The Folic Acid Requirements of Starting Broiler Chicks Fed Diets Based on Practical Ingredients.

Abstract

Two experiments were conducted to determine the effects of dietary supplemental folic acid and methionine on the performance of starting broiler chicks for 18 d. Four levels of dietary folic acid (.24, .54, 1.14, and 2.34 mg/kg) and four levels of dietary methionine (.45, .53, .61, and .69%) were fed in a factorial design. There were three replicates of eight chicks each per each treatment. The basal diet was based on corn, isolated soybean protein, meat and bone meal, and fish meal. It contained adequate amounts of all nutrients except methionine and folic acid. Increased growth was observed in chicks fed the basal diet supplemented with either folic acid or methionine. Total dietary folic acid and methionine plus cysteine requirements for maximum growth were estimated to be 1.80 mg/kg and .85% in Experiment 1 and 1.47 mg/kg and .87% in Experiment 2, respectively. There were interactions between dietary folic acid and methionine on weight gain in both experiments. Chicks fed the diet containing 2.34 mg folic acid/kg tended to have depressed growth, as in previous experiments. There was a significant linear feed conversion response to folic acid in Experiment 1 and to methionine in Experiment 2. There were both linear and quadratic liver folic acid responses to dietary folic acid in both experiments. There was no indication that dietary methionine had any effect on liver folic acid content. No differences in bone ash, hemoglobin, hematocrit, or incidence of tibial dyschondroplasia were detected due to methionine or folic acid supplementation.

Effect of methyl donors supplementation on performance, immune responses and anti-oxidant variables in broiler chicken fed diet without supplemental methionine

“…Similarly, the albumin concentration in all the MD supplemented groups improved similar to those fed the CD. Similar to these observations, improvement in FEwas observed with supplementation of Bet [8,2728] or FA [2829] to diet containing sub-optimal concentrations of Met.…”

The effect of methionine and folic acid administered in ovo on the hematological parameters of chickens (Gallus gallus domesticus)

“…( Table 5 ). In contrast, Ryu et al. (1995) did not find differences in Hb or Ht owing to Met or FA supplementation in the initial broiler diet.…”

Efeito da suplementação de betaína em dietas de frangos de corte em condições de termoneutralidade

“…Em outro estudo Ryu et al (1995b) observaram que a exigência de ácido fólico estava ligada à concentração de metionina da ração, de forma que a máxima resposta se verificou com a suplementação de 2,34 ppm de ácido fólico ou 2400 ppm de metionina. No entanto, os dados dos autores sugerem que em rações com alto nível de metionina a exigência de ácido fólico seja minimizada a 0,24 ppm, metade da recomendação do NRC (1994).…”

“…A ração do grupo controle negativo continha 2660 ppm de metionina suplementar, concentração suficiente para atender à exigência de ácido fólico (0,24 ppm) segundo Ryu et al (1995b). Isto explica, em parte, a similaridade das respostas obtidas para os controles positivo e negativo nas variáveis de desempenho zootécnico.…”