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1.
Adult wethers (n = 750) were lot-fed for 13 days, 8 days or 3 days before a simulated voyage lasting 18 days to examine whether the period of lot-feeding affected the proportion of sheep that ate pelleted feed and their body weight change during simulated shipping. There was no significant difference in the proportion of non-feeders between treatment groups on days 7 and 14 of the voyage. Body weights were not significantly different between the treatment groups on days 14 and 18 of the voyage. Overall body weight loss, from the farm to the end of simulated shipping, was 4.08 kg (+/- 0.28, s.e.m.), 4.58 kg (+/- 0.28) and 4.51 kg (+/- 0.28) in sheep lot-fed for 13 days, 8 days and 3 days, respectively, and was not significantly different between treatments. It was concluded that lot-feeding for 13 days conferred no advantage in body weight or numbers of non-feeders compared with shorter periods in this study.  相似文献   

2.
Truck-drivers and previous owners of sheep from 133 farms (lines of sheep) were asked for information on possible risk factors for inappetance during lot-feeding and for shipboard mortality during 5 voyages to the Middle East. There was no consistent association between a number of factors prior to trucking or during trucking to the feedlot and inappetance during lot-feeding or mortality aboard ship. The factors included: whether sheep were bred or purchased by the owner, whether sheep were mixed with sheep from another farm in the previous 2 or 6 months, previous experience of trucking, frequency of yarding, experience of supplementary feeding, age, rainfall zone of the farm of origin, distance trucked, time on the truck and time off feed on arrival at the feedlot. Inappetance during lot-feeding was significantly associated with total deaths aboard ship for individuals and for lines of sheep. Failure to eat late in the feedlot period was also a risk factor for individuals that died with inanition (relative risk = 6.9) or salmonellosis (relative risk = 5.9). In 2 voyages, there was no significant difference in shipboard death rate between groups that were previously lot-fed in sheds or in paddocks. This was despite significantly more non-feeders in the sheds than in the paddocks prior to one voyage. This finding suggested that some nonfeeders commenced eating pellets aboard the ship. Although inappetance in the feedlot was a risk factor for shipboard deaths, there was no difference in shipboard weight change between feedlot non-feeders and feeders in 2 voyages. It was concluded that most non-feeders began eating pelleted feed aboard ship.  相似文献   

3.
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   

4.
Abstract

Pigs weaned at 31 to 34 days of age (n=280) were mixed into groups of 10 and fed from either feeders (2 feeding places per pen) or troughs (10 feeding places per pen). Analyses on performance, diarrhoea scores and feeding behaviour were made separately on small-, medium- and large-sized pigs, defined as their relative size in the group. During the second week after weaning, feed conversion ratio (FCR) was lower for pigs fed from feeders. Trough feeding resulted in lower total diarrhoea scores for small (p=0.002) and large (p=0.04), and higher scores for medium pigs (p=0.03). Small pigs had lower scores on individual days around the peak on day 6. All three size categories of pigs spent a numerically higher amount of time feeding when fed from a trough. Feeding bouts were longer in pigs fed from a trough (p=0.0002 – 0.05).  相似文献   

5.
Mortality reports were studied for 181 shipments of live sheep from Western Australia to the Middle East and Singapore in 1985 and 1986. Samples of pelleted feed for 93 shipments were analysed for quality. Overall death rate in the 6.46 million sheep exported in the period of the study was 2.18%. In sheep bound for the Middle East, most of the deaths occurred during the voyage (overall rate 1.7%, range 0.4-4.4% per shipment), although substantial mortality was recorded during discharge (rate 0.4%, range 0.0-1.8%). There were few deaths during loading (rate 0.07%, range 0.0-0.8%). Deaths in sheep bound for Singapore were almost 10-fold lower than those sent to the Middle East. Several findings suggested that ship design and management may contribute to mortality. Death rates were invariably low on some ships and often high on others. Death rates were nearly always higher in enclosed decks than in open decks on 4 vessels, and point epidemics of mortality were observed in several shipments. Temperature and relative humidity measured on the ship's bridge were not closely related to daily death rate. Antibiotics estimated to cost $226,000 were used during 33 voyages in 1986 and were considered of dubious efficacy on shipboard mortality. Analysis of feed pellets used on ship showed that the quality of the diet was within the range set by draft national standards for pellets used in the live sheep export industry.  相似文献   

6.
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   

7.
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. 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 sheep from escaping is about 190-210 mm.  相似文献   

8.

Ten batches of pigs (608 pigs) were used in this investigation (live weight interval 20-120 kg). Four different feeding systems were tested: one dry feeder, four dry feeders, trough feeding or one wet/dry feeder per pen of 16 pigs, respectively. The one dry feeder treatment led to an increase in skin injuries, a more spread feed intake pattern, an increased variation in carcass meat percentage and an increased variation in daily weight gain (DWG) when the pigs were restrictively fed, compared with observations for the pigs in the four dry feeders treatment. The effect of a reduced number of feeding places was most pronounced when the pigs were fed restrictively. Besides the possible negative financial effects for pig producers, these findings indicated that competition for feed impaired the well-being of the pigs. Pigs fed in a trough had a lower DWG and higher feed conversion ratio than did those fed using four dry feeders, probably due to feed spillage and the different feed intake pattern. Giving pigs the possibility of adding water to the feed increased the daily feed intake when feeding ad libitum, resulting in a higher DWG. It also reduced the negative effects of competition on performance, but not the negative effects on skin injuries.  相似文献   

9.
The objective of this study was to compare the behaviors and feather conditions of caged laying hens fed by two different types of feeders. Seven tennis balls were placed on the feed trough to hide the feed for each of 6 experimental cages (treatment B). The same feed troughs without balls were used for 6 control cages (treatment NB). Forty-eight commercial white leghorn type hens were housed as 4 birds per cage (474 cm2 per bird). The experimental period was from 22 to 32 weeks of age. At 28 weeks of age, the hens spent more time feeding in treatment NB (35%) than in B (27%). On the other hand, prefeeding behavior (extension of the neck over the trough or pecking at the balls) occupied more time in B (14%) than in NB (6%). The birds in B spent more time thrusting (thrusting other birds aside and trying to eat) than did the birds in NB (2 vs 0%). At 32 weeks of age, the mean proportion of hens feeding and prefeeding behavior in both treatments was similar to those at 28 weeks of age; however, differences of the behavior between the B and NB were relatively small. Feather damage on a scale of 0 (no damage) to 15 (denuded) increased with age, and the scores in B were less than those in NB at 27 weeks (0.75 vs 1.37), although not at 32 weeks. Egg production in the two treatments was the same, and the type of feeder used did not affect body weight. This device might provide hens with a more attractive environment than the conventional feeders; however, the enrichment feeder might need more improvement for the welfare of caged laying hens.  相似文献   

10.
Objective: To investigate control options for contagious ecthyma (scabby mouth) in Australian sheep exported live to the Middle East.
Design: Prevalence, vaccination and modelling studies.
Procedure: One hundred and forty weaner sheep (less than 1 year old) on each of 106 farms in Western Australia (WA) and 18 farm groups of adult wethers received at a WA commercial feedlot were examined for lesions of scabby mouth. Sheep on a total of 26 farms in 3 States were divided into treatment and control groups for the vaccination study. A simple deterministic compartmental model was developed to establish which parameters had the greater effect on disease prevalence.
Results: The proportion of farms with evidence of scabby mouth in weaner sheep was 23.6% and, on those farms with the disease, the overall prevalence was 6.1%. At the feedlot, 4 out of 18 farm groups had 5 or more sheep with lesions on arrival. The overall prevalence in the 4 diseased groups was 5.2%. Sheep vaccinated on farm before trucking to the feed-lot had a lower prevalence of scabby mouth at the end of simulated shipping than controls. The main determinant of scabby mouth prevalence was the proportion of sheep immune to the disease.
Conclusion: A program of vaccination for scabby mouth will reduce the prevalence of disease during live export. However, using current technology it is not possible to deliver shipments of sheep to the Middle East that are guaranteed completely free of scabby mouth.  相似文献   

11.
This study compared a feeder with molded cups on the bottom (Pre-Vent feeder) with a commonly used rubber tub and hanging bucket feeder to determine differences in time spent eating and feed wastage. Nine Quarter Horse geldings were fed a 12% crude protein pellet diet at 0.75% body weight twice daily from one of the three feeders twice daily for 3 days, and then switched to the next feeder, following a 3 × 3 replicated Latin square design (n = 9). The horses spent more time eating from the cup feeders (31.15 ± 1.43 minutes) than from bucket (19.39 ± 0.42 minutes) and tub (18.87 ± 0.49 minutes, P < .0001) feeders. When fed from cup feeder, horses dropped significantly less feed (3.2 ± 0.52%) of their ration than when fed from bucket (10.2 ± 1.75%) and from tub (7.0 ± 1.32%, P = .001) feeders. When the most wasteful horse was fed from the cup feeder, he lost a mean of 8.7% of his ration, compared with 32.8% when fed from the bucket, and 26.2% when fed from the tub feeders. The cup design is useful for increasing time spent eating and reducing feed wastage.  相似文献   

12.
Post-mortem examinations were conducted on 950 dead and terminally ill sheep during assembly for export and during transport by sea from Fremantle, Western Australia to various Middle East ports. Causes of death were grouped into 5 major categories; inanition (deaths associated with reduced feed intake, including hypocalcaemia and hypomagnesaemia), salmonellosis (enteric and septicaemic), trauma, diseases associated with excessive feed intake (lactic acidosis and enterotoxaemia) and miscellaneous diseases (mostly of farm origin). During assembly the causes of death were salmonellosis 53.4%, miscellaneous diseases 23.8%, trauma 12.6%, inanition 10.2%, acidosis 3.9%, enterotoxaemia 3.4% and no diagnosis was made in 3.4%. During shipping the causes of death in defined populations of sheep in 5 voyages were; inanition 43.4%, salmonellosis 20.2%, trauma 10.6%, miscellaneous diseases 5.9%, enterotoxaemia 1.0% and no diagnosis was made in 19.0%. The range of mortality rates per 10,000 sheep at risk for the first 11 days at sea in 5 voyages were inanition 52.6 to 76.7, salmonellosis 7.8 to 109.8, trauma 2.1 to 17.1, miscellaneous diseases 5.9 to 17.1 and enterotoxaemia nil to 10.3.  相似文献   

13.
The in vitro incubation technique of Zhao and Lebzien (2000; Arch. Anim. Nutr. 53, 293-302) was used for the estimation of utilizable amino acids (uAA) (sum of amino acids from undegraded feed protein and microbial protein, when N is not limiting) of feeds for ruminants. The rumen fluid from a cow fed only with hay (Expt. 1) and that from a sheep fed with a mixed ration (Expt. 2) was compared with respect to estimation of uAA. In Expt. 1, 30 feeds and feed mixtures were tested and in Expt. 2, 33 feeds and feed mixtures were tested. A close linear relationship was found between the utilizable crude protein (uCP=undegraded feed protein + microbial protein) (X, g/kg) calculated from in vivo experiments and the uAA (Y, g/kg) estimated from in vitro incubations both in Expt. 1: y= 0.95 x-1.39, r2=0.85, p<0.001,n=30; and in Expt. 2: Y=0.85X-6.67,r2= 0.85,p<0.001,n=33. Statistical analysis indicates that there was a significant regressive relationship between uAA determined with the rumen fluid of a sheep (X, g/kg) and uAA determined with the rumen fluid of a cow (Y, g/kg): Y=1.06X+12.4,r2= 0.80,p<0.001,n=27. The results indicate that the in vitro incubation technique of Zhao and Lebzien (2000) can be used for the estimation of uAA of feeds for ruminants. As a rumen-fistulated cow is more expensive than a rumen-fistulated sheep, it is suggested to use a sheep fed a mixed ration as the donor of rumen fluid for the estimation of uAA of feeds with in vitro incubation. Further experiments should be performed to standardize the method and to test the most valid length of the incubation period.  相似文献   

14.
The effects of feeding Cd to sheep at a level that is typical of polluted regions were investigated, as well as possible amelioration by adding Zn to the diet. Welsh Mountain ewes (n = 24) were fed herb-age and concentrate in metabolism crates, with four supplement treatments in a two-factor factorial design: no supplement, Cd supplement only, Zn supplement only, and a combination of both the Cd and Zn supplement. Cadmium (286 microg/kg of feed DMI) and Zn (8.6 mg/kg feed DMI) were added as sulfates. Food and water intakes and element balances were recorded over 20 d after 7 d dietary adaptation, and element concentrations were determined in wool samples. Neither metal affected DMI or digestibility (P > 0.15), but water intake (P = 0.001) and urine output (P = 0.03) were decreased when only the Zn supplement was added. Water retention was increased by the Cd supplement (P = 0.04). In wool, the Cd supplement greatly increased the K concentration if no Zn supplement was fed (P = 0.02), and the Zn supplement decreased Mn concentration (P = 0.02). Cadmium in feed increased the Cd balance and produced several mineral disturbances, in particular a decrease in Na balance that is typical of renal tubular disorders. Adding Zn as well as Cd to feed returned the Cd balance to a level similar to that of sheep receiving neither Cd nor Zn, which suggests that Zn status is critical in determining whether Cd in feed increases the Cd balance in sheep. Feeding Cd also increased urinary K, Fe, Mo, Cr, B, and Ca concentrations, even when supplementary Zn was fed. It is concluded that low levels of Cd in sheep feed can increase the Cd balance if adequate Zn is not provided, which can lead to subclinical mineral disturbances and changes in the mineral concentrations in wool.  相似文献   

15.
旨在探究不同颗粒日粮对育肥羊生长性能、养分表观消化率及血清生化指标的影响。选取体重相近、（70±10）日龄的滩羊羯羔羊60只,随机分为4组：对照组（n=15）、试验Ⅰ组（n=15）、试验Ⅱ组（n=15）、试验Ⅲ组（n=15）。对照组饲喂自配全混合日粮（40%自配精饲料+60%自配粗饲料）,试验Ⅰ组饲喂50%自配全混合日粮（20%自配精饲料+30%自配粗饲料）+50%育肥羊全混合颗粒饲料,试验Ⅱ组饲喂育肥羊全混合颗粒饲料,试验Ⅲ组饲喂45%颗粒化精补料+55%草颗粒饲料。饲喂试验预试期16 d,正试期87 d。测定各组育肥羊的试验初重和试验末重,计算试验期间的平均日增重。记录各组育肥羊的采食情况,计算平均日采食量和料重比。饲喂试验结束时,采用常规方法测定并比较各组干物质、有机物、粗蛋白质和中性洗涤纤维的表观消化率,以及血清生化指标。结果表明,试验Ⅱ组的平均日增重最高,显著（P<0.05）高于试验Ⅰ组和试验Ⅲ组,极显著（P<0.01）高于对照组;试验Ⅱ组的平均日采食量显著（P<0.05）低于试验Ⅰ组和对照组;试验Ⅱ组的料重比最低,分别比对照组、试验Ⅰ组和试验Ⅲ组降低了60.63%、35.69%、9.41%。试验Ⅱ组的干物质、有机物、粗蛋白质和中性洗涤纤维的表观消化率均高于其他3组,其中,粗蛋白质的表观消化率与其他3组差异均显著（P<0.05）。各组育肥羊血清生化指标差异均不显著（P>0.05）。综上提示,饲喂全混合颗粒日粮能够改善滩羊育肥羊生长性能,提高养分表观消化率,对育肥羊健康无明显影响。  相似文献   

16.

Over a 3-year period, seven batches of growing-finishing pigs in groups of 16 pigs (total 672 pigs) were fed using one or two singlespace feeders. The pigs with access to two feeders had a significantly lower number of skin lesions (P<0.0001) and higher daily weight gain than did the pigs with access to one feeder (863 vs. 837 g day- 1 , P<0.05). The within-pen variation in daily weight gain was higher in the pens with one feeder than in the pens with two feeders (SD 139 vs. 106g day- 1 , P<0.0001). The pigs with access to two feeders consumed more feed during the period when they were allowed to eat ad libitum , in comparison to the pigs with access to one feeder (2.07 vs. 1.97 kg day- 1 , P<0.05). The feed conversion ratio of the pigs did not differ between the two treatments. No differences in carcass meat percentage, health or number of remarks at slaughter were detected. A comparison was made between using computerized IVOG® feeders, with individual recording of feed intake, and conventional feeders. The feed conversion ratio was poorer for the pigs fed with the IVOG-feeders than for those fed with conventional feeders. The automatic recordings from the IVOG-system showed that there had been a higher daily feed intake during the ad libitum period. During the restricted period the pigs had a lower daily weight gain than with the conventional feeders.  相似文献   

17.
Locoweed species (Astragalus and Oxytropis spp.) are a serious toxic plant problem for grazing livestock. Horses and sheep have been conditioned to avoid eating locoweed using the aversive agent LiCl. The objective of this study was to determine if previous locoweed intoxication affects food aversion learning in horses and sheep. Horses and sheep were divided into 3 treatment groups: control (not fed locoweed and not averted to a novel feed); locoweed-novel feed averted (fed locoweed and averted to a novel feed); and averted (not fed locoweed and averted to a novel feed). Animals in the locoweed-novel feed averted groups were fed locoweed during 2 periods of 21 and 14 d, respectively, with each feeding period followed by a 14-d recovery period. Animals were averted to a novel test feed at the end of the first locoweed-feeding period, and periodically evaluated for the strength and persistence of the aversion. During the first recovery period, locoweed-novel feed averted horses ate less (9.5% of amount offered) of the test feed than did control horses (99.8%) and did not generally differ from averted horses (0%). During recovery period 2, locoweed-novel feed averted horses (4.3%) differed (P = 0.001) in consumption (% of offered) of the test feed from controls (100%) and the averted group (0%). Locoweed-novel feed averted sheep differed (P = 0.001) from controls (14.4 vs. 99.5%, respectively, during recovery period 1), whereas locoweed-novel feed averted sheep did not differ (P > 0.50) from averted sheep (0.6%). During the second recovery period, control sheep (100%) differed (P < 0.05) from averted (0%) and locoweed-novel feed averted (12.2%) groups. Two intoxicated sheep (locoweed-novel feed averted) partially extinguished the aversion during the first recovery period, but an additional dose of LiCl restored the aversion. Two of 3 intoxicated horses had strong aversions that persisted without extinction; 1 horse in the locoweed-novel feed averted group had a weaker aversion. These findings suggest that horses and sheep previously intoxicated by locoweeds can form strong and persistent aversions to a novel feed, but in some animals, those aversions may not be as strong as in animals that were never intoxicated.  相似文献   

18.
Angus bulls and heifers from lines divergently selected for serum IGF-I concentration were used to evaluate the effects of IGF-I selection line on growth performance and feed efficiency in 2 studies. In study 1, bulls (low line, n = 9; high line, n = 8; initial BW = 367.1 +/- 22.9 kg) and heifers (low line, n = 9; high line, n = 13; initial BW = 286.4 +/- 28.6 kg) were adapted to a roughage-based diet (ME = 1.95 Mcal/kg of DM) for 24 d and fed individually for 77 d by using Calan gate feeders. In study 2, bulls (low line, n = 15; high line, n = 12; initial BW = 297.5 +/- 34.4 kg) and heifers (low line, n = 9; high line, n = 20; initial BW = 256.0 +/- 25.1 kg) were adapted to a grain-based diet (ME = 2.85 Mcal/kg of DM) for 32 d and fed individually for 70 d by using Calan gate feeders. Blood samples were collected at weaning and at the start and end of each study, and serum IGF-I concentration was determined. Residual feed intake (RFI) was calculated, within study, as the residual from the linear regression of DMI on midtest BW(0.75), ADG, sex, sex by midtest BW(0.75) and sex by ADG. In study 1, calves from the low IGF-I selection line had similar initial and final BW and ADG, compared with calves from the high IGF-I selection line. In addition, DMI and feed conversion ratio were similar between IGF-I selection lines; however, calves from the low IGF-I selection line tended (P < 0.10) to have lesser RFI than calves from the high IGF-I selection line (-0.26 vs. 0.24 +/- 0.31 kg/d). In study 2, IGF-I selection line had no influence on performance or feed efficiency traits. However, there was a tendency (P = 0.15) for an IGF-I selection line x sex interaction for RFI. Bulls from the low IGF-I selection line had numerically lesser RFI than those from the high IGF-I selection line, whereas in heifers, the IGF-I selection line had no effect on RFI. In studies 1 and 2, weaning and initial IGF-I concentrations were not correlated with either feed conversion ratio or RFI. However, regression analysis revealed a sex x IGF-I concentration interaction for initial IGF-I concentration in study 1 and weaning IGF-I concentration in study 2 such that the regression coefficient was positive for bulls and negative for heifers. These data suggest that genetic selection for postweaning serum IGF-I concentration had a minimal effect on RFI in beef cattle.  相似文献   

19.
A study was conducted to record the deaths that occurred during export, and to examine the temporal pattern of pellet feeding in the feedlot and ascertain the variation in mortality between groups of sheep from different farms. Between November 1985 and April 1987, 5 cohorts of sheep were selected on arrival at a feedlot before live export by sea from Western Australia to the Middle East. Each cohort consisted of 4,118 to 9,612 Merino wethers from 15 to 35 farms (lines). There were few deaths during trucking to the feedlot (rate 0.9, range 0.0 to 3.0 per 10,000 sheep) and during lot-feeding (rate 6.2, range 1.2 to 12.2 per 10,000 sheep). Most of the deaths occurred aboard ship (rate 210.7, range 152.7 to 271.5 per 10,000 sheep). The proportion of sheep that ate pelleted feed increased with increasing length of time in the feedlot. By the end of lot-feeding the percentage of sheep that had not eaten pellets was 23.3, 4.4, 1.2, 2.1 and 0.2 in a representative sample of each of the 5 cohorts. It was considered that offering hay throughout lot-feeding was undesirable for the purpose of maximising the number of sheep that ate pellets before loading on the ship. Half of the deaths aboard ship occurred in 25% of 133 lines of sheep in the 5 cohorts. In each cohort the median per cent death rate (and range) per line was 1.3 (0.3 to 11.9), 1.1 (0.0 to 5.7), 1.8 (0.0 to 6.8), 2.3 (0.0 to 14.3) and 0.9 (0.1 to 5.4).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

20.
用平菇菌糠按不同比例替换绵羊日粮精补料中的玉米,检验菌糠的饲用效果。体重25 kg左右的育成绵羊40只,分为5组,每日每只羊补充0.6 kg精补料,各组分别用平菇菌糠按风干重的0%、5%、10%、15%、20%的比例等量替换精补料中的玉米,粗饲料玉米秸自由采食。试验期28 d,称量绵羊始重、末重和精补料量。菌糠替换绵羊精补料中玉米的比例与增重相关,在试验各组间的统计差异不显著(P>0.05),替换比例在5%~15%增重和经济效果最佳。  相似文献   

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