Bioefficacy of L-lysine·H2SO4relative to L-lysine·HCl in broiler chickens, estimated by slope-ratio model

Growth curves of broilers fed different nutritional relationships using the Gompertz model

The study aimed to evaluate performance and growth curves of broilers fed different nutritional relations. A total of 1,440 Cobb-500 male day-old chicks were assigned to eight treatments in a 2 x 2 x 2 factorial arrangement with six replicates of 30 birds each. The main factors were nutritional density (control and high), lysine source (HCl and sulfate), and calcium pidolate (presence and absence). Analyses were made for body weight gain (BWG), and feed conversion rate (FCR) at 21, and 42 days of age. The growth curves were adjusted by weighing a bird per plot every three days. Data for BWG were tested by ANOVA to evaluate the effects of treatments and their interactions at 5% significance, and the Gompertz model was adjusted by NLS. Birds fed a high nutritional density had higher BWG and lower FCR. Calcium pidolate and different sources of lysine did not influence the FCR of broilers, however a triple interaction was evidenced for BWG at 1 to 42 days of age. The day with maximum gain adjusted by Gompertz of all treatments was at the 32nd day of age and the maximum weight (A) was around 5.85 kg.

Effects of L-lysine·H2SO4 product on the intestinal morphology and liver pathology using broiler model

Background

Lysine is used widely in livestock production due to the shortage of feed protein resources. L-lysine·H₂SO₄ contains L-lysine sulphate as well as fermentation co-products which contain other amino acids and phosphorus. However, there are few articles about L-lysine·H₂SO₄ product regarding intestinal morphology and liver pathology of broiler chickens. In this article, we focus on the absorption and metabolism of L-lysine·H₂SO₄ revealed in the variation of intestinal morphology and liver pathology to determine the tolerance of chicks for L-lysine·H₂SO₄.

Methods

To evaluate the tolerance of broilers for L-lysine·H₂SO₄, 240 one day old broilers were allocated randomly to one of five dietary treatments which included corn-soybean diets containing 0, 1%, 4%, 7% or 10% L-lysine·H₂SO₄ (L-lysine content = 55%).

Results

Supplementation of 1% L-lysine·H₂SO₄ in the diet had no negative effects. However, 4%, 7% or 10% L-lysine·H₂SO₄ supplementation produced negative responses on broiler performance, carcass characteristics, blood biochemistry, and particularly on intestinal morphology and liver pathology compared with broilers fed the control diet.

Conclusion

Our results show that supplementation with 1% L-lysine·H₂SO₄ had no negative effects on performance, carcass characteristics, blood biochemistry, intestinal morphology and liver pathology in broilers, but supplementation with 4%, 7% or 10% L-lysine·H₂SO₄ produced a negative response, particularly with respect to intestinal morphology and liver pathology.