How the anti-inflammatory drugs given to sows affect the piglets

Paper

E Mainau, D Temple, X Manteca. Experimental study on the effect of oral meloxicam administration in sows on pre-weaning mortality and growth and immunoglobulin G transfer to piglets. Preventive Veterinary Medicine 126 (2016) 48–53

What are they studying?

They investigated the effect of meloxicam given orally to sows around farrowing. The primary objective was to investigate the effect on IgG transfer to piglets, piglet mortality and piglet performance.

How was it done?

A total of thirty multiparous sows were assigned to either a treatment with oral meloxicam or placebo. Treatments were applied immediately when farrowing began and the parameters captured during the process included: number of piglets born alive, stillborn and mummified foetuses as well as number of pigs weaned. During lactation, the numbers of treatments per sow and piglet mortality were recorded. Piglet’s weight was measured at birth and at weaning, and average daily gain (ADG) was calculated. Four piglets per sow were selected for blood sampling on days 1, 2 and 20 post-farrowing for IgG analysis.

What are the results?

Oral meloxicam given around the time of farrowing resulted in significantly heavier piglets at weaning and improved ADG. Piglets born from oral-meloxicam-treated sows gained on average 19g/d more until weaning. IgG levels in piglets from sows treated with oral meloxicam were significantly higher on days one and 2 post-farrowing when compared to piglets born from placebo-treated sows. There was no significant effect on pre-weaning mortality.

What implications does this paper have?

Trauma and inflammation associated with parturition and dystocia have a negative impact on health, welfare and productivity in livestock. An early and sufficient intake of immunoglobulins is a crucial factor for piglet growth and survival, as newborn piglets have almost no body reserves. Because of the sow’s placenta structure, antibody transfer prior to birth is not possible. Protection by maternal immunity includes systemic humoral immunity, mostly IgG transferred during the first 36 hours of life.

The view from the field by Enric Marco

Genetic improvement has allowed for an impressive increase of litter size. Litters of over 15 piglets born alive are becoming normal in many farms. However, this improvement is linked to other effects, such as increased pre-weaning mortality and reduced weaning weights. Consequently, a shared interest in trying to reduce mortality and increase piglets weight at weaning is the driving force behind the current investigation into all sorts of strategies that can be adopted to achieve this goal. The use of anti-inflammatory drugs in sows at or after farrowing is one of them, and many studies have confirmed that they improve the sow's body condition and kickstart milk production.

Conducting this kind of studies is not easy, least of all when their aim is to detect differences in pre-weaning mortality. Interestingly, when such studies are conducted, mortalities are always reduced (both in the treatment group and the control group), possibly due to the best care the test itself entails, especially with reduced sample sizes, as in this case; this is why the lack of differences between groups comes as no surprise.

What did surprise me, in the article, is that IgG levels in piglets in the treated group were higher than those in the control groups, especially in the first day. An educated guess would be that it is the result of an improved suckling ability, which would consequently lead to more immunoglobulins being ingested. Treating sows at the onset of farrowing (they were treated after the birth of the second piglet) has very likely been crucial to achieve this improvement. This is perhaps the most significant difference between this study and the previous ones, where sows were treated just after farrowing.

Further investigation would be interesting to find out whether this improvement is also achieved with more delayed treatments, and to know if this early treatment has any effects on the cellular immunity acquired by the piglets. Piglets do not only acquire their dam's antibody immunity (IgG) but also cellular immunity. They are only able to absorb maternal cells during the first hours post-farrowing, so the sooner they take colostrum, the bigger the difference. Cellular immunity acquired from the dam is essential for piglets to develop a powerful active immunity against many bacteria (including all the ones called early colonizers), so if a new study were to be conducted, it would be interesting to know its results in the post-weaning phase, because this is when the consequences of a quick and adequate colostrum intake (or lack of) can be seen.

While it is well know that oral meloxicam has a beneficial effect in sows by reducing puerperal septicaemia and toxaemia (Mastitis-Metritis-Agalactia syndrome MMA), its indirect effects on piglets are not clear.

This study clearly demonstrates that oral meloxicam administered around the time of farrowing results in significantly higher IgG levels in piglets during the first 48 hours of life, which then allows for better growth until weaning. The results can be explained by the reduction of inflammation and pain in the meloxicam-treated sows which, in turn, may have a positive influence on maternal behaviour, resulting in better nursing behaviour and colostrum intake. Both quality and quantity of colostrum is crucial for further development of pigs in terms of immunity and body condition.