The influence of drinker location and colour on drinking behaviour and water intake of newborn pigs under hot environments

Welfare of pigs on farm

This scientific opinion focuses on the welfare of pigs on farm, and is based on literature and expert opinion. All pig categories were assessed: gilts and dry sows, farrowing and lactating sows, suckling piglets, weaners, rearing pigs and boars. The most relevant husbandry systems used in Europe are described. For each system, highly relevant welfare consequences were identified, as well as related animal-based measures (ABMs), and hazards leading to the welfare consequences. Moreover, measures to prevent or correct the hazards and/or mitigate the welfare consequences are recommended. Recommendations are also provided on quantitative or qualitative criteria to answer specific questions on the welfare of pigs related to tail biting and related to the European Citizen's Initiative 'End the Cage Age'. For example, the AHAW Panel recommends how to mitigate group stress when dry sows and gilts are grouped immediately after weaning or in early pregnancy. Results of a comparative qualitative assessment suggested that long-stemmed or long-cut straw, hay or haylage is the most suitable material for nest-building. A period of time will be needed for staff and animals to adapt to housing lactating sows and their piglets in farrowing pens (as opposed to crates) before achieving stable welfare outcomes. The panel recommends a minimum available space to the lactating sow to ensure piglet welfare (measured by live-born piglet mortality). Among the main risk factors for tail biting are space allowance, types of flooring, air quality, health status and diet composition, while weaning age was not associated directly with tail biting in later life. The relationship between the availability of space and growth rate, lying behaviour and tail biting in rearing pigs is quantified and presented. Finally, the panel suggests a set of ABMs to use at slaughter for monitoring on-farm welfare of cull sows and rearing pigs.

Provision Point-Source Materials Stimulates Play in Sows but Does Not Affect Aggression at Regrouping

When sows are mixed into groups, hierarchies form and resulting aggression and stress can affect production and welfare. This study determined the effect of providing point-source materials on aggressive and play behaviors in gestating sows. Large white cross Landrace sows were mixed after insemination; six pens of 12 sows were housed in 'standard' pens, and six pens of 12 sows were housed in 'enhanced' pens. The 'enhanced' pens each contained two rubber mats, eight strands of 24 mm-thick sisal rope and two yellow plastic disks, suspended from the roof. The sows remained in these pens until pregnancy confirmation. Salivary cortisol concentration, injury counts, and sow behaviors were recorded the day before mixing (day 1), mixing (day 0) and post-mixing day 1, day 4, day 7 and day 20. At farrowing, reproductive outcomes were obtained. Play was observed (including locomotor and object play) in the 'enhanced' pen, and percentage of time spent playing was greater on d4 (1.48 ± 0.3 Square root transformed data (2.84% non-transformed adjusted mean)), d7 (1.43 ± 0.3 (2.97%)) and d20 (1.64 ± 0.3 (3.84%)), compared to d0 (0.56 ± 0.3 (0.70%)) and d1 (0.87 ± 0.3 (1.67%) (p < 0.05)). No play was observed in standard housing. Aggression, salivary free cortisol concentrations and injuries were unaffected (p > 0.05). The provision of materials had no impact on aggression, although their presence maintained sow interest and play behavior, suggesting a positive effect.

Colour preferences in pigs

The aim of the study was to determine the behavioural response of weaners to feeders of different colours. Eighteen weaners, crosses of Polish Landrace x Polish Large White, were observed. The pigs received compound feed in blue, red or yellow feeders, ad libitum. The behaviour of the pigs was observed using an industrial surveillance camera and recorded in a time-lapse system. The number of visits to each feeder, the time spent at the feeder and the amount of feed eaten were noted. The piglets spent the most time at the blue feeder (on average 41 minutes per day) and the least time at the yellow feeder (28 minutes). These preferences were similar in individuals of both sexes.

Bait Preference of Free-Ranging Feral Swine for Delivery of a Novel Toxicant

Invasive feral swine (Sus scrofa) cause extensive damage to agricultural and wildlife resources throughout the United States. Development of sodium nitrite as a new, orally delivered toxicant is underway to provide an additional tool to curtail growth and expansion of feral swine populations. A micro-encapsulation coating around sodium nitrite is used to minimize detection by feral swine and maximize stability for the reactive molecule. To maximize uptake of this toxicant by feral swine, development a bait matrix is needed to 1) protect the micro-encapsulation coating so that sodium nitrite remains undetectable to feral swine, 2) achieve a high degree of acceptance by feral swine, and 3) be minimally appealing to non-target species. With these purposes, a field evaluation at 88 sites in south-central Texas was conducted using remote cameras to evaluate preferences by feral swine for several oil-based bait matrices including uncolored peanut paste, black-colored peanut paste, and peanut-based slurry mixed onto whole-kernel corn. These placebo baits were compared to a reference food, whole-kernel corn, known to be readily taken by feral swine (i.e., control). The amount of bait consumed by feral swine was also estimated using remote cameras and grid boards at 5 additional sites. On initial exposure, feral swine showed reduced visitations to the uncolored peanut paste and peanut slurry treatments. This reduced visitation subsided by the end of the treatment period, suggesting that feral swine needed time to accept these bait types. The black-colored peanut paste was visited equally to the control throughout the study, and enough of this matrix was consumed to deliver lethal doses of micro-encapsulated sodium nitrite to most feral swine during 1–2 feeding events. None of the treatment matrices reduced visitations by nontarget species, but feral swine dominated visitations for all matrices. It was concluded that black-colored peanut paste achieved satisfactory preference and consumption by feral swine, and no discernable preference by non-target species, compared to the other treatments.

Water palatability, a matter of taste

Background

The aim of this trial was to test whether the temperature or additives of the drinking water affected water uptake by nursery pigs. We designed a repeated 4 × 4 Latin Square to control for confounding factors such as; carry-over effects, learning of a preferential taste, daily variation within groups and regular increase of uptake over a day due to diurnal drinking patterns. Water types tested were control water (A); warm water (33 °C); (B); organic acid additive 1 (C), and organic acid additive 2 (D).

Results

The piglets drank more of water C than of control water (A). The uptake of water D was marginally higher than control water (A). There was no difference in uptake of water B and A. However, a learning effect was observed resulting in increasing amounts of water type C and D taken up over the four consecutive days. A carry-over was not fully prevented as pigs always consumed less during the second hour and water D was consumed less during the fourth and final hourly observation period each day.

Conclusions

The experimental design can be used in future trials for evaluation of the water uptake and preference of water additives for pigs. The tested commercial organic acid additives did not adversely affect water uptake of drinking water, water uptake increased instead.

Electronic supplementary material

The online version of this article (doi:10.1186/s40813-015-0004-z) contains supplementary material, which is available to authorized users.

Tetracycline residues in porcine stomach after administration via drinking water on a swine farm

Tetracycline is a broad-spectrum antibiotic used to treat infections in swine. The maximum residue levels of tetracycline in pork stomach tissue in Russia, Europe, and the United States are 10, 200, and 2,000 ppb, respectively. This difference in accepted safety levels may be the reason why stomach tissues that the United States exports continue to be residue violators in overseas markets. In this study, 30 pigs at two different stages of production (weanling and finisher) were treated with tetracycline at 22 mg/kg of body weight per day for a total of 5 days via a water medicator. Blood samples were collected at 0, 72, 78, 96, and 102 h after the start of medication. The medication was stopped at 120 h, and blood samples were again collected at 126, 144, 168, 192, and 216 h after exposure. Five animals were slaughtered for stomach tissue 0, 24, 48, 96, and 192 h after the drug was flushed from the water line. All blood and tissue samples were analyzed by high-performance liquid chromatography-UV methods. The tetracycline levels in plasma were below the level of detection after the U.S.-labeled withdrawal time of 4 days. The stomach tissue residues averaged 671.72, 330.31, 297.77, 136.36, and 268.08 ppb on withdrawal days 0, 1, 2, 4, and 8, respectively. Using the U.S. Food and Drug Administration tolerance limit method and a population-based pharmacokinetic model with Monte Carlo simulation, a withdrawal interval was estimated. This study demonstrated that tetracycline residues are still detectable in the stomach tissues after the established United States withdrawal time of 4 days. These residue levels may explain why stomach tissues tested in Russia and Europe show positive residues for tetracycline, even though the meat may pass inspection here in the United States prior to export.

Toward a better understanding of pig behavior and pig welfare

Pork production began to flourish in the USA after the practice of finishing pigs on corn was popularized in the late 1600s. By the 1840s, there were 35 million pigs and 20 million people in the USA and Cincinnati was the world's largest pork market. Between 1890 and the present, the total number of pigs in the USA has remained at 50-60 million, but dramatic changes in swine husbandry over the course of the 20th century have metamorphosed pig production from small, extensive (outdoor), labor-dependent enterprises into large, intensive (indoor), capital-dependent, production systems. This development has led to debate concerning the impact of swine production on animal/human health, the environment, and the welfare of the animals under our care. In a very tangible way, the future of pork production depends on effectively addressing the public's concerns regarding animal welfare and health. Here, we review basic sensory and behavioral aspects of swine with the objective of reaching a better understanding of pig behavior and pig welfare. The premise of this discussion is that safeguarding animal welfare and health is good for pigs, pork producers and the animal-conscious public.