Growth performance, meat yield and blood lipid profile of broiler and Sonali chickens

Highlights • Comparative growth, meat yield and lipid profiles of broiler and Sonali chickens were investigated.• Broiler chickens performed better than Sonali chickens in terms of growth and meat yield traits.• Sonali chicken tended to reduce serum cholesterol and increase net profit (p>0.05).• Sonali chicken was superior to broiler in terms of preference, net profit and serum cholesterol content.


Introduction
Chicken meat is one of the cheapest and most available sources of animal protein, preferred by all classes of people irrespective of religion and age. Poultry farming provides meat and egg essential for humans (Regar et al., 2019). Poultry contributes about 22-27% of the total animal protein from different animal sources (Islam et al., 2019). Poultry is the most important and emerging sector of Agriculture in Bangladesh. Over the years, the demand for poultry products (meat and eggs) in Bangladesh has grown significantly; the consumption (per capita per year) of poultry meat and egg in 2019 was 8.5 kg and 104 pieces, respectively. However, to meet the growing domestic demand for meat and eggs, there is a need to increase poultry production (EKNB, 2020).
As per the Department of Livestock Services (DLS) report (2020), the total poultry population of Bangladesh is about 356.318 million of which chickens are 296.602 million. An adult person needs 120 g of meat per day and 104 eggs annually. Therefore, the availability of meat (g/day/person) and egg (per person per year) is 126.20 and 104.23, respectively. The annual meat and egg production in Bangladesh is 7.67 million metric tons and 17,364.30 million, respectively which can satisfy the requirement of the people (DLS, 2020). The poultry industry is growing rapidly and contributes 1.5-1.6 percent to the country's GDP, involving at least 6.0 million people in this sector (Karmoker, 2022). In the poultry sector, broiler meat is produced within the shortest possible period with a minimum investment having maximum profit (Whitehead, 2002).
Poultry meat and eggs are easily digestible and minimize the risks of blood pressure, heart diseases, and prevent cancer in human beings (Mazmanyan, 2021). Broiler meat is very popular with consumers regardless of age and religion because of its availability, digestibility, and lower price. It is also advantageous because of its rapid growth, better feed conversion efficiency, and meat quality, especially for breast meat or lean meat (Amin et al., 2013).
Sonali is a crossbred of Rhode Island Red (RIR) x Fayoumi with a phenotypic appearance similar to a local chicken called 'Sonali' are well adapted to tropical climates that require less care and attention to rear compared with broiler chickens (Saleque & Saha, 2013). At present, Sonali provides about 30% of the total required chicken meat in Bangladesh (Huque et al., 2011). Consumers prefer Sonali chicken meat over regular broiler meat and it looks like indigenous chicken meat. In 2018, the percentage of preference for Sonali chicken and around 20% of total poultry meat reached 23% in 2019 (EKNB, 2020).
Although Sonali crossbred is popular with the farmers but the problem is a slower growth rate. It takes more than 60 days to get a marketable live weight (1.00 kg). The rearing of Sonali birds is more profitable than commercial broilers. Practically it has been found that farmers earned more returns from Sonali chicken farming than from commercial broiler farming. Because of the higher prices of Sonali birds compared to the commercial broilers (Azharul et al., 2005;Jahan et al., 2021). In addition, the price fluctuation of Sonali chickens is lesser than commercial broilers, because consumers prefer Sonali chickens to broilers (Uddin et al., 2015). Nowadays, consumers are so conscious of the carcass quality and lipid profile content of the bird (Jahan et al., 2015). In the case of a broiler, fat is deposited into the abdomen which deteriorates the meat quality and increases the cholesterol level in the meat which is so harmful to the body of human beings (Tohala, 2010). On the other hand, Sonali chickens have no abdominal fat which is why Sonali chickens produce quality meat. Therefore, consumers prefer Sonali chicken meat more than broiler chicken meat.
Considering the above points, the present study was planned to assess the growth performance, meat yield, and lipid profiles of broiler and Sonali chickens to identify a potential chicken type for producing quality, preferable and cost-effective chicken meat.

Experimental site
The experiment was carried out at different commercial broiler and Sonali chicken farms located at Subarnachar Upazila, Noakhali district, and the laboratory of the Department of Dairy and Poultry Science, Faculty of Veterinary Medicine and Animal Science, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh

Preparation of poultry house and diet
The house was prepared before receiving the day-old chicks in the house. The diets were prepared by 'Nahar Poultry Feed' and 'Teer Poultry Feed' Mill for broiler and Sonali chickens as per their requirements, respectively.

Feeding trial
A total of 14,200, day-old broiler chicks were allotted into two batches (B 1 = Winter and B 2 = Summer) with 6 replicates each for 30 days, and 16,000, day-old Sonali chicks were allotted into 2 batches with 4 replicates each for 60 days ( Table 1). The birds were reared on a littered floor management system. The broiler chicks were fed a starter diet containing 22% CP and 3035 Kcal ME/kg (1-10 days) and a finisher diet containing 21% CP and 3150 Kcal ME/kg (11-30 days) ( Table 2).
The Sonali chicks were fed a starter diet containing 19.50% CP and 2950 Kcal ME/kg (1-30 days) and a finisher diet containing 19.00% CP and 3000 Kcal ME/kg (31-60 days) ( Table 2). Clean and fresh water was provided ad-libitum to the birds during the experimental period. The standard management practices as per the standard of the breeder were provided to the birds during the investigation.

Data recording
The following data were recorded during the investigation.
a Growth performance i Body weight and feed intake: bi-weekly replication-wise.
ii Dead birds: when occurred. iii FCR (Feed intake/live weight) = Feed intake Live weight iv Production cost (Taka/kg live weight) was calculated considering the chick cost, feed cost, labor cost and vaccine cost, etc. v Net profit (Taka/kg live weight) = Price of per kg live birdproduction cost of per kg live bird. b Meat yield traits A total of 20 birds at the end of the experiment, 1 bird in each replicate were taken randomly and then slaughtered and processed (slaughtering, bleeding, scalding, de-feathering, evisceration, washing)  to make dressed/ready-to-cook carcass. Thereafter, the dressed carcass was processed as cut-up parts.
a Lipid profiles At the end of the experiment, blood samples were collected from the birds during slaughter. Thereafter, the serum of the blood was separated from the blood samples using a centrifuge machine (4000 rpm for 10 min). Then the lipid profiles (total cholesterol, triglyceride, HDL, and LDL) of the samples were measured using a lipid profiles kit (Crescent Diagnostic Lab) by spectrophotometric method.

Statistical analysis
The collected data were analyzed in 2 chicken type × 2 batch factorial design using the Statistix10 computer package program.

Statistical model
The following statistical model was used for the analysis of data.
Where Y ijk is the observation in the k th replication of the i th chicken type and the j th batch.
µ is the overall mean. S i is the fixed effect of the i th chicken type (i = 1, 2). B j is the fixed effect of the j th batch (j = 1, 2). (S × B) ij is the interaction effect of the i th chicken type and the j th batch. e ijk is the random error.

Growth performances of broiler and Sonali chickens
Body weight, feed intake, feed conversion ratio (FCR), and production cost differed significantly between chicken types (Table 3). Broiler chicken had a higher body weight and feed intake than Sonali chicken. On the other hand, broiler chicken had a lower FCR and production cost than Sonali chicken. Mortality did not differ (p>0.05) between broiler and Sonali chickens (p>0.05). Although there was no significant difference between broiler and Sonali chickens for net profit, Sonali chickens tended to show a higher net profit than the broiler chickens.
As for the effect of the batch, no significant difference was observed between broiler and Sonali chickens for body weight, feed intake, FCR, production cost, net profit, and mortality. Similarly, no significant difference was found in the interaction of chicken type and batch for the growth performances (p>0.05).
In this study, the broiler performed better than the Sonali chicken in terms of body weight, feed intake, FCR, and production cost. Khawaja et al. (2013) reported that the body weight gain and FCR of Rural Leghorn (RLH), Fayoumi Rhode Island Red crossbred (FRIR), and Rhode Island Red Fayoumi crossbred (RIRF) crossbreds were 1253.68 g and 4.46, 1230.00 g and 4.55 and 1188.00 g and 4.40, respectively which partially supported the present findings. However, Sonali chicken tended to show a higher net profit than broiler chicken because of the preference of consumers and the higher price of Sonali chicken. The higher price of chickens depends on the preference of consumers and meat quality. The quality and taste of Sonali chicken meat are close to the indigenous chicken meat. Sarker et al. (2008) reported a higher net profit in Sonali chicken than in broiler chicken consistent with the present findings. Dutta et al. (2012) reported that the broiler had the highest body weight gain as well as FCR compared to the Fayoumi, ISA Brown and Sonali chicken, whereas the highest net profit was in the ISA Brown, followed by Sonali, Fayoumi, and broiler chicken, respectively. The net profit in the present study tended to show higher in the Sonali chicken compared to the broiler chicken which corroborates with Hannan et al. (2020). They reported the highest net profit in Sonali chicken followed by Cockerel and Cobb 500 chickens, respectively. A previous study showed a lower net profit in Sonali chickens than in broilers or layers, but higher than in deshi chickens (Sarker et al., 2008).
The interaction between chicken type and batch was not significant for the growth performance traits. No previous work was found on the interaction effect of batch and chicken types on their growth performance traits.

Meat yield traits of broiler and Sonali chickens
The chicken type was different for live weight, dressed weight, dressing percentage, thigh weight, breast weight, breast meat percentage, dark meat weight, dark meat percentage, and giblet weight (p<0.001) ( Table. 4). Meat yield traits; live weight, dressed weight,  dressing percentage, thigh weight, breast weight, breast meat percentage, dark meat weight, and giblet weight were higher in broiler compared to the Sonali chicken, except for dark meat percentage. Sonali chicken yielded higher dark meat than broiler chicken. The batch was not different for live weight, dressed weight, dressing percentage, thigh weight, breast weight, breast meat percentage, dark meat weight, and giblet weight (p>0.05), except for dressing percentage (p<0.05). The B 1 had a higher dressing percentage than B 2 .
The interaction between chicken type and batch was not significant for meat yield traits (p>0.05).
In the present study, broiler chicken performed better than Sonali chicken in terms of live weight, dressed weight, dressing percentage, thigh weight, breast weight, breast meat percentage, dark meat weight and giblet weight. However, broiler chicken had lower dark meat percentage (p>0.05) than Sonali chickens. The previous findings showed the highest edible meat in the cockerel, moderate in the broiler, Sonali, and indigenous chickens, and the lowest in RIR chicken which partially supported the present findings (Islam & Dutta, 2010). On the other hand, Khawaja et al. (2013) reported the highest dressing percentage in Fayoumi male_ Rhode Island Red female (FRIR) moderate in reciprocal F 1 crossbred of RIR_Fayoumi (RIRF) and the lowest in White Leghorn male_F 1 female (RLH) which was also partially supported the present findings.
There was no literature of previous work found on the effect of the batch and the interaction of chicken type and batch on meat yield traits of broiler and Sonali chickens.

Lipid profiles of broiler and Sonali chicken
The chicken type was not different for total cholesterol, triglyceride, high-density lipoprotein, and low-density lipoprotein (p>0.05) ( Table. 5). However, broiler tended to increase total cholesterol, triglyceride, and high-density lipoprotein compared to Sonali chickens.
As to the effect of the batch, there was no significant difference between batches for total cholesterol, triglyceride, high-density lipoprotein, and low-density lipoprotein (p>0.05). Lipid profiles did not differ  between B 1 and B 2 . The chicken type did not interact with the batch for total cholesterol, triglyceride, high-density lipoprotein and low-density lipoprotein.
Chicken types did not differ for lipid profiles (total cholesterol, triglyceride, high-density lipoprotein, and low-density lipoprotein (p>0.05). However, broiler chickens tended to increase lipid profiles, except for low-density lipoprotein compared with Sonali chickens. The present findings contradicted the findings of Dutta et al. (2013). They estimated the highest amount of cholesterol in RIR, followed by Sonali, Cobb 500, Cockerel, Fayoumi, and Indigenous chickens, respectively.
No previous work was found on the effect of the batch, and the interaction between chicken type and batch on the lipid profile content of the blood of broiler and Sonali chickens.

Conclusions
The present study reveals that broiler chicken performed better than Sonali chicken in terms of growth performance and meat yield traits. The chicken type did not affect lipid profiles (total cholesterol, Triglyceride, HDL, and LDL) content in the blood of chickens and net profit. However, Sonali chicken tended to show higher net profit and lower total cholesterol and triglyceride compared to broiler chicken. As to the effect of batch (B), batches (B 1 and B 2 ) did not affect growth performance, meat yield, and lipid profile content in the blood of chickens. No interaction between chicken type and the batch was found in growth performance, meat yield traits, and lipid profile content in the blood of chickens. Therefore, Sonali chicken may be suitable for producing consumer preferable and profitable chicken meat. However, more studies are needed to confirm the present findings and suggest to use of a suitable chicken type for commercial purposes.

Funding
This research received no specific grant from funding agencies in the public, commercial, or private sectors.

Ethical statement
The study was approved by the Institutional Committee on Animal Care and Use in Research (ICACUR) of Bangabandhu Sheikh Mujibur Rahman Agricultural University (No. BSMRAU/DEAN/FVMAS/25/ ICACUR/19).

Declaration of Competing Interest
No potential conflicts of interest to declare