Animal Welfare and Production Challenges Associated with Pasture Pig Systems: A Review

Abstract

A review of published literature was conducted to identify pasture pig production system features that pose risks to animal welfare, and to develop recommendations aimed at improving the wellbeing of the animals managed in those systems. Pasture pig production systems present specific challenges to animal welfare that are inherent to the nature of these systems where producers have little room to make improvements. However, these systems present other challenges that could be reduced with a carefully designed system, by adopting appropriate management strategies and by avoiding management practices that are likely to negatively affect animal wellbeing. In pasture pig production systems, exposure to extreme temperatures, potential contact with wildlife and pathogens (especially parasites), vulnerability to predators, risk of malnutrition, pre-weaning piglet mortality, complexity of processes for monitoring and treating sick animals, and for cleaning and disinfection of facilities and equipment are among the main threats to animal welfare.

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

“…The effect of environmental temperature on feed intake is known and taken into account for energy requirements (NRC, FEDNA). Voluntary feed intake increased when the temperature was under the lower limit of the comfort zone [ 59 , 60 ] and decreased when the environmental temperature surpassed the upper limit of the temperature comfort zone which decreases as pig age [ 5 , 61 ]. Other reason for this higher winter feed intake is the lower pasture availability in winter respect to spring.…”

“…The weekly movement of shelter and drinking structures in the strip grazing paddocks could have produced a lower water consumption and as a consequence lower feed intake. Moreover, the change of all these structures could have disrupted the daily routine of this group of pigs and potentially imposed some sort of stress on them [ 5 , 71 ]. Contrary to these results, no differences in animal weight gain between pigs grazing white clover managed continuously, alternately or rotationally were reported in Brazil [ 64 ].…”

“…Pasture-based pig production represents a production alternative to small scale or limited resource farmers due to its relatively low initial investment requirements and the possibility to brand their products via diversification. It also offers an option for consumers searching for pork perceived as produced in more animal-welfare and environmentally-friendly circumstances [ 4 , 5 ] due to emerging or niche markets, considered a good approximation to sustainable meat production [ 6 ]. Paradoxically, the same advantage of pasture-based pig systems that allow the expression of natural behaviors could represent a disadvantage in conditions of mismanagement of the animals.…”

Understanding German Pig Farmers’ Intentions to Design and Construct Pig Housing for the Improvement of Animal Welfare

“…In addition to financial uncertainties, most pig farmers cannot rely on their own expertise, as they have hardly any experience in alternative husbandry methods [ 19 ]. Supposed FAW measures that have not been fully researched may also have negative consequences for FAW (e.g., pigs with long tails, group farrowing, and pasture pig production systems) [ 20 , 21 , 22 ]. In Alarcon et al [ 23 ], other producers, especially those from abroad, seemed to considerably influence farmers’ decision-making.…”

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

“…Therefore, intensification of the grazing management via the implementation of high stocking rates has been considered a way to increase production and profitability of livestock operations but this strategy could involve environmental risks, especially in pasture pig systems. Pasture pigs have a better opportunity to express natural behavior compared to pigs raised indoors [7]. Nonetheless, if left uncontrolled behavior expressions such as grazing, rooting, trampling, wallowing and selecting dunging areas could trigger damages to the vegetation and the soil.…”