Feed additive in sow diets benefits litter performance
Does good piglet management start at birth? Or is it wiser to prepare for well-performing litters one stage earlier? When using certain feed additives in sow nutrition, the latter appears to hold true. There is value to be reaped later on at various stages of the offspring’s life.
by EUNICE LEE, Technical consultant organic acids, published in Pig Progress
During intensive pork production, a high proportion of pig losses can occur during farrowing and lactation periods. It is a critical time to determine the overall performance for a production pig. During those periods, not only the welfare of the sows should be addressed, but also the nutrients and elements needed to prepare them for body maintenance and the ability to encounter all the types of disorders that may occur.
Some nutritionists treat this time as a transition period, as sows’ metabolism switches from anabolism to catabolism. While during the gestation period the energy that sows ingest is mostly for body maintenance and partially for foetal production, during the lactation period, most of the energy intake is used for milk production. The requirement of energy level, protein level, fibre level and micronutrients between the gestation diet and lactation diet have enormous quantitative and qualitative differences. That, in practice, can be easily underestimated and overlooked.
The nutritional knowledge and supportive elements for that transition period have started to receive further attention. Feed additives that are designed to support sows physiologically and systemically are also generally accepted and applied during the transition period.
Feed additive: Lauric acid and monolaurin
Saturated fatty acids, also commonly known as organic acids, are widely applied in piglet diets for their supporting role in nutrient digestion. Another group of these organic acids is the medium chain fatty acids (MCFAs), which are saturated carboxylic acids with a carbon chain length from C6 to C12. They are abundant in coconut oil or palm kernel oil in triglycerides form.
The antimicrobial activity of MCFAs has been extensively studied. It has been shown that the antimicrobial effect of lauric acid is quite potent among MCFAs. Its derivative, glycerol monolaurate (GML), which is produced by the esterification of a molecule of glycerol and a molecule of lauric acid, also has strong antimicrobial effect.
The antimicrobial mode of action for lauric acid and GML is mainly through discomposing the homeostasis of the bacterial cell membrane and inducing inhibition of the bacterial growth.
A synergistic effect between lauric acid and GML had been found against Streptococcus pyogenes at different mixture ratios, where the combination exhibits stronger inhibition activities than using the single ingredients. Both lauric acid and GML have been proven to have antiviral properties against different enveloped viruses.
Metabolism and immune modulation
MCFAs are shorter chains of carboxylic fatty acids than long chain fatty acids, and they can bypass the micelle formation and be absorbed directly by the enterocytes and utilised as energy or transferred through the portal vein to the liver. MCFAs require no binding protein while entering the mitochondrial membrane and more readily undergo oxidation within the mitochondria.
Those MCFAs have been found to interact with immune or non-immune cells via G protein-coupled receptors (GPCR). It has been shown that GPR40 is activated by MCFAs, with which lauric acid has a high affinity. GPR40 is highly expressed in monocytes, where it suggests that MCFAs have immune modulation effect. It has also been shown that MCFAs reduce viral replication by acting on MARC-145 cells where it prevented the attachment of Porcine Respiratory and Reproductive Syndrome virus (PRRSv) or membrane fusion in the cytoplasm. It is shown that supplying triglycerides of MCFAs to rats conferred a protective effect on the intestine by increasing the IgA secretion and modulating the inflammatory immune response while challenged with endotoxin.
Proof of concept: field trial result
A field trial was conducted in a commercial sow farm in Germany, with 33 sows in the control group and 34 sows in the treatment group. The breed was Danbred×Pietrain. A comparative trial was designed especially in the transition period in sows, which was one week before farrowing and the whole lactation period. The control group was fed a conventional lactation diet without any feed additive supplementation.
The treatment group was fed a conventional lactation diet with 1.5 kg of a proprietary MCFA, called DaaFit G, per ton of feed added.
The piglet performance at farrowing is shown in Table 1. Litter weights during farrowing in the MCFA product’s group were higher than in the control group. Liveborn piglets were 1.8% higher than the control group. The average birth weight in the group with the MCFA product was 70 g more than in the control group. The piglet performance at weaning is shown in Table 2. The number of weaned piglets in the MCFA product group was greater than in the control group as was the aver- age weaning weight, which was significantly different (P < 0.05), 8.9% higher than in the control group. And the average daily gain was also significantly different (P < 0.05), with 9.7% improvement over the control group. Even though there was no statistical difference in mortality, it was less in the MCFA group (5.9% vs 7.5% in the control group).
Healthier sows and larger piglets
For the mode of action of lauric acid and GML studied in this feed trial, it is hypothesised that the feed additive, lauric acid and GML can support the sows to overcome the critical transition period by different actions. Lauric acid and GML can either directly act on the pathogenic load through feed or in animals, be utilised by the intestinal enterocytes in a short pathway for energy supply or act through GPCR at different sites of monocytes for immune modulation.
Through improving the health status of the sows, a larger litter number is achieved and piglets are born at a higher starting weight. Through the lactation period, the vitality of the piglets also stimulates better milk production at the sows, and it certainly provides better availability of nutrients to the piglets and better performance at the weaning stage.
