Experiment team: Department of Animal Nutrition in Huazhong
Agricultural University
Experiment location: Farm of Shilong Animal Husbandry Group in Guangxi
Province, China
Experiment duration: March 16th ~ May 27th, 2021
China is a meat duck breeding country, the number, and consumption of the first in the world. Our department is one of the TOP 3 Animal Nutrition R&D teams in China, so it is our responsibility to test the effectiveness of the use of powder DL-methionine 99% and liquid Hydorxy Analogue of Methionine 88%. Our experiment report will be important and useful for feed manufacturers, farming enterprises, and research scholars. Methionine is the first restricted amino acid in the corn-soybean meal-type diet of meat ducks. It is mainly involved in protein synthesis, active methyl for cell metabolism, and the synthesis of bioactive substances containing sulfur. Methionine is also crucial to the growth of duck feathers. Feathers contain up to 90% protein, of which keratin accounts for more than 85% of protein, and the lack of sulfur-containing amino acids will directly affect the synthesis of keratin, resulting in feather shedding, affecting the growth performance and slaughter performance of meat ducks. A large number of experiments have shown that Hydroxy Analogue of Methionine(We take HB88-MHA manufactured by Hebang as the materials for this experiment) is without any difference from DL-methionine (We take Met-AMINO manufactured by EVONIK as the materials for this experiment) in supporting the growth and development of chickens and pigs. Can Hydorxy Analogue of Methionine also play the same role as solid methionine in the production of meat ducks? This issue of Methionine Lecture Hall to share with you such an article: Ling Z, Ni-Ya Z, Yun-Xin P, et al. Efficacy of 2-hydroxy-4-methylth iobutanoic acid compared to DL-Methionine on growth performance, carcass traits, feather growth, and redox status of Cherry Valley ducks[J]. Poultry Science, 2018. The purpose of this experiment was to compare the effects of Hydorxy. Methionine and DL-methionine on the growth performance and feather development of Cherry Valley ducks aged 0–42 days. Second, the biological efficacy of Hydorxy Methioninerelative to DL-methionine was calculated. Animal and experimental design.The experiment was completed on the farm of Shilong Animal Husbandry Group in Guangxi Province, China. A total of 630 Cherry Valley ducks were randomly divided into 9 groups with 7 replicates per group and 10 ducks per replicate. The experiment lasted from 1 to 42 days of age. Rations are based on corn, wheat, and soybean meal and are based on NRC (1994) standards. The control group was the basal diet group, without any exogenous methionine source (TSA deficient group); Eight experimental groups were supplemented with DL-methionine or Hydorxy Analogue of Methionine
(Table 1).
The experiment was divided into two cycles. Four gradients of DL-methionine or Hydorxy Analogue of Methionine (0.04%, 0.12%, 0.16%, 0.20%) were added to the diets of the eight experimental groups at 0 to 21 days. Four gradients of DL-methionine or Hydorxy Analogue of Methionine (0.02%, 0.06%, 0.10%, 0.14%)were added to the diets of the eight experimental groups at 22–42 days. The animals were free to eat and drink throughout the experiment. Bodyweight and featherweight were measured at 21 d and 42 d. The feed intake, body weight, and feed conversion rate of each feeding period and the whole experiment period were calculated respectively. Feathers were collected at D21 and D42 respectively (n=14). Two Cherry Valley ducks were randomly selected from each replicate for the determination of carcass weight and breast muscle weight (14 ducks per group and 2ducks per replicate). Statistical analysis Analysis of variance (ANOVA) was used to compare growth performance and carcass traits among groups. The effects of different methionine sources and different doses on animal growth performance and carcass traits were determined by a two-factor analysis of variance between the experimental groups. The significance of the mean difference was P < 0.05. The mean value test was pairwise compared with the Tukey method. Exponential models with separate platform-stage were established to compare the effects of different methionine sources on animal growth:
Wherein, Y is body weight gain, A is a fixed value, A + B1 and A + B2 represent the maximum reaction of each methionine source, X1 and X2 represent the total sulfur-containing amino acid value of each methionine source ingested, and C1 and C2 are steepness coefficients of each methionine source. (?2/ Al1) was used to calculate the relative biological efficacy of the two methionine sources. Results and discussion The results of growth performance among each group are shown in Table 2.
There was a significant difference in feed intake between the control group and the experimental group. There was no difference in feed intake between the Hydorxy Methionine(5916 g) group and the DL-methionine (5927 g) group. However, with the increase of methionine level, the body weight and body weight gain of Cherry Valley ducks increased significantly. The body weight gain of Cherry Valley ducks in the DL-methionine group was similar to that in the DL-methionine group (3007 g and 3019 g, respectively) during the whole 0–42d experiment period. However, to our surprise, the feed conversion rate of the experimental group was significantly higher than that of the control group. Similar results were also observed by Kluge et al during the 0–21d experiment. Up to now, we only know the nutritional requirements of a few essential amino acids for ducks, but there are few literature records on the total nutrient recommendations of amino acids. Since the experimental diets were based on the NRC (1994), we inferred that another amino acid acted as a limiting factor. According to the report of Baeza (2016), methionine, lysine, threonine, and tryptophan are the four most restricted amino acids in duck feed. However, we found that dietary threonine levels (Table 3)
were lower than the recommended amount in the relevant literature. In addition, the dietary energy levels of the experimental diets were slightly lower than the recommended amount in the relevant literature. We believe that these minor differences may be responsible for the higher FCR in the experimental group than in the control group. Therefore, it is necessary to update the amino acid requirements of ducks. In addition, the Hydorxy Analogue of Methionine and DL-methionine sources have the same biological effects: the same amount of methionine in an animal can produce the same body weight gain. This experimental model takes into account the intake of total sulfur-containing amino acids so that the true biological efficiency ratio between Hydorxy Analogue of Methionine, and DL-methionine can be more accurately determined. As shown in Figure 1, bodyweight gain had the same exponential response to the two methionine sources without significant difference (P= 0.88). The biological efficacy ratio of the two was 99% in the confidence interval of 86%-112% by calculating the steepness coefficient ratio. Therefore, it is certain that the Hydorxy Analogue of Methionine and DL-methionine has the same biological effect on body weight gain. Carcass yield and feather growth were similar between DL-methionine and HB88-MHA groups. Table 4
shows the carcass yield and featherweight of Primrose Valley ducks. The carcass weight and breast muscle weight of meat ducks were significantly increased after methionine supplementation. There were significant differences between the control group and the treatment group. This is consistent with other findings that methionine (Conde-Aguilera et al., 2016) and lysine deficiency (Tesseraud et al., 2001) reduce breast muscle weight. DL-methionine and HB88-MHA had similar effects on carcass weight and chest muscle weight. However, there was no significant difference between treatments. However, a linear regression model for breast muscle weight showed a linear increase with methionine addition (P = 0.001). Failure to reach a plateau in pectoral weight indicates that other amino acid requirements are not being met, which is consistent with the findings in the FCR. A comparison of slopes showed no significant difference in breast muscle weight between DL-methionine and Hydorxy Analogue of Methionine (P = 0.47), thus confirming the bioequivalence of the two methionine sources.In addition, featherweights were measured on days 21 and 42. There was no significant difference in featherweight or yield at day 21. On day 42, there were significant differences in featherweight between the basal diet (150 g) and the DL-methionine group (172 g, P = 0.003) and the HB88-MHA group (174 g, P = 0.001). There were no significant differences in either featherweight or yield between DL-methionine and Hydorxy Analogue of Methionine. All these indicated that there was no difference between the two methionine sources in promoting feather growth. conclusion This experiment proves that HB88-MHA can promote growth performance and feather development of Cherry Valley ducks, and there is no difference between DL-methionine and Hydorxy Analogue of Methionine, and the biological efficacy of MHA is 100% relative to DL-methionine.
