Assessment of the effects of the season of transport on the performance of early-weaned piglets

Effect of season on weaned piglet mortality during transport greater than 8 h under Canadian conditions

North American swine producers commonly transport piglets away from sow farms at weaning. However, limited information on factors associated with piglet mortality during these transports is available. The objectives of this study were to identify transport characteristics that were associated with the occurrence of in-transit mortality (≥1 piglet found dead on arrival) and/or associated with increased rates of in-transit mortality using records of weaned piglet transport voluntarily provided by Canadian swine companies. Following cleaning and validation, records of 810 long duration (>8 h to <28 h) weaned piglet (min.: 4.2, max.: 7.7 kg) transports conducted between 2016 and 2017 by four companies were available to investigate risk factors for the occurrence of in-transit mortality. Transports originated in Ontario, Saskatchewan, or Alberta and 30% of transports had one or more mortality events recorded. Season of transport was significant in the final logistic regression model; the odds of a transport having mortality occur was greater during the winter (December, January, February) compared to the spring (March, April, May) (OR=1.8; 95% CI: 1.13-2.96; P = 0.013), summer (June, July, August) (OR= 2.1; 95% CI: 1.28-3.34; P = 0.003) and fall (September, October, November) (OR=2.2; 95% CI: 1.36-3.62; P = 0.001), with no differences observed between the other seasons. Additionally, records from 755 long duration weaned piglet (min.: 4.2, max.: 7.9 kg) transports conducted between 2014 and 2017 by a single company was used to identify risk factors for increased rates of in-transit mortality. Transports originated in Saskatchewan or Alberta and 44.9% of transports had one or more mortality events recorded with in-transit mortality rates ranging from 0.00% to 6.16%. Season of transport was again significant in the final negative binomial regression model. The rate of piglet death in-transit was increased in all seasons compared to the summer with winter transport having the highest predicted rate of in-transit mortality. Transports conducted during the winter had a rate of in-transit mortality nearly five times greater compared to transports conducted during the summer (IRR= 4.94; 95% CI: 3.11-7.87; P = 0.000) and approximately three times greater compared to transports conducted during the fall (IRR=2.7; 95% CI: 1.73-4.30; P = 0.000) and spring (IRR=3.1; 95% CI: 1.96-4.99; P = 0.000). These results suggest that winter transport in Western Canada is an area of opportunity to reduce in-transit mortality during long duration weaned piglet transport. Research investigating transport practices that may mitigate the effects of extreme cold (e.g., space allowance, bedding provision) would be useful for informing specific recommendations for this age group.

Road Transport: A Review of Its Effects on the Welfare of Piglets

The purpose of this review is to present the best available scientific knowledge on key effects of pre-transport and transport factors influencing the response of piglets to transport stress and post-transport recovery. To date, research on piglet transportation particularly focused on the effects of season (i.e., heat and cold stress), vehicle design features (ventilation type and deck/compartment location), space allowance and transport duration, and piglet genetics. More specifically, in this review the effect of transport duration has been dealt with through its impact on death rate, behaviour and physiological response, and feeling of hunger and thirst. Based on the available literature, clear conclusions can be drawn on the vulnerability of piglets to heat stress during transport. Both short and long transportation have an effect on piglet welfare, with effects being biased by the genetic background, ambient conditions and vehicle design. Further studies investigating the impact of factors such as vehicle design, truck stocking density and environment, piglet genetic background, and weaning age are needed.

Evaluation and mitigation of the effects of in utero heat stress on piglet growth performance, postabsorptive metabolism, and stress response following weaning and transport

In utero heat stress (IUHS) increases the energy requirements of pigs during postnatal life, and this may compound weaning and transport stress. The study objective was to evaluate and mitigate the negative effects of IUHS following weaning and transport through the provision of a nutrient-dense (ND) nursery diet formulated to meet the greater energy requirements of IUHS pigs during the first 14 d postweaning and transport. Twenty-four pregnant gilts were exposed to thermoneutral (TN; n = 12; 17.5 ± 2.1 °C) or heat stress (HS; n = 12; cycling 26 to 36 °C) conditions for the first half of gestation (day 6 to 59) and then TN conditions (20.9 ± 2.3 °C) until farrowing. Nine TN gilts and 12 HS gilts produced litters. At weaning (16.2 ± 0.4 d), mixed-sex piglets (N = 160; 4.78 ± 0.15 kg body weight [BW]) were transported (loading + transport + unloading) for 11 h 40 min. Following transport, piglets were blocked into pens (n = 4 pigs/pen) by in utero and dietary treatments: in utero thermoneutral (IUTN) + control (C) diet (n = 10 pens), IUTN + ND (n = 10 pens), IUHS + C (n = 10 pens), and IUHS + ND (n = 10 pens). Treatment diets were fed from day 1 to 14 postweaning and transport (period 1), and the C diet was fed to all pigs from day 14 to 35 postweaning and transport (period 2). Production measures were taken in 7 d intervals to calculate average daily gain (ADG), average daily feed intake (ADFI), average daily net energy intake (ADEI), gain:feed, and gain:net energy intake. Blood samples were collected prior to transport, following transport, and on days 2, 7, 14, 28, and 35 postweaning and transport to analyze cortisol, glucose, insulin, and nonesterified fatty acids. Behavior was assessed through video-recording on days 3, 5, 8, 11, and 13 postweaning and transport. In period 1, ADG was reduced (P = 0.04; 20.0 g/d) in IUHS vs. IUTN pigs. Pigs fed ND diets had reduced ADFI (P = 0.02; 9.3%) compared with C diet-fed pigs during period 1, which resulted in similar ADEI (P = 0.23; 1,115 ± 35 kcal/d). During transport, cortisol was decreased (P = 0.03; 25.8%) in IUHS vs. IUTN pigs. On day 2, glucose was decreased (P = 0.01; 13.8%) in IUHS vs. IUTN pigs. No in utero treatment-related behavior differences were observed but lying was reduced (P = 0.03; 6.5%) and standing was increased (P = 0.04; 14.1%) in ND vs. C pigs overall. In summary, IUHS reduced growth performance in pigs following weaning and transport, and providing an ND diet did not rescue the lost performance.

Early life thermal stress: Impact on future thermotolerance, stress response, behavior, and intestinal morphology in piglets exposed to a heat stress challenge during simulated transport

Study objectives were to evaluate the impact of early life thermal stress (ELTS) on thermoregulation, stress response, and intestinal health of piglets subjected to a future heat stress (HS) challenge during simulated transport. From d 7 to 9 post-farrowing, 12 first-parity sows and their litters were exposed to thermoneutral (ELTN; 25.4 ± 1.1 °C w/heat lamp; n = 4), HS (ELHS; cycling 32-38 °C w/heat lamp; n = 4), or cold stress (ELCS; 25.4 ± 1.1 °C w/no heat lamp; n = 4) conditions, and then from d 10 until weaning all piglets were exposed to thermoneutral (TN) conditions (25.3 ± 1.9 °C w/heat lamp). During the ELTS period, respiration rate, rectal temperature (TR), and skin temperature (TS) of three mixed-sex piglets per dam were monitored daily (0800, 1200, 1600, 2000 h). At 13 ± 1.3 d of age, temperature recorders were implanted intra-abdominally into all piglets. At weaning (20.0 ± 1.3 d of age), piglets were bled and then herded up a ramp into a simulated transport trailer and exposed to HS conditions (cycling 32-38 °C) for 8 h. During the 8 h simulated transport, core body temperature (TC) and TS were assessed every 15 min. After the simulated transport, piglets were unloaded from the trailer, bled, weighed, and then housed individually in TN conditions (28.5 ± 0.7 °C) for 7 d. During this time, ADFI and ADG were monitored, blood samples were taken on d 1, 4, and 7, and piglets were video-recorded to assess behavior. Piglets were sacrificed on d 8 post-simulated transport and intestinal morphology was assessed. Data were analyzed using PROC MIXED in SAS 9.4. In the ELTS period, piglet TR was increased overall (P = 0.01) in ELHS (39.77 ± 0.05 °C) compared to ELTN (39.34 ± 0.05 °C) and ELCS (39.40 ± 0.05 °C) litters. During simulated transport, TC was greater (P = 0.02) in ELHS (40.84 ± 0.12 °C) compared to ELTN (40.49 ± 0.12 °C) and ELCS (40.39 ± 0.12 °C) pigs. Following simulated transport, BW loss was greater (P = 0.01; 40%) for ELHS compared to ELTN and ELCS pigs and ADFI was reduced (P = 0.05; 28.6%) in ELHS compared to ELTN pigs. Sitting behavior tended to be increased (P = 0.06; 47.4%) in ELHS vs. ELCS or ELTN pigs. Overall, circulating cortisol was greater for ELHS (P ≤ 0.01; 38.8%) compared to ELCS and ELTN pigs. Goblet cells per villi were reduced (P = 0.02; 20%) in the jejunum of ELHS vs. ELCS and ELTN pigs. In summary, ELHS reduced thermotolerance and increased the future stress response of piglets compared to ELCS and ELTN.

Impact of Providing Feed and/or Water on Performance, Physiology, and Behavior of Weaned Pigs during a 32-h Transport

Simple Summary

Transportation has the potential to negatively affect the health and welfare of weaned pigs, especially those already experiencing weaning stress. Piglets were transported for 32 h, with and without feed and water, and measures of performance, physiology, and behavior were taken to assess piglet welfare. Transportation negatively impacted body weight, Neutrophil to Lymphocyte Ratio (N:L), and post-transport body weight gain, indicating that not providing water during transport can negatively impact the well-being of recently weaned pigs. Provision of water may aid in reducing stress during long distance transport and improve the animals’ well-being.

Abstract

Transportation at weaning is a complex stressor made up of many factors, including withdrawal from feed and water, which can potentially negatively affect the health and welfare of pigs, especially those already experiencing weaning stress. The objective of this study was to evaluate the effect of weaning and extended transport durations (up to 32 h), with and without the provision of feed and/or water, on pig welfare. Treatment groups included: pigs neither weaned nor transported, control (CON); weaned pigs transported and provided with feed and water (T+); weaned pigs transported without feed and water (T−); weaned pigs transported with only feed (T+F); and weaned pigs transported with only water provided (TRAN+W). The effect of transport (with and without feed and/or water) on weaned pigs was assessed using behavior, performance, and physiology. After a 32-h transport period, pigs transported without water lost markedly more weight than those transported with water (p < 0.01). Furthermore, the neutrophil to lymphocyte ratio was markedly higher in male pigs transported without water (p < 0.05). Overall, transportation had a negative effect on pig well-being, especially when water was not provided.

Effect of Provision of Feed and Water during Transport on the Welfare of Weaned Pigs

Simple Summary

Transportation is a complex stressor, which has the potential to negatively impact the health and welfare of weaned pigs. Transport duration and withdrawal from feed and water are two factors that could potentially adversely affect the welfare of pigs transported at weaning. In this study, the effect of a 32 h transport period and the provision of feed and water on the welfare of weaned pigs was investigated using a multi-disciplinary approach. Body weight decreased in weaned pigs over time and this response was exacerbated by exposing pigs to a 32 h transport period and withdrawing feed and water. The greatest changes in body weight loss were observed after 8 h of transport or weaning. Furthermore, the neutrophil to lymphocyte ratio (N:L) stress measure was elevated in pigs in response to an 8 h transport period or 8 h after weaning alone. With the exception of weaned pigs provided with feed and water, transported and weaned pigs continued to be different from control pigs until 16 h after weaning or exposure to a 16 h transport period. These findings suggest that pigs experience an acute stress response due to transport and weaning, but these two stressors do not appear to be additive. Overall, transportation had a negative effect on performance, physiology and behavior of weaned and transported pigs, especially if not provided with feed and water for more than 24 h.

Abstract

Transportation is a complex stressor made up of factors including weaning itself and withdrawal from feed and water. Therefore, transportation has the potential to negatively impact the health and welfare of weaned pigs. Pigs were transported for 32 h and measures of performance, physiology, and behavior were taken to assess piglet welfare. Treatment groups included pigs not weaned or transported (CON), weaned pigs provided with feed and water (WEAN+), weaned pigs not provided with feed and water (WEAN−), weaned and transported pigs provided with feed and water (TRANS+), and weaned and transported pigs not provided with feed and water (TRANS−). Body weight loss was different among treatments (p < 0.01). CON pigs had a 6.5% ± 0.45% gain in body weight after 32 h. WEAN+, WEAN−, TRANS+, and TRANS− groups all had a loss in body weight of 5.9% ± 0.45%, 7.8% ± 0.45%, 6.5% ± 0.45% and 9.1% ± 0.46%, respectively. The N:L was greater in all weaned pigs at 8 h compared to CON pigs (p < 0.01). WEAN− and transported pigs had significantly higher N:L than CON pigs from 8 h through 16 h, however, all treatment groups were similar to CON pigs after 16 h irrespective of provision of feed and water. Blood glucose levels were lower in transported and/or weaned pigs than CON pigs after 16 h irrespective of the provision of feed and water. TRANS+ females had higher creatine kinase (CK) levels than males (p < 0.05). After a 16 h transport period, TRANS− pigs had higher total plasma protein (TP) levels than all other treatment groups (p < 0.05). Significant changes in behavior were observed during and after transportation, which could also be indicative of stress. Overall, transportation and weaning had a negative effect on performance, physiology and behavior (both during and post-weaning) of pigs, especially when feed and water was not provided. Transporting pigs without feed and water for more than 24 h was a welfare concern as indicated by changes in body weight and physiology measures of stress.

Effects of Transport at Weaning on the Behavior, Physiology and Performance of Pigs

Simple Summary

Pigs are commonly transported to separate production facilities at weaning to reduce disease transfer, enhance productivity and to improve overall operational efficiency. A review of the scientific literature suggests that these animals experience stress due to concurrent weaning and transport; however, gaps in the knowledge include the short and long term health and welfare implications of transporting pigs at weaning. Pig welfare and the efficiency of the swine industry may improve if science-based recommendations were in place.

Abstract

Transport of pigs to separate production facilities at the time of weaning is a common practice, primarily performed to reduce vertical transfer of disease and enhance production and overall farm efficiency. During transport, pigs are exposed to numerous stressors in conjunction with the stress experienced as a result of weaning. In this review, the behavioral and physiological response of pigs experiencing weaning and transport simultaneously will be described, including the effects of space allowance, season and transport duration. Based on the scientific literature, the gaps in the knowledge regarding potential welfare issues are discussed. Changes in behavior and physiology suggest that weaned pigs may experience stress due to transport. Space allowance, season and duration are aspects of transport that can have a marked impact on these responses. To date, the literature regarding the effects of transport on weaned pigs has primarily focused on the short term stress response and little is known about the effects of concurrent weaning and transport on other aspects of pig welfare including morbidity and mortality rates. Greater understanding of the short and long term consequences of transport on weaned pig welfare particularly in relation to factors such as trip duration, provision of feed and water, and best handling practices would benefit the swine industry. Furthermore, the development of guidelines and recommendations to enhance the short and long term welfare of weaned pigs in relation to transport are needed.

Establishing Bedding Requirements during Transport and Monitoring Skin Temperature during Cold and Mild Seasons after Transport for Finishing Pigs

Simple Summary

Typically, bedding is used to improve pig comfort and welfare during transport. This study assesses the level of bedding required during transport of finishing pigs in semi-truck trailers. The present study shows that adding more than six bales/trailer of bedding in cold weather and more than three bales/trailer of bedding in mild weather provides no benefit to the pigs. Economic forces would not favor increased bedding with no benefit. Use of infrared thermography may provide a useful tool to indicate when cooling interventions are needed during warm weather.

Abstract

The broad aim of this study was to determine whether bedding level in the transport trailer influenced pig performance and welfare. Specifically, the objective was to define the bedding requirements of pigs during transportation in commercial settings during cold and mild weather. Animals (n = 112,078 pigs on 572 trailers) used were raised in commercial finishing sites and transported in trailers to commercial processing plants. Dead on arrival (DOA), non-ambulatory (NA), and total dead and down (D&D) data were collected and skin surface temperatures of the pigs were measured by infrared thermography. Data were collected during winter (Experiment 1) and fall/spring (Experiment 2). Total D&D percent showed no interaction between bedding level and outside air temperature in any experiments. Average skin surface temperature during unloading increased with outside air temperature linearly in both experiments (P < 0.01). In conclusion, over-use of bedding may be economically inefficient. Pig skin surface temperature could be a useful measure of pig welfare during or after transport.