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1.
In three experiments the interrelationship between dietary CP and recombinant porcine somatotropin (rpSt, i.m. daily) on ADG, feed efficiency (F/G) and carcass traits was examined in crossbred Yorkshire gilts and barrows given ad libitum access to their diets during the finishing period (55 to 110 kg BW). Pigs, blocked by BW and gender, were assigned (four/pen) within block. In Exp. 1, 140 pigs were assigned two/gender per pen to each of five pens/block and received a diet of either 12%, 18% or 24% CP (n = 2, 1 and 2 pens/block, respectively). Pigs received rpSt, either 0 or 120 micrograms/kg BW (12% and 24% CP groups) or 60 micrograms/kg BW (18% CP group). When CP was 12%, rpSt decreased ADG and increased F/G (P less than .05), whereas when CP was 18% or 24%, rpSt increased ADG and lowered F/G (P less than .05). Backfat thickness was reduced (P less than .05) by rpSt regardless of CP. In Exp. 2, 120 pigs were assigned two/gender per pen to each of five pens/block and received a diet of 24% CP. Either 0, 15, 30, 60 or 120 micrograms of rpSt/kg BW was administered to each pig. All doses of rpSt increased ADG, lowered F/G and decreased backfat thickness compared with measurements for control pigs (P less than .05). In Exp. 3, 140 pigs were assigned two/gender per pen to each of seven pens/block and received a diet of either 14%, 18% or 24% CP (n = 3, 2 and 2 pens/block, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

2.
Long distance transportation of weaned piglets (Sus scrofa) is increasingly common in the united states and may result in delayed eating, drinking, or normal social behaviors. A potential solution is a mid-journey rest (lairage). The objective of this study was to determine if a lairage altered behavior after a 16-h transport. Pigs that weighed approximately 18 kg each (n = 894) were housed in 16 pens with 8 pens per treatment. Lairaged pigs were transported for 8 h and given an 8-h rest with food and water, whereas control pigs were transported continuously for 16 h. The heaviest, the lightest, and 2 average-BW pigs relative to the average weight of the pen were observed by video recording for 24 h immediately before and after transport, and during d 6 and 13 after transport. Postures (lying, sitting, and standing) were recorded using 10-min-interval scan sampling, and behavioral categories included inactivity, activities (eating, drinking, alert, manipulating pen, rooting, and walking) and social interactions (aggression, belly nosing, playing, tail biting, and positive social behaviors). In both treatments, sitting occurred most before transport (P < 0.01) than at other times, but did not differ between treatments. Standing increased (time effect; P < 0.01) for both treatments immediately after transport through d 6, but returned to pre-transport values by d 13. In contrast, lying decreased (time effect; P < 0.01) after transport, but returned to above pre-transport values by d 13. Time effects were evident for activity (P < 0.01), pen manipulation (P = 0.05), rooting (P < 0.01), initiation of belly-nosing (P = 0.01), and receiving belly-nosing (P = 0.03); however, initiation of aggression did not differ for day (P = 0.19) or treatment (P = 0.56). Lairaged pigs initiated more (P = 0.05) play than continuously transported pigs, but no differences (P = 0.84) were seen in receipt of play behavior. Pigs that were to be transported for 16 h continuously walked less pre-transport, walked more post-transport (treatment × time interaction; P = 0.02), and drank less pre-transport, but drank more on all days post-transport compared with the lairage group (treatment × time interaction; P = 0.001). This study indicated that extended transport without lairage alters some swine behaviors relevant to production (water consumption) and demonstrated that a long-duration transport, regardless of the mid-journey lairage treatment, affects a number of behaviors up to 13 d after transportation.  相似文献   

3.
To determine growth performance during and after injection of recombinant porcine somatotropin (rpSt), crossbred Yorkshire gilts and barrows (n = 54/gender, 27 to 42 kg BW) were blocked by BW and gender (n = 3 blocks/gender). Within each block, three pigs/gender were assigned randomly to each of six pens/block. A diet containing 24.8% CP was fed ad libitum. During the live weight period of 30 to 110 kg, pigs either remained as controls (one pen/block) or were injected (i.m.) daily with rpSt (120 micrograms/kg BW) during either 30 to 60, 30 to 100, 30 to 110, 60 to 100 or 60 to 110 kg BW. Thus, three gilts and three barrows in each of three pens received each treatment. Pigs were slaughtered at either 60 kg BW (1 d after rpSt injection) or 110 kg BW (1 d, 10 d or 70 d after rpSt injection). Relative to controls, pigs injected with rpSt exhibited faster and more efficient growth during the injection period (P less than .05) but slower and less efficient growth during 10 d after cessation of injection (P less than .05). Carcasses of pigs slaughtered 1 d or 10 d after rpSt injection were leaner than controls (P less than .05), but among the pigs treated with rpSt, carcasses of pigs withdrawn from rpSt for 10 d contained more fat (P less than .05) and had a lower percentage of muscle (P less than .05) than carcasses of pigs withdrawn from rpSt for 1 d. Growth and carcass measurements were similar (P greater than .05) between controls and pigs killed 70 d after rpSt injection.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

4.
The objective of this experiment was to determine if increased space and exercise for finisher pigs (0.90 vs 9.45 m2/pig) affects performance, meat quality, or muscle fiber characteristics. Newsham barrows (n = 32, 4 pens/treatment) were placed in one of two space allocations: control space allowance (CONT) or in a long pen with increased space allowance (10x). Pigs were weighed every 28 d and feed intake/pen was calculated. Pigs were filmed for behavioral analysis on d 70 and 100 using video recorders to determine walking distances over a 24-h period. After a 5-h transport and 2-h rest period, pigs (approximately 115 kg) were slaughtered on the same day at a commercial facility. Muscle samples were obtained from the longissimus lumborum (LL) and semimembranosus (SM) muscles within 1 h postmortem for muscle fiber typing. Backfat thickness and pH decline were measured on the left side of each carcass. After 24-h chilling, a boneless loin was collected from each pig and stored at 2 degrees C until analyzed. On d 14 postmortem, loins were cut at the 10th rib for color evaluations, and chops were cut for Warner-Bratzler shear (WBS) force and sensory analysis. Histochemical staining methods were used for the detection of type I, IIA, and IIB/X muscle fiber types. There were no significant differences (P > 0.10) in live weight, ADG, ADFI, or G:F ratio of the two experimental groups evaluated. Pigs finished in 10x pens walked a greater (P < 0.01) distance over a 24-h period than pigs finished in the CONT pens. Pigs finished in the lOx pens were fatter (P < 0.05) at the last lumbar vertebra than pigs finished in the CONT pens, but no significant differences were found in loineye area, loin color, marbling scores, WBS, sensory panel scores, retail display measures, or muscle fiber type percentages. Expanded space allowance to increase exercise resulted in no improvements in pig performance, pork loin measures, or muscle characteristics.  相似文献   

5.
A 2 X 2 factorial experiment was conducted using growing lambs to compare single-level vs double-decked pens and high (.32 m2/lamb) vs low (.48 m2/lamb) densities. Three replicates of each treatment combination were involved using 30 lambs/pen. In the double-decked pens, an upper deck located over the rear section of the lower level provided one-third of the total floor area. Feed and water were provided on the lower level only and lambs could move freely between levels by means of a slatted ramp. All floors were of expanded metal. Use of the various areas of the pens was determined during a 24-h observation and by a videotape recording of the double-decked pens during the daylight hours. Fleece contamination was determined by visual observation and standard wool testing procedures. Gain was determined over the 8-wk period of each replicate. The high density treatment resulted in 1.5 kg/lamb (10%) less gain (P less than .01) and, in the case of double-decked pens, different patterns of space utilization compared with the low density treatment. Lambs in the low density pens were able to move more successfully from resting areas to the feeding area in the afternoon (P less than .01). The double-decked system did not significantly affect weight gain, but resulted in dirtier fleeces (P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

6.
Temperature and body weight affect fouling of pig pens   总被引：1，自引：0，他引：1  
Fouling of the solid lying area in pig housing is undesirable for reasons of animal welfare, animal health, environmental pollution, and labor costs. In this study the influence of temperature on the excreting and lying behavior of growing-finishing pigs of different BW (25, 45, 65, 85, or 105 kg) was studied. Ten groups of 5 pigs were placed in partially slatted pens (60% solid concrete, 40% metal-slatted) in climate respiration chambers. After an adaptation period, temperatures were raised daily for 9 d. Results showed that above certain inflection temperatures (IT; mean 22.6 degrees C, SE = 0.78) the number of excretions (relative to the total number of excretions) on the solid floor increased with temperature (mean increase 9.7%/ degrees C, SE = 1.41). Below the IT, the number of excretions on the solid floor was low and not influenced by temperature (mean 13.2%, SE = 3.5). On average, the IT for excretion on the solid floor decreased with increasing BW, from approximately 25 degrees C at 25 kg to 20 degrees C at 100 kg of BW (P < 0.05). Increasing temperature also affected the pattern and postural lying. The temperature at which a maximum number of pigs lay on the slatted floor (i.e., the IT for lying) decreased from approximately 27 degrees C at 25 kg to 23 degrees C at 100 kg of BW (P < 0.001). At increasing temperatures, pigs lay more on their sides and less against other pigs (P < 0.001). Temperature affects lying and excreting behavior of growing-finishing pigs in partially slatted pens. Above certain IT, pen fouling increases linearly with temperature. Inflection temperatures decrease at increasing BW.  相似文献   

7.
The objectives of this study were to examine the effects of ractopamine (RAC) on the behavior and physiology of pigs during handling and transport. Twenty-four groups of three gilts were randomly assigned to one of two treatments 4 wk before slaughter: finishing feed plus RAC (10 ppm) or finishing feed alone. Pigs were housed in the same building in adjacent pens with fully slatted floors and ad libitum access to feed and water. Behavioral time budgets were determined in six pens per treatment over a single 24-h period during each week. Behavioral responses of these pigs to routine handling and weighing were determined at the start of the trial and at the end of each week. Heart-rate responses to unfamiliar human presence were measured in all pigs and blood samples were taken from a single pig in each pen on different days during wk 4. At the end of wk 4, all pigs were transported for 22 min to processing. Heart rate was recorded from at least one pig per pen during transport and a postmortem blood sample was taken from those pigs that were previously sampled. During wk 1 and 2, RAC pigs spent more time active (P < 0.05), more time alert (P < 0.05), and less time lying in lateral recumbency (P < 0.05). They also spent more time at the feeder in wk 1 (P < 0.05). At the start of the trial, there were no differences in behavioral responses to handling. However, over each of the next 4 wk, fewer RAC pigs exited the home pen voluntarily, they took longer to remove from the home pen, longer to handle into the weighing scale and needed more pats, slaps, and pushes from the handler to enter the scales. At the end of wk 4, RAC pigs had higher heart rates in the presence of an unfamiliar human (P < 0.05) and during transport (P < 0.05), but not during loading and unloading. Also at the end of wk 4, RAC pigs had higher circulating catecholamine concentrations (P < 0.05) than control pigs. Circulating cortisol concentrations and cortisol responses to transport did not differ between treatments. The results show that ractopamine affected behavior, heart rate, and catecholamine profile of finishing pigs and made them more difficult to handle and potentially more susceptible to handling and transport stress.  相似文献   

8.
Two experiments were conducted to evaluate the possible interaction of nursery space allocations and grow-finish space allocations in swine. In Exp. 1, crowding was achieved by varying the number of pigs per pen. During the nursery phase, decreasing the space allocation (0.16 m2/pig vs 0.25 m2/pig; 8 and 12 pens per treatment, respectively) by increasing the number of pigs per pen (18 vs 12) resulted in a decrease in daily feed intake (0.609 vs 0.683 kg/d; P < 0.001) and daily gain (0.364 vs 0.408 kg/d; P < 0.001). Pigs were mixed within nursery treatment groups and reassigned to grow-finish pens (6 pens per treatment) at the end of the 35-d nursery period providing either 0.56 m2/pig (14 pigs/pen) or 0.78 m2/pig (10 pigs/pen). Crowding during the grow-finish phase decreased daily feed intake (P < 0.003) and daily gain (P < 0.001). In Exp. 2, space allocations of 0.16 m2/pig vs 0.23 m2/pig during the nursery phase (24 pens per treatment) resulted in a decrease in daily feed intake (0.612 vs 0.654 kg/d; P < 0.005) and daily gain (0.403 vs 0.430 kg/d; P < 0.001). Pigs remained in the same (social) groups when moved to the grow-finish phase. Unlike Exp. 1, there was no effect of crowding during the grow-finish phase (0.60 m2/pig vs 0. 74 m2/pig) on daily feed intake or daily gain. The difference in results between experiments suggests that the response to crowding during the grow-finish phase may depend in part on whether pigs are mixed and sorted following movement from the nursery.  相似文献   

9.
Two experiments were conducted to determine the effect of lightweight pig removal and remixing on performance to slaughter. Experiment 1 was a growing-finishing trial utilizing a total of 900 pigs (26.2+/-0.1 kg initial weight) that were sorted and remixed at a mean replicate BW of 72 kg. Experiment 2 was a wean-to-finish trial (17 d mean wean age; 4.8 kg +/- 0.1 BW) utilizing 225 barrows with sorting and remixing occurring 3 wk after weaning. Treatments were 15 pigs/ pen from initial weight to slaughter (15S), 20 pigs/pen from initial weight to time of sort and remix and then reduced to 15 pigs/pen (20/15), and 15 pigs/pen from time of sort and remix to slaughter comprised of the five lightest pigs from each of three 20/15 pens per replicate (15M). Space allocation was 0.56 m2/pig from 26 to 70 kg and 0.74 m2/pig thereafter in Exp. 1. In Exp. 2, pen size was fixed at 2.44 x 4.27 m. In Exp. 1, there was no effect (P > 0.20) of treatment on performance prior to 70 kg. Least squares means for ADG from time of sort and remix to first pig removal from a pen for slaughter at 113 kg were 0.93, 0.87, and 0.91 kg/d for the 20/15, 15M, and 15S treatments, respectively (P < 0.05). When comparing the population represented by the 20/15 + 15M treatments vs the 15S population, there was no difference (P > 0.20) in ADG, ADFI, feed conversion, or carcass lean content. In Exp. 2, pigs in the 20/15 treatment grew slower (P < 0.05) than 15S pigs for the first 21 d (0.20 vs 0.22 kg/d, respectively) with a lower ADFI (P = 0.06) and no difference in feed conversion. When comparing the population represented by the 20/15 + 15M treatments vs the 15S population after sorting and remixing, there was no effect (P > 0.15) of experimental treatments on ADG, ADFI, feed conversion efficiency, carcass lean content, or daily lean gain. These results suggest that removal of lightweight pigs and remixing of the removed pigs into pens of similar-weight pigs is ineffective in improving the overall performance of a population of pigs during the postweaning period.  相似文献   

10.
Two studies were carried out with the same group of pigs within a wean-to-finish system. In Study 1 (weaning to wk 8 postweaning), the effect of feeder-trough space in pens that were double-stocked on pig growth was evaluated. In Study 2 (end of wk 8 to 112 +/- 1.5 kg BW), the effect of variation in pig BW within a pen on growth was investigated. In Study 1, a randomized block design was used to compare two feeder-trough space treatments (Double [4 cm/pig] vs Control [2 cm/pig]). Pigs (n = 1,728) were randomly allocated at weaning (5.4 +/- 0.01 kg BW; 16 d of age) to mixed-sex pens (8 pens/treatment) of 108 pigs/pen on the basis of BW. Floor-space (0.30 m2/pig) and drinker allocation (13 pigs/drinker) were the same for both treatments. Two six-place (35 cm/place) feeders were positioned together in the center of each pen and were accessible from both sides. For the Double treatment, both feeders contained feed, whereas for the Control only one feeder contained feed. In Study 2, a randomized block design was used to compare three BW/variation in BW treatments: 1) Heavy BW/Low variation, 2) Light BW/Low variation, and 3) Mixed BW/Normal variation. The double-stocked pens of pigs from within previous feeder-trough space treatment were split into two groups of 54 pigs (equal sex ratio) having either high or low BW variation within pen. Pigs had free access to feed and water throughout the studies. In Study 1, doubling feeder-trough space did not affect (P > 0.05) pig growth from weaning to the end of wk 6. From wk 6 to 8, pigs on the Double treatment compared to the Control treatment had higher (P < 0.05) ADG and were heavier (P < 0.05), but had similar (P > 0.05) ADFI and gain:feed ratio. In Study 2, pen-BW treatment did not impact (P > 0.05) ADG or gain:feed ratio; however, Heavy/Low had greater (P < 0.01) ADFI than Light/Low with Mixed/Normal being intermediate for ADFI. At 112 kg BW, CV of BW within a pen was similar (P > 0.05) across treatments; however, days to market BW was greater (P < 0.001) for Light/Low than Heavy/ Low with Mixed/Normal being intermediate. In summary, increasing feeder-trough space from 2 to 4 cm per pig increased daily gain after wk 6 postweaning in double-stocked pens of pigs; however, sorting pigs on the basis of BW when splitting pens did not impact growth rate or variation in BW within a pen at market BW.  相似文献   

11.
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12.
A study was conducted to determine the effect of social crowding on the development of endocrine organs involved in the reproductive process in growing and finishing gilts. One hundred four littermate gilts weighing approximately 30 kg were randomly assigned to treatment groups of either 8 or 16 pigs/pen. Gilts raised in pens of eight were allotted 1.06 m2 per pig from 30 to 65 kg and 1.25 m2 from 65 to 100 kg; whereas, one-half the area was provided for gilts raised in pens of 16. Littermate gilts raised in pens of 8 and 16 were slaughtered on the same day when the average weight of pigs reached 100 kg. At slaughter, the brain, adrenals, pituitary, uterus and ovaries were removed and weighted. The brain was lyophilyzed and reweighed to yield dry brain weight. Gilts raised in the low-density groups had heavier adrenal (P less than .01), pituitary (P less than .08), brain (P less than .11), dry-brain (P less than .02), uterine (P less than .09) and ovarian (P less than .07) tissues. Furthermore, significantly more gilts in the low-density, compared with the high-density groups, had ovulated at slaughter. In a second study, eight littermate gilts raised in pens of 8 or 16 and weighing approximately 100 kg were moved to individual pens and fitted with a jugular vein catheter. Following blood sample collection at 15-min intervals for 2 h, 200 IU of adrenocorticotropin (ACTH) were infused into the cannula. Blood samples were collected at 15-min intervals for an additional 2 h. There were no differences between basal or ACTH-stimulated concentrations of plasma cortisol between treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
In each of three trials, 240 crossbred barrows weaned at 17 d of age (5.1 kg BW) were assigned to one of three experimental treatments based on light and heavy weight outcome groups. Experimental treatments were 1) wean-to-finish at 0.69 m2/pig and 15 pigs/pen; 2) wean-to-finish double-stocked at 0.35 m2/pig, 30 pigs per pen for 8 wk and then randomly split into two pens (either stayed in same pen or moved to new pen) for growth to slaughter at 0.69 m2/pig; and 3) nursery facility for 8 wk at 0.35 m2/pig and 15 pigs/pen followed by move to the same grow-finish facility housing wean-to-finish and double-stocked pigs and maintaining pen integrity. Beginning at 38 kg BW, diets were supplemented with either bacitracin methylenedisalicylate at 33 mg/kg to slaughter or tylosin at 44 mg/kg to 59 kg BW and 22 mg/kg thereafter. There were no trial x treatment interactions, even though there was considerable variation in health status among trials. At the end of the 56-d nursery period, wean-to-finish pigs weighed more than nursery (28.7 vs 27.7 kg; P = 0.071) and double-stocked pigs (28.7 vs 26.9 kg; P = 0.002), due to greater ADG (wean-to-finish vs nursery; P = 0.062; wean-to-finish vs double-stocked; P = 0.002) and greater ADFI (wean-to-finish vs nursery; P = 0.024; wean-to-finish vs double-stocked, P = 0.002). There was no effect of treatments (P > 0.1) on ADG, feed conversion, carcass lean percentage, or lean gain during the growing-finishing period. There was also no effect of treatment (P > 0.1) on ADG or ADFI from weaning to slaughter. There was no difference (P > 0.1) between bacitracin methylenedisalicylate and tylosin for ADG, feed conversion, carcass lean percentage, or daily lean gain. These data suggest that housing 5-kg weaned pigs in fully slatted growing-finishing facilities from weaning to slaughter was not detrimental to overall performance. In this experiment, dietary additions of bacitracin methylenedisalicylate or tylosin from 38 kg BW to slaughter weight resulted in similar growth performance.  相似文献   

14.
The effects on agonistic interactions of installing a tire in a pen with 24 weanling pigs allocated to six pens, with four animals in each, were determined. At the first grouping, two pigs were transferred from each pen to another pen where non‐littermates existed. Then half of the pens were equipped with a tire (Grouping 1). After one week, the pigs transferred at Grouping 1 were again transferred to other pens were non‐littermates existed (Grouping 2). At Grouping 2, any pen was not newly equipped with a tire and no pig was exposed to a tire for the first time. After another week, the pigs transferred at the previous groupings were once more transferred to other pens where non‐littermates existed (Grouping 3). At Grouping 3, the pigs in the pens with a tire were transferred to pens without a tire, and the pigs in the pens without a tire were transferred to pens with a tire. Then all pens were equipped with a tire. In Grouping 1, the effects on agonistic interactions of installing a tire were not significant. However, the injury score (less the score, less the number and damage of injury) was higher in the pens without a tire than in the pens with a tire (P < 0.05). In Grouping 2, pigs in the pens with a tire were attacked more than pigs in the pens without a tire (P < 0.05). The number of agonistic behaviors positively correlated with access to the tire (rs = 0.31; P < 0.01). In Grouping 3, the number of attacks received by pigs with no experience in using a tire was larger on the first day after grouping than on the 4th day (P < 0.05). The injury score was higher for pigs being transferred than for pigs not being transferred (P < 0.05). In conclusion: (i) installing a tire in a pen did not reduce the agonistic interactions of pigs, but it could change the style of their attacks, and (ii) initially having pigs experienced in using a tire can be useful for reducing the damage caused by agonistic interactions.  相似文献   

15.
A study was conducted to compare growth performance and behaviors of group-farrowed pigs with those of confinement-farrowed pigs. A total of 216 pigs (8 wk of age) were used, with an equal number of group-farrowed or confinement-farrowed pigs from 1 farrowing batch. Group-farrowed pigs were farrowed in bedded, individual pens and mingled into a group of 8 litters at 12 (±1.3) d of age. Pigs were weaned at 33 (±1.3) d and remained in the farrowing room until 8 wk of age. Confinement-farrowed pigs were farrowed in farrowing crates. At weaning (32 ± 2.0 d of age), confinement-farrowed pigs were mixed and moved to pens of 9 pigs in a confinement nursery and remained there until 8 wk of age. At 8 wk of age, pigs from the 2 housing systems were allocated to 24 pens of 9 pigs in a confinement growing-finishing barn, with 12 pens from each of the housing systems. Within farrowing system, pigs from different groups or pens were mixed upon entering the growing-finishing barn. Individual BW was recorded at allotment (wk 0) to the growing-finishing barn and every 2 wk thereafter for 14 wk. Feed intake and G:F were monitored on a pen basis every 2 wk between wk 0 and 14 of the study period. Behaviors of pigs were video recorded in 6 pens of each housing treatment for 24 h on the day of mixing (d 0), d 7, and d 14 after mixing in the finisher barn. The video recordings were scanned at 5-min intervals to calculate behavioral time budgets for lying, standing, eating, drinking, and belly nosing. Data were analyzed using the Proc Mixed model of SAS with repeated measures. Compared with confinement-farrowed pigs, group-farrowed pigs spent more time lying (85.7 vs. 82.7%; SE = 0.75; P < 0.001) and belly nosing (0.05 vs. 0.02%; P < 0.05) and less time standing (5.8 vs. 7.5%; SE = 0.49; P < 0.01) and eating (7.3 vs. 9.3%; SE = 0.40; P < 0.001). The difference in behavioral time budgets was associated with differences in performance of pigs from the 2 housing systems. Group-farrowed pigs exhibited greater ADG (866 vs. 814 g; SE = 10.3; P < 0.01) for the initial 2 wk after mixing, less ADFI (2,004 vs. 2,188 g; SE = 42.5; P < 0.05), and improved G:F (0.431 vs. 0.393; SE = 0.0078; P < 0.01) for the entire 14-wk study period compared with confinement-farrowed pigs. These results suggest that group-farrowed pigs were more efficient than confinement-farrowed pigs in utilizing dietary energy for BW gain by lying more and standing and eating less during the growing and finishing period.  相似文献   

16.
A study was conducted to elucidate the effects of social factors on the concentrations of boar taint substances, androstenone and skatole, in boars. The factors included dominance (social rank) and the effects of strongly tainted animals on other members of the group. Four successive replicates of 100 pigs (50 boars + 50 gilts) with an average live weight of 24 kg were randomly allocated to 10 pens of 10. Data for this study were collected during the period of 67 to 114 kg of live weight and included the repetitive recording of agonistic behavior during competitive feeding; blood sampling for determination of plasma androstenone, skatole and testosterone in boars; feces sampling for determination of skatole content; and collection of bulbourethral glands in boars, and uteri plus ovaries in gilts at slaughter, for the assessment of sexual maturity. Results show an influence of social rank on plasma concentrations of androstenone (P = .0001) and testosterone (P = .0001), the weight of the bulbourethral glands (P = .0001), and plasma skatole (P = .02). Pens were classified according to the pig with the highest concentration of androstenone in the pen into high, medium, and low maximum pens. In pens with high maximum concentrations of androstenone, the second-highest androstenone concentration (P = .0001), and the average concentration (P = .0003) in the pen were higher than those in pens with medium or low maximum concentrations of androstenone. Mean aggression level was also higher (P = .02), but pens with high maximum aggression level did not have higher mean androstenone concentration. Rank effect on androstenone was more important than aggression effect. Neither maximum androstenone concentration nor maximum aggression level in a pen was related to the pen mean stage of sexual maturity in either sex. No influences of rank, aggression, or aggression received were found on the feces skatole level, and no pheromonal communicative function was demonstrated for skatole. High androstenone concentrations did not have a suppressive effect on androstenone concentrations in other males of the group; on the contrary, the levels were increased. This may be due to a stimulating effect of androstenone and, possibly, mating activity. Consequently, in the production of boars for slaughter, strongly tainted animals should be avoided or removed and mating activity minimized. This could be facilitated by, for instance, slaughtering before sexual maturity or separate rearing of the sexes.  相似文献   

17.
Four trials were conducted with 1,480 pigs (initial wt: 23 kg in trial 1,29 kg in trial 2 and 49 kg in trial 3 and 4) to determine the effect of dietary fat on pig performance, nutrient separation in an automated feed distribution system, dust levels in swine buildings and integrity of the respiratory system of swine. Two modified-open-front (B-1 and B-2) and two environmentally regulated (E-1 and E-2) growing-finishing buildings, of identical design, were used in each trial. In trial 1, 250 pigs (25 pens of 10 pigs/pen) in B-1 were fed a ground, mixed, corn-soybean meal diet (15% crude protein) with added tallow (5%), and 250 pigs in B-2 were fed the same diet but without added tallow. The assignment of diets to buildings were reversed in trial 2 in which 2.5% tallow was used instead of 5%. Each diet was fed ad libitum to pigs, and was distributed by an automated "Flexauger" system in trials 1 and 2. In each of trials 3 and 4, 120 pigs (12 pens of 10 10 pigs/pen) in E-1 were fed a corn-soybean meal diet (14% crude protein) with added tallow (5%) and 120 pigs in E-2 were fed the same diet but without added tallow. Overall, pigs fed the diet with tallow gained faster (P less than .002), consumed less feed (P less than .02) and converted feed more efficiently (P less than .002) than those fed the diet without tallow in trials 1 and 2. Pig performance was also improved by the addition of tallow to the diet in trials 3 and 4 (P less than .002). Crude protein, Ca, P and Cu contents of both diets were similar at each location sampled throughout the automated distribution system in trials 1 and 2. Addition of tallow to the diets reduced aerial dust levels, both with the feed distribution auger running (P less than .002) and without the auger running (P = .06) in trials 1 and 2. In trials 3 and 4, adding 5% tallow to the diet reduced aerial dust concentrations of of particle sizes of 14, 4, and 1.5 micron (P less than .002) and .4 micron (P = .07). The amount of settled dust was lower (P less than .001, trials 1, 3 and 4) when tallow was included in the diet.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

18.
Salbutamol has potential for use as a repartioning agent in swine. The aims of this experiment were to determine effects of salbutamol on behavior and physiology of finishing pigs. The study used 192 pigs (88.8 +/- 0.9 kg of BW) housed in groups of 6 in 32 pens and assigned to 1 of 4 treatments: 1) control-0 mg/kg of salbutamol, 2) 2R--control diet with 2 mg/kg of the pure R-enantiomer of salbutamol, 3) 4R--control diet with 4 mg/kg of pure R-salbutamol, or 4) 8RS--control diet with 8 mg/kg of a 50:50 mixture of the R- and S-enantiomers. All diets were offered ad libitum for 4 wk. Salbutamol diets were replaced with control diets 24 to 48 h before slaughter. Behavioral responses to handling during weighing were recorded immediately before assignment to the treatments (wk 0) and at weekly intervals over the next 4-wk period. Behavioral and heart rate (HR) responses to a 10-min human presence test in the home pen were measured during wk 0, wk 1, and wk 3. Heart rate responses to a 36-min transportation were recorded. One pig from each pen had blood collected 4 times: during wk 0, 2, 4, and at exsanguination. Blood was analyzed for NEFA, creatine kinase, glucose, lactate, blood urea nitrogen, ammonia, insulin, cortisol, norepinephrine, and epinephrine. Data were analyzed using PROC GLM of SAS, with pen as the experimental unit. Treatment had no effect on time spent lying laterally, overall activity, or time spent alert. Treatment had no effect on handling measures (P > 0.05) or on behavioral responses to human presence (P > 0.05), with all pigs willing to spend similar amounts of time close to and touching the human. However, during the human presence test in wk 1 and wk 3, control pigs had HR around 10 peats per minute less (P < 0.05) than pigs in the other 3 treatments. During transport, overall HR were similar across treatments (P > 0.05). However, at certain 1-min time points, control pigs had greater HR than salbutamol-treated pigs (P < 0.05). There were no treatment differences in lactate, epinephrine, or norepinephrine concentrations at any point. During wk 4, control pigs had less creatine kinase (P < 0.02) and greater blood urea nitrogen (P < 0.005) compared with pigs fed all the salbutamol treatments. The home pen behavior, handling, human presence test, and transport results indicate that salbutamol-treated pigs do not show marked differences in home pen time budgets and behavioral and HR responses to handling and transportation compared with control pigs. Thus, salbutamol did not have a negative effect on finishing pig well-being during this study.  相似文献   

19.
Five hundred forty crossbred pigs were utilized in four trials (10 replications) at two stations to determine the separate and interacting effects of decreasing floor space allowance with or without the addition of virginiamycin to the diet on performance of growing-finishing pigs. Pigs were allowed .37, .33 or .28 m2/pig during the growing phase (23 to 55 kg) and .74, .66, .56 m2/pig during the finishing phase (55 to 100 kg) and fed either a corn-soybean meal control diet or the control diet plus 11 mg of virginiamycin/kg of diet. Floor space allowances were achieved by varying pen size, so the number of pigs and feeder space per pig were constant for all pens. During the growing phase, daily gain (P less than .01) daily feed intake (P less than .05) and feed conversion ratio (P less than .05) decreased as floor space allowance decreased. During the finishing phase and for the total test period, daily gain (P less than .01) and feed conversion ratio (P less than .05) were reduced but daily feed intake was not affected (P greater than .05) by restricted floor space allowance. The addition of virginiamycin to the diet had no effect on pig performance. The virginiamycin X floor space allowance interaction was not significant, suggesting that pigs fed a diet with or without virginiamycin responded similarly to restricted floor space allowance. The data suggest that the addition of virginiamycin to the diet was ineffective in overcoming the decrease in performance of growing-finishing pigs caused by crowded conditions.  相似文献   

20.
Five experiments were conducted to test the effects of various dietary humic substances (HS; HS1, 2, 3, and 4, each with different fulvic and humic acid contents) on pig growth, carcass characteristics, and ammonia emission from manure. In Exp. 1, 120 pigs were allotted to 3 dietary treatments without HS (control) or with HS1 at 0.5 and 1.0% (8 pens/treatment and 5 pigs/pen) and fed diets, based on a 5-phase feeding program, from weaning (d 21.3 +/- 0.3 of age) to 60 kg of BW. In Exp. 2 and 3, 384 pigs (192 for each experiment) were allotted to 3 dietary treatments without HS, with HS1, or with HS2 (0.5%) for Exp. 2 and without HS, or with HS3 or HS4 (0.5%) for Exp. 3 (8 pens/treatment and 8 pigs/pen in each experiment). Pigs were fed diets, based on a 6-phase feeding program, from weaning (25.4 +/-0.2 and 23.6 +/-0.3 d of age for Exp. 2 and 3, respectively) to 110 kg of BW. In Exp. 4, 96 pigs were weaned at 22.1 +/-0.2 d of age and allotted to 2 treatments without or with HS1 at 0.5% (6 pens/treatment and 8 pigs/pen), and in Exp. 5 96 pigs were weaned at 20.9 +/-0.3 d of age and allotted to 3 treatments without HS, or with HS3 or HS4 (0.5%; 4 pens/treatment and 8 pigs/pen). Pigs were fed the diets for at least 2 wk before they were moved to an environmental chamber to measure aerial ammonia and hydrogen sulfide for 48 h at 5-min intervals. In Exp. 1, pigs fed diets with HS1 at 0.5% had greater (P < 0.05) ADG during phase 3 and greater (P < 0.05) G:F during phases 3 and 5 than control pigs. In Exp. 2, pigs fed diets with HS1 or HS2 at 0.5% had greater (P < 0.05) ADG and G:F than control pigs during the entire feeding period, whereas in Exp. 3 HS3 or HS4 did not improve pig growth performance. Ammonia emission from manure was reduced by 18 or 16% when pigs were fed diets with HS1 (P = 0.067) or HS4 (P = 0.054), respectively. The results of this study indicate that the effects of dietary HS are variable but may improve growth performance of pigs and reduce ammonia emission from manure. Further research is needed to clarify these effects and the mechanisms by which HS may cause them.  相似文献   

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