Recent advances in commercial EU dam genetic lines have led to sows producing more piglets born alive, leading to more finished pigs, than ever before. Therefore, the extent of support offered to the modern sow is important to ensure maximum lifetime performance. Sow feed intake and management during lactation is one fundamental aspect in maintaining optimum performance and with increasing numbers of piglets born alive, the requirement for high quality milk is amplified. Meeting such milk requirements can lead to a higher incidence of sow body condition loss and put her under an increasing degree of oxidative stress. This can result in adverse effects on subsequent oocyte quality and fertility, particularly following poor intakes in parity one, which has a profound lifetime impact.

“I strongly believe that sow management is the most important aspect in a productive and efficient pig unit,” says Heidi Hall, Anpario’s swine technical manager. “Ensuring gilts are supported nutritionally and their immune systems are well developed before joining the breeding herd is paramount to lifetime performance.” During parity one, the gilt must meet challenging energy requirements for maternal growth and foetal development. There are multiple factors involved in maximising feed intakes during lactation, this includes provision of high quality feed and feed hygiene, as well as ensuring feed palatability and form allows for adequate voluntary intakes. “Flavours and some essential oils can help to increase feed interest and so could provide a benefit to lactation intakes. It is well known that average intakes need to be greater than 6.5kg/day per sow,” says Hall. Oregano essential oil contains two key compounds involved in improving feed intake; these are carvacrol and thymol. The mode of action of oregano oil within the animal is complex; however, oregano oil has been found to have a role in appetite enhancement and antioxidant function, as well as in both immunomodulatory and anti-inflammatory processes. It also has been shown to have a beneficial effect on the gut microflora of sows (unpublished Anpario data).

Oregano essential oil has been shown to enhance voluntary feed intake as a result of the positive response it has on the olfactory pathways, which are responsible for appetite stimulation and digestive enzyme secretion. In recent trial work, the inclusion of oregano oil within sow diets has been shown to help increase feed intakes during lactation (Figure 1). “This increase coincided with peak milk production,” explains Hall. “This would help ensure body condition of the sow is not detrimentally affected in the last few days of lactation.” Maintaining body condition score would ultimately be expected to improve metabolic status of the sow and can help improve hormone status and conception rates associated with subsequent parities2.

Sows of a prolific nature are more likely to produce piglets with lower birth weights and increased litter variability3. Piglets of low birth weights can struggle to consume sufficient quantities of colostrum and therefore incidence of pre-weaning mortality has risen as litter size continues to increase4. Pre-weaning piglet growth performance is directly related to colostrum and milk intake5, therefore maximising sow intakes and driving milk production is the most cost-effective method to improve sow and progeny performance. “Before we look to provide supplementary piglet nutrition, which will always require increased resources, we should look to ensure our sows are supported to perform optimally,” recommends Hall. The increased feed intake of sows as a result of the addition of oregano essential oil (Figure 1) led to increased milk yields during lactation in this study, which corresponded to significantly improved piglet pre-weaning growth rate (Figure 2) and significantly heavier weaning weights, with an average benefit of 500g per piglet. “This study is interesting as it suggests we can do more to better support our sows, and this work is the foundation of our new research into the mode of action of oregano essential oil in sows’ diets,” says Hall. It is well documented that increases in pre-weaning growth rate and weaning weights benefit growth performance post-weaning and survivability6,7, therefore improving pre-weaning average daily gain may impact lifetime performance, with more pigs reaching finisher weights earlier. This would help to reduce cost of production, improve herd profitability, and help to free up valuable pig space on the unit.

Early microbial colonisation in young pigs represents a window of opportunity to modulate the mature gut microbiome. The composition of the pigs’ intestinal microbiota population has been linked with overall growth performance8 and the functionality of the microbiota present has been associated with lifetime feed efficiency9. Oregano essential oil has been found to have many beneficial effects on gut health and microbiome populations in pigs; for example, inclusion of oregano essential oil has been associated with decreased intestinal E. coli populations, most likely as a result of its effect on the promotion of intestinal barrier integrity and immune status10. Addition of oregano essential oil to sow gestation diets has shown significant benefits to the sow microbial population (Figure 3), with decreases in E. coli spp. And Enterococcus spp. and increases in beneficial bacteria such as Lactobacillus spp.. A beneficial sow microflora will subsequently benefit piglet health and performance as initial microbial colonisation occurs by transfer from the sow at birth, during lactation and possibly during gestation11. Our future work is looking to elucidate these links and understand how the changes in the microbial population affects sow and subsequently piglet performance following oregano essential oil supplementation.

“The relationship between gut health and animal performance has always interested me,” explains Hall. This year Heidi is embarking on travels to the US, Canada, Denmark, Spain and China in the hope of further exploring the relationship between gut health, nutrition and management. “I want to understand how we can better provide for pigs and other livestock and ensure they are as healthy as possible in order to perform to their genetic potential without antibiotics,” said Hall. “My project is titled ‘The Power of Microbiome to Produce Happy, Healthy Pigs’. I am very grateful to have been awarded a Nuffield Scholarship and have been supported generously by The John Oldacre Foundation to follow my passion and investigate what I feel is a fundamental project for the future of British pig farming.”