An experiment was conducted for a period of 42 days to assess the efficacy of herbal methionine (Nutrimethionine) supplementation on the performance of broiler chicken reared on deep litter. A total of 180 day old chicks (Vencobb 400) were divided into one control and three treatment groups, each group with three replicates of 15 birds per replicate. Group I (GI) of birds was kept as control and fed the basal diet without any supplemental Methionine. Group II (GII) of birds was fed the basal diet supplemented with synthetic DL-Methionine @ 100g per quintal. Group III (GIII) of birds were fed the basal diet supplemented with Nutri-Methionine @ 100g per quintal feed in the diet. Group IV (GIV) of birds was fed the basal diet supplemented with 50g Nutrimethionine and 50g DL-Methionine per quintal of feed in the diet. The body weight of birds fed combination of herbal Methionine (Nutrimethionine) and DL-methionine (GIV) was significantly (P< 0.05) higher when compared with the other treatment groups and control group. Also the groups supplemented with DL-methionine and herbal methionine had significantly higher body weights than the control group. Cumulative feed intake was comparable among the groups of birds fed diets supplemented with synthetic Methionine or herbal methionine or both. However, feed intake was significantly (P<0.05) higher in control group as compared to supplemented groups. The feed conversion ratio was significantly (P<0.05) better in GIII fed with combination of herbal and synthetic methionine as compared to other groups. FCR was comparative between the GII and GIII, which was significantly better than control group (GI). No significant (P>0.05) variation was observed in the defeathered weights among various groups. The dressed weight percentage was significantly higher in methionine-supplemented groups and was highest in GIV. Broiler chicken fed diets supplemented with methionine showed significantly (P<0.05) higher serum total protein values than the control group and was highest in GIV. A significant (P<0.05) decrease in serum cholesterol level with the inclusion of herbal methionine and was least in GIII.
Poultry industry is growing significantly with more demand for economic and safe source of protein in the form of meat and eggs. It is conspicuous that nutrition plays most important role in poultry rearing. Among amino acids, methionine is the most critical and first limiting amino acid for poultry usually consuming maize and soyabean based diets. Being the essential amino acid, methionine must be supplied in the diet of poultry and supplementation of methionine in poultry ration is well established to improve growth and performance in broilers (Swick et al., 1990). More amount of methionine is required to comply with the increased tissue demands when bird is predisposed to fast growth along with high production performance. Methionine plays an important role in energy production, protein synthesis and helps in enhancing overall growth performance, feed utilization and livability in broilers (Binder, 2003). Sulfur-adenosyl methionine provides methyl groups, which are needed for several metabolic reactions such as synthesis of epinephrine, choline, carnithine and creatine (Schutte et al., 1997). Methionine may act as a lipotropic agent through its role as a methyl donor and involvement in choline, betaine, folic acid and vitamin B12 metabolism (March and Bieley, 1956; Chen et al., 1993). Methionine is precursor for cysteine and an important source of sulphur. Economic and speedy production of birds has lead to usage of synthetic source of methionine. Recently the safety of such practices has been questioned and their use is becoming restricted to many regions of the world. The DL-methionine supplementation in growing chicken feeds is a common practice especially in cereal and vegetable protein based ration (Swick et al., 1990). The starting materials for production of DL-methionine are acrolein (a 3-carbon aldehyde) derived from propylene (a petroleum derivative), methyl mercaptan derived from methanol and various sulfur sources and hydrocyanic acid (HCN). Acrolein and methyl mercaptan are reacted to form a relatively stable intermediate, 3-methylmercaptopropionaldehyde, known as MMP. The MMP is then reacted with HCN to form a rudimentary mix of DL-methionine and contaminants. Within the body, DL-methionine is metabolized into highly toxic compounds such as methyl thiopropionate (Baker, 1991) thereby adversely altering the performance of poultry birds. The synthetic methionine is listed among the prohibited synthetic substances (Anon, 1999). Hazardous nature, soaring prices and limited availability of DL-methionine have forced the researchers to get an alternative to replace DL-methionine in poultry diet. Various phytogenic formulations have claimed to be the alternatives for DL-methionine. Current study was taken to evaluate the claim of replacement of DL-methionine by one such phytogenic source viz. Nutrimethionine (Nutricare Life Sciences, Dehradun) in poultry diets.
Materials and Methods
One hundred and eighty, day old Vencobb broiler chicks were divided into one control and three treatment groups having 45 chicks in each group with three replicates of 15 chicks each reared on deep-litter system for a period of 42 days. The research was carried out in the Division of Livestock production & Management, SKUAST of Kashmir. Three types of corn-soyabean meal based diets were offered to the birds i.e., pre-starter (for first 14 days), starter (from 15th to 28thday) and finisher diet (from 29th to 42th day) (Table 1).
Table 1: Ingredient composition and chemical composition of basal diet
|Soyabean meal (kg)||38.70||33.40||29.20|
|Vegetable oil (kg)||2.15||3.32||3.28|
|Trace mineral premix(kg)||0.120||0.120||0.120|
|Vitamin E & Se(kg)||0.020||0.020||0.020|
|Available P (%)||0.50||0.50||0.46|
All the diets were formulated according to BIS (1992). Group I (GI) of birds was kept as control and fed the basal diet without any supplemental methionine. Group II (GII) of birds was fed the basal diet supplemented with synthetic DL-methionine @ 100g per quintal. Group III (GIII) of birds was fed the basal diet supplemented with Nutri-methionine @ 100g per quintal feed in the diet. Group IV (GIV) of birds was fed the basal diet supplemented with 50g Nutri-methionine and 50g DL-methionine per quintal of feed in the diet. All the groups were maintained under similar conditions of brooding, feeding and management. Feed was offered adlib throughout the experimental period as mash. Weekly body weight and feed consumption were recorded and feed conversion ratio (unit feed intake/unit body weight gain) was calculated. The mortality of birds was recorded. At the end of experimental period blood was collected from two birds from each replicate group (6 birds per replicate) for blood biochemical analysis using commercially available diagnostic kits of SPAN diagnostics. Similarly two birds from each replicate group (6 birds per treatment) were selected randomly and sacrificed as per standard methods, for determining the dressing percentage and carcass yield.
The data obtained was subjected to statistical analysis by the soft ware SPSS 10 (SPSS, 1997). Levels of significance were calculated as per the standard methods described by Duncan (1995).
Results and Discussion
The results of the comparative effect of feeding diets supplemented with synthetic and herbal methionine on the performance of broiler chicken is shown in the Table 2.
Table 2: Comparative effect of feeding diets supplemented with synthetic and herbal methionine on the performance of broiler chicken
|Initial body weight (g)||45.05||45.27||45.54||45.15|
|Final body weight (g)||1560.91a±9.56||1761.87b ±11.21||1750.52b±10.43||1790.52c±12.11|
|Body weight gain (g)||1515.86 a±21.21||1716.6b±32.31||1705.02b±28.76||1745.37c±30.12|
|Feed consumption (g)||3356a±38.32||3241b±37.54||3282b±36.76||3178b±32.98|
|Feed conversion ratio||2.21a±0.08||1.89b±0.05||1.92b±0.07||1.77c±0.03|
The figures bearing different superscript in a row differ significantly (P<0.05).
* GI-Group not supplemented with methionine; GII-Group supplemented with synthetic methionine (DLM); GIII-Group supplemented with herbal methionine (Nutrimethionine); GIV-Group supplemented with both synthetic and herbal methionine
The body weight of birds fed combination of herbal methionine (Nutrimethionine) and DL-methionine (GIV) was significantly (P< 0.05) highest when compared with the other treatment groups and control group. Also the groups supplemented with DL-methionine and herbal methionine had significantly higher body weights than the control group. The observed increase in body weight and weight gain of chicks with methionine supplementation is similar to the findings of Chattopadhyay et al. (2006), Kalbande et al. (2009) and Kadam et al. (2009). The increase in body weight and weight gain is attributed to the potential role of Methionine in promoting growth. Kalbande et al. (2009), and Naryanswamy and Bhagwat (2010) reported that the live body weight gain of birds at 21 days increased significantly with supplementation with semi-synthetic methionine in the diet of broiler chicken. Similarly, Naranswamy and Bhagwat (2010) reported that the chicks fed herbal methionine showed a significant (P<0.05) gain in body weight when compared with control group.
Cumulative feed intake was comparable among the groups of birds fed diets supplemented with synthetic Methionine or herbal methionine or both. However, feed intake was significantly (P<0.05) higher in control group as compared to supplemented groups. These results corroborate with the earlier reports of Chattopadhyay et al. (2006) who noted higher feed intake in the control birds than birds supplemented with methionine (DL-or herbal). However, Kalbande et al. (2009) observed no significant effect of herbal or DL-methionine supplementation on feed consumption of birds. The feed conversion ratio was significantly (P<0.05) better in GIII fed with combination of herbal and synthetic methionine as compared to other groups. FCR was comparative between the GII and GIII, which was significantly better than control group (GI). The results were in accordance with Chattopadhyay, (2003) and Kiran et al. (2012) who reported better FCR compared to DL-methionine supplemented birds. The better FCR in GIV group may be due to more bioavailability of L-methionine to the birds. There was no significant (P>0.05) difference in mortality among groups GII and GIV, however least mortality was observed in GIII. The same may be due to health promoting effect of herbal extracts in herbal methionine.
The effect of herbal and synthetic amino acids on carcass traits expressed as percentage live weight is shown in Table 3.
Table 3: Effect of synthetic and herbal Methionine on carcass traits and blood biochemical of broiler chicken
|Carcass Traits as % Live Weight|
No significant (P>0.05) variation was observed in the defeathered weights among various groups. The dressed weight percentage was significantly higher in methionine-supplemented groups and was highest in GIV. The percentage weight for gizzard and liver was significantly higher in methionine-supplemented groups as compared to control group. The percentage weight for heart was comparable among all groups. Significantly lower abdominal fat content was found in methionine-supplemented groups. Igbasan et al. (2012) observed similar results and the can be attributed to lipotropic effects of methionine. Percentage weights of breast and thigh were significantly higher in methionine-supplemented and was highest in GIV. The results were in accordance with those of Kiran et al. (2012), who reported no variation between diets with synthetic and herbal source of methionine. However, the combination of two has shown complimentary effects, which likely may be due to higher bioavailability in the combination. The higher dressed percentage in GIV may be due to growth promoting effects of herbal extracts in herbal methionine. The blood biochemical parameters are shown in Table 3. Broiler chicken fed diets supplemented with methionine showed significantly (P<0.05) higher serum total protein values than the control group and was highest in GIV. The results are in consonance to those of Igbasan et al. (2012). The same may be due to more availability of methionine, which acts as initiation codon for protein synthesis. These results are contrary to those of Halder and Roy (2007) and Rekhatel et al. (2010) who did not observe any significant effect of HM supplementation on total protein and albumin concentrations of broiler chickens. A significantly (P<0.05) higher blood glucose level was observed in the groups fed diets supplemented with methionine when compared with the control. The same may be due role of methionine in energy metabolism. However comparative glucose levels were observed among the supplemented groups. There was a significantly (P<0.05) decrease in serum cholesterol level with the inclusion of herbal methionine and was least in GIII. The findings can be well correlated to those reported by Halder and Roy (2007), Kalbande et al. (2009) and Rekhatel et al. (2010) that herbal methionine proved better than DL-methionine in lowering total cholesterol and according to the authors, this may be attributed to the hypo-cholesterolemic activity of certain constituent herbs in herbal methionine formulation.
The study concludes that herbal methionine has potential to replace synthetic methionine. However the optimum results were observed when both combination of synthetic and herbal methionine are used. The same reduces economical and availability repercussions associated with synthetic methionine. The study reveals that it is safer and wiser to use to herbal sources owing to their health benefits, better carcass traits and economic production. The study needs to be confirmed on larger scale and in varied environments.
The authors gratefully acknowledge and appreciate the support from Head, Division of Livestock Production & Management, and Nutricare Life Sciences Saharanpur for conducting this research work.