Broiler farming is one of the most promising and sustainable businesses in agricultural sector and the fast growing phenomena are said to have been due to availability of improved germplasm, good quality feed and better care and management. One of the great economic problems of the broiler is that the broilers are not the same weight at market age. The growth pattern of male and female broilers is different. Under similar managemental conditions males grow faster, converts feed more efficiently, achieve marketable weight earlier and have less carcass fat (Kalita and Hazarika, 2014). Studies report that sexes influence the growth rates; females show higher breast proportion than males, but lower leg and thigh proportions. Sex differences are also known to influence carcass and abdominal fat deposition. The marking of poultry has been greatly diversified with a significant increase in cut up (parts) and processed products.

Materials and Methods

The experiment was carried out in the experimental shed of Instructional Poultry Farm, Department of Poultry Science, College of Veterinary Science, Assam Agricultural University, Khanapara, to assess the carcass characteristics of broiler chicken meat under sex separate rearing in deep litter system. For the present study, 210 numbers of day-old commercial broiler chicks having similar body weight from a single hatch was procured, wing banded and reared for 21 days under standard managemental practices and at 22 days of age, sex separation was done by observing the early appearance of comb in case of male birds, 180 birds were randomly selected from the flock and categorized into three treatment groups viz. T₀ (60 straight-run or mixed sex i.e. 30 males and 30 females), T₁ (60 males) and T₂ (60 females) which was further subdivided into 3 replicates with 20 chicks in each. The remaining birds were discarded. All the 3 treatment groups of broilers were reared separately and were maintained under uniform managemental condition with ad libitum broiler pre-starter, starter and finisher ration throughout the experimental period of 42 days (6 weeks). Commercial brand of broiler pre starter feed was given from 1^st day to 12^th day, starter feed was given from 13^th day to 21^st day and finisher feed was provided from 22^nd day to 42^nd day of age. All birds were offered ad libitum clean potable drinking water throughout the whole experimental period. The carcass quality was determined at the end of the experiment. Four birds from each replicate (total 36 numbers of birds) were randomly selected for carcass characteristics which included live weight, dressed weight, dressing percentage, and relative organ weights. Processing (slaughtering, bleeding, scalding, and de-feathering) of the birds were carried out following standard procedure. The dressed weight of the carcass was noted after removing head, shank, tip of wings and oil glands and expressed on the basis of pre-slaughtered live weight percentage. Evisceration was done by the method of Panda (1971). The gall bladder was detached from liver, heart was free from pericardium, internal clots and adhering vessels and the gizzards was cleaned by removing the inner lining and weighed separately to determine the weight of these organs and the giblet yields (liver, gizzard and heart) were calculated accordingly. After dressing, the giblet was retained with the carcass and the weight of the carcass with giblet was expressed as ready to cook weight which was expressed in terms of pre-slaughter live weight.  These were weighted separately as relative weight (gm/kg live weight). Data were analyzed by using standard statistical method (One-way analysis of variance technique was used) in the year of 2016. The experiment was conducted for 6 weeks (42 days).

Results and Discussion

The mean pre-slaughter live weight under the three different experimental groups were recorded as  2265.83 ± 101.29, 2428.33 ± 59.97 and 2186.25 ± 56.93 g for T₀ (mixed) group, T₁ (male) group, T₂ (female), respectively.

Table 1:  Carcass traits (Mean ±SE) and relative organ weight (%) of broilers chicken of different sexes.

Means bearing different superscripts within a row differ significantly (P≤0.05).

The analysis of variance revealed that the differences in average pre-slaughter body weight of broilers under the three different experimental groups were statistically non-significant (P>0.05) though marginal differences were existed. Similar findings were also reported by Veerapen and Driver (1999), Shahin and Elazeem (2005) and Azahan et al. (2007). This might be due to their genetic capability of which, male broilers can grow faster compared to female (Kalita and Hazarika, 2014). The mean dressed yield under the three different experimental groups was recorded as 70.22 ± 0.05, 71.56 ± 0.01 and 69.31 ± 0.07 for T₀ (mixed), T₁ (male) and T₂ (female) group respectively. The analysis of variance revealed, there was significant difference (P<0.05) of dressed weight among the three treatment groups.  The findings are in line with the findings reported by Veerapan and Driver (1999), Ojedapo et al. (2008) and Beg et al. (2016).The dressing yield might be higher in T₁ (male)   group due to the higher body weight in male than the females.

The mean gizzard yield under the three different experimental groups was recorded 0.97 ± 0.04, 0.98 ±    0.04 and 1.00 ± 0.04 % for T₀ (mixed sex), T₁ (male) and T₂ (female) group respectively. The analysis of variance revealed that there was no significant difference (P>0.05) among the 3 groups. In contrary to the present result, Ojedapo et al. (2008) recorded significantly (P<0.05) highest gizzard yield in male compared to the female. The mean liver yield under the three different experimental groups were recorded as 1.33 ± 0.03, 1.74 ±  0.13 and 1.66 ± 0.03 for T₀ (mixed sex) group, T₁ (male) group and T₂ (female) group respectively The analysis of variance revealed non-significant difference (P>0.05) between T₁(male) and T₂ (female) group, while T₀ (mixed sex) group was found to be significantly different (P<0.01) from other two groups. The higher liver yield may be due to the higher body weight and better growth pattern which may have subsequently influenced the liver weight. The mean heart yield under the three different experimental groups were recorded as 0.39 ± 0.02, 0.44 ± 0.01 and 0.38 ± 0.02 for T₀ (mixed sex), T₁ (male)and T₂ (female) group respectively. The analysis of variance revealed, statistically non-significant (P>0.05) though marginal differences were existed. This may be due to the higher male cardiac output (Sturkic, 1976), which normally involves oxygenation responsible for the heavier heart of the male broiler. This is in accordance with the findings of Laseinde and Oluyemi (1994).

The mean giblet yield under the three different experimental groups were recorded as 2.70 ± 0.05, 3.17 ±     0.14   and 3.06 ± 0.07 for T₀ (mixed sex) group, T₁ (male) group and T₂ (female) group respectively. The analysis of variance revealed, non-significant difference (P>0.05) between T₀ (mixed-sex) group and, T₂ (female) group, while T₁ (male) group was found to be significantly different (P<0.01) from other two groups. This finding is in accordance with the findings of Laseinde and Oluyemi (1994).

Table 2:  Yield of various cut up parts (%) of broilers under different treatment groups.

Means bearing different superscripts within a row differ significantly (P≤0.05).

In sex separate rearing of broilers, the per cent neck yield was found to have significant difference (P<0.05) when compared to the other two groups i.e. T₁ (male) and T₂ (female). Similarly, the per cent breast yield (%) was also found to differ significantly (P<0.05). However, numerically higher breast yield (%) is recorded in T₂ (female) group compared to T₀ (mixed sex) and T₁ (male) respectively. The higher breast yield was also found by Faria et al. (2010) and Sogunle et al. (2013). It might be due to sexual dimorphism of carcass conformation, with females presenting higher breast development. The per cent yield of cut up parts like wing, back, thigh and drumstick, did not differ significantly (P>0.05) among the different groups. In case of wing yield (%) numerically higher value was observed in T₂ (female) group followed by T₁ (male) and T₀ (mixed-sex) respectively. However, higher numerical value of   back yield (%) was observed in T₁(male) group followed by T₂(female)and T₀(mixed-sex). Similar result was reported by Sam et al.(2010). In case thigh yield (%), numerically higher value was observed in T₁ group than the other 2 groups i.e., T₀ (mixed-sex) and T₂ (female) respectively. In agreement with the present findings Sam et al. (2010) reported that the male had more back yield than the female broilers. Numerically higher value of drumstick was also seen in T₀ (mixed-sex) compared to the other 2 groups i.e. T₁ (male) and T₂ (female) respectively. Similar result was seen by Ojedapo et al. (2008).

Conclusion

Now a day specified market requirement is obligatory. The female can be reared, dressed and sold as whole chicken; whereas the male carcasses will be exclusively used for deboning and various cut up parts with heavier carcass weight and high meat yield in the choice cut. The processing units and the wholesalers prefer to buy uniform sex separate flock. Sex separate rearing gives the possibility of better market value for the broilers at the time of marketing duo to flock uniformity. Therefore, this study aimed at separating the broilers into sexes and separately comparing the carcass characteristics.

References

1. Azahan, E., A Engku Marini, A.M and Noraziah, M .2007. Evaluation on the effects of sex on growth and carcass characteristics of broiler. Journal of Tropical Agricultural and Food Science, 35(2):313-318
2. Beg, MAH., Saiful, IKBM., Aftabuzzamam, M. and Mahbub, ASM. 2016. Effects of separate sex growing on performance and metabolic disorders of broilers. International Journal of Animal Resources, 1(1):19-26.
3. Faria, P.B., Bressan, M.C., Souza, X.R.De and Gama, L.T. Da. 2010. Carcass and parts yield of broilers reared under a semi-extensive system. Revista Brasileira de Ciencia Avicola, 12 (3):153-159.
4. Kalita, K.P. and Hazarika,R. 2014. Commercial Broiler Production for N.E. Region. 1^st Edition 15^th April 2014.
5. Laseinde, E.A.O. and Oluyemi, J.A. 1994. Effect of sex separation at the finisher phase on the comparative growth performance, carcass characteristics and breast muscle development between male and female broiler chickens. Nigerian Journal of Animal production, 21:11-18
6. Ojedapo, L.O., Akinokun, O., Adedeji, T.A., Olayeni, T.B., Ameen, S.A. and Amao, S.R. 2008. Effect of Strain and Sex on carcass characteristics of three commercial broilers reared in Deep litter System in the Derived Savannah Area of Nigeria. World Journal of Agricultural Science, 4(4):487-491.
7. Panda, P.C. 1971. Bacterological conditions of dressed chicken during processing and relating. Indian Vet. J., 48: 927-931.
8. Sam, I.M., Akpa, G.N., Alphonsus, C., Iyeghe-Erakpotobor, G.I. and Agubosi, O.C.P. 2010. Effect of sex separation on growth performance and carcass characteristics of broilers raised to maturity. Continental Journal of Animal and  Veterinary Research, 2:35-40
9. Shahin, K.A. And Elazeem, FathyABD. 2005. Effects of breed, sex and diet and their interactions on carcass composition and tissue weight distribution of broiler chickens. Tierz., Dummerstorf., 48(6): 612-626.
10. Sogunle, O.M., Akinosi, O. K ., Adeyemi, O.A., Sobayo, R.A., Bello, K.O.,  Ekunseitan, D.A. and Olaniyi. 2013. Performance and carcass yield of sexed broiler chickens reared on two housing types. Bull. Animal  Health Production in Africa, 61:435-444
11. Sturkie, P.D. 1976. Avian Physiology. 3^rd, Spinger Verlag. New York. Pp.91-92
12. Veerapen, D.S. and Driver, B.M.F. 1999. Separate sex growing of Ross 208 broilers and effects on broilers performance and carcass quality. Science and Technology Research Journal, 4, pp.