Pig elimination behavior—A review

Implementation of a Pig Toilet in a Nursery Pen with a Straw-Littered Lying Area

Simple Summary

Generally, pigs are known to be very clean and intelligent animals. The present study tested whether it is possible to train nursery pigs to defaecate and urinate in a pig toilet while keeping a straw-bedded lying area clean. The pig toilet was separated into a defaecation area and a urination area. An automatic rewarding system installed in the urination area and pig faeces placed in the corners of the defaecation area were used to help the pigs to identify the elimination area. By means of direct observation and video analysis, all eliminations within the experimental pen were analysed. Altogether, the pig toilet was very well accepted by the pigs, but a spatial separation of faeces and urine was not achieved. The lying area was kept clean, so that keeping pigs on straw in combination with a pig toilet would be quite conceivable in the future to enable a more animal-friendly life.

Abstract

In this study, a pig toilet was installed on an organic pig farm, which enabled pigs to use a lying area littered with straw and keep it clean. The pig toilet was separated into a defaecation area and a urination area and nursery pigs were trained to use the urination area by means of a rewarding system. A total of 24 piglets were weaned at 6–7 weeks of age and housed in the experimental system for four-week periods. Per trial, a group of four pigs was formed, and videos were recorded on two days per week (08:00 to 18:00). Direct observation was carried out in the first and last week of each trial. In total, 1500 eliminations were video-analysed. An individual pig had an average of 7.1 ± 1.4 defaecations and 4.8 ± 0.8 urinations per day. In total, 96.4% of all urinations and 97.4% of all defaecations were performed in the pig toilet. However, most urinations took place in the defaecation area as well (90.4%). Even if the training to spatially separate defecation and urination behaviour was not successful, we showed that a pig toilet offers the possibility to create littered lying areas, possibly increasing animal welfare.

Soiling of Pig Pens: A Review of Eliminative Behaviour

Simple Summary

The soiling of pig pens has important negative consequences in terms of animal welfare, health, workload, and environmental emissions of pig farming. The aim of this review is to present the state-of-the-art regarding pigs’ normal eliminatory behaviour (i.e., defaecation and urination) and pen soiling, aimed here at solving pen-soiling problems in existing systems, and in a following publication aimed at the design of a more sustainable pig-farming system. To this end, we summarize a large body of literature on pen soiling and pigs’ eliminative behaviour in different farming systems. We propose a “disease framework” interpretation of pen soiling, to help identify its causes, underlying mechanisms, and solutions.

Abstract

This is a comprehensive review on the pigs’ normal eliminatory behaviour (i.e., defaecation and urination) and pen soiling. This review is aimed primarily at solving issues with pen soiling in current systems, and ultimately at the future design of a well-functioning pig toilet, which we intend to elaborate on in a subsequent publication. In this paper, first, normal elimination is described in relation to what is known about its phylogeny, ontogeny, causation, and function, i.e., according to Tinbergen’s four why questions concerning animal behaviour. Then, pen soiling is described as if it were a medical disorder, highlighting its importance, aetiology, symptoms, diagnosis, pathogenesis, treatment, and prevention. Due to its negative consequences in terms of animal welfare, health, workload, and environmental emissions, possible methods to address pen soiling in current systems are described. Probably, pigs do not choose a specific place to eliminate but rather choose the most comfortable place for resting, and avoid eliminating there. We identified four main strategies to reduce pen soiling: (1) reducing the suitability of the designated elimination area to be used for other functions, especially resting or thermoregulation; (2) improving the suitability of other functional areas in the pen to be used for their specific function, such as resting and activity; (3) reducing the suitability of other functional areas to be used for elimination; and (4) improving the suitability of the elimination area for elimination. These prevention strategies and the encompassing disease framework provide a structured approach to deal with pen soiling in existing systems and to support the future design, development, and implementation of a well-functioning pig toilet that can help to achieve some of the main goals of modern pig production, namely reducing environmental emissions as well as substantially improving pig welfare.

A Comparison of Stocking Methods for Pasture-Based Growing-Finishing Pig Production Systems

Simple Summary

A sustainable pasture-based production system should provide benefits to the vegetation, soil and animals while providing means of economic support for the household that operates the system. If best management practices are implemented, this would allow the development of resilience for the pasture system and ameliorate the natural resources for present and future generations. Pasture-based pig production represents a production alternative for small scale or limited-resources farmers, offering them the possibility to brand their products. The implementation of best management practices would allow managers to reach productive and conservation goals. This study was conducted to compare the effects of continuous, rotational and strip-grazing stocking methods for growing-finishing pigs on tall fescue pastures. Stocking methods had effect on soil bulk density and some soil nutrients, vegetative ground cover, animal weight gain and feed use efficiency. The rotational and strip grazing stocking methods offer potential to improve the sustainability of pasture-based pig systems.

Abstract

Two alternative stocking methods (rotational and strip-grazing) were compared to continuous stocking at a stocking rate of 47 pigs ha⁻¹ in tall fescue pastures. The research was conducted during two twelve-weeks grazing periods in North Carolina (USA). In total 144 (females and castrated males, 17.5 and 29.1 kg initial body weight) crossbred Yorkshire X Berkshire, Yorkshire/Landrace X Hampshire and Yorkshire/Landrace X Duroc pigs without nose rings were used. Greater soil bulk density and soil concentrations of NO₃⁻, P, K, Mn, Zn and Cu were observed in paddocks managed continuously, while greater final ground cover (+22%) was recorded in paddocks managed with rotational and strip-grazing stocking methods. No differences were detected in botanical composition of the paddocks. Greater weight gains (+8.5%) were registered for rotationally managed pigs. Feed efficiency was better (+8%) for rotationally than for continuously stocked pigs, while strip-grazed pigs presented intermediate values. The results indicated the potential of both alternative stocking methods to be implemented in sustainable pasture-based pig production systems.

Effects of Growing-Finishing Pig Stocking Rates on Bermudagrass Ground Cover and Soil Properties

Simple Summary

A common challenge for most livestock industries is to identify more productive, efficient and sustainable pasture-based production systems that have a positive effect on animal welfare, biodiversity and long-term operation profitability without negatively influencing the environment. Implementing best management practices allows producers to achieve profitability and environmental goals. Maintaining an appropriate ground cover, minimizing the use of external inputs as fertilizers and pesticides and adopting agroecological approaches are key for sustainable pasture management. Pasture-based pig production systems are considered animal welfare and environmentally friendly. However, the number of animals grazing can influence the vegetation ground cover and the amount of nutrients imported to the systems. This study compared the effects of four different pig stocking rates (37, 74, 111 or 148 pigs ha⁻¹) over two 14-week grazing periods, on the vegetation ground cover and soil properties of bermudagrass paddocks. Increasing the number of animals aggravated the damage to the vegetative ground cover and raised the amount of nutrients deposited on the soil. For conservation purposes, the number of pigs grazing bermudagrass should be equal to or less than 37 pigs ha⁻¹.

Abstract

This study compares four stocking rates (37, 74, 111 and 148 pigs ha⁻¹) for growing to finishing pigs (18.4 ± 0.5 kg and 118.5 ± 2.0 kg and 35.7 ± 2.1 kg and 125.7 ± 2.3 kg initial and final BW for grazing periods 1 and 2, respectively) and their effect on ground cover and soil traits in bermudagrass (Cynodon dactylon [L.] Pers) pastures, over two 14-week grazing periods (July–September and May–August). The study was conducted at the Center for Environmental Farming systems at the Cherry Research Station, Goldsboro North Carolina. A continuous stocking method was implemented to manage the pasture. The percent ground cover was estimated with a modified step point technique. Soil samples were collected in three sampling positions (center, inner and outer areas of the paddocks) and two soil sampling depths (0–30 and 30–90 cm). The experimental design was a completely randomized block with three field replicates. Data were analyzed using the PROC GLIMMIX procedure of SAS/STAT ^® Version 9.4. Greater ground cover and lesser soil nutrient concentrations were registered in bermudagrass paddocks managed with 37 pigs ha⁻¹. The results of this study also validated the existence of a spatial pattern of soil properties, which differed among sampling positions and depths.