Comparison of Synthetic Lysine Sources on Growth Performance, Nutrient Digestibility and Nitrogen Retention in Weaning Pigs

Abstract

We compared the effects of supplementing L-lysine⋅SO 4 to L-lysine⋅HCl on growth performance, nutrient digestibility and nitrogen retention in weaning pigs. A total of 96 crossbred pigs, weaned at 21±3 days of age and with an average initial body weight (BW) 6.23±0.01 kg, were given one of 4 treatments, which translated into 6 replicates of 4 pigs in each pen. The animals were randomly assigned to four dietary treatments according to a randomized completely block design (RCBD) as follows: 1) control-no synthetic lysine, lysine deficient (0.80% total lysine); 2) L-C (= 0.2% L-lysine⋅HCl); 3) K-L-S (= 0.332% L-lysine⋅SO 4 , A company); 4) C-L-S (= 0.332% L-lysine⋅SO 4 , B company). Diets were formulated with corn, soy bean meal, and corn gluten meal as the major ingredients, and all nutrients except the lysine met or exceeded NRC requirements (1998). The lysine content of supplemented synthetic lysine was the same in all treatment groups except the control. No clinical health problems associated with the dietary treatments were observed. During the entire experimental period, body weight, average daily gain (ADG) and feed efficiency (G:F ratio) increased (p<0.01) in pigs fed the experimental diets supplemented with L-lysine⋅HCl or L-lysine⋅SO 4 produced by A company, irrespective of the two synthetic lysine sources. Although the supplementation of L-lysine⋅SO 4 produced by B company tended to improve the ADG and G:F ratio, significant differences were not seen among all treatments and tended to be lower than the L-C (L-lysine⋅HCl) and K-L-S (L-lysine•SO 4 groups using the product from A company). The digestibility of crude protein (CP) was increased by the supplementation of synthetic lysine (p<0.05), irrespective of the L-lysine source (L-C, K-L-S, C-L-S). The results of this study showed that ADG, G:F ratio, and CP digestibility improved when L-lysine⋅SO 4 or L-lysine⋅HCl was supplemented into the weaning pigs' diet. There was a clear difference in efficacy between the two lysine⋅SO 4 products based upon the growth performance of weaning pigs. Consequently, the bioavailability of lysine⋅SO 4 products should be evaluated before supplementation of synthetic lysine in swine diets.

Scientific Opinion on the safety and efficacy of l‐lysine monohydrochloride, technically pure, produced with Escherichia coli CGMCC 3705 and l‐lysine sulphate produced with Corynebacterium glutamicum CGMCC 3704 for all animal species, based on a dossier submitted by HELM AG

“…The efficacy of this essential amino acid in non-ruminant and ruminant nutrition was recently reviewed in two previous opinions (EFSA FEEDAP Panel, 2013, 2014 Since the mid-1980s, several studies have been carried out in non-ruminant animals to compare the efficacy of the different L-lysine forms (sulphate vs. monohydrochloride). From a general standpoint it can be concluded that the dietary supplementation either with L-lysine HCl (standard L-lysine source) or L-lysine sulphate did not result in any significant difference with respect to growth parameters (average daily gain and food conversion rate), nutrient digestibility, nitrogen retention or carcass composition of piglets and pigs for fattening (Bourdon and Henry, 1985;Roth et al, 1994;Smiricky-Tjardes et al, 2004;Liu et al, 2007;Ju et al, 2008). Similar conclusions on the equivalence between L-lysine sulphate and L-lysine HCl can be drawn from studies on chickens for fattening (Liebert, 1995;Neme et al, 2001;Ahmad et al, 2007;Bobeck et al, 2013).…”

Scientific Opinion on the safety and efficacy of l‐lysine sulphate produced by fermentation with Escherichia coli CGMCC 3705 for all animal species

“…L-lysine HCl, L-lysine sulphate and free lysine base) in monogastric animals. From a general standpoint, it can be concluded that dietary supplementation with either L-lysine HCl (standard L-lysine source) or L-lysine sulphate did not result in any significant difference with respect to growth parameters (average daily gain and feed conversion ratio), nutrient digestibility, nitrogen retention or carcass composition of piglets and pigs for fattening (Bourdon and Henry, 1985;Roth et al, 1994;Smiricky-Tjardes et al, 2004;Liu et al, 2007;Ju et al, 2008). Similar conclusions on the equivalence between L-lysine sulphate and L-lysine HCl can be drawn from studies on chickens for fattening (Liebert, 1995;Neme et al, 2001;Ahmad et al, 2007;Bobeck et al, 2013).…”