 55.4 +/- 1.0 cm) at birth. At 63 and 250 d of postnatal age, wether lambs were subjected to a glucose tolerance test, in which a bolus of glucose was administered i.v. to evaluate changes in glucose and insulin concentrations. After i.v. glucose administration at 63 d of age, lambs from nutrient-restricted ewes exhibited a greater area under the curve for glucose (AUCg; 6,281 vs. 5,242 +/- 429; P < 0.05) and insulin (AUCi; 21.0 vs. 8.6 +/- 1.9; P < 0.001) than lambs from control-fed ewes. After glucose administration at 250 d of age, lambs from nutrient-restricted ewes had greater AUCg (7,147 vs. 5,823 +/- 361; P < 0.01) but a lower AUCi (6.4 vs. 10.2 +/- 1.9; P = 0.05) than lambs from control-fed ewes. Lambs from nutrient-restricted ewes were heavier (26.6 vs. 21.8 +/- 2.3 kg; P < 0.05) and had more backfat (0.30 vs. 0.21 +/- 0.03 cm, P < 0.05) by 4 mo of age than the lambs from control-fed ewes. At slaughter at 280 d of age, lambs from nutrient-restricted ewes remained heavier than lambs from control-fed ewes, had greater (P < 0.05) amounts of kidney and pelvic-area adipose tissue, and tended (P < 0.10) to have reduced LM and semitendinosus muscle weights as a percentage of HCW. These data demonstrate that a bout of maternal undernutrition during early to midgestation in sheep increased BW and fat deposition during adolescence and dysregulated glucose uptake in the absence of any change in birth weight.  相似文献   

20.
为了研究波尔山羊与河南淮山羊杂交羊的生长发育情况以及肌肉品质特性,本研究采用生长性能常规测定以及国标法和组织化学染色法对舍饲条件下的波淮杂交羊的体重体尺指标、屠宰性能、胴体肌肉的常规营养成分（水分、粗蛋白质、粗脂肪、粗灰分、钙、磷、镁、铁和硒）、17种氨基酸含量和不同部位（臂三头肌、股二头肌、背最长肌）肌肉的纤维组织特性（肌纤维直径、肌纤维密度）进行测定分析。结果显示,波淮杂交羊初生阶段公羊体重、体斜长、体高、管围均显著高于母羊（P<0.05）;1月龄、3月龄和6月龄时公羊体重、体斜长、体高和胸围均显著高于母羊（P<0.05）;1岁以及1.5岁时公羊体重和体尺等指标均显著高于母羊（P<0.05）。6月龄屠宰的波淮杂交羊公母羊胴体重分别为12.94和11.33 kg,屠宰率分别为49.01%和48.34%,屠宰性能的各项指标均差异不显著（P>0.05）。胴体肌肉中水分、粗脂肪、粗蛋白质、粗灰分分别占比71.00%、2.10%、19.17%和2.31%,胆固醇含量为62.93 mg/100 g;镁、钙、铁、硒、磷的含量分别为248.00、40.57、17.00、0.08、210.12 mg/kg。赖氨酸、组氨酸、精氨酸占FAO指标比例分别为123.87%、140.42%、102.88%,这3种氨基酸含量均高于FAO/WHO（理想蛋白模式）的评价标准;苏氨酸、亮氨酸占FAO指标分别为86.80%、82.00%,与FAO理想蛋白模式的氨基酸含量差距不大。苯丙氨酸占FAO指标的36.90%,与FAO理想蛋白模式的氨基酸含量差距较明显。臂三头肌的肌纤维直径（39.98 μm） > 股二头肌的肌纤维直径（36.53 μm） > 背最长肌的肌纤维直径（27.06 μm）。本试验结果表明,舍饲条件下波淮杂交羊屠宰性能较好,肌肉中的氨基酸、蛋白质、脂肪和主要几种矿物质含量丰富,肌肉中脂肪呈现大理石纹状分布,为下一步地方山羊品种的杂交改良和优质羊肉产品开发提供了参考依据。  相似文献   

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