Methodische Untersuchungen zur Stoffwechsel-orientierten Lysinbedarfsbestimmung an Broilerküken

In a preliminary experiment the time course of 35S-excretion following a single injection of 35S-methionine in male broiler chickens was measured for 5 days. Within 2 days 65 to 69% of the amount of 35S excreted during the whole 5-day-period were recovered. Therefore, in the main experiment excrements for 35S measurement were collected only 2 days. During the main experiment starting 7 days posthatching 48 male broiler chickens received diets based on peas and wheat. The basal diet was supplemented with DL-methionine at 8 levels increasing the methionine content from 3.3 to 7.5 g/kg DM or 1,51 to 3.42 g/16 g N and the content of sulphur containing amino acids varied from 6.8 to 11.8 g/kg DM or 3.11 to 5.02 g/16 g N, respectively. Daily body weight gain was followed up to day 30 posthatching and N-balance was estimated during the 21st to 26th day posthatching. Up to day 26 a methionine content of 3.9 g/kg DM was sufficient for maximum weight gain. However, during the last period of the experiment highest weight gains were observed in animals receiving diets with 4.5 or more methionine/kg DM. Highest N-retention (1.2 g N/d) was measured if the diet contained 3.9 g methionine/kg DM or more. At day 28 posthatching 35S-methionine was injected intravenously and the subsequent 35S-excretion was measured. The 35S-excretion started to increase at a methionine content in the diet of 4.5 g/kg DM and continued to rise up to the highest methionine content of 7.5 g/kg DM. The metabolism oriented methionine requirement determination indicates for male broiler chickens at the beginning of the 5th week posthatching a methionine requirement of 3.9 to 4.5 g/kg DM (1.78 to 2.05 g/16 g N) and a requirement of S-containing amino acids of 7.4 to 8.0 g/kg DM (3.38 to 3.65 g/16 g N). The method used is potential in studying the age-dependent changes in methionine requirement.

Methodische Untersuchungen zur stoffwechselorientierten Methioninbedarfsbestimmung an Broilerküken

Wilke¹,

Bergner²,

Tn³

1987

Einfluss der fütterungsfrequenz auf das ergebnis der stoffwechselorientierten lysinbedarfsbestimmung und der N‐bilanz bei masthähnchen‐küken

Bergner

Mnilk

1993

Two feeding regimes were used for investigation into the effect of meal frequency on the lysine requirement in chickens estimated with metabolism-oriented determination. 1-day-old male broiler chickens were fed either twice a day for 1 hour (one group) or 6 times a day for 1/2 hour (other group). 7 to 21 days posthatching the birds received a wheat-wheat gluten diet which was L-lysine-supplemented at 6 levels. Using lysine deficient diets chickens fed twice a day eat more and grow faster than chickens fed 6 times a day. The N-balance was 6 to 7% higher in the case of the feeding regime 2 times a day. After feeding period 14C-U-L-lysine was injected intravenously and 14CO2-excretion measured. The estimated range for lysine requirement was 11.9-13.1 g lysine/kg DM and 13.1-14.3 g lysine/kg DM for chickens fed 2 times and 6 times a day, respectively. A feeding regime of 6 meals a day does not improve the utilization of diets contains crystalline lysine compared with feeding of 2 meals a day.

Methodical investigations on the metabolism oriented determination of methionine requirement of broiler chickens

Simon

Bergner²,

Dinh³

1995

Self Cite

In a chicken experiment was investigated, whether the kind of applied isotope and labelling site influence the results of the metabolism oriented estimation of the methionine requirement. Furthermore it was studied, if this method can give additional informations to weight gain and N-retention data concerning methionine requirement. 48 male broiler chickens received synthetic diets with a complete amino acid mixture from day 7 posthatching. The methionine content of the 8 experimental diets varied from 2.25 to 7.5 g methionine/kg DM (1.17 to 3.87 g/16 g N). The low weight gain (13 to 22 g/d) and N-retention (0.55 to 0.87 g/d; from day 13 to 17 posthatching) was due to the inferior intake of the synthetic diets. Methionine supplementation increased weight gain and N-retention only up to 3 g methionine/kg DM. The metabolic methionine requirement was measured after i.v. injection of 14C-(CH3)- and 35S-methionine by 14CO2-excretion with breath and 35S-excretion with excrements. Both parameters gave similar results and showed an increased methionine degradation at methionine contents exceeding 4.5 g methionine/kg DM. Because there was no increase in methionine degradation up to 4.5 g/kg DM, an increased reutilization of methionine within the range between 3 and 4.5 g methionine/kg DM was supposed, which may act as a spare-mechanism. For practical feeding applications, also in case of low feed intake, a minimal methionine content of 4.5 g/kg DM is recommended.