Scoring shoulder ulcers in breeding sows - is a distinction between substantial and insubstantial animal welfare-related lesions possible on clinical examination?

Part II: understanding pain in pigs-pain assessment in pigs with spontaneously occurring diseases or injuries

BACKGROUND

Pain in pigs needs to be managed and treated to the benefit of individual pigs. It is imperative for veterinarians and farmers to assure that pigs do not suffer from unnecessary pain that can be relieved. This review focusses on pain related to spontaneously occurring diseases and injuries since this topic is often neglected. The aim is to identify ways to accelerate knowledge and evidence in this area to prevent painful conditions in pigs in the future.

METHODS

A scoping review was conducted with results from a search of the electronic databases VetSearch and CABI Rxiv. The findings of selected publications are narratively synthesized and reported orienting on the PRISMA ScR guideline.

RESULTS

The results emphasize that pigs experience pain due to spontaneously occurring diseases and injuries, but systematic knowledge about this topic is scarce. More research is especially needed for rare diseases (such as UTIs). Moreover, research conducted about the topic pain in pigs should involve standardized protocols to document, analyse and share results on pain detection beyond a projects' timeframe. The findings of this review suggest that such a protocol would comprise validated pain identification measures over time and in relation to administered pain treatment.

CONCLUSION

The results of this study invite veterinary practitioners to reconsider in each pig patient whether pain and related indicators are present, how to handle the situation and document the process to ensure the welfare of individual compromised pigs.

Effects of free farrowing system on the productive performance and welfare of sows and piglets

Regardless of international animal welfare regulations, most sows in production currently spend most of their lives and the peripartum period in caged housing systems. Although this type of management is intended to reduce neonatal mortality in piglets, several studies consider that there has been no significant reduction in its incidence over the last 30 years. On the contrary, cage housing has promoted the appearance of alterations during the farrowing process such as dystocia, as well as in maternal behavior and health, promoting stereotypes, skin lesions and other alterations, which not only impact the sows but also their progeny during the lactational period. Therefore, the aim of the present review is to compare the productive performance and welfare of sows and their piglets within the farrowing, lactation, and post-weaning period in both traditional and free-farrowing systems, highlighting the differences in these indicators in each of them.

Marine derived Ca-Mg complex supplementation basal diet during four subsequent parities improved longevity and performance of sows and their litters

The aim of the present study was to evaluate the effects of dietary supplementation of Ca-Mg complex on the longevity and reproductive performance of sows. In total, seventy-two gilts ([Yorkshire × Landrace] × Duroc, average body weight 181 kg) were randomly allocated to 1 of 3 treatments during 4 successive parity in a 4 × 3 factorial arrangement. Treatments consisted of CON (basal diet), CM1 (basal diet -MgO - 0.3% limestone + 0.4% Ca-Mg complex), and CM2 (basal diet - MgO - 0.7% limestone + 0.4% Ca-Mg complex). A higher (p < 0.05) number of totals born and live piglets, and sows increased feed intake during gestation and lactation, increased backfat thickness, and increased estrus interval were observed (p < 0.05) during their third and fourth parity than during their first and second parity. Ca-Mg complex supplementation improved (p < 0.05) the number of total piglets during the first and second parity as well as live-born piglets during the first to third parity, reduction (p < 0.05) in backfat thickness during the third and fourth parity, a higher (p < 0.05) initial and final number of suckling piglets as well as higher weaning weight compared with sows fed CON diet during the first, second, and third parity. The average daily gain (ADG) was higher (p < 0.05) in piglets born to CM1 and CM2 sows regardless of parity. The treatment diets fed to sows lowered (p < 0.05) the duration of first to last piglet birth and placenta expulsion time compared with CON sows. A significant interactive effect (p = 0.042) between parities and treatment diets was observed for the first to last piglet birth. Thus, Ca-Mg complex supplementation by partially replacing limestone in the basal diet enhanced sow performance, specifically during their third and fourth parity, thereby improving sow longevity.

Infrared Thermography for Early Identification and Treatment of Shoulder Sores to Improve Sow and Piglet Welfare

Shoulder sores in sows cause pain, may lead to early weaning and resultant piglet distress, and premature culling. Early detection and intervention is key to avoid these substantial production and welfare imposts. In this experiment we tested infrared thermography (IRT) to identify shoulder sores before wound eruption, and effectiveness of four wound healing treatments; mānuka honey (n = 11); Derisal^® (n = 11); Chloromide^® (n = 13) and Repiderma^® (n = 16), all of which contain no antibiotics. Three hundred and ten sows (parity 2.3 ± 0.2) were monitored daily from entry to the farrowing sheds until weaning using a thermal camera. IRT successfully detected 88% of shoulder sores as hot spots and provided a lead in time of 7 days. Sixteen percent of all sows had a hotspot detected and were randomly allocated to one of four daily treatment groups. At the end of the treatment period, sore diameter was significantly reduced for all treatments, except the Repiderma^® group. Sow traits had little influence on susceptibility to shoulder sores. There may be a link between prewean mortality and shoulder sores, but this requires further investigation. The use of IRT to monitor for hotspots for early intervention is validated. Future work should concentrate on methods to prevent wound eruption after detection with IRT to improve the health and welfare of both the sow and her litter.

Practical Application of the Five Domains Animal Welfare Framework for Supply Food Animal Chain Managers

The author has worked as a consultant with global commercial supply managers for over 20 years. The focus of this commentary will be practical application of The Five Domains Model in commercial systems. Commercial buyers of meat need simple easy-to-use guidelines. They have to use auditors that can be trained in a workshop that lasts for only a few days. Auditing of slaughter plants by major buyers has resulted in great improvements. Supply chain managers need clear guidance on conditions that would result in a failed audit. Animal based outcome measures that can be easily assessed should be emphasized in commercial systems. Some examples of these key animal welfare indicators are: percentage of animals stunned effectively with a single application of the stunner, percentage of lame animals, foot pad lesions on poultry, and body condition scoring. A farm that supplies a buyer must also comply with housing specifications. The farm either has the specified housing or does not have it. It will be removed from the approved supplier list if housing does not comply. These types of easy to assess indicators can be easily evaluated within the four domains of nutrition, environment, health and behavioral interactions. The Five Domains Framework can also be used in a program for continuous improvement of animal welfare.

EFSA Panel on Animal Health and Welfare (AHAW), Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin‐Bastuji B, Gonzales Rojas JL, Schmidt G, Herskin M, Michel V, Miranda Chueca MÁ, Mosbach‐Schulz O, Padalino B, Roberts HC, Stahl K, Velarde A, Viltrop A, Winckler C, Edwards S, Ivanova S, Leeb C, Wechsler B, Fabris C, Lima E, Mosbach‐Schulz O, Van der Stede Y, Vitali M, Spoolder H. 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.

How effective are clinical pre-farrowing risk assessment and the use of soft rubber mats in preventing shoulder ulcers in at-risk sows?

Background

Lameness, low BCS and scar tissue in the skin covering the tuber spina scapulae are known as risk factors for shoulder ulcer in sows. In a two-step study, the predictive ability of pre-farrowing clinical examination and the preventive effect of rubber mats on the development of shoulder ulcers in at-risk sows were evaluated.

Material and methods

The study included 659 sows that were clinically examined one week before farrowing to distinguish risk sows from no-risk sows. Sows with a BCS ≤ 2 and/or a locomotion score > 3 and/or scar tissue in the skin covering the tuber spina scapulae were classified as at risk of developing shoulder ulcers. The at-risk sows were randomly assigned to either a prevention group in which sows were stalled in farrowing crates equipped with rubber mats, or a non-prevention group in which sows were stalled in standard crates. The shoulder areas were photographed during the first two weeks of the lactation period.

Results

The chance of developing a shoulder ulcer was significantly higher for at-risk sows than for non-at-risk sows (OR 5.55, p < 0.0001). At-risk sows stalled in crates equipped with rubber mats as preventive substrates had a significantly lower chance of developing shoulder ulcers than did those stalled in standard pens (OR 0.54, p = 0.0358).

Conclusions

The development of shoulder ulcers in sows can be predicted by clinical pre-farrowing risk assessment based on BCS, locomotion score and scar tissue scoring. Providing at-risk sows with farrowing crates equipped with rubber mats had a statistically significant protective effect.