An easy farrowing enhances piglet health

The well-being of the sows continues to be of primary importance for producers and vets. In particular, concerns around the farrowing period have both welfare and production impacts. Farrowing is a painful process with health risks for the sow and her offspring. Injuries and inflammation caused by parturition have a negative impact on health, welfare and performance. Particularly, difficult and prolonged farrowing has been identified as risk factors for mastitis-metritis-agalactia (MMA) syndrome, leading to a reduced production of colostrum.

Performing studies on pain control

Pain is a major welfare issue in farm animals and yet pain caused by parturition has been under-researched. At the same time, the pig industry has come to realise the importance of proper sow management around farrowing and the fact that reducing stress during this period (including stress caused by farrowing pain) has positive effects on performance.

Therefore, this is an interesting area to do research and offer science-based, practical recommendations to improve sow welfare and performance. Boehringer Ingelheim offered the opportunity to test Metacam, a non-steroidal anti-inflammatory drug (NSAID) to reduce pain caused by farrowing. Since 2006, research has been done in this area.

Sows in pain around farrowing

Assessing pain in animals is not easy. In humans, the gold standard of pain assessment is self-reporting, which is not applicable to animals. In veterinary medicine, pain assessment has relied on 3 different types of measures:

1. general measures
2. physiological indicators
3. behavioural changes.

A reduction in feed intake would be an example of the first group of measures. Acute phase proteins, which are physiological markers of inflammation and have an increased concentration in blood after farrowing, are an example of the second category. Finally, behavioural changes are the most commonly used measures, as they are sensitive and non-invasive indicators of pain. They include the frequency of postural changes, trembling, tail flicking and pawing, all of which may increase during and/or after farrowing.

Overall, as pain in animals can be assessed by different and complementary approaches, the integration of these indicators into a pain scale may be very useful. For instance, this is why FAWEC developed an ‘Ease of Farrowing Score’ in sows, based on behavioural and production indicators.

Consequences of sow discomfort

Parturition is a risky process for both sow and piglets. Injury and inflammation associated with farrowing, particularly in dystocia cases (difficult birth) may have important negative effects on health, welfare and productivity.

For example, pain at farrowing may reduce feed intake and, as a result, increase weight loss and reduce milk production in sows. Dystocia increases the risk of several conditions including endometritis, vulvar discharge, retained placenta, MMA syndrome, impaired fertility and early culling. Pain also causes a stress response, as demonstrated by an increase in plasma cortisol, and stress may result in longer farrowing, reduced colostrum and milk let down and altered maternal behaviour.

A higher level of activity for sows

Both increased and reduced physical activity may be a consequence of discomfort or pain. There are 2 main measures of activity in sows around farrowing that need to be analysed separately:

1. The number of position changes; and
2. The total time lying or standing.

A higher frequency of postural changes after farrowing increases the risk of piglet crushing and interferes with teat seeking and suckling attempts. According to results, however, number of position changes was not affected by the treatment with NSAID. As lactation advances, an increase in activity indicates that the sow is recovering from the farrowing process.

Different studies have reported that a high activity (i.e. an increase in total standing time) at the beginning of lactation might be a positive maternal characteristic, as active sows seems to be more ‘aware’ of piglets and drink more water, which results in more milk and a better performance of piglets. In the FAWEC studies, sows treated with NSAID increased their total time standing on day 3 after farrowing compared to non-treated sows.

Oral administration and immunoglobulins

During the research, the team found that on days 1 and 2 after birth, IgG levels in piglets from sows treated with oral meloxicam (Metacam Oral for swine) during farrowing were higher than in piglets from non-treated sows.

As piglets are born with an immature immune system, the acquisition of immunoglobulin from colostrum is fundamentally important. In fact, piglets from sows treated with oral meloxicam during farrowing also showed higher pre-weaning growth than piglets from non-treated sows. The fact that the NSAID enhances maternal immunity transfer is a promising result. Further research should aim at understanding the mechanisms and at testing whether the NSAID could have other positive effects related to immunity.

Improved ADG during lactation

The team also observed that weight at weaning in piglets born to sows treated with oral meloxicam was 418g higher than in the control group. It would be interesting to perform a cost-benefit analysis to quantify if this difference may result in long-term economic benefits.

Indeed, although animals were not followed during the transition and finishing period, a higher weaning weight may have long-term economic benefits as it may decrease the time needed to reach slaughter weight. It is unknown as yet what is the mechanism underlying this effect, but some of the hypotheses are that treated sows show a better maternal behaviour that results in longer suckling bouts or that treatment leads to increased immunity transfer to piglets.

Change in farrowing management

Hyperprolific sows are nowadays a reality and so a relevant question should be: are we able to guarantee the productivity and welfare of these hyperprolific sows?

Several interventions are used when litter size exceeds the ability of individual sows to successfully rear all their piglets, including cross-fostering, split suckling, use of nurse sows, early weaning and/or the use of artificial rearing systems. All these practices raise welfare questions for both the piglets and the sow, particularly when they are poorly implemented. For that reason, good stockmanship is nowadays, more than ever, one of the key points to consider. For instance, adequate criteria to select nurse sows, good supervision at farrowing or the implementation of management strategies to improve the temperament of sows, all could contribute to better welfare for both sows and piglets. Clearly, training of personnel and more research in this area are the keys to success.

Learn more about FAWEC at www.fawec.org.