Nutrient Utilization in Mewari Chicks Fed Different Levels of Metabolizable Energy under Intensive System

Introduction

Poultry farming is a major and profitable industry, offering job opportunities to many people. It encompasses the raising of chickens, quails, ducks, geese, and turkeys by humans for their eggs, meat, and feathers. The poultry sector includes activities such as breeding, hatching, raising, and processing these domesticated birds. India ranks 7 th in the world poultry population at 851.81 million of which 534.74 million numbers in commercial poultry and 317.07 million number in backyard poultry, (BAHS, 2024). Backyard poultry farming is a traditional and profitable practice in India, contributing about 15% to the country's total poultry output. In Southern Rajasthan, the indigenous Mewari chicken is commonly reared in backyard systems. The home tract of Mewari breed is Udaipur, Bhilwara, Dungarpur, Banswara, Rajasamand and Pratapgarh District of Rajasthan. However, with an average annual egg production of 37-52 eggs and age at first egg ranging from 6 to 7.5 months, its productivity remains low (Mishra et al., 2022) [7] . Energy plays a vital role in the nutrition of indigenous layer chicks, directly impacting their early growth, health, and future egg-laying ability. Unlike fast-growing commercial breeds, indigenous chicks tend to grow more slowly and are well-suited to local climates, which influences their specific dietary needs. An appropriate level of metabolizable energy (ME) in their feed is important during the initial stages to ensure proper body development, immune strength, and internal organ growth. If the energy level is too low, it can result in stunted growth, late onset of laying, and lower productivity. On the other hand, too much energy may lead to excessive fat accumulation and inefficient feed use. Hence, it is important to provide a diet that maintains the right balance between energy and protein to promote healthy development and optimal performance in indigenous layer birds.

Adjusting dietary energy levels according to the bird's age, production phase and environmental conditions is critical for optimizing productivity and maintaining bird health (Lesson and Summers, 2005). In case of poultry group feeding is done so the nutrient requirement is expressed in terms of percent or per kg of ration, the CP requirement is expressed as CP% and energy expressed as ME kcal/kg of ration. The information with respect to metabolizable energy in the diet of Mewari chicks is not available. The present research paper is the part of feeding trial to study the energy requirement of Mewari chicks and a metabolism trial was conducted to study nutrient utilization.

Materials and Methods

Experimental birds and diets

Five hundred ten mixed sex day old Mewari chicks were randomly allocated to five dietary treatments in six replicates of 17 chicks each. Five iso-nitrogenous diets containing metabolizable energy at 2600 (T1), 2700 (T2), 2800 (T3), 2900 (T4) and 3000 (T5) kcal per kg were formulated and fed to the chicks for the entire experimental period of 8 weeks. The experimental diets comprised of Maize, Soybean deoiled cake, De-oiled rice bran (DORB), Rice bran oil, Dicalcium Phosphate and Vitamin mineral premix, the detailed ingredient and nutrient composition of experimental diets used for feeding of chicks is presented in Table-1. The chicks were fed as per recommendation of BIS (2007) feeding standard to meet energy and protein requirements during chick stage for the entire experimental period. The birds were reared deep litter in cages of 5 x 3 x 2.5 ft dimensions of each replicate. Standard brooding management practices and vaccination schedule were followed, for the first two weeks, chicks were fed using feed trays and thereafter chick feeders were used for feeding. Free choice clean and fresh drinking water was made available to all experimental birds for the entire duration of the experiment.

Observations

Metabolic trial

At the end of feeding trial, after 8 th week, a metabolic trial was conducted. Six birds from each treatment were randomly selected and shifted into metabolic cage. There was arrangement for measured quality of feed and collection of faeces in the metabolic energy free choose water was available through nipple dripper. The birds were individually fed with experimental treatment diet. The birds were given an adaptation period followed by 3 days collection of excreta. The quantity of excreta voided by individual treatment bird was collected and weighed quantitatively after every 24 hours and representative feed sample were collected and similarly aliquot of faecal samples were also processed for proximate principle in the feed and faeces as per AOAC, 2005. The digestibility of nutrients was calculated using the following formula.

Statistical Analysis

The observations recorded during the experiment were statistically analyzed by using standard procedure for analysis of variance of CRD (Completely Randomized Design) as suggested by Snedecor and Cochran (1994).

Results and Discussion

All dietary treatments were isonitrogenous with crude protein ranged from 20.04 to 20.22 per cent. However, the calculated metabolizable energy were 2616, 2712, 2810, 2906 and 3003 kcal per kg diet. All other nutrients in experimental diets were in normal range across all the dietary treatment groups (Table -1). The nutrient intake, digestible nutrient intake and digestibility coefficients are presented in Table 2 and Fig. 1.

The intake and digestible intakes of nutrients viz DM, CP, EE, CF and NFE was significantly (P<0.01) higher in T1, T2 and T3 compared to T4 and T5 except DMI was found to be lowest in T1. The significantly higher (P<0.01) in T 1 and T 2 group as compare to T 4 , T 5 values observed in T 3 and T 4 didn't differ with T 1 , T 2 and T 5 groups, respectively. The ether extract intake was significantly higher (P<0.01) in groups T 1 , T 2 and T 5 , with no significant difference among them, while T 3 and T 4 showed significantly lower intake. The result revealed was significantly (P<0.01) higher in T 1 group. Crude fiber intake was significantly (P<0.01) higher in T 1 , followed by T 2 and T 3 group. T1 showed the highest digestible CF intake followed by T3 and lowest in T4 and T5 groups. Nitrogen-free extract intake was significantly higher in T [4,10] , who reported improved dry matter digestibility in similar energy levels as reported in the present study. Significantly (P<0.01) highest (82.46%), CP digestibility was observed at moderate ME levels (2800 kcal) in present study which corroborates the results of Feitosa et al. (2023) [4] , who observed improved CP digestibility with nutrient-balanced high ME diets.

International Journal of Agriculture and Food Science https://www.agriculturaljournals.com EE intake and digestibility were higher in T 1 and T 3 , consistent with Hernandez et al. (2024) [5] . CF intake and digestibility declined at higher ME levels, likely due to reduced fiber utilization, supporting energy-fiber interaction effects. NFE digestibility and nitrogen balance were highest in T 1 and T 2 . Higher ME diets led to lower values, suggesting decreased carbohydrate and nitrogen utilization, as also noted by Yang et al. (2020) [4] . Nitrogen intake was not significantly affected by treatments. However, nitrogen balance was significantly (P<0.01) higher in T 1 and T 2 followed by T 3 , while T 4 and T 5 had the lowest values. This indicates better protein utilization in diets with 2800 kcal ME/kg.

Conclusion

It may be inferred from present study that diets containing 2800 kcal ME/kg energy and 20% crude protein found to be optimal for maximizing nutrient efficiency.

References

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2. Government of India. Basic Animal Husbandry Statistics 2024. New Delhi: Ministry of Fisheries, Animal Husbandry and Dairying, Department of Animal Husbandry and Dairying, Krishi Bhawan; 2024.
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