Association between in-transit loss, internal trailer temperature, and distance traveled by Ontario market hogs

An observational study was conducted from July to October 2004 to determine the association between in-transit losses of swine and internal trailer temperature after controlling for loading density, trip distance, herd size, and random trip effect. A convenience sample of 3 trucking companies was used to collect temperature, relative humidity, and global positioning data for 104 trips that delivered 21 834 pigs from 371 producers to Ontario abattoirs. The association between in-transit loss and trailer temperature was determined using the 90th percentiles of internal temperature for each trip. Average loading density was 0.36 m²/100 kg pig (range 0.28 to 0.50 m²/100 kg pig). Average in-transit loss was 0.12%; however, 94% of producers experienced no losses. As the 90th percentile of internal trailer temperature increased from a range of 8.6°C to 23.3°C to a range of 23.4°C to 26.1°C, average in-transit loss ratio increased approximately 3-fold, with an additional 2-fold increase as the range increased from 26.2°C to 28.9°C to 29.0°C to 30.5°C. As the 90th percentile of temperature increased by 1°C over the full range of temperatures in this study, in-transit loss was expected to increase 1.26 times. The in-transit loss was expected to decrease 0.81 times for each 50-km increase in distance traveled between the farm and the abattoir.     

Space requirements of weaned pigs during a sixty-minute transport in summer

Currently, there are no trucking quality assurance recommendations for space allowance of weaned pigs during transport in the United States. The objective of this research was to establish a first estimate of the space requirements of weaned pigs during transport in summer based on measures of animal well-being. A commercial semi-trailer was fitted with compartments that provided 0.05, 0.06, and 0.07 m(2)/pig, which were replicated on the upper and lower deck, with a constant 100 pigs per compartment. Cameras were placed in each experimental compartment to record behaviors and postures of pigs during transport. The frequencies of standing, lying, sitting, standing/rearing on another pig, and lying/huddling on top of another pig were recorded using 1-min scan samples during the entire duration of transport. Blood samples were collected and BW and lesion scores recorded from 32 pigs per space allowance for physiological and immune measures before and after transport (n = 32 pigs/treatment). Pigs were transported for 60 +/- 5 min to the wean-to-finishing site using the same route for each replicate during summer (temperature: 28.4 +/- 1.2 degrees C and relative humidity: 59.8 +/- 4.4% within the trailer). Data were analyzed using the MIXED procedure (SAS Institute Inc., Cary, NC). Cortisol, hematocrit, blood urea nitrogen, total protein, albumin, aspartate aminotransferase, creatine kinase, and gamma-glutamyl transferase increased (P < 0.05) after transport regardless of space allowance. Plasma glucose and BW decreased (P < 0.05) after transport regardless of space allowance. Lesion scores increased (P < 0.001) after transport and were greater (P < 0.05) for barrows compared with gilts. The neutrophil to lymphocyte ratio was greater (P < 0.005) for pigs transported at 0.05 m(2)/pig compared with pigs transported at 0.06 and 0.07 m(2)/pig. Pigs transported at 0.05 m(2)/pig lay down less (P < 0.05) than pigs transported at 0.06 and 0.07 m(2)/pig between 30 and 60 min of transport. Greater neutrophil to lymphocyte ratio and less lying behavior performed by pigs transported at 0.05 m(2)/pig suggest that a minimum space allowance of 0.06 m(2)/pig was preferable when transporting weaned pigs for 60 min during summer in this study.     

Factors associated with in-transit losses of market hogs in Ontario in 2001

In-transit losses and stage of transport when deaths occurred were determined for 4 760 213 market-weight pigs produced in 2001 by 4159 Ontario producers and marketed through 117 transport companies to 33 packers located in Canada (96%) and the United States. Approximately 73% and 21% of producers marketed < 2000 pigs and < 500 pigs, respectively. In-transit loss was 0.017%, with 75% of producers losing ≤ 5 pigs annually. Approximately half of in-transit losses occurred on the truck, with 14% of the other deaths occurring at the assembly yards, 4% on the producers’ trucks, and 24% at the abattoir. Fifteen percent of in-transit deaths, representing 1212 pigs, occurred in pigs that were previously identified as abnormal by the transporter or personnel working at the assembly yard or abattoir. Average losses were higher for producers marketing < 2000 pigs, and in-transit loss ratio (ITLR) was highest among those marketing < 100 pigs. Pigs from small farms traveled greater distances than those from larger operations. In-transit losses increased sharply between 590 and 720 km traveled, and decreased at distances > 980 km. Environmental temperatures reached ≥ 31°C for 4.2% of pigs shipped in June, July, and August, with median and mean temperatures of 20.6°C and 20.3°C, respectively, for these months. Twenty percent of all in-transit losses (1617 pigs) occurred in August.     

Effects of distance moved during loading and floor space on the trailer during transport on losses of market weight pigs on arrival at the packing plant

Effects of distance moved during loading and floor space on the trailer during transport on the incidence of transport losses (dead and nonambulatory pigs) on arrival at the packing plant were evaluated in a study involving 42 loads of pigs (average BW = 131.2 kg, SD 5.05). A split-plot design was used with a 2 x 6 factorial arrangement of the following treatments: 1) distance moved from the pen to the exit of the building [short (0 to 30.5 m) vs. long (61.0 to 91.4 m)] and 2) transport floor space (0.396, 0.415, 0.437, 0.462, 0.489, or 0.520 m(2)/pig). Loading distance treatments (sub-plots) were compared within transport floor space treatments (main plot). Pigs were loaded at the farm using sorting boards and, if necessary, electric goads, transported approximately 3 h to a commercial packing plant and unloaded using livestock paddles. The number of nonambulatory pigs during loading and the number of dead and nonambulatory pigs at the plant were recorded. Nonambulatory pigs were classified as fatigued, injured, or injured and fatigued. In addition, the incidence of pigs exhibiting signs of stress (open-mouth breathing, skin discoloration, and muscle tremors) during loading and unloading was recorded. There were no interactions (P > 0.05) between distance moved and transport floor space treatments. Moving pigs long compared with short distances during loading increased (P < 0.001) the incidence of open-mouth breathing after loading (24.9 vs. 11.0 +/- 1.03%, respectively) and tended to increase the incidence of nonambulatory pigs during loading (0.32 vs. 0.08 +/- 0.09%, respectively; P = 0.09) and of nonambulatory, injured pigs at the plant (0.24 vs. 0.04 +/- 0.07%, respectively; P = 0.06). However, distance moved did not affect other losses at the plant. Total losses at the plant were greater (P < 0.05) for the 3 lowest floor spaces compared with the 2 highest floor spaces, and pigs provided 0.462 m(2)/pig during transport had similar transport losses to those provided 0.489 and 0.520 m(2)/pig (total losses at the plant = 2.84, 1.88, 1.87, 0.98, 0.13, and 0.98 +/- 0.43% of pigs transported, for 0.396, 0.415, 0.437, 0.462, 0.489, and 0.520 m(2)/pig, respectively). These data confirm previous findings that transport floor space has a major effect on transport losses and suggest that these losses are minimized at a floor space of 0.462 m(2)/pig or greater.     

Response of growing-finishing pigs to decreasing floor space allowance and(or) virginiamycin in diet

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.     

Effect of dietary supplementation with vitamin C or carbadox on weanling pigs subjected to crowding stress

A 2 X 3 factorial arrangement was used in each of two trials with two levels of floor space allowance (.25, .13 m2/pig) and three dietary treatments (basal, basal + 660 ppm vitamin C, basal + 55 ppm carbadox). The reduction in floor space allowance was achieved in trial 1 by doubling the number of pigs/pen from eight to 16 and in trial 2 by reducing the size of pens by half. An 18% protein starter diet was used as the basal diet. Total numbers of pigs used were 216 in trial 1 and 144 in trial 2. Pigs were weaned between 4 and 5 wk of age (7.5 kg average wt) and fed ad libitum for 28 d. Reducing floor space allowance caused a (P less than .05) reduction in weight gain of weanling pigs in both trials. When the reduction of floor space allowance was done by increasing number of pigs/pen (trial 1), pigs responded with a significantly reduced feed intake with no change in efficiency of feed utilization. However, when floor space allowance was reduced by changing the size of the pen (trial 2), feed intake of pigs was not affected but efficiency of feed utilization was reduced significantly. Neither form of crowding affected vitamin C concentration in adrenal glands and weights of adrenal glands, spleen and thymus. Dietary supplementation of carbadox, but not vitamin C, produced significantly greater weight gain, feed efficiency, and spleen weight of pigs in both trials. Although there was no interaction between crowding and dietary treatment in affecting the performance of pigs, supplemental carbadox improved the performance of crowding-stressed pigs by maintaining an adequate level of feed intake and improving feed efficiency, whether crowding was caused by increased pig density or by reduced pen size. No significant differences in phytohemagglutinin (PHA) skin test response or in the neutrophil-to-lymphocyte ratio (N/L) were observed among treatments in trial 1, while a significantly reduced response to PHA and a higher N/L were detected in crowding-stressed pigs in trial 2.     

Effect of floor space during transport of market-weight pigs on the incidence of transport losses at the packing plant and the relationships between transport conditions and losses

Data on 74 trailer loads of finishing pigs (mean BW = 129.0, SEM = 0.63 kg) from wean-to-finish buildings on 2 farms within 1 production system were collected to investigate the effect of amount of floor space on the trailer (0.39 or 0.48 m2/pig) during transport on the incidence of losses (dead and nonambulatory pigs) at the packing plant and to study the relationships between transport conditions and losses. Pigs were loaded using standard commercial procedures for pig handling and transportation. Two designs of flat-deck trailers with 2 decks were used. Floor space treatments were compared in 2 similarly sized compartments on each deck of each trailer type. Differences in floor space were created by varying the number of pigs in each compartment. The incidence of nonambulatory pigs at the farm during loading and at the plant after unloading, average load weight, load number within each day, event times, and temperature and relative humidity in the trailer from loading to unloading were recorded. Of the 12,511 pigs transported, 0.26% were non-ambulatory at the farm, 0.23% were dead on arrival, and 0.85% were nonambulatory at the plant. Increasing transport floor space from 0.39 to 0.48 m2/pig reduced the percentage of total nonambulatory pigs (0.62 vs. 0.27 +/- 0.13%, respectively; P < 0.05), nonambulatory, noninjured pigs (0.52 vs. 0.15 +/- 0.11%, respectively; P < 0.01), and total losses (dead and nonambulatory pigs) at the plant (0.88 vs. 0.36 +/- 0.16%, respectively; P < 0.05) and tended to reduce dead pigs (0.27 vs. 0.08 +/- 0.08%, respectively; P = 0.06). However, transport floor space did not affect the percentage of nonambulatory, injured pigs at the plant. Nonambulatory pigs at the farm were positively correlated with relative humidity during loading and load number within the day (r = 0.46 and 0.25, respectively; P < 0.05). The percentage of total losses at the plant was positively correlated to waiting time at the plant, unloading time, and total time from loading to unloading (r = 0.24, 0.51, and 0.36, respectively; P < 0.05). Average temperature during loading, waiting at the farm, transport, waiting at the plant, unloading, and average pig weight on the trailer were not correlated to losses. These results suggest that floor space per pig on the trailer and transport conditions can affect transport losses.     

Effects of floor space during transport and journey time on indicators of stress and transport losses of market-weight pigs

The effects of floor space on the trailer and journey time during transport from the farm to the packing plant on indicators of stress (open-mouth breathing, muscle tremors, and skin discoloration) and on the incidence of transport losses (dead on arrival, nonambulatory, noninjured, and nonambulatory, injured) were evaluated in a study involving 160 loads of market-weight pigs (BW 124.7 ± 4.38 kg) using a split-plot design with a 2 × 6 factorial arrangement of treatments: 1) journey time [main plot; short (<1 h) and long (3 h)] and 2) floor space (subplot; 0.396, 0.415, 0.437, 0.462, 0.489, and 0.520 m(2)/pig, which is equivalent to 0.317, 0.332, 0.350, 0.370, 0.391, and 0.416 m(2)/100 kg of BW, respectively). Two consecutively loaded trailers were randomly allotted to journey time treatment. Floor space treatments were compared in the front 3 compartments on the top and bottom decks of the trailer and were created by varying the number of pigs per compartment, which confounds the effect of floor space with group size. Of the 17,652 pigs transported in 954 test compartments, 0.24% died or became nonambulatory. Neither journey time nor floor space had an effect (P > 0.05) on the incidence of dead and nonambulatory, injured pigs, or on total transport losses. There were interactions (P < 0.05) between journey time and floor space treatments for the incidences of nonambulatory, noninjured pigs and open-mouth breathing. For 2 of the smallest floor spaces (0.415 and 0.437 m(2)/pig), the incidence of nonambulatory, noninjured pigs was greater on short than on long journeys; for the other 4 floor spaces there was no effect (P > 0.05) of journey time. The incidence of open-mouth breathing for the 3 smallest floor spaces was greater (P < 0.05) for short than long journeys, whereas there was no effect (P > 0.05) of journey time for the 3 greatest floor spaces. The frequency of skin discoloration was greater (P < 0.001) for pigs transported at the 2 smallest floor spaces compared with the other 4 floor spaces. In summary, short journey time increased the frequency of indicators of stress after unloading at the plant for pigs transported at smaller floor spaces and also increased the incidence of nonambulatory, noninjured pigs at 2 of the 3 smallest floor spaces. However, neither transport floor space nor journey time had an effect on total losses.     

Effects of housing finishing pigs in two group sizes and at two floor space allocations on production, health, behavior, and physiological variables

With the current shift in the industry toward housing pigs in groups of 100 to 1,000 per pen have come questions as to whether pigs can perform as well in large groups as they do in small and whether large groups of pigs can use the space provided more efficiently. This study examined effects of small (18 pigs) vs. large (108 pigs) group sizes provided 0.52 m(2)/ pig (crowded) or 0.78 m(2)/pig (uncrowded) of space on production, health, behavior, and physiological variables. Eight 7-to 8-wk-long blocks, each involving 288 pigs, were completed. The average BW at the beginning of the study was 37.4 +/- 0.26 kg. Overall, ADG was 1.032 kg/d and 1.077 (+/-0.015) kg/d for crowded and uncrowded pigs, respectively (P = 0.018). Differences between the space allowance treatments were most evident during the final week of study. Overall G:F was also reduced (P = 0.002) in the crowded treatment. Pigs in the crowded groups spent less (P = 0.003) time eating over the 8-wk study than did pigs in noncrowded groups, but ADFI did not differ (P = 0.34) between treatments. Overall, ADG of large-group pigs was 1.035 kg/d, whereas small group pigs gained 1.073 kg/d (+/-0.015; P = 0.039). Average daily gain differences between the group sizes were most evident during the first 2 wk of the study. Over the entire study, G:F also differed, with large groups being less efficient (P = 0.005) than small groups. Although large-group pigs had poorer scores for lameness (P = 0.012) and leg scores (P = 0.02) throughout the 8-wk period, morbidity levels did not differ (P = 0.32) between the group sizes. Minimal changes in postural behavior and feeding patterns were noted in large groups. An interaction (P = 0.04) of group size and space allowance for lameness indicated that pigs housed in large groups at restricted space allowances were more susceptible to lameness. Although some behavioral variables, such as lying postures, suggest that pigs in large groups were able to use space more efficiently, overall productivity and health variables indicate that pigs in large and small groups were similarly affected by the crowding imposed in this study. Broken-line analysis of ADG indicated no difference in the response to crowding by pigs in large and small groups. Little support was found for reducing space allowances for pigs in large groups.     

Group size and floor-space allowance can affect weanling-pig performance

Crossbred weanling piglets (n = 1,920; mean initial BW, 5.3 +/- .7 kg) were used in two 9-wk trials employing a randomized block design in a 2 x 2 factorial arrangement of treatments to determine effects of group size (20 [Small = S] or 100 [Large = L] pigs/pen) and floor-space allowance (calculated requirement [CR] or calculated requirement less 50% of estimated "free space" [CR-50]) on growth performance. Free space was estimated for each group size. From wk 1 through 4 after weaning, S and L groups at CR were allowed a floor space of .17 m2/pig, and at CR-50, S and L groups were allowed .15 m2/pig and .13 m2/pig, respectively. From wk 5 through 9 after weaning, all CR treatment pigs were provided a floor space of .38 m2/pig, and for the CR-50 treatment, S and L pigs were allowed .32 m2/pig and .28 m2/pig, respectively. Piglets had free access to feed and water. Feeder-trough space per pig was the same for both group sizes. Feed-intake data were collected for only wk 1 through 4. Group size by floor-space allowance interactions (P < .05) were found for gain/feed ratio (G/F) for wk 1 and wk 2 through 4, but not for wk 1 through 4. Piglets in L groups were lighter (P < .001) at the end of wk 1, 4, and 9 by 2, 4, and 5%, respectively, and had lower ADG (6%; P < .001) throughout the trial than S piglets. During wk 1 through 4, feed intake was lower (7%, P < .001) in L piglets than in S piglets, but G/F was similar (P > .05). Piglets in CR groups had greater ADG (5%; P < .01) throughout the trial, with a greater G/F (P < .05) for wk 1 through 4, and were heavier (P < .01) than those in CR-50 groups at the end of wk 4 (3%) and 9 (4%). Pigs in L groups had a greater within-pen coefficient of variation in BW at the end of wk 9 than pigs in S groups. Large groups and reduced floor-space allowance reduced piglet growth performance in the nursery.     

The effect of three space allowances on the physiology and behavior of weaned pigs during transportation

Stocking density is an important aspect of transport, which could affect animal health and welfare, especially in pigs simultaneously experiencing weaning stress. The objective of this research was to evaluate the effect of three different space allowances on the physiology and behavior of weaned pigs during transport. A commercial semi-trailer with compartments that provided 0.05, 0.06 and 0.07 m²/pig was used throughout the study. All three space allowances were represented on both the upper and lower decks during each replicate. A constant of 100 pigs were loaded into each experimental compartment. Pigs were then transported for 112.5 ± 6.5 min to the wean-to-finishing site using the same route for each replication. This experiment was replicated 4 times. The experimental unit was the compartment. Prior to and after transport, blood samples were taken from a sub-set of pigs (n = 32 pigs/space allowance) for analysis of physiological and immune measures, and body weights and lesion scores were also recorded. Data loggers were fitted inside the trailer to record temperature, humidity, and wind speed. Cameras were placed in each experimental compartment to record behavior and postures of pigs during transport. The frequencies of standing, lying, sitting, standing-rearing on another pig, lying/huddling on top of another pig, total active and total inactive behaviors were recorded using 1-min scan samples during the entire duration of transport. Inside trailer temperature ranged from − 2.4 to 21.7 °C and inside trailer relative humidity ranged from 28.4 to 89.2% during transport. Cortisol, the neutrophil:lymphocyte (N:L) ratio, blood urea nitrogen, total bilirubin, total protein, albumin, aspartate aminotransferase, and creatine kinase were higher (p < 0.05) in pigs after transport regardless of space allowance. Skin lesions were more severe (p < 0.001) in pigs after transport regardless of space allowance. Pigs spent more (p < 0.001) time active during the first 75 min of transport compared with the last 30 min, regardless of space allowance. Pigs spent less (p < 0.01) time standing on another pig during transport at 0.07 m²/pig compared with pigs transported at 0.06 m²/pig. Higher cortisol concentrations and N:L ratio in weaned pigs after transport suggest that these pigs experienced stress, however space allowance did not appear to influence this response. Space allowances of 0.05, 0.06 or 0.07 m²/pig did not differentially influence pig well-being during a 112-min transport period as measured by changes in physiological measures.     

Effects of multiple concurrent stressors on rectal temperature, blood acid-base status, and longissimus muscle glycolytic potential in market-weight pigs

Sixty-four market-weight (130.0 +/- 0.65 kg) barrows (n = 16) and gilts (n = 48) were used in a split-plot design with a 2 x 2 x 2 factorial arrangement of treatments: 1) handling intensity (gentle vs. aggressive), 2) transport floor space (0.39 vs. 0.49 m(2)/pig), and 3) distance moved during handling (25 vs. 125 m) to determine the effects of multiple concurrent stressors on metabolic responses. For the handling intensity treatment, pigs were moved individually approximately 50 m through a handling course with either 0 (gentle) or 8 (aggressive) shocks from an electric goad. Pigs were loaded onto a trailer and transported for approximately 1 h at floor spaces of either 0.39 or 0.49 m(2)/pig. After transport, pigs were unloaded, and the distance moved treatment was applied; pigs were moved 25 or 125 m through a handling course using livestock paddles. Rectal temperature was measured, and blood samples (to measure blood acid-base status) were collected 2 h before the handling intensity treatment was applied and immediately after the distance moved treatment was applied. A LM sample to measure glycolytic potential was collected after the distance moved treatments on a subset of 32 pigs. There were handling intensity x distance moved interactions (P < 0.05) for several blood acid-base measurements. In general, there was no effect of distance moved on these traits when pigs were previously handled gently. However, when pigs were previously handled aggressively, pigs moved 125 compared with 25 m had greater (P < 0.05) blood lactate and less (P < 0.05) blood pH, bicarbonate, and base-excess. Pigs transported at 0.39 compared with 0.49 m(2)/pig had a greater (P < 0.01) increase in creatine kinase values; however, transport floor space did not affect any other measurements. Data were analyzed by the number of stressors (the aggressive handling, restricted transport floor space, and 125-m distance moved treatments) experienced by each pig (0, 1, 2, or 3). As the number of stressors experienced by the pig increased, rectal temperature, blood lactate, and LM lactate increased linearly (P 相似文献   

Effect of space allowance during rearing and selection criteria on performance of gilts over three parities in a commercial swine production system

A total of 1,257 gilts were used to determine the effect of space allowance during rearing and age at puberty on total pigs produced and removal rate over 3 parities. There were 2 treatments. In treatment 1, gilts were given a space allowance of 1.13 m(2)/gilt (15 gilts per pen), and in treatment 2, gilts were given 0.77 m(2)/gilt (22 gilts per pen). Gilts (38 kg and 75 d of age) were individually weighed upon entry and before leaving the rearing site. They were scanned for backfat thickness and loin depth and had their feet and legs scored for structure, movement, and toe evenness before leaving the rearing site. Commencing at approximately 140 d of age, gilts were exposed to a vasectomized boar once daily with age of puberty recorded for all gilts attaining puberty before leaving the rearing site. Gilts were then moved to a specialized gilt breeding farm. When confirmed pregnant, they were moved to 1 of 9 sow farms at random, where gilts remained until removal from that herd. Space allowance in rearing had no effect (P > 0.29) on growth rate in rearing, backfat thickness and loin depth, total pigs produced, or removal rate. A greater percentage of gilts attained puberty (P = 0.02) and attained puberty at a younger age (P < 0.01) when given the greater space allowance in rearing. Gilts given the lower space allowance in rearing had more (P = 0.04) cracks on their rear hooves. Gilts attaining puberty at a younger age (<185 d) had a greater growth rate in rearing, greater backfat thickness at 200 d of age, and produced more (P < 0.05) pigs over parities 1 to 3. Gilts in the fastest growth-rate group in rearing (>860 g/d) had greater (P < 0.05) total born in parity 1, but total pigs produced to the end of parity 3 was not different (P = 0.47). Contrary to expectation, a fast growth rate in rearing did not negatively affect removal rate. Gilts served between 240 to 260 d of age produced more (P < 0.01) pigs by the end of parity 3 than those served at >260 d of age, whereas a greater (P < 0.01) percentage of gilts served at >280 d of age were removed by the end of parity 3. In conclusion, space allowance in rearing did not affect total pigs produced or removal rate; however, gilts that attained puberty at a younger age produced more pigs over parities 1 to 3.     

Impact of spontaneous exercise on performance,meat quality,and muscle fiber characteristics of growing/finishing pigs

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.     

Effects of temperature stress on growth performance and bacon quality in grow-finish pigs housed at two densities

Managing stressors is essential for optimizing pig growth performance. To determine the effects of temperature and space allocation on growth performance and carcass characteristics, pigs were housed within their thermoneutral zone, at 23.9 degrees C, or above their thermoneutral zone, at 32.2 degrees C, and were provided either 0.66 or 0.93 m(2)/pig for the final 35 d of the grow-finish period. Individual BW were recorded on d 1, 10, 20, and 30. At slaughter, carcass measurements and samples of backfat and belly fat were collected. Final BW was decreased (P < or = 0.05) from 113 to 103 kg for pigs housed at 32.2 degrees C. The ADG was reduced (P < 0.05) for pigs housed at 32.2 degrees C (0.89 vs. 0.54 kg/d), as was G:F (0.28 vs. 0.24). Housing at 0.66 m(2)/pig resulted in pigs that were lighter (P < or = 0.05), at 106 compared with 110 kg, as a result of decreased (P < or = 0.05) ADG (0.78 to 0.65 kg/d) and decreased (P < or = 0.05) G:F (0.275 to 0.255) compared with pigs housed at 0.93 m(2)/pig. Pigs housed at a greater spatial allocation had elevated (P < or = 0.05) ADFI. The interaction of housing at 32.2 degrees C and decreasing spatial allocation increased (P < or = 0.05) the adipose iodine value from 66.8 to 70.4, decreased (P < or = 0.05) the saturated:unsaturated fatty acids ratio from 0.59 to 0.56, and increased (P < or = 0.05) the n-6:n-3 from 23.56 to 25.27. Decreased spatial allocation resulted in decreased (P < or = 0.05) belly weights. Although increased temperature did not affect belly weight, the 32.2 degrees C pigs had decreased (P < or = 0.05) raw and cooked slice weights, increased (P < or = 0.05) percentage lean of bacon, increased (P < or = 0.05) lean:fat ratio of bacon slices, increased (P < or = 0.05) raw slice scores, and increased (P < or = 0.05) quantity of collagen in belly fat. Some of these changes may have resulted from changes in lipid metabolism. Increasing spatial allocation in the 32.2 degrees C pigs decreased fatty acid synthase (P = 0.03) and stearoyl-CoA desaturase- 1 (P = 0.08) mRNA expression in adipose tissue. The results from this study demonstrated decreased growth, carcass lipid quality, and bacon quality in pigs housed at temperatures above the thermoneutral zone; however, increasing the spatial allocation for housing may be a means to ameliorate the negative effects of temperature stress.     

The assessment of thermal environment in relation to pig production

The thermal environment comprises factors which influence an animal's heat exchange through the channels of evaporation, radiation, convection and conduction. The air temperature is often used by itself as an assessment of the thermal environment, but air temperature by itself is inadequate for this purpose unless conditions are standardized with air and mean radiant temperatures equal to each other, free convection, and an insulated floor. Farming environments are not standardized, but climatic investigations allow an equivalent standardized environmental temperature (ESET) to be calculated for a given situation.Information on energy retention and heat loss in the pig has been derived from experiments under standardized conditions. ESET can be used to transfer the results of these experiments to pig farming conditions, and to determine for different types of housing the air temperatures equivalent to the effective critical temperatures found under standardized conditions.Experimental results can then be used to estimate the production losses which occur when ESET falls below the critical temperature, and the decision can be taken on increasing feed or improving heating or nsulation. For pigs in gorups in the body weight range 20–50 kg, the calculated air temperatures for maximum productivity range from 14°C in an insulated house free from draughts to 22°C in an uninsulated house with draughts in winter. Below these temperatures the animals' heat losses increase by approximately 4 kJ/°C per kg per day. For a feed with 1 g  12 kJ metabolizable energy, the increased heat loss leads to an increased feed requirement of 0.3 g/°C per kg per day for maintaining maximum production.     

Methicillin resistant Staphylococcus aureus colonization in pigs and pig farmers

Methicillin resistant Staphylococcus aureus (MRSA) colonization has recently been identified in pigs and people that work with pigs, raising concerns about the role of pigs as reservoirs of MRSA for human infection. The objectives of this study were to evaluate the prevalence of MRSA colonization in pigs and pig farmers in Ontario, Canada and to characterize MRSA strains. Nasal and rectal swabs were collected from 285 pigs from three different age groups from 20 pig farms. Nasal swabs were collected from farm personnel and a brief questionnaire was also administered. The prevalence of MRSA colonization in farms was 45% (9/20) whereas the prevalence in pigs was 24.9% (71/285). There was no difference in MRSA colonization between age groups. The prevalence of MRSA colonization in pig farmers was 20% (5/25). There was a correlation between the presence of MRSA in pigs and humans on farms (P value=0.001). The results of spa typing revealed the predominant strain in pigs and humans was eGenomics spa type 539 (Ridom t034, clonal complex 398) which accounted for 59.2% of isolates and has been reported in pigs in Europe. A common human epidemic clone, CMRSA-2 (USA100, clonal complex 5) was also found in both pigs and pig personnel. Indistinguishable strains were found in pigs and pig personnel on all five farms with a colonized human. This study demonstrates that MRSA is common in pigs in Ontario, Canada, and provides further support to concerns about transmission of MRSA between pigs and humans.     

Application of broken-line analysis to assess floor space requirements of nursery and grower-finisher pigs expressed on an allometric basis

Few issues in swine production are as complex as floor space allowances. One method for pork producers to calculate floor space allowance (A) is to convert BW into a 2-dimensional concept yielding an expression of A = k * BW(0.667). Data on ADG, ADFI, and G:F were obtained from published peer-reviewed studies. Five data sets were created: A = grower-finisher pigs, fully slatted floors, and consistent group size; B = grower-finisher pigs and fully slatted floors (group size did not need to be consistent); C = grower-finisher pigs, partially slatted floors, and consistent group size; D = grower-finisher pigs, partially slatted floors (group size did not need to be consistent); and E = nursery pigs, fully slatted or woven wire floors (group size did not need to be consistent). Each data set was analyzed using a broken-line analysis and a linear regression. For the broken-line analyses, the critical k value, below which a decrease in ADG occurred, varied from 0.0317 to 0.0348. In all cases the effect of space allowance on ADG was significant (P < 0.05). Using the linear analyses based on data with k values of < 0.030, the critical k values for the 4 grower-finisher data sets did not differ from those obtained using the broken-line analysis (0.0358 vs. 0.0336, respectively; P > 0.10); however, none of the linear regressions explained a significant proportion of the variation in ADG. The slopes for the nonplateau portion of the broken-line analyses based on percent values varied among data sets. For every 0.001 decrease in k (approximately 3% of the critical k value), ADG decreased by 0.56 to 1.41%, with an average value of 0.98% for the 5%-based analyses. The use of an allometric approach to express space allowance and broken-line analysis to establish space requirements seem to be useful tools for pig production. The critical k value at which crowding becomes detrimental to the growth of the pig is similar in full- and partial-slat systems and in nursery and grower-finisher stages. The critical point for crowding determined in these analyses approximated current recommendations to ensure the welfare of pigs.     

Relationships of barometric pressure and environmental temperature with incidence of parturition in beef cows

ABSTRACT:The relationship between barometric pressure (BARO) and maximum (MAX_T) and minimum (MIN_T) environmental temperatures with the incidence of parturition in beef cows was examined through exploratory data analysis. Spring- and fall-calving records from a 5-yr period (2005 through 2009) collected at the University of Arkansas, Livestock and Forestry Research Station (Batesville) and the Department of Animal Science Savoy Research Unit (Savoy, AR) were used. All cows were multiparous, predominantly Angus, and naturally bred. During this period, 2,210 calves were born over a cumulative 1,547 d. Local weather station BARO and MAX_T and MIN_T data were obtained from the Southern Regional Climate Center, Louisiana State University, Baton Rouge. The combined calving record and climate variables were used to determine differences in BARO, MAX_T, and MIN_T on d 0 (d of calving) and -1, -2, or -3 d, respectively, before calving occurred (CALFD) or did not occur (NOCALFD). Location and season also were included in the model. For fall-calving cows, BARO on d 0 and -1, -2, or -3 was not different between CALFD and NOCALFD (P > 0.10). For spring-calving cows, BARO on d 0, -1, -2, and -3 was greater (P < 0.05) for CALFD compared with NOCALFD. The MAX_T was greater on d -1 (24.4 vs. 22.9°C) and -3 (24.8 vs. 23.4°C) for CALFD in the fall compared with NOCALFD (P < 0.05). No differences were detected in the fall for MAX_T on d 0 or -2 (P > 0.10). In the spring, a decreased MAX_T was associated with CALFD. Maximum environmental temperatures on d 0 (14.7 vs. 16.0°C), -1 (14.4 vs. 16.0°C), and -3 (14.0 vs. 15.7°C) were less for CALFD compared with NOCALFD (P < 0.05). No difference was detected on d -2 (P > 0.10). For fall, MIN_T was greater on d -1 (12.8 vs. 11.3°C), -2 (13.0 vs. 11.4°C), and -3 (13.1 vs. 11.7°C) for CALFD compared with NOCALFD (P < 0.05). In spring, MIN_T for d 0 (2.6 vs. 3.9°C), -1 (2.5 vs. 3.7°C), -2 (2.1 vs. 3.7°C), and -3 (1.8 vs. 3.8°C) were lesser (P < 0.05) for CALFD vs. NOCALFD. These data indicate that for spring-calving cows, a greater BARO and decreased MAX_T and MIN_T were associated with CALFD, whereas for fall-calving cows, an increase in MAX_T and MIN_T was associated with CALFD. Therefore, monitoring weather conditions may assist producers in preparing for the obstetric assistance of beef cattle.     

Increasing energy and lysine in diets for growing-finishing pigs in hot environmental conditions: consequences on performance, digestibility, slurry composition, and gas emission

The influence of dietary nutrient concentration on growth performance, manure composition, and gas emission was studied in pigs in hot environmental conditions. A total of 64 intact males and 64 females [(Landrace × Large White) × Pietrain] weighing 63.1 ± 9.7 kg were divided into 2 dietary treatments: high (HD: 14.39 MJ of DE/kg and 1.11% Lys) and low (LD: 13.97 MJ of DE/kg and 1.01% Lys) in energy and Lys contents. Pigs were allocated to 32 split-sex pens with 4 pigs/pen and 16 pens/treatment. Average productive performance was recorded for 41 d (phase 1). After phase 1, 12 females of 103.3 ± 3.15 kg (6 per treatment) were selected and housed individually, and feces and slurry were collected during 3 and 4 consecutive days, respectively, to calculate nutrient digestibility and measure gas emissions (phase 2). For gas emission measurements, slurry was pooled by treatment and stored for 76 d. Initial composition of slurry and pH were analyzed. Maximum and minimum temperatures registered in the barn throughout the growing period were 35.1 and 18.1°C, respectively. Animals fed the HD diet grew more efficiently than pigs fed the LD diet (G:F, 0.43 vs. 0.40; SEM = 0.01; P < 0.05). Fat digestibility was greater in HD compared with LD pigs (88.0 vs. 84.9%; SEM = 0.9; P < 0.05). Slurry from pigs fed the LD diet showed greater DM, OM, total N, and VFA contents than slurry from pigs fed the HD diet. Cumulative NH(3), CO(2), and especially CH(4) emissions were greater in the HD slurry compared with the LD slurry (192.4 vs. 210.g of NH(3)/m(3); 2,712 vs. 3,210 g of CO(2)/m(3); 1,502 vs. 2,647 mL of CH(4)/kg of OM). Increasing feed density in the present study led to a more efficient growth, a decreased nutrient concentration in the slurry, and a greater gas emission.