The substantial increase of total born piglets is a potential productive advantage. Nevertheless, it usually goes hand-in-hand with a greater birth weight variability (0.8 - 1.1 kg) and more small and non-viable piglets (≤0.8 kg). The increase in prolificacy has not been accompanied by a proportional increase in the amount of colostrum, putting piglets with a lower birth weight at a disadvantage.
L-carnitine has increasingly been used as a supplement in livestock animals. Trials consistently demonstrate the beneficial effects of dietary L-carnitine supplementation on performance characteristics in several animal species (pigs, chickens, cattle, horses). Impressive effects of L-carnitine supplementation have also been observed in the reproductive performance of sows.
Benefits of carnitine
Various metabolic processes take place in the liver and thus good liver function is crucial for optimal performance. Carnitine and choline chloride are derived from dietary sources and endogenous biosynthesis. However, endogenous synthesis is insufficient to meet the metabolic requirement during gestation. Both compounds are essential for fat metabolism and transport of fatty acids into the mitochondria. These structures are considered to be the powerhouses of the cells and provide energy.
L-carnitine supplementation to sows also stimulates the glucose metabolism in the foetuses, providing extra energy for foetal development. This boost results in higher litter weights at birth. Moreover, the higher milk production largely contributes to a better performance of the suckling piglets (Figure 1).
Carnitol-L®
Carnitol-L is a complementary feed. Its liquid and palatable formulation contains high concentrations of L-carnitine, choline chloride, sorbitol and selected plant extracts. These ingredients with hepatoprotective properties especially contribute to:
- boosting metabolic liver function and preventing fatty liver in sows
- optimising the efficiency of energy production from feed
- detoxifying and eliminating harmful waste products
- stimulating appetite
As a result, Carnitol-L® substantially optimises reproductive performance and has no withdrawal time.
Field trials
The benefits of supplementing Carnitol-L® on the average number of live and stillborn piglets was investigated in a trial in a highly-productive Danish sow herd (Table 1).
At entering the farrowing crates, sows received 40 ml Carnitol-L® daily in the feed troughs for the 5 days prior to farrowing. The daily dose per sow corresponded to 1.2 g L-carnitine, 1.5 g choline chloride and 11.4 g sorbitol. A specially developed and adjustable drench fitting on the product container was used (Figure 2).
Average litter data of farrowings before (control) and after the supplementation were recorded and compared. Moreover, data was determined on an annual basis, taking the farrowing index into account.
Carnitol-L® supplementation for the last 5 days before farrowing resulted in:
- an average increase of 0.4 live born piglets/sow/litter, corresponding to 0.95 (= 0.4 x 2.38) live born piglets/sow/year (Figure 3)
- an average decrease of 0.37 stillborn piglets/sow/litter, corresponding to 0.88 (= 0.37 x 2.38) stillborn piglets/sow/year (Figure 4)
The return on investment was 1:4.8 when comparing the control farrowings with the Carnitol-L® supplemented farrowings.
The efficacy of Carnitol-L® supplementation was also evaluated in two other trials in Danish sow herds:
- 120 mg L-carnitine/sow/day for the last 4 weeks of gestation resulted in a significant increase in the body weight of piglets at birth by 33 g/piglet
- 60 mg L-carnitine/sow/day for the first 12 weeks of gestation in combination with 120 mg L-carnitine/sow/day for the last 4 weeks of gestation resulted in
- a significant reduction in the number of weak born piglets (-0.75)
- lower pre-weaning mortality (-0.28 piglets)
- higher body weights at weaning (+0.2 kg)
Conclusion
Studies reported in the literature and recent field trials consistently demonstrate that dietary L-carnitine supplementation during gestation increases the reproductive performance of sows. The supplementation of 40 ml Carnitol-L® during the last 5 days prior to farrowing results in a substantial increase in the number of live born piglets and a decrease in the number of still births.
