GROWTH PERFORMANCE AND MORPHOLOGY OF IN 28-84 DAY-OLD VIETNAMESE LOCAL NOI CHICKEN

: Noi chicken is one of the most popular native breeds in the South of Vietnam because their good meat quality and disease resistance. Therefore, although price of their products (eggs and meat) is always high, they are always preferred. However, there have not been many studies on the morphology of this breed yet. In the current study, a total of 355 Noi chickens (164 males and 191 females) at 28 days old were selected and randomly allotted to individual cages until they reached the market weight at 84 days old. During the experiment, Noi broilers were fed ad libitum a diet with 17% crude protein and 3.000 kcal/kg ME produced by GreenFeed Vietnam Joint Stock Company. Average daily gain, feed conversion ratio and some morphological dimensions were recorded at two different stages of age (28-56 and 56-84 days old). Results were demonstrated that (i) significant differences in feed intake (P=0.006), body weight (P=0.019), beak length (P=0.014), thigh length (P=0.004), shank length (P=0.003), breast diameter (P=0.000), and thigh diameter (P=0.001) were found between males and females as well as between different stages; and (ii) body weight and some dimensions will increase rapidly at the first stage. An understanding on these economic traits helps researchers and producers have a more detailed glance on developing of each part of Noi chicken at different stages of age which they are the basic scientific foundation for further studies on this breed.


Introduction
Chicken industry in Vietnam has been developing rapidly and strongly in recent years. Many poultry companies have exported commercial chicken meat and eggs to China, Cambodia, Japan market, etc. However, similar to other countries owing native breeds, Vietnamese customers tend to choose the products of these breeds because of their specific quality (taste, flavor, toughness, stiffness, sweetness, etc.).
Noi is known as one of the native chicken breeds who are easy to raise in different conditions of environment, micro-climate, nutrition, and nursing from rural to urban areas for improving farmers' income and meals quality as well as sometimes for fighting games. Noi chickens have strong tough muscles, good natural disease resistance and produce delicious meat. Thus, this breed is chosen as a potential genetic for the sustainable poultry production system in Vietnam. In earlier studies, (i) some performance characteristics (feather color, shank color, eyes color, beak color, comb color) and estimation of allele frequencies of 2 microsatellite markers in chromosome 7 (Linh, 2013), (ii) genetic association of some candidate genes with eggs performance (Vu and Ngu, 2016), (iii) effects of garlic on growth performance (Thuong, 2014), (iv) influence of different ME and CP levels on growth and laying rate (Quyen, 2008) in Noi chicken were investigated. Recently, Khoa et al. (2019) reported some quantitative genetic traits including body weight, average daily gain, feed intake, feed conversion ratio, and some dimensions in 0-28 day-old Noi chicken. Nowadays, with the increasing demand of domestic customers, Noi chicken breed needs to be studied in many ways/methods to produce high quality products. It is also the reason why this study was subsequently conducted and focused on some indicators of growth performance, feed conversion ratio and morphology, as a basic foundation for further studies on this breed.

Materials and methods
This study was conducted at the Can Tho Center for Breeds of Seed, Livestock and Fish, where it is cooperating with Can Tho University in many scientific research activities, located at O Mon district, Can Tho city, Vietnam.
A total of 355 Noi individuals (164 males and 191 females) at 28 days old were selected from a resource population of 1.200 birds investigated in previous studies (Vu and Ngu, 2016;Khoa et al., 2019). All they were kept in private cage with dimensions of 47cm length, 40cm front height, 38cm back height and 40cm width. Each cage had a separate feeder and drinker. Cages were put inside of the opened housing system. Whole flocks were fed ad libitum a diet containing 17% crude protein and 3.000 kcal ME (Table 1). During the experiment, multivitamins and beta-glucan were supplied some days at time points of stress (suddenly high temperature, vaccinating, catching, etc.). At the end of each month, body weight (BW, g/head), average daily gain (ADG, g/head/day), feed intake (FI, g/head/day), feed conversion ratio (FCR) as well as some parameters such as beak length (BL, mm), skull length (SL, mm), skull width (SW, mm), neck length (NL, mm), back length (BaL, mm), wings length (WL, mm), thigh length (TL, mm), shank length (ShL, mm), keel length (KL, mm), breast diameter (BD, mm), and thigh diameter (TD, mm) (FAO, 2012) Do Vo Anh Khoa et al. 304 were recorded and calculated. Increasing percentage (IP) of observed traits was calculated as below: the end of the month -Measurement at the beginning of the month x 100 Measurement at the beginning of the month Collected data were statistically analyzed by using R program (ver. 3.4.2). General Linear Model was applied to analyze effects of gender or old stage on observed traits.

Average daily gain, feed intake and feed conversion ratio
The obtained results revealed that (i) there was high significant difference in ADG, FI and FCR between males and females at each various stage of age (P=0.000) ( Table 2). It is easy to recognize that BW of males was always higher than that of females. This was probably due to much more feed consumption of males. However, males showed lower FCR than females. This was normal biological development in poultry production industry in which males were used economically to produce meat; (ii) significant difference between two stages was found for FI (P=0.006) ( Table 2). Feed consumption gradually increased in aging of broilers. Under intensive management condition in Northwest Ethiopia, ADG, FI and FCR of the native chicken breeds such as Tilili, Gellilia, Debre-Ellias, Mello-Hamusit, Gassay, Guangua, and Mecha from 35-56 days old were 8.8-11.5, 36.4-47.3, and 3.3-4.9, respectively. At 154 days old, they weighed 1,038-1,257 kg/head of BW although during the experiment they were offered a standard starter ration for a period of 56 days and then, a commercial grower ration for an additional period of 84 days ad libitum (Hassen et al., 2006). In another early study, at the stages of 0-  et al., 2002). It was clear that Noi chicken breed had advantages in terms of ADG and FCR compared with some native ones in the world but strategies for developing this breed has not been noticed and focused in national poultry breeding programs yet.

Body weight and morphology
Significant difference for BW and all dimensions were found between two sexes at various time points of age, in which male was always higher than the female for these observed traits (P<0.05) (Table 3). At 84 days old, BW of Noi broiler (female 1,196.71 and male 1,424.09) was higher than the Thai native one (1,156.05) (Jaturasitha et al., 2002), Chum Long Dau broiler (female 1,095.79 and male 1,298.50) (Thanh, 2012) and Ho chicken breed (female 1,124.51 and male 1,297.21) (Doan and Luu, 2006), but it was similar to Ninh Hoa Ri breed (female 1,195.65 and male 1,571.79) (Thinh et al., 2017) and Long Cam one (female 1,069.41 and male 1,440.34) (Mui et al., 2012). These evidence indirectly point to the advantages of carcass traits of Noi chicken and their potential for domestic poultry meat production industry in the future. Table 4  The measurement of weight and some dimensions on body helps us predict the development of muscle and skeleton, which they may be important data for setting up healthy diets and appropriate nursing modes to maximize genetic potential at different growing stages of Noi chickens.

Conclusion
It can included that growth rate and feed conversion ratio in Noi chicken were better that some other native chicken breeds in Vietnam and other countries. Furthermore, reasonable high nutritional diets as well as most appropriate nursing should be noted during the stage of 28-56 days old to maximize genetic potential for meat and skeleton traits in Noi chicken in the future.