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1.
A trial was carried out to determine the optimal height of feeding troughs above floor level and the spacing between pen railings which would enable sheep to access feed troughs but prevent them from getting out of pens during sea voyages. The trial involved a group of 16 large (79 kg) wether sheep and 24 small (30 kg) wether lambs which were held in pens and trained to eat lucerne pellets. Feed troughs similar to those used on ships were constructed 260 mm deep and 220 mm wide. A system of adjustable railings were used to alter the trough height and to determine the optimal spacing to allow the large sheep to get their heads through, but to prevent small sheep from escaping.

In order that sheep of various sizes can access feed from the bottom of feed troughs, the height of the top edge of the trough should not exceed 360 mm above floor level for 30 kg sheep or 460 mm for mature sheep. This range is due to differences between the groups in their shoulder height, and variation between individuals within each group. Shoulder heights of the small sheep used in this trial ranged from 505 to 590 mm, and for the 16 mature animals the range was 610–715 mm. It is important that the feed troughs are low enough for all animals to access the feed on offer.

In order that sheep of various sizes can access feed from the bottom of feed troughs, the height of the top edge of the trough should not exceed 360 mm above floor level for 30 kg sheep or 460 mm for mature sheep. This range is due to differences between the groups in their shoulder height, and variation between individuals within each group. Shoulder heights of the small sheep used in this trial ranged from 505 to 590 mm, and for the 16 mature animals the range was 610–715 mm. It is important that the feed troughs are low enough for all animals to access the feed on offer.

Mature sheep were able to pass their heads between rails spaced at 200 mm without difficulty, but some difficulty was experienced when the space was reduced to 180 mm. The maximum rail spacing which prevented the escape of 30 kg lambs could not be determined with certainty because they could pass through a space of only 180 mm when laid on their side, but the smallest space through which they passed voluntarily was 220 mm. Hence the optimal spacing between railings which would allow all sheep good access to feed and would prevent almost all small sheen from escaping is about 190–210 mm.  相似文献   

2.
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   

3.
In the first of 2 experiments, a simulated voyage was conducted to examine the effects of various treatments on bodyweight change and feeding frequency of inappetant sheep at the end of lot-feeding (non-feeders). The treatments, applied during simulated shipping, were: normal quantities of feed and length of troughs; extra trough length; extra feed. Adult Merino wethers (n = 108) were used in each treatment. A voyage to the Middle East was then conducted to establish whether shipboard mortality could be reduced by separating non-feeders (n = 305) from feeders (n = 5,620) late in the feedlot hase and housing the groups separately aboard ship. A control group of non-feeders (n = 215) mixed with feeders (n = 5,732) was used for comparison. Bars (marker bars), containing a coloured dye, were attached to feed troughs to mark sheep that fed. Most non-feeders (82%) began eating when placed in shipping pens in both studies. However, there was no significant difference in percentage of sheep that fed between non-feeders given extra trough length or extra feed compared with non-feeders given standard management at any stage of simulated shipping. There was no significant difference in mean bodyweights between treatment groups on days 1, 8 and 15 of simulated shipping. Differences in bodyweight on d 22 were probably associated with different levels of gut fill. Death rates were not significantly different in separated and control groups (1.1%, 0.9%, P = 0.6) in the voyage of 14 d to the Middle East.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

4.
Sixteen Debouillet wether lambs (approximately 3 mo old) were placed indoors in 1.5- x 3-m pens (14 h light:10 h dark) 28 d after weaning. Lambs received no implant or a 12-mg zeranol implant on d-2 (eight lambs/group). Two days later (d 0), animals received either 0 or 2.5 mg ovine growth hormone (oGH, eight lambs/group) s.c. on alternate days for 42 d. Animals had ad libitum access to water, salt, mineral and a pelleted alfalfa diet (16% CP). After 42 d, lambs were slaughtered to evaluate carcass traits, organ weights and femur characteristics. Zeranol by oGH interactions were not detected (P greater than .20). Zeranol increased (P less than .05) BW, improved (P less than .05) feed:gain during the first 20 d and increased (P less than .10) feed intake during the last 22 d of the 42-d trial compared with controls. Carcass characteristics were not altered (P greater than .10) by 12 mg zeranol. Serum insulin and prolactin were elevated (P less than .05), but serum GH was not influenced by zeranol compared with controls. Exogenous oGH decreased feed intake (P less than .10) and improved feed:gain (P less than .05) during the initial 20 d compared with controls, but did not influence (P greater than .20) these variables during the last 22 d of the study. Carcass traits were not influenced (P greater than .10) by oGH. Exogenous ovine GH dramatically elevated (P less than .05) serum GH, but did not affect serum insulin or prolactin (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
Two trials were conducted to evaluate effects of dietary potassium (K) concentration and lasalocid (L) in lamb finishing diets. Treatments were arranged in a 2 X 2 factorial and consisted of a 65% concentrate diet with 1.1% K (C), .9% K + 21.3 mg L/kg (CL), 2.1% K (P) and 2.5% K + 20 mg L/kg (PL). In trial 1, 64 fine-wool lambs (initial wt 35.3 kg) were randomly assigned to the four treatments (two pens of four wethers and four ewes/treatment) for a 56-d feeding trial. Average daily gain was not affected by K, but was increased (P less than .10) by L (.23 vs .26 kg/d). Lasalocid tended (P less than .20) to improve feed:gain ratio (5.6 vs 6.3). A K X L interaction (P less than .06) was noted for feed intake, with values of 1.37, 1.45, 1.49 and 1.51 kg X head-1 X d-1 for the C, CL, P and PL groups, respectively. In trial 2, 16 wether lambs (four/treatment fed at 2% of body weight) were used in a site and extent of digestion and nitrogen (N) balance trial, using the same four diets as in trial 1. Site of digestion was estimated from abomasal samples taken at slaughter, with indigestible acid detergent fiber as a marker. Total tract organic matter digestibility was increased (P less than .05) with added K (80.1 vs 76.4%) and L (80 vs 76.4%). Ruminal starch digestibility was not affected by added K, but was decreased (P less than .10) by added L (71.8 vs 88.2%).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

6.
Dried tansy ragwort (Senecio jacobaea), which contains pyrrolizidine alkaloids (PA), was fed to sheep to determine whether PA consumption influenced liver Cu concentrations. Nine Polypay wether lambs were allotted to 3 groups according to the diets: control diet + 50 micrograms of Cu/g of feed (control + Cu); tansy ragwort (TR) diet + 50 micrograms of Cu/g of feed (TR + Cu); and TR diet + 50 micrograms of Cu/g of feed and 10 micrograms of Mo/g of feed (TR + Cu + Mo). Liver Cu concentrations were sharply increased (13-fold) after 8 weeks of feeding the diets, and then decreased slightly. There were no significant differences in concentrations of liver Cu among treatment groups. All lambs in the group fed TR + Cu + Mo died by the end of 23 weeks, with the usual signs of PA poisoning, including liver necrosis, hepatic megalocytosis, and biliary hyperplasia. The TR intake was about 2.7 to 3.0 kg/kg of their initial body weight. All lambs in the group fed the control + Cu diet survived. The results indicated that sheep fed TR do not preferentially accumulate liver Cu. There was an indication that dietary Mo increased susceptibility to TR intoxication.  相似文献   

7.
Blockade of satiety factors by central injection of neuropeptide Y in sheep   总被引：1，自引：0，他引：1  
The ability of neuropeptide Y (NPY) to stimulate feed intake was tested in combination with two treatments known to depress feed intake in sheep. Six ewe and three wether lambs (mean BW = 40 kg) fitted with lateral cerebral ventricular guide cannulas and ruminal cannulas had free access to a nutritionally complete, pelleted diet. Balloons placed into the rumen were filled with either 0, 30 or 60 ml of water/kg BW and left in place for 6 h; intake was measured. Based on the decline in feed intake observed with increasing balloon volume in the rumen, Exp. 2 was designed to test effects of NPY injection (0 or 3.0 nmol) into the lateral cerebral ventricle and ruminal distension (0 or 35 ml/kg BW) for 6 h. During the 6-h test period, feed intake was depressed (P less than .05) by intraruminal balloon distension, but feed intake was increased by NPY injection (P less than .05); no interaction between NPY and distension was detected. Ruminal evacuation revealed that digesta occupied only 43% of the rumen's total volume capacity. Balloons occupied 14% of capacity, whereas meal size in control sheep following a 1.5-h fast equaled 7% of capacity. In Exp. 3, intraruminal infusion of 8 mmol/min of propionate depressed (P = .11) feed intake, whereas NPY injection enhanced (P less than .05) intake. There was no interaction between NPY and propionate infusion. In none of these experiments was cumulative feed consumption at 24 h influenced. We conclude that NPY is a versatile feeding stimulant. It promotes feed intake in feed-satiated, ruminally distended and propionate-infused sheep.  相似文献   

8.
Four Suffolk x Hampshire wether lambs averaging 55 kg with permanent ruminal cannulas were used in a 4 x 4 Latin square design to determine the effects of exchange of ruminal contents between fed and fasted lambs on subsequent DMI and ruminal characteristics. Lambs were fed a pelleted 70% roughage diet at 2% of BW for 17 d. During each period of the Latin square two lambs were deprived of feed and water for 3 d. At the end of the fasting period ruminal contents from one fed and one fasted lamb were exchanged. Lambs were then given ad libitum access to feed for 8 d, during which DMI, feeding pattern, and ruminal characteristics were monitored. Measurements of ruminal volume determined by total collection and indigestible marker (lithium sulfate) suggested that only about 50% of total ruminal contents were actually exchanged. Fasted lambs had lower (P less than .05) DMI, ruminal fermentative capacity, ruminal DM weight, and ruminal DM percentage than fed lambs during the first 4 d of realimentation. Exchange of ruminal contents did not (P greater than .10) affect DMI, feeding pattern, ruminal fluid pH, ruminal fermentative capacity, ruminal contents DM percentage, ruminal nucleic acid concentration, or VFA. Dosing fasted lambs with ruminal contents from nonfasted lambs reduced (P less than .05) ruminal liquid volume, dry weight of ruminal contents, and propionate concentration. Results of this trial are interpreted to indicate that although decreased ruminal function is a factor in the low feed intakes of fasted ruminants, the possibility of increasing postfast feed intake via improved ruminal function is limited because other metabolic factors may play a more important role.  相似文献   

9.
Five methods for estimating the stocking density of sheep confined in a pen were assessed. The pen (2.35 m x 3.01 m) simulated the pens on a normal road transporter. The trial used 50 lambs (average weight 34 kg) of mixed sex and breed, held at five stocking densities--0.466 to 0.824 m2/100 kg or 214 to 121 kg/m2--covering the range used in commercial practice, and 14 assessors, all experienced in handling animals. The best method was that based on the girth measurement of a sample of animals to estimate liveweight and a count of the animals in the pen. The methods based on using a moveable gate to take up free floor space, assessing the difficulty of moving through the pen of animals, using photographic scales, and counting the numbers of sheep across transects were generally less successful.  相似文献   

10.
Twenty-four crossbred Florida native wether lambs, 28 kg initially, were assigned randomly to a basal diet (31 ppm Mn dry matter basis) supplemented with either 0, 500, 1,000, 2,000 or 4,000 ppm Mn from feed grade MnO or 2,000, 4,000 or 8,000 ppm Mn from reagent grade MnCO3. There were three sheep/treatment, with ad libitum access to feed and tap water. After 84 d, all animals were slaughtered and tissues removed for analysis. Dietary Mn at the highest levels from either source reduced (P less than .05) average daily feed intake and average daily gain. Hemoglobin and hematocrit were not affected by dietary Mn. Manganese concentration in kidney, spleen, heart, skeletal muscle, bone, serum (P less than .01) and liver (P less than .05) increased as dietary Mn increased. Kidney P was reduced (P less than .05) as dietary Mn increased; however, no other tissue minerals were affected. At comparable levels of supplementation, sheep fed feed-grade MnO exhibited numerically greater tissue Mn concentration than did those fed reagent-grade MnCO3 and regression analysis indicated higher rates of tissue uptake in MnO-supplemented sheep. Reduced feed intake and gain and apparent Mn homeostatic failure in liver were the only observed effects that may have been related to Mn toxicosis.  相似文献   

11.
本试验旨在研究饲粮中添加番茄红素对绵羊生长发育、屠宰性能和血清抗氧化指标的影响。选取体重为(22.0±0.5)kg的3月龄湖羊公羔30只,随机分为3组,每组10只,单栏饲养。对照组每天饲喂基础饲粮,试验组每天分别在基础饲粮中添加200和400 mg番茄红素。试验期共110 d,其中预试期10 d,正试期100 d。结果显示:与对照组相比,1)饲粮添加200和400mg/d番茄红素有提高绵羊平均日增重的趋势(0.05≤P0.10),并可显著降低料重比(P0.05);2)饲粮添加200和400 mg/d番茄红素可显著提高绵羊胸宽(P0.05),添加200 mg/d番茄红素有提高体长、体高和胸围的趋势(0.05≤P0.10);3)饲粮添加200和400 mg/d番茄红素有提高宰前活重、背肌重、肾脏重和GR值的趋势(0.05≤P0.10),添加400 mg/d番茄红素可显著提高皮重(P0.05),其他屠宰性能指标各组间无显著差异(P0.05);4)饲粮添加200和400 mg/d番茄红素有提高血清超氧化物歧化酶活性的趋势(0.05≤P0.10),添加200mg/d番茄红素可显著提高血清过氧化氢酶和谷胱甘肽过氧化物酶活性(P0.05)。结果表明,饲粮添加番茄红素对绵羊生长发育、屠宰性能和血清抗氧化能力有一定的提高作用,本试验条件下以200 mg/d添加量的效果较优。  相似文献   

12.
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   

13.
The behaviour of two pens of mixed British breed male sheep transported by ship from New Zealand to Saudi Arabia was studied. One of the groups was carried above decks (n = 128) and one below decks (n = 116). Observations were conducted four to five times daily throughout the 24-day voyage. Over the whole voyage the most common activities were standing, lying and feeding. Overall, the animals adapted reasonably well to the shipboard environment, with most gaining weight. The mortality rate in the study pens averaged 2.5%, which was similar to that of the total shipment and average for this type of voyage. The behavioural measures appeared to provide sensitive indices of changes in the welfare of the sheep. An increase in lying activity, panting and drinking and a decrease in feeding during the latter part of the voyage were indicative of increasing heat stress. Plunging at the feed and water troughs led to loss of footing and increased the likelihood of smothering. This activity occurred after periods without feed or without water. Plunging also occurred when sheep moved towards the ventilators. Other factors associated with reduced well-being were the high stocking density which, combined with a wet faecal pad, limited movement towards feed or water and increased the likelihood of smothering.  相似文献   

14.
Ingestion of small amounts of condensed tannin (CT) by ruminants can produce valuable outcomes such as improved nitrogen use and reduced bloating, methane output, and gastrointestinal parasitism. However, many grasses and forbs contain little if any CT. The specific types of CT vary in plants and can have somewhat different effects on ruminants. Individual ruminants can respond differently to CT intake. Not all livestock will consistently consume supplements while grazing, but they all usually drink water daily. Therefore, in order to determine how sheep would respond to CT in their drinking water, eight lambs with the same initial weight of 43 kg were individually penned, fed alfalfa pellets twice daily, and had ad libitum access to two waters. Water intake was measured daily. After an adjustment period to pens, feeding, watering conditions, and water containing CT, three sequential week-long trials were conducted. In Trial 1, lambs chose between tap water and a quebracho tannin (QT)–water mixture (0.19% QT w/w; ca. 1% dry matter intake of QT). In Trial 2, lambs chose between tap water and a QT–water mixture of lower concentration (0.14% QT w/w). In Trial 3, lambs chose between a QT–water mixture and a wattle tannin–water mixture, both with the same concentration (0.14% CT w/w). In Trials 1 and 2, lambs had inconsistent intakes of tannin water and tap water from day to day (P ≤ 0.02) and neither preferred nor avoided tannin solutions. They also had inconsistent daily intakes of the two different tannin solutions offered simultaneously (P = 0.01), and showed no preference for either tannin solution (P ≥ 0.15). Results support other observations that sheep will voluntarily consume water with small amounts of CT in it, and provide no evidence that sheep prefer consuming small amounts of QT vs. black wattle tannin in water.  相似文献   

15.
Histological properties from the longissimus (LD) and semimembranosus (SM) muscles of 51 wether and ewe lambs from Hampshire rams and two ewe genetic types (SR, 1/2 Suffolk and 1/2 Rambouillet, and FS, 1/2 Finnish Landrace and 1/2 Southdown) and three slaughter live weights (32, 41 and 50 kg) were compared. Fibers in both muscles were classified as beta R (red), alpha R (intermediate) or alpha W (white). All LD muscle fiber types from FS ewe lambs increased in diameter from 32 to 41 kg, but decreased in diameter from 41 to 50 kg. Also, this quadratic effect with slaughter weight was found in alpha R and alpha W fibers from the SM muscle of FS wether and ewe lambs. However, diameters of alpha R and alpha W fibers from SR wether and ewe lambs and beta R fibers from SR ewe lambs increased linearly in the SM muscle with increasing slaughter weight. As slaughter weight increased, the proportion of alpha R fibers decreased in both the LD and SM muscles for SR wether and FS wether and ewe lambs. Concurrent with the increase in slaughter weight and decrease in alpha R fiber percentage, the proportion of alpha W fibers increased in the LD muscle of SR wether lambs, the SM muscle of SR ewe lambs and both muscles of FS wether and ewe lambs. Genetic type and sex groups, except SR ewe lambs, support the theory of transformation of alpha R to alpha W fibers with increasing slaughter weights. Fat-cell diameters increased in both muscles of SR wether and FS ewe lambs with increasing slaughter weights. Increases in fat traits of lamb carcasses were related to increases in red-fiber size. Alpha red fiber numbers were inversely related (P less than .05) to alpha W fiber numbers in both the LD and SM muscles (r = -.83 and -.79). The proportion of alpha R to alpha W fibers might be used as an indicator of physiological maturity for lambs.  相似文献   

16.
为探讨全株玉米青贮(WCS)和谷草干草(MH)日粮粗饲料不同比例组合对杜×湖杂交肉羊生长、屠宰性能以及经济效益的影响。挑选体况相近的60日龄杜泊羊和湖羊杂交F1代公羔羊60只,分为A组(WCS:MH=100:0)、B组(WCS:MH=60:40)、C组(WCS:MH=20:80)、D组(WCS:MH=0:100),每组设置5个隔栏,按每个隔栏3只羊单独投料测定采食量,每隔14 d对羊只进行称重,饲养84 d出栏进行屠宰。结果表明:随着谷草替换比例升高,B、C、D组与A组相比干物质采食量线性降低(P<0.05),平均日增重分别下降2.2%、6.6%、15.0%(P<0.05),耗料增重比先降低再升高(P<0.05);随着谷草添加量增加,A至D组的屠宰率未呈显著性差异,但胴体净肉率依次升高;B、C、D组胴体脂肪含量(GR值)较A组分别升高8%、26%、3%;从活羊收益分析,C组的饲料报酬最高;从屠宰收益分析,D组的饲料报酬最高。综上所述,谷草替代全株玉米青贮比例在40%~80%时,对生长性能无显著影响,但可提高胴体净肉率,C组活羊饲料报酬最高,D组获得的屠宰收益最高。  相似文献   

17.
Metabolism and excretion of ochratoxin A fed to sheep.   总被引：1，自引：0，他引：1  
Hydrolysis of the mycotoxin ochratoxin A (OA) to ochratoxin alpha (Oalpha) by microorganisms within the gastrointestinal tract leads to the excretion of OA as the nontoxic alpha form. The Oalpha form is the principal means for the detoxification of OA. In the current experiment, three groups of four sheep were fed diets consisting of 70% concentrates and 30% hay (dry matter basis, energy to supply 1.1 times the requirement for maintenance) for 4 wk with three dietary concentrations of OA (0, 2, or 5 mg/kg of concentrate feed). The OA content did not affect feed intake or nutrient digestibility. In a preliminary experiment, an OA dose of 20 mg/kg of concentrate feed greatly reduced feed intake. After 1, 2, 3, and 4 wk of the trial, significant concentrations of OA were detected in the serum of the animals fed 2 or 5 mg of OA/kg feed. This suggested that even at a dosage of 2 mg of OA/kg of concentrate feed, considerable amounts of OA were not degraded by ruminal and intestinal microorganisms. The analysis of the feces and urine samples reflected these findings; OA and Oalpha were found in significant concentrations, escaping fermentation in the rumen and in the hindgut. The current experiment demonstrates that OA hydrolysis in the gastrointestinal tract of sheep is substantially less than previously described, especially if OA is ingested in combination with concentrate-rich diets.  相似文献   

18.
This study was conducted to investigate relationships between mitochondrial respiratory chain complex activities, feed efficiency, and carcass traits in sheep. A group of Ghezel male lambs sired by a single ram were randomly allotted to individual pens. The lambs were fed ad libitum with a fattening diet containing 30% roughage (corn silage and alfalfa hay) and 70% concentrate for 70 d to individually phenotype each lamb for feed conversion ratio (FCR), adjusted FCR (aFCR), and residual feed intake (RFI). The lambs were then humanely killed and the liver, abdominal fat, pelvic fat, cardiac fat, warm carcass weight, and cold carcass weight, as well as the cross-sectional area of the LM and the fat depth over the 12th rib, were determined. A portion of LM was obtained to determine mitochondrial protein and respiratory chain complex activities (complexes I to V). Statistical analysis was carried out based on lambs exhibiting high and low RFI (n = 8), FCR (n = 8), or aFCR (n = 8) phenotypes. The lambs exhibiting the high-RFI phenotype consumed 110 g more feed daily (P < 0.05) than did the phenotype exhibiting low RFI, with no difference in ADG. Conversely, there was no difference in feed intake between the low- or high-FCR groups, but sheep exhibiting the low-FCR phenotype gained 70 g more (P < 0.05) per day compared with those exhibiting the high-FCR phenotype. It was determined that all 5 respiratory chain complex activities were greater (P < 0.05) in sheep exhibiting the low-RFI phenotype compared with those exhibiting the high-RFI phenotype, with significant (P < 0.001) negative correlation coefficients between RFI and respiratory chain complex activity. When efficiency was assessed using FCR, only activities of respiratory chain complexes III, IV, and V were less (P < 0.05) in the low-FCR phenotype compared with the high-FCR phenotype, and there were no differences (P > 0.1) in respiratory chain complex activities between groups when FCR was adjusted for metabolic BW (aFCR). There were no differences (P > 0.1) in carcass traits among any of the feed efficiency phenotypes. The results suggest that the inclusion of respiratory chain complex activities in breeding programs may be helpful in selecting for sheep exhibiting the low-RFI phenotype.  相似文献   

19.
Immunization against cholecystokinin decreases appetite in lambs.   总被引：1，自引：0，他引：1  
The effects of immunization against cholecystokinin (CCK) on feed intake, weight gain, and carcass characteristics were studied in sheep. Nine wether lambs at 10 wk of age were immunized with a conjugate of sulphated CCK octapeptide and human serum globulin or against human globulin alone. All CCK-immunized lambs produced antibodies, and the average titer 5 wk after the primary immunization was calculated to be sufficient to bind normal circulating levels of CCK. Mean daily feed intakes and BW were similar in the CCK-immunized and the control-immunized groups at the start of treatment, but after immunization, feed intake, appetite, and BW gain were decreased in the CCK-immunized animals. There was no effect on carcass composition or organ growth relative to body growth. It is concluded that the immunization procedure used in this study may have potentiated the actions of CCK rather than neutralizing its action as an appetite regulator.  相似文献   

20.
The results of a growth experiment are explained which was carried out as basis for the control slaughtering method and for N-balance experiments with hybrid fattening lambs of both sexes and of three different genetic constructions in comparison with male merino mutton lambs. The animals were kept individually on perforated floor and received pelleted fattening feed for lambs ad libitum. In the live weight range between 15 and 30 kg the male hybrid lambs reached significantly higher live weight gains than the merino mutton sheep, the former tending towards higher feed intake and lower energy expenditure. The male hybrid lambs showed a significantly higher live weight gain and a significantly lower energy expenditure than the female animals of equal live weight whereas there were no differences between the sexes in feed intake.  相似文献   

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