Anna K. Johnson

EVIEW: Compilation of the Scientific Literature Comparing Housing Systems for Gestating Sows and Gilts Using Measures of Physiology, Behavior, Performance, and Health 1

The objective of this review was two-fold. First, a series of meta-analyses (analyses of treatment effects across studies) were performed on available data from scientific literature to determine whether sow behavior, performance, or physiology differed for sows in group pens or individual stalls. Second, research publications in areas of performance and health, physiology, and behavior of pregnant gilts and sows in studies that directly compared gestation sow housing systems were summarized. Common systems were stalls, tethers, and various types of group housing systems. Results of meta-analyses showed that the average levels of productivity, oral-nasal-facial behaviors (ONF), and blood cortisol were statistically similar for sows in group pens and stalls. For the review, in some studies, circulating cortisol concentrations were greater among gestating females kept in tethers compared with other systems; however, overall cortisol was not altered by housing system. Immune parameters were largely not influenced by housing system. Housing system did not alter heart rate. Gestation housing system may influence sow behavior including stereotypic ONF, postural locomotory, feeding behaviors, or social behaviors. Overall, total ONF behaviors were comparable between gestation sow housing systems. However, tethered and stalled sows exhibited more stereotypic ONF compared with sows in group or outdoor systems. Compared with group housing, individually confining sows during gestation resulted in postural and movement restrictions. Stall size and design can impact postural adjustments and inter-stall aggression of individually housed sows. Inconsistent performance and health results were found among sow housing studies. Sows in stalls consistently had equal or greater reproductive performance compared with sows in other systems. Farrowing rate for sows in individual stalls was equal to or superior to sows in other systems. Farrowing rate was clearly superior among sows in stalls compared with group systems, where dynamic social groups were employed. However, tethered sows may have reduced litter size and increased piglet birth weight. Sows in group housing systems, particularly electronic sow feeder (ESF) systems, had injury scores greater than sows in either stalls or tethers. Gestation housing system (individual vs group) may impact sow welfare in the farrowing area (using stalls or pens). In conclusion, although individual studies found significant housing system effects, subjected to the overall evidence from adequately designed studies meta-analyses revealed that gestation stalls (non-tethered) or well-managed pens generally (but not in all cases) produced similar states of welfare for pregnant gilts or sows in terms of physiology, behavior, performance, and health.

Review:Transport Losses in Market Weight Pigs: I. A Review of Definitions, Incidence, and Economic Impact

ABSTRACT Transport losses (dead and nonambulatory pigs) present animal welfare, legal, and economic challenges to the US swine industry. The objectives of this review are to explore 1) the historical perspective of transport losses; 2) the incidence and economic implications of transport losses; and 3) the symptoms and metabolic characteristics of fatigued pigs. In 1933 and 1934, the incidence of dead and nonambulatory pigs was reported to be 0.08 and 0.16%, respectively. More recently, 23 commercial field trials (n = 6,660,569 pigs) were summarized and the frequency of dead pigs, nonambulatory pigs, and total transport losses at the processing plant were 0.25, 0.44, and 0.69% respectively. In 2006, total economic losses associated with these transport losses were estimated to cost the US pork industry approximately

Factors associated with fatigued, injured, and dead pig frequency during transport and lairage at a commercial abattoir

46 million. Furthermore, 0.37 and 0.05% of the nonambulatory pigs were classified as either fatigued (nonambulatory, noninjured) or injured, respectively, in 18 of these trials (n = 4,966,419 pigs). Fatigued pigs display signs of acute stress (open-mouth breathing, skin discoloration, muscle tremors) and are in a metabolic state of acidosis, characterized by low blood pH and high blood lactate concentrations; however, the majority of fatigued pigs will recover with rest. Transport losses are a multifactorial problem consisting of people, pig, facility design, management, transportation, processing plant, and environmental factors, and, because of these multiple factors, continued research efforts are needed to understand how each of the factors and the relationships among factors affect the well-being of the pig during the marketing process.

Dietary Inclusion of Colicin E1 Is Effective in Preventing Postweaning Diarrhea Caused by F18-Positive Escherichia coli in Pigs

The objective of this study was to identify environmental and management factors that are associated with the frequency of fatigued, injured, and dead pigs on arrival and in resting pens during lairage at a commercial Midwest abattoir. The terms transport losses or total losses refer to pigs that die or become nonambulatory at any stage of the marketing process. In this study, fatigued, injured, and dead pigs were summed into a variable termed total losses. Relative humidity (%), temperature ( degrees C), wind speed (m/s), and dew point ( degrees C) data were collected on 12,333 trailer loads of pigs. Week, sort from barn (first or third pig removal from barn), farm, normal vs. split load type (from 1 or multiple barns), load crew, driver, trailer, and wind direction were used as fixed effects in the model for the analysis of losses per load using generalized mixed models for Poisson distributions. Seven temperature-humidity indices (THI) were calculated and compared as model covariates. Load time per pig, trailer density (pigs per trailer x average BW/trailer space; kg/m(2)), wait time before unloading at the abattoir, and wind speed were used as model covariates. The log of the number of hogs per trailer was used to standardize the response variable. The linear covariate density accounted for the greatest portion of variance (based on F-value) followed by the fixed effect sort from barn, the fixed effect load type (pigs from 1 or multiple barns within a farm), load time per pig linear covariate, and THI. Pigs transported to the abattoir from June through July experienced fewer losses (P < 0.001) when compared with pigs that were transported from November through December. Keeping other factors constant, the log of total losses (%) per load increased by 0.0102x + 0.000541x(2) per unit of THI and 0.0191 kg/m(2) of density. Similarly, of 9 farms, the poorest-performing farm in regards to total loss percentage experienced 0.93% more losses per load when compared with the farm with the least loss percentage. This study demonstrates that multiple environment and management factors influence the incidence of market hog transport losses.

Genetic associations for gilt growth, compositional, and structural soundness traits with sow longevity and lifetime reproductive performance

ABSTRACT With worldwide concern over the use of antibiotics in animal agriculture and their contribution to the spread of antibiotic resistance, alternatives to conventional antibiotics are needed. Previous research in our laboratories has shown that colicin E1 is effective against some Escherichia coli strains responsible for postweaning diarrhea (PWD) in vitro. In this study we examined the efficacy of the dietary inclusion of colicin E1 in preventing experimentally induced PWD caused by F18-positive enterotoxigenic E. coli in young pigs. Twenty-four weaned pigs (23 days of age), identified by genotyping to be susceptible to F18-positive E. coli infections, were individually housed and fed diets containing 0, 11, or 16.5 mg colicin E1/kg diet. Two days after the start of the trial, all animals were orally inoculated with 1 × 109 CFU of each of two F18-positive E. coli strains isolated from pigs with PWD. The dietary inclusion of colicin E1 decreased the incidence and severity of PWD caused by F18-positive enterotoxigenic E. coli and improved the growth performance of the piglets. Additionally, the reduced incidence of PWD due to dietary colicin E1, lowered the levels of expression of the genes for interleukin 1β and tumor necrosis factor beta in ileal tissues from these animals. The dietary inclusion of colicin E1 may be an effective alternative to conventional antibiotics in the diets of weaning pigs for the prevention of PWD caused by F18-positive enterotoxigenic E. coli.

The effect of selection for residual feed intake on general behavioral activity and the occurrence of lesions in Yorkshire gilts

The objective of this study was to estimate genetic associations for gilt growth, compositional, and structural soundness with sow longevity and lifetime reproduction. Performance and pedigree information from 1,447 commercial females from 2 genetic lines were included in the data analyzed. Growth was expressed as days to 113.5 kg BW (DAYS) and compositional traits included loin muscle area (LMA), 10th rib backfat (BF10), and last rib backfat (LRF). Structural soundness traits included body structure traits [length (BL), depth (BD), width (BWD), rib shape (BRS), top line (BTL), and hip structure (BHS)], leg structure traits [front legs: legs turned (FLT), buck knees (FBK), pastern posture (FPP), foot size (FFS), and uneven toes (FUT); rear legs: legs turned (RLT), leg posture (RLP), pastern posture (RPP), foot size (RFS), and uneven toes (RUT)], and overall leg action (OLA). Lifetime (LT) and removal parity (RP) were considered as longevity traits whereas lifetime reproductive traits included lifetime total number born (LNB), lifetime number born alive (LBA), number born alive per lifetime day (LBA/LT), and percentage productive days from total herd days (PD%). Genetic parameters were estimated with linear animal models using the average information REML algorithm. Second, to account for censored longevity and lifetime reproduction records, genetic parameters were estimated using Markov Chain Monte Carlo and Gibbs sampling methods. Similar estimates were obtained across the analysis methods. Heritability estimates for growth and compositional traits ranged from 0.50 to 0.70 and for structural soundness traits from 0.07 to 0.31. Longevity and lifetime reproductive trait heritability estimates ranged from 0.14 to 0.17 when REML was used. Unfavorable genetic correlations were obtained for DAYS with LT, RP, LNB, LBA, and PD% and for LRF with PD%. However, LMA was favorably associated with LT, RP, and LNB. Moderate to high correlations were obtained for BL and BRS with all longevity and lifetime reproductive traits. Correlations of BWD with LT and RP were moderate. Associations for leg soundness traits with longevity and lifetime reproductive traits were mainly low and nonsignificant (P ≥ 0.10). However, RLP was moderately correlated with LBA/LT and PD%. Current results indicate that selection for fewer DAYS has an antagonistic effect on lifetime performance. Furthermore, great BL, flat BRS, narrow BWD, and upright RLP seem detrimental to sow longevity and lifetime reproduction.

Welfare of Pigs in the Farrowing Environment

The objectives of this study were to determine the effect of selection for improved residual feed intake on behavior, activity, and lesion scores in gilts in their home pen. A total of 192 gilts were used, 96 from a line that had been selected for decreased residual feed intake over 5 generations (LRFI) and 96 from a randomly bred control line. Gilts were housed in 12 pens (16 gilts/pen; 0.82 m(2)/gilt) containing 8 gilts from each line in a conventional grow-finish unit. Twelve hours of video footage were collected on the day of placement and then every 4 wk for 3 more observational periods. Video was scored using a 10-min instantaneous scan sampling technique for 4 postures (standing, lying, sitting, and locomotion) and 1 behavior (at drinker). Categories of active (standing, locomotion, and at drinker) and inactive (sitting and lying) were also created. Lesion scores were collected 24 h after behavior collection had begun. The body of a gilt was divided into 4 regions, with each region receiving a score of 0 (0 lesions) to 3 (5+ lesions). All statistical analyses used Proc Mixed of SAS. Data were analyzed separately for the day of placement and the subsequent 3 rounds. General activity was summarized on a percentage basis by each posture and behavior and subjected to an arcsine square root transformation to normalize data and stabilize variance. Analysis was performed on each behavior and posture. Lesion scores for each region of the body were analyzed as repeated measures. There were no differences (P > 0.05) between genetic lines for all postures and the behavior at drinker on the day of placement. However, over subsequent rounds it was observed that LRFI gilts spent less (P = 0.03) time standing, more time sitting (P = 0.05), and were less active (P = 0.03) overall. Gilts from the LRFI line had decreased (P < 0.045) lesion scores on the day after placement. However, over subsequent rounds there were no (P > 0.05) differences between the genetic lines. In conclusion, on the day of placement there were no postural, behavior, or general activity differences between genetic lines, but LRFI gilts had decreased lesion scores. Behavioral differences were observed between genetic lines over subsequent rounds, with LRFI gilts becoming less active, but there were no differences in lesion scores.

Development of an Embedded Microcomputer-based Force Plate System for Measuring Sow Weight Distribution and Detection of Lameness

In the U.S.A., housing for the lactating sow and her piglets can be divided into five main areas. Total confinement, defined as the farrowing crate, houses the highest number of sows at 83.4 4.0%. Remaining operations house fewer sows with open buildings that have outside access at 12.4 4.1%, open building with no outside access, 2.9 0.5%, lot with hut or no building, 0.6 0.2% and pasture with hut or no building the lowest at 0.7 0.3% (NAHMS, 2000). In the U.K., it is estimated that around 70% of sows farrow in crates, 27% farrow outdoors in farrowing arks and only 3% farrow in loose-housed indoor systems (BPEX, 2004). Farrowing crates have become widely accepted by the industry for numerous reasons: it has made sow management easier, it allows for a higher stocking density of sows/unit of land and it can help to reduce piglet mortality (Fraser and Broom, 1997). However, the farrowing crate has received criticism due to potential detrimental effects it may inflict on the welfare of the sow. The prevalence of decubital ulcers (Davies et al., 1996; Rountree et al., 1997), behaviours considered maladaptive (Cronin and Wiepkema, 1984; Rushen, 1984; Haskell andHutson, 1996), and a limitation on allowing the sow complete postural adjustments are a few considerations. The development of an alternative, economical farrowing system that retains the advantages of the conventional farrowing crate could be beneficial to the industry (Collins, 1987). Alternative outdoor swine operations for the gestating sow are increasing in popularity in some countries. In 1975, only 6% of the U.K.’s national herd was housed outdoors. This trend can be seen in other European countries, France now houses 10% of its herd outdoors, and Denmark and Sweden are conducting feasibility studies to determine if their cooler climates would permit

2011 and 2012 Early Careers Achievement Awards: farm and pig factors affecting welfare during the marketing process.

Measuring sow weight distribution is vital for scientists to identify lame animals before clinical signs can be visually observed and help livestock producers decrease lameness incidence in their swine breeding herd. In this study, an embedded microcomputer-based force plate system was developed to measure vertical forces produced by each limb of the sow and evaluate data accuracy to the sows known weight. It was found that all tested sows averaged more weight on their front legs than their hind legs and side-to-side weight differences had more variation than front-to-hind distribution. The deviation in front-to-hind weight distribution might be indicative of lameness in both hind or both front feet. To better illustrate the capabilities of the force plate, a 60-s data rolling average protocol was employed for the collected weight data which were recorded every second from each sow leg. The preliminary results indicate that the force plate system was able to identify sow lameness by separately measuring the weight of each leg. Future work will need to evaluate the magnitude of the difference in weight distribution between legs detected by the force plate system in order for producers to effectively determine lameness in sows.

Analytical Methods for Chemical and Sensory Characterization of Scent-Markings in Large Wild Mammals: A Review

The objective of this paper is to review the scientific literature to identify on-farm factors that contribute to market weight pig transportation losses. Transportation of market weight pigs is an essential element to the multisite pork production model used in the United States. In 2011 alone, approximately 111 million market weight pigs were transported from the finishing site to the abattoir. For pigs, the marketing process can present a combination of potentially novel, physical, and/or unfamiliar experiences that can be stressful. If the pig cannot cope with these sequential and additive stressors, then an increased rate of transportation losses could occur with a detrimental effect on pork carcass value. Current yearly estimates for transport losses are 1 million pigs (1%). A variety of market weight pig and farm factors have been reported to detrimentally affect transportation losses. By understanding how pigs interact with their environment during marketing, researchers, producers, and personnel at the abattoir may begin to identify, prioritize, and attempt to minimize or eliminate these stressors. This process will ultimately decrease transportation losses, improve pork quality, and increase profitability.