Benefits of extra liquid methionine for sows

Liquid methionine added to diets for lactating sows leads to both more fat and lactose concentration in the milk as well as a better gut absorption of nutrients in the suckling piglets’ guts. Jointly, these factors explain a higher piglet body weight before and after weaning.

Nutritionists must find solutions to feed the modern and hyper-prolific sows and develop new strategies to meet increasing nutrient requirements. Lactation is an essential phase, as sow milk quantity and quality play a central role in the growth of suckling piglets. Trials carried out by French animal nutrition company Adisseo prove that extra methionine added in the diets beyond requirements leads to an improvement of milk quality.

Comparing methionine

Recently, a trial was carried out in China on cross-bred primiparous sows in order to compare lactating sow diets with an extra supply of methionine with a control diet containing 0.25% of total methionine, at a level in agreement with the recommendations of the United States National Research Council (NRC). Three methionine sources are available for the feed industry. In this trial, 2 forms of methionine were compared: a powder form, DL-methionine (1.34 kg/tonne) and a liquid form: DL-hydroxy methionine, DL-HMTBA (1.51 kg/tonne).

Compared to the control diet and the DL-methionine diet, the diet containing DL-HMTBA leads to a significant improvement of fat and lactose content of the milk of the sows (Figure 1), the 2 sources of energy supply for suckling piglets. The authors also demonstrated that a better milk composition stimulates intestinal gene expression and increases absorption capacity of the suckling piglets gut.

As a consequence of the higher nutritional milk content regarding macronutrients and amino acids, the body weight of suckling piglets at day 14 post-farrowing in the DL-HMTBA group was significantly higher (+510 g) than in the control group and tended to be higher (+310 g) than in the DL-methionine group.

Figure 1 - Content of fat and lactose in milk of sows fed with different sources of methionine.

Body weights increase

These new data confirm the better efficacy of the liquid form of methionine which were observed earlier by researcher Hao Li and his team, affiliated to Sichuan Agricultural University, China. In that trial, where both sows and piglets received a diet with increased levels of sulphur amino acids through DL-HMTBA or DL-methionine, the scientists demonstrated that the body weight of 35 day old piglets was significantly higher when sows and piglets received methionine as DL-HMTBA compared with DL-methionine, also see Figure 2.

Figure 2 - Piglet weight at 35 days (kg).

Furthermore, those piglets had a better gut morphology, with higher villus heights and villus height/crypt depth ratio (Figure 3) leading to a better absorption capacity. Moreover, during the post weaning period, the effect of dietary treatments on jejunal glutathione status showed that DL-HMTBA treatment allowed a better red-ox status than in the other treatments (as shown by higher reduced glutathione and lower oxidised glutathione to reduced glutathione ratio).

Figure 3 - Ileal global intestinal cells of piglets. When sows and piglets receive increased levels of methionine, especially through DL-HMTBA, piglets have a significantly better gut morphology, with higher villus heights and height/crypt depth ratio, leading to a better nutrients absorption capacity.

Higher feed intake

Another interesting finding was that weaned piglets receiving the DL-HMTBA source of methionine in their complete feed, show a higher feed intake across post-weaning days (P<0.05) compared to those in the control or dl-methionine groups, leading to a better average daily weight gain.>

The researchers also concluded that increased consumption of methionine as DL-HMTBA might alleviate stresses associated with early weaning. Compared to the control group, higher villus height, villus height/crypt depth ratio and number of goblet cells were observed in the DL-HMTBA treatment group providing evidence for its positive effect on weaning stress.

The team at Sichuan Agricultural University concluded that early-weaning induced growth retardation appears to be attenuated through changes in plasma amino acid profiles and elevation of growth performance and intestinal antioxidant capacity in piglets, following increased consumption of methionine as DL-HMTBA.

These observations offer novel insights into the mechanism of sulphur amino acids metabolism, with important nutrition and health implications.