Responses of Laying Hens to Diets Containing up to 2% DL-Methionine or Equimolar (2.25%) 2-Hydroxy-4-(Methylthio)Butanoic Acid

Abstract

Diets supplemented with up to .6% DL-Met (DLM) or .68% 2-hydroxy-4-(methylthio)butanoic acid (HMB, Alimet) acidify the urine and reduce the incidence of urolithiasis in pullets and laying hens. Excessive acidification potentially may reduce eggshell quality and bone mineralization by interfering with Ca metabolism and may severely challenge the liver and kidneys, which are the primary organs responsible for attenuating metabolic acidosis. To evaluate these possibilities, 30-wk-old Single Comb White Leghorn hens in full production (five hens per replicate, six replicates per diet treatment) were fed for 30 d a 15.7% CP corn and soybean meal-based control layer ration alone or supplemented with DLM (.5, 1, 1.5, or 2%) or equimolar HMB (.56, 1.13, 1.69, or 2.25%). None of the diets caused mortality or gross hepatic or renal damage. Hens fed diets supplemented with the highest levels of DLM and HMB exhibited significant reductions in feed intake, hen-day egg production, and liver mass and had lower plasma concentrations of alanine amino-transferase and isocitrate dehydrogenase when compared with hens fed the control diet. Kidney mass was not significantly affected by high levels of DLM or HMB, but plasma uric acid was significantly higher in hens fed 2% DLM compared with hens fed the control diet. The highest levels of DLM and HMB did not significantly alter total plasma Ca or inorganic phosphate concentrations, nor were percentage eggshell or femur mineralization (femur ash mass:defatted bone mass, femur ash mass:bone volume) significantly reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary methionine source and level affect hepatic sulfur amino acid metabolism of broiler breeder hens

“…This may be the main reason there was no effects of methionine source and level on egg production performance of broiler breeder hens and no deficient symptom for hens fed basal diets. Adding methionine at 1% (from HMTBA or DLM) did not suppress the production performance of broiler breeders in the present study, which was not in line with those reports by Xie et al (2007) and Wideman et al (1994). Adding DLM at 1% or HMTBA at 1.13% by Xie et al (2007) reduced average daily feed intake (ADFI) of ducks to 207.6 g/ bird/day or 224.1 g/bird/day, respectively, but the ADFI was higher than that of broiler breeders in the present study (130 g/bird/day at peak).…”

“…Adding DLM at 1% or HMTBA at 1.13% by Xie et al (2007) reduced average daily feed intake (ADFI) of ducks to 207.6 g/ bird/day or 224.1 g/bird/day, respectively, but the ADFI was higher than that of broiler breeders in the present study (130 g/bird/day at peak). ADFI of commercial laying hens was significantly reduced by adding DLM at 1% or HMTBA at 1.13% when compared with the control group (Wideman et al 1994). These results showed that broiler breeders can tolerate a higher methionine level than commercial laying hens.…”

“…ADFI of commercial laying hens was significantly reduced by adding DLM at 1% or HMTBA at 1.13% when compared with the control group (Wideman et al . ). These results showed that broiler breeders can tolerate a higher methionine level than commercial laying hens.…”

Effect of Dietary Folic Acid Supplementation to Diets of Low Levels of Energy and Methionine of Developed Laying Hens in Summer Season on Performance, Physiological Status and Immune Response

“…On the other hand, feed intake was not affected by a range of dietary ME from 2400 to 2900 kcal ME/kg (Adeyemo and Longe, 1996). Depression in feed intake is a highly sensitive response to excessive amino acid supplementation because diets supplemented with 0.10% DL-methionine significantly reduced feed intake (Wideman et al 1994).…”

Comparative Effects of Supplemental DL-2-hydroxy-4-[methylthio] Butanoic Acid and DL-methionine in Diet on Egg Production and Quality in Laying Hens

“…6% (egg weight) with the exponential model, and was 89.7% (egg production), 89.6% (egg mass), and 86.8% (egg weight) with the slope-ratio model. However, several researchers reported that there was no difference in bioefficacy between DLM and HMB (Reid et al, 1982;Harms and Russell, 1994;Wideman et al, 1994). In broiler chickens, moreover, we have concluded that as long as TSAA requirement is set at the commercial or maximal requirement, bioefficacy of HMB relative to DLM on a weight basis seems to be 88% Bunchasak, 2009).…”