Nutrient intake based on selection behavior of Nhan Chan Xanh chickens

Do Vo Anh Khoa^1,2, Nguyen Huy Tuong^3,4, Nguyen Tuyet Giang^5,6, Huynh Thi Phuong Loan⁴ and Takeshi Shimogiri⁷

¹ Thai Nguyen University of Agriculture and Forestry, Vietnam
² Animal Husbandry Association of Vietnam
³ Community College of Vinh Long, Vietnam
⁴ Can Tho University, Vietnam
⁵ An Giang University, An Giang, Vietnam
⁶ Vietnam National University Ho Chi Minh City, Vietnam
⁷ Kagoshima University, Japan
* Corresponding author: dvakhoa@gmail.com, Tel.: +84-918026653

Abstract

This study was conducted to assess the eating behavior of the Nhan Chan Xanh chickens from 7 to 16 weeks of age under the choice feeding system. A total of 240 Nhan Chan Xanh chickens (120 males and 120 females) at 5 weeks old were divided into 6 barns. Fourteen feedstuffs were used, including pellet feed, crumble feed, whole corn kernels, ground corn, paddy rice, polished rice, large broken rice, small broken rice, whole green bean grains, soybean meal, fish meal, elephant grass meal, large gravel particles and small gravel particles. All the feedstuffs were supplied in separate feeders. The results indicated that each broiler consumed 73.5-74.3 g daily and there was not a significant difference between sexes. Although complete feed (pellet and crumble) was supplied, chickens still consumed the other feedstuffs, indicating their ability to regulate the intake of ingredients according to their nutritional requirements and hobbies. Approximate intake of dry matter, crude protein, crude fat and crude fiber were around 64.8 g/day, 9.2 g/day, 1.8 g/day, and 3.1 g/day, respectively. Nhan Chan Xanh chickens can make good nutritional choices and pick out the amount of feed intake that they need to be healthy and productive. The present findings corroborate previous studies about the alimentary preference and capacity of birds to balance their intake to fulfil nutritional requirements.

Keywords: Nhan Chan Xanh chickens, choice feeding, behavior, nutrient intake

Introduction

Raising backyard chicken at small scale is one of the common jobs to increase income and improve the quality of daily meals for rural people in the Mekong Delta region of Vietnam (Lan Phuong et al 2015). Nhan Chan Xanh (NCX) with white feathers and green legs is one of the lines of the Noi breed which is a dual-purpose type reared for both meat and eggs. Similar to other indigenous birds, NCX chickens are commonly raised at households and well-adapted to conditions of intensive, semi-intensive and free-range systems, providing immediate cash and animal genetic preservation. In addition, they are also used in chicken fighting games (Do et al 2019a,b). Regarding nutritional aspects, the diet formulated to meet the requirement of chickens generally contains excessive levels of energy and protein for native chickens (Ramlah et al 1994). Not only NCX chickens but also the other domestic birds can regulate their nutrient intake when they are allowed to select between feedstuff containing high and low nutrient values (Pousga et al 2005). Hence, choice feeding regime provides economic advantages by effectively reducing feed costs (Iskandar 2008; Fanatico et al 2013). However, to varying extents, it also generates improvements in energy utilization and feed efficiency (Liu et al 2015).

A choice feeding, or cafeteria method, allows the birds to formulate their diet from select from various feedstuffs, such as whole or ground grains (Rutkowski and Wiqz 2001; Moss et al 2017), protein concentrates (Fanatico et al 2016), energy or protein sources (Cruz et al 2005; Şahin et al 2006), from which they can adjust their nutrient intake suited to different dietary requirement (Syafwan et al 2011). Using free-choice feeding, nutritionists may predict the nutrient requirements of the birds as it accommodates their needs of different breeds, under different conditions (Henuk and Dingle, 2002; Syafwan et al 2012). When provided a clear choice, the birds will learn which feeders to go to and how much to consume to satisfy their basic nutritional needs and could substantially reduce the cost of feed. Some choices may not be clear enough to the birds, such as wheat and peas. Both grains are high in starch and have moderate levels of protein and when supplied in separate feeders they may not provide a nutritional difference enough for the chickens (Simeneh 2019). Diet selection has value in understanding the specific requirements of the birds, and this could be used to recommend diet specifications (Sinuart and Balnave, 1986; Syafwan et al 2012). Therefore, it is necessary to investigate the ways the birds select compound feed with raw materials in a free-choice feeding system. The present study aimed to determine dietary selectivity of NCX broilers when different feedstuffs are available.

Materials and methods

The experiment was conducted from July 2018 to March 2019 at the Can Tho Center for Agricultural Service (formerly Can Tho Center for Breeds of Seed, Livestock and Fish). A total of 240 NCX broilers (120 males and 120 females) were fed on a commercial feed (3.000 Kcal ME and 21% CP) until 20 days of age and from 21-28 days old they were given by paddy rice. Paddy rice is the common source of feed for backyard chickens in households in the Mekong Delta region, while industrial feed has recently been used to increase productivity, improve health and reduce mortality in the early stages of age after hatching. Then, on the day 29^th, chickens (439g±16.7 in body weight) were randomly divided into 6 barns (40 male or female broilers in each barn) which dimensions were 8m in length, 6m in width and 4m in height, corresponding to the farming density of 1.2 m²/head. The floor was covered with a rice husk layer of 20cm thick. Containers for feed and drink were placed outside the barns to make an easy preference for feed selection.

A total of 14 feedstuffs was used in the experiment, including pellet feed, crumble feed, whole corn kernels, ground corn, paddy rice, polished rice, large broken rice, small broken rice, whole green bean grains, soybean meal, fish meal, elephant grass meal, large gravel particles and small gravel particles. The large and small broken rice comprised of kernels which 50-75% of the size of the whole kernel and less than 25% of the size of the kernel, respectively, as described by Dhankhar (2014). All the feedstuff were obtained locally and their proximate compositions were shown in Table 1. The feed items were contained in separate cups. The amount of feed offered and leftovers in each feeder was recorded daily until the end of the experiment to calculate the amount of feed intake in and the amount of nutrient intake (dry matter, crude protein, crude fat and crude fiber) in 14 days. Chickens were weighed fortnightly to calculate growth parameters, expressed as average daily gain (ADG) and feed conversion ratio (FCR). During the experiment, all chickens were free accessed to feed and water. They were also vaccinated as recommended by the Can Tho Department for Animal Husbandry and Veterinary Medicine. Statistical analyses were performed using Minitab software (version 16.0). The data were subjected to one-way analyses of variance for completely randomized design and tested for significance between the means by Fisher’s least significant difference at P≤0.05.

Results and discussion

Table 2 shows the means for feed intake in NCX chickens up to 16 weeks of age. When offered free-choice feeding, male and female chickens consumed 73.5-74.3 gam feed per bird daily, and there was not a significant difference (P>0.05) between sexes. However, the amount of feed intake varied due to the age period and interaction between sex and age (P<0.05). Intake was lowest in 7-8 weeks of age (60.1 g /day), then increased and got the highest value in 15-16 weeks of age (89.9 g/day). The male NCX chicken consumed higher amounts of pellet feed (the complete diet) but lower amounts in paddy rice, grass meal, large and small gravel particles compared to the female chickens. The total intake observed in the present study is in agreement with the results obtained by Do et al. (2019b), who evaluate the growth performance and morphology of Vietnamese local Noi chicken in the 28-84 day-old period. However, chickens fed the complete diet presented significantly higher feed intake compared to the chickens in the free choice system (Cruz et al 2005).

Regarding separate feedstuffs, pellet feed was most preferable because of its tasty and flavor, followed by crumble feed, broken rice, paddy rice, ground corn and other ingredients. However, the amount of feed intake has been changed by time. For example, chickens consumed more pellet feed at 7-8-week-old period, and then steadily reduced (21.9-16.2 g/day). The intake of corn kernels, ground corn, paddy rice, polished rice, large and small broken rice, and green bean grains increased by time and reached the highest values at15-16-week-old period. Grass meal, as well as large and small gravel particles, provided the smallest intakes, probably because of the lower values in nutritional content. Although chickens were given various feedstuffs, including commercial feed, they still ate gravel. Interestingly, female birds consumed more gravel compared to males. According to Singh and Cowieson (2013), free-ranged chickens eat gravel because they are lack of teeth. The presence of gravel in the gizzard helps to mash up the feed and ease digestion. Also, the retention of gravel particles may be used to increase the input of calcium to form the eggshells of the hens. Rose and Kyriazakis (1991) found that chickens were able to select a diet from nine ingredients that provided a nutrient intake similar to the requirements announced by NRC (National Research Council, 1994).

The chickens consumed more cereal grains (whole and ground corn, paddy rice and rice polishing products) compared to the protein feedstuffs (green bean, soybean meal and fish meal). Siegel et al (1997) also found that when given a choice, broiler chickens tend to have a preference for high energy diets and, therefore they grow slower than control fed birds. It was suggested that birds do not select a diet to maximize growth in the short term but perhaps for long-term survival with moderate growth. Comparing the intakes between the whole and ground grains of rice and corn, it showed that the chickens preferred the polished rice compared to broken rice. However, they consumed fewer corn kernels than the ground corn, as evident in Table 2. According to Rutkowski and Wiqz (2001), in the proper diet for chicken, grains are normally ground to well incorporate with other ingredients in the mixture and improve the digestibility. However, the cost of the feed is increased by 20% due to the energy used for the milling process.

From Table 2, it was shown that feed intake increased with ageing. This is particularly evident from Table 3 to Table 6 where intakes of nutrients such as dry matter, crude protein, crude fat and crude fiber, respectively, also increased due to ageing. Approximate intake of dry matter, crude protein, crude fat and crude fiber were around 64.8 g/day, 9.2 g/day, 1.8 g/day, and 3.1 g/day, respectively. As shown in these Tables, it is suggested that at older ages, birds may have a higher demand for most of the nutrients needed, particularly for protein synthesis. Results in Table 4 showed that the birds consume more soybean meal and fish meal than whole green bean grain. The reason for this preference for soybean meal and fish meal is not obvious because feed selection is influenced by several factors, such as age or stage of production, nutrient requirements of individual birds, nutritive value, physical and chemical properties of the feedstuff (Hossain et al 2014). In addition, sensory properties of the materials, such as color, taste, smell, flavor, or even birds’ palatability might also play a crucial role in feed selection of broiler chickens (Pousga et al. 2005). Moss et al (2018), using Ross 308, a fast-growing broiler strain, found a preference for the high-protein diets over whole grain. Gous and Swatson (2000) also found that broilers can select between diets differing in protein content to adjust the protein intake for optimal growth. According to Şahin (2003), choice fed-broiler chickens ate less protein compared to that of control chickens consuming a conventional commercial diet.

Tables 3 and 4 show the daily means for dry matter and crude protein intakes, respectively. An effect of age, as well as interaction between sex and age, were found in both Tables (P<0.05). A similar trend was found in Table 6 for the crude fiber intake (P<0.05). In contrast, regardless of age (P>0.05), sex and interaction between sex and age caused the difference in the crude fat intake (Table 5).

Despite the high content in the crude fiber of paddy rice (15.2%) due to the husk fraction, the chickens still consume this feedstuff. The intake of paddy rice was higher than whole corn kernels and ground corn, as shown in Table 2. The crude fiber intake of paddy rice was consequently higher than other ingredients, ranked third, just after the intakes of pellet and crumble feed. This preference was probably due to the habit in which chicks were familiar with paddy rice since 21days old.

Table 7 shows the means for body weight, average daily gain (ADG), and feed conversion ratio (FCR), in Nhan Chan Xanh chickens up to 16 weeks of age. There were differences (P<0.05) among the categories of bird sex and age for all variables, except the ADG. The interaction of sex and age did not influence these traits (P>0.05). Bodyweight of males was higher than that of females and showed lower FCR than females. The result of FCR observed in the study higher than that reported by Do et al. (2019b) in Noi chickens, from 28 to 84 days old, probably due to different diet supplied. However, a similar result has been reported in local chickens supplied protein-rich forages (duckweed, water spinach and taro leaves) in cafeteria trials (Saroeun et al 2010).

Conclusion

It was concluded that NCX chickens had the ability in selecting a balanced diet required to support their potential production. The intake of these ingredients was significantly altered as a function of the feeding systems. Although complete broiler chicken feed (pellet and crumble) was supplied, chickens still consumed the other feedstuffs, indicating their ability to regulate the intake of ingredients according to their nutritional requirements and hobbies. This current study should be used by poultry nutritionists to improve new feeding systems and reduce feeding cost for native chickens.

Acknowledgement

This study is funded in part by the Can Tho University Improvement Project VN14-P6, supported by a Japanese ODA loan.

References

Cruz V C, Pezzato A C, Pinheiro D F, Gonçalves J C, and Sartori J R 2005 Effect of free-choice feeding on the performance and ileal digestibility of nutrients in broilers. Brazilian Journal of Poultry Science, 7: 143-150.

Dhankhar P 2014 Rice milling. IOSR Journal of Engineering, 4: 34-42.

Do V A K, Nguyen T H T, Nguyen T N, Nguyen T D T, Okamoto S, Kawabe K, and Shimogigri T 2019a Some quantitative genetic traits in Vietnamese indigenous Noi chicken from 0 to 28 days old. Biotechnology in Animal Husbandry, 35: 141-151.

Do V A K, Nguyen T H T, Nguyen T D T, Okamoto S, Kawabe K, Nguyen T K K, Nguyen T G, and Shimogigri T 2019b Growth performance and morphology of in 28-84 day-old Vietnamese local Noi chicken. Biotechnology in Animal Husbandry, 35: 301-310.

Fanatico A C, Brewer V B, Owens-Hanning C M, Donoghue D J, and Donoghue A M 2013 Free-choice feeding of free-range meat chickens. Journal of Applied Poultry Research, 22: 750-758.

Fanatico A C, Owens-Hanning C M, Gunsaulis V B, and Donoghue A M 2016 Choice feeding of protein concentrate and grain to organic meat chickens. Journal of Applied Poultry Research, 25: 156-164.

Gous R M and Swatson H K 2000 Mixture experiments: a severe test of the ability of a broiler chicken to make the right choice. British Poultry Science, 41:136–-140.

Henuk Y L and Dingle J G 2002 Practical and economic advantages of choice feeding systems for laying poultry. World's Poultry Science Journal, 58: 199-208.

Hossain M A, Islam A F, and Iji P A 2014 Effect of production phase on growth, enzyme activities and feed selection of broilers raised on vegetable protein diet. Asian-Australasian Journal of Animal Sciences, 27: 1593-1599.

Iskandar S 2008 Laying performance of wareng chicken under free choice feeding and different cage density. Media Peternakan, 2011: 58-63.

Lan Phuong T N, Dong Xuan K D T, and Szalay I 2015 Traditions and local use of native Vietnamese chicken breeds in sustainable rural farming. World's Poultry Science Journal, 71: 385-396.

Liu S Y, Truong H H, and Selle P H 2015 Whole-grain feeding for chicken-meat production: possible mechanisms driving enhanced energy utilization and feed conversion. Animal Production Science, 55: 559-572.

Moss A F, Chrystal P V, Truong H H, Selle P H, and Liu S Y 2017 Evaluation of ground grain versus pre- and postpellet whole grain additions to poultry diets via a response surface design. British Poultry Science, 58: 718-728.

Moss A F, Truong H H, Liu S Y, and Selle P H 2018 Inclusion levels and modes of whole grain incorporation into wheat-based rations differentially influence the performance of broiler chickens. British Poultry Science, 59: 110-120.

National Research Council 1994 Nutrient requirements of poultry. 9^th ed. rev. Washington (DC): National Academy Press, p.155.

Pousga S, Boly H, and Ogle B 2005 Choice feeding of poultry: a review. Livestock Research for Rural Development, 17 (4).

Ramlah A, Mohd-Husni H, and Sarinah A 1994 Effects of choice feeding on the performance of village chicken after the peak of egg production. Asian-Australasian Journal of Animal Sciences, 7: 317-320.

Rose S P and Kyriazakis I 1991 Diet selection of pigs and poultry. Proceedings of the Nutrition Society, 50: 87-98.

Rutkowski A and Wiqz M 2001 Effect of feeding whole or ground wheat grain on the weight of the gizzard and pH of digesta in broiler chickens. Journal of Animal and Feed Sciences, 10: 285-289.

Şahin A 2003 Cereals in choice feeding of finishing broiler chickens. Journal of Applied Animal Research, 24: 213-217.

Şahin A, Duru M, Kaya Ş, and Camci Ö 2006 Effects of raw material in finisher diet on broiler performance in choice feeding system. Archiv fur Geflugelkunde, 70: 8-13.

Saroeun K, Ogle B, Preston T R, and Borin K 2010 Feed selection and growth performance of local chickens offered different carbohydrate sources in fresh and dried form supplemented with protein-rich forages. Livestock Research for Rural Development 22 (12).

Siegel P B, Picard M, Nir I, Dunnington, E A, Willemsen M H A, and Williams P E V 1997 Responses of meat-type chickens to choice feeding of diets differing in protein and energy from hatch to market weight. Poultry Science, 76: 1183-1192.

Simeneh G 2019 Review on the effect of feed and feeding on chicken performance. Animal Husbandry, Dairy and Veterinary Science, 3: 1-4.

Singh M and Cowieson A J 2013 Range use and pasture consumption in free-range poultry production. Animal Production Science, 53: 1202-1208.

Sinurat A P and Balnave D 1986 Free-choice feeding of broilers at high temperature. British Poultry Science, 27: 577-584.

Syafwan S, Kwakkel R P, and Verstegen M W A 2011 Heat stress and feeding strategies in meat-type chickens. World's Poultry Science Journal, 67: 653-674.

Syafwan S, Wermink G J D, Kwakkel R P, Verstegen M W A 2012 Dietary self-selection by broilers at normal and high temperature changes feed intake behavior, nutrient intake, and performance. Poultry Science, 91: 537-549.

Received 18 April 2020; Accepted 20 April 2020; Published 1 June 2020

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