L-arginine supplementation in pregnant sows

Sexually mature sows gestate a relatively low number of piglets (approximately 8.5 piglets per litter) when fed diets without Arginine. This is due to their ability to synthesize the necessary amounts of this amino acid.

However, this endogenous synthesis can be modified in hyperprolific sows.

In turn, the addition of L-Arginine in the final stages of gestation reduces the percentage of stillborn and underweight piglets (Nuntapaitoon et al.  2018).

On the other hand, arginine is a precursor of numerous physiological processes such as lipid metabolism in gestation and the production of polyamines and nitrous oxide which are necessary in placental angiogenesis.

It has been hypothesized that arginine can modify the intestinal microbial profile, as observed in mice supplemented with this amino acid (Ren et al. 2014).

However, whether arginine supplementation in gestation diets has an impact on the composition of the sow’s microbial flora and therefore on the first days of piglets’ lives, remains unknown.

Objective

The objective of the following study was to verify the efficacy of diets enriched with arginine. Evaluating its influence on:

• The number of piglets born
• The number of live births
• The number of malformations
• Intestinal microbial balance of sows and their humoral immune response
• Maternal performance evaluated in terms of litter homogeneity, survival rate and weaning weight

Materials and methods

The trial was conducted at a commercial farm located in Italy. 205 Landrace Large White bristles were used.

The experiment was carried out using a 2×5 factorial design, in which there were 2 diets and 5 sow classes. The sows were divided into two experimental groups, balanced by the number of piglets:

• Control group (CON). 102 sows were fed the gestation diet usually employed on the farm, formulated to cover the nutritional requirements of pregnant sows according to the NRC (National Research Council, 2012).

• Arginine group (ARG).  103 sows were fed the same diet as the CON group, supplemented with 0.25% arginine, having a final concentration of 0.97% total arginine.

Results