Comparative analysis of early growth phase performance in F3 crossbred Indonesian chickens

Body mass and ratio of feed conversion (FCR) are crucial factors for assessing production potential in local chickens. This study utilized a total of 116 F3 crossbred chickens resulting from the mating of Indonesian local chicken breeds, including Kampung Unggul Balitbangtan, Murung Panggang, Merawang Bangka, and Merawang Sembawa. The chickens were divided into six crossbred groups: BS1 (n = 19), BS2 (n = 19), BS3 (n = 20), BS4 (n = 19), BS5 (n = 20), and BS6 (n = 19), all managed under uniform conditions. Measurements of body mass and feed consumption during the pre-starter phase were taken at weeks 0, 1, 2, 3 and 4 using a digital scale. Data from this study were subjected to ANOVA analysis, followed by a Duncan multiple range test The findings showed notable variations in body mass and FCR among all BS chicken groups (P < 0.05). Notably, BS5 exhibited the highest performance in both body mass and FCR analyses, achieving 392.50 ± 42.76g at week 4, and an overall FCR of 2.01 ± 0.80.


Introduction
The demand for food, particularly animal protein, in Indonesia, has been on the rise due to population growth, increased purchasing power, and a growing awareness of the importance of nutrition for a healthy lifestyle [1].One strategy to enhance livestock potential and ensure food security is crossbreeding [18].Currently, local Indonesian chicken breeds require further exploration to unlock untapped advantages, thereby obtaining high-quality breeding stock that can improve efficiency and production, providing more opportunities [2].
Murung Panggang chickens, Merawang chickens, and Kampung Unggul Balitbangtan (KUB) chickens are indigenous Indonesian chicken breeds that can be developed through genetic manipulation.Murung Panggang chickens are known for their productivity in meat and egg production, low Ratio of IOP Publishing doi:10.1088/1755-1315/1317/1/012014 2 feed conversion (FCR), disease resistance, and an impressive egg hatchability rate of over 75%.Additionally, they exhibit a unique trait of not going broody [3][6] [10].KUB chickens, on the other hand, possess the advantage of rapid re-laying, faster growth compared to ordinary native chickens, and tastier meat [4][6] [10].In contrast, Merawang chickens share similar characteristics with Murung Panggang, including disease resistance and a non-brooding nature [2].Combining these three types of chickens aims to produce new breeds that grow quickly, consume less feed, and are disease resistant without compromising the taste of the meat, which has become a characteristic of the parent chickens.
It is essential to recognize that the early growth phase of chickens plays a crucial role in their subsequent development [8].This phase sets the foundation for their overall growth and productivity [13,19].Recognizing the significant potential of these local chicken breeds, our research aims to evaluate their performance during the pre-starter phase by measuring parameters such as body mass, the intake and conversion ratio of feed for crossbreed chickens.

Data Gathering Methodology
The methodology of this study was based on 116 crossbred chickens, referred to as "BS chickens" or "Bulaksumur chickens" which were created through a breeding program involving Merawang Sembawa, Merawang Bangka, Murung Panggang (males), and KUB (females).BS chickens are F1 chickens which are the result of crossing various local chickens, then mating them using the inter se method to produce F2 offspring.The F2 chickens were bred again using the inter se method to produce F3 offspring which were used as samples for the current research.The KUB category comprised KUB 1 and KUB 2. KUB or Kampung Unggul Balitbangtan is one of the chicken lines developed by the West Java Province Agricultural Research and Development Center from breeding free-range chickens (Gallus-gallus domesticus).KUB 1 chickens were developed to produce high-quality chicken meat with a high protein content, whereas KUB 2 chickens were developed to produce high-quality, free-range chicken eggs.The research encompassed six distinct groups of BS chickens, denoted as BS1, BS2, BS3, BS4, BS5, and BS6.For a detailed illustration of the breeding patterns, please refer to Figure 1.
All BS chickens were randomly selected and received uniform management protocols.This included morning and evening feedings with PAR-S crumble commercial feed, consists of 12% water content, 8% ash content, 19% crude protein, 3% crude fat, and 7% crude fiber.Access to ad libitum drinking water enriched with Vitachicks to minimize stress with a 5 gram dose per 7 liters of drinking water, and housing within brooding cages to keep the chicken warm so that it can grow and develop properly.The study's variables of interest included body mass, average weekly growth in weight, amount of feed consumed, and ratio of feed conversion throughout weeks 0 to 4.
To obtain body mass measurements and determine remaining feed quantities, digital scales were utilized.Weekly feed intake (measured in grams per chicken per week) was calculated by subtracting the amount of feed provided from the remaining feed at the end of each week.The ratio of feed conversion was computed by comparing feed consumption to the increase in body mass.Body mass gain (measured in grams per chicken per week) was determined by subtracting the average body mass per chicken at the end of the week from the previous week's average.

Data Analysis
To ascertain the performance differences between BS group of chickens, the collected data were statistically analyzed using ANOVA and then Duncan's multiple range test.The ANOVA (Analysis of Variance) method is used to compare the means of two or more groups.If the ANOVA results show that there are significant differences between the groups, additional tests such as the Duncan's Multiple Range Test (DMRT) can be used to determine which pairs of groups have significant differences and provide more detailed information about the differences between the groups.

Results and Discussion
Body mass of all BS always increases every week.Based on body mass measurements of BS chicken, obtained the average body mass of chickens aged 1-4 weeks as showed in Table 1.According to the study's findings, at one week of age, there were no significant differences (P > 0.05) between any of the groups.Nonetheless, notable distinctions were noted between the different BS groups at weeks 2, 3, and 4 (P < 0.05).Notably, BS3 consistently exhibited superior body mass performance across all age groups.At the end of the pre-starter phase, BS5's body mass was superior.It is essential to emphasize that variations in body mass growth performance are primarily influenced by genetic traits [6,8,11,13].Furthermore, it is worth noting that environmental factors, as well as feed and maintenance management, did not significantly impact the differences in body mass performance [7,17].This is attributed to the equalization of these three factors among all BS chickens in this research.A statistically significant difference (P < 0.05) was ascertained displayed in Table 2.In the first week, BS6 displayed the highest weight gain performance.Between weeks 1 and 2, BS5 outperformed BS3 in terms of weight gain.As the pre-starter phase showed, BS5 once again exhibited the most remarkable performance, achieving an average of 153.25 ± 6.08 grams per chicken per week.BS5 can be considered a reliable choice for achieving rapid weight gain targets, especially during the pre-starter phase.Chick feed consumption will increase during growth and age according to needs [8,9].In the aspect of feed consumption, between each of the BS groups, there were significant differences (P < 0.05).For 3 consecutive weeks, BS4 had the most wasteful feed consumption characteristics among all BS chickens, with total consumption reaching 643.25 ± 16.63 g/chicken/3 weeks, but BS4 were superior in weeks 3-4.Meanwhile, BS1 and BS5 were superior during weeks 0-1 and BS1 was superior during weeks 2-3.For weeks 1-2, the most economical feed consumption is achieved by BS2.Overall, BS3 is economical in terms of feed consumption.The results of the average ratio of feed conversion over a span of 4 weeks showed that BS5 chickens exhibited the best performance, with a value of 2.01 ± 0.80.(P < 0.05) indicated a significant difference in this value compared to the other BS groups.In contrast, BS4 demonstrated the poorest feed efficiency during the pre-starter phase, with a notably high value of 3.23 ± 0.80.The irregular increase in ratio of feed conversion in the case of BS4 was attributed to two main factors.First, it was influenced by the behavior of chickens in the growth period or pre-starter phase, as described by [5,14], who tend to select and scavenge granular feed.This behavior often results in feed spillage and its mixing with litter, leading to wasted feed and an overestimation of feed consumption.BS4 is characterized by rapid movement and a high pecking activity, which causes food to splatter and mix with feces.To increase efficiency, an extension between the feed bin and the litter bin could be added to accommodate fallen feed.Second, it was found that the genetic characteristics of BS4 played a significant role, as these chickens exhibited slower growth and a tendency to consume feed less efficiently [20,21].This characteristic is evident in the relatively consistent feed conversion values observed from week to week, reflecting their suboptimal feed utilization [12,15].Other studies, such as [7,16], also reported similar irregularities in FCR during the pre-starter phase, primarily due to the behavior of the chickens at this developmental stage.

Conclusion
Merawang Bangka and KUB 2 crossbreeding produces BS5, a dependable choice for rapid weight gain and low maintenance costs.During the early growth phase, this chicken consumes the least amount of feed while delivering commendable body mass performance.To achieve the best results, additional research on growth in subsequent phases is required, as well as a more specific comparative analysis between males and females.

Table 3 .
Average weekly feed consumption of BS chickens aged 0-4 weeks (g/chicken/week) a, b, c Various superscripts revealed notably different (P < 0.05)