Carcass Traits and Meat Quality Characteristics of Malabari Male Kids Reared under Different Production System

The increase in demand for goat products has prompted goat producers to move towards more intensive and alternative production systems with more dietary concentrate supplementation in Indian conditions. Alternative rearing systems will improves the farm profitability for sustainable goat production (Palo et al., 2015). Production of young kids for meat purpose is common in well-developed countries (Webb et al., 2005). The meat from kids will be quite lean with little intramuscular or subcutaneous fat as compared with beef, lamb and pork (Genandoy et al., 2002). Animal age, changes in feeding regime, birth type, rearing system and slaughter season will influence the intrinsic characteristics of goat meat (Borgogno et al., 2015), including its sensory attributes.
       
The kids are raised solely on milk in the pre-weaning phase, along with the roughages. But, the bottle feeding of concentrates supplements by restricting the natural suckling of milk also stimulates oesophageal reflex, which prevents swallowed fluids entering the reticulo-rumen, helping abomasal development, consequently improving the growth rate (Genandoy et al., 2002). Ryan et al., (2007) reported that increasing concentrates in meat-goat diet results in increased live-harvest weights as well as increased carcass weights. Pre-weaning growth rate of kids is invariably faster than post-weaning growth. In this context, the broiler goat production system has vast scope. Broiler goat production system is an intensive system of rearing goats to provide energy, protein and other nutrients in required proportion by feeding semi-solid concentrate diet up to three months of age. This system aims to achieve 15-20 kg body weight by three months of age, where the meat quality is better, while it takes approximately one year to attain this body weight in traditional system of rearing (Prasad et al., 2017). Research on Malabari male kids, especially with regard to meat goat production system is scanty. Therefore, the current study was aimed to examine the impact of broiler goat production system on the performance, carcass traits and meat quality of Malabari male kids.

Location and animals
 
The experiment was conducted at Instructional Livestock Farm Complex, College of Veterinary and Animal Sciences, Pookode, Wayanad from the month of October to December, 2015. Total of 14 Malabari male kids were randomly divided into two experimental groups (T₁ and T₂) of 7 each, considering their morphological characters and birth weight. The mean birth weight of kids, randomly allotted to two treatments T₁ and T₂ were 2.26±0.19 and 2.26±0.10 kg, respectively.
 
Feeding
 
The kids were with their dams till 7 days to ensure the colostrum intake. Thereafter, the kids in the control group (T₁) were allowed to suckle milk from their respective dams for 30 minutes interval, thrice a day during first four weeks and twice in a day during consequent weeks, until 12 weeks. Kids were offered ad-libitum green grass from 15^th day along with clean drinking water. Goat kids in Treatment-2 were weaned at 7 days of age and fed formulated semi solid concentrate diet as per ICAR feeding standards (2013). The semi-solid concentrate feed was fed by mixing finely ground broiler goat concentrate feed with equal quantity of rice gruel from a feeding bottle. In addition, the liver tonics and fish oil (5 ml each) were provided daily. Animal feed grade sodium bicarbonate at the rate of 0.75% of dry matter intake was added as a buffer.
       
Weighed quantity of feed was provided thrice daily at 8.00 am, 2.00 pm and 8.00 pm in the feeding bottle fixed in the pen for individual animals and fresh potable water was made available. The chemical composition of broiler goat concentrate ration is furnished in Table 1 and was analysed as per A.O.A.C., (2005) (Prasad et al., 2019).


 
Slaughtering, sampling and carcass traits analysis
 
After 12 weeks of feeding all the kids were transported to the Meat Processing Facility of the private registered slaughter house with standard procedures. The carcass weight was recorded. The dressing, evisceration and legging were performed according to the standard procedure described by Gerrand (1964). The non-carcass components (Skin, head, feet, lung, heart, liver, spleen, kidneys and scrotum) and the gastro intestinal tract were removed and weighed. Then, the stomach contents were emptied to assess the weight of empty gastro intestinal tract and the primal cuts were divided and weighed.
 
Analysis of meat quality 
 
Triplicate pH of meat sample was determined two hours after slaughtering using a pH meter. Fresh meat surface colour was determined using L*, a* and b* system with Mini scan EZ D-65/10 Hunter-Lab colorimeter (Hunter Associates Laboratory, Fairfax). Three colour coordinate values were expressed as the mean values of lightness (L*⁾, redness (a*) and yellowness (b*). The cooking loss of meat for both treatments was estimated following the method prescribed by Najafi et al., (2012). The cooking loss was calculated as a percentage of weight loss (Palo et al., 2015).
   
The cooked samples were used to determine Warner-Bratzler Shear Force (WBSF) value.
 
Statistical analysis
 
The data was analysed statistically using the SPSS version 21.0^® software (Snedecor and Cochran, 1994). Group difference at each time period was analysed by using independent t-test. 

Carcass traits
 
The pre-slaughter body weights of the kids were 7.21±0.31 and 15.26±0.35 kg in T₁ and T₂ respectively. The production system of kids had significantly positive effect on all the carcass parameters studied (Table 2). The dressing percentage was significantly (P<0.01) higher in T₂ than in T₁. All the carcass traits like carcass length, heart girth, weight of fore limb, hind limb, shoulder, neck, rack and flank were significantly (P<0.01) higher in T₂ compared to T₁.
       


The meat quality characteristics of goat kids is influenced by the production systems (Ozcan et al., 2014) and type of diet offered (Ryan et al., 2007). There was significant effect of feeding broiler goat concentrate feed on the carcass characteristics. The carcass weight of T₂ was 2.27 times the car cass weight of natural suckling kids at slaughter. The results are in agreement with Ryan et al., (2007) who reported significantly (P<0.05) increased live weight, hot carcass weight, dressing percentage and length of carcass of concentrate diets fed goats compared to range-fed goats. Though, Adam et al., (2010) found no influence of type of diet on carcass characteristics, the results are in confirmation with Rhee et al., (2000) and Safari et al., (2009). The results are in contrary to Ozcan et al., (2014) as they reported higher growth rate of unweaned lambs and kids compared to weaned ones. They attributed those results to higher digestibility of dams milk than milk replacer and also the presence of a growth promoter in dams’ milk, which is absent in milk replacer (Baumrucker and Blum, 1993). The higher weight gain among the broiler goat concentrate fed kids is due to availability of nutrients in the growing period (Delgado-Pertínez et al., 2009) and due to development of digestive system as discussed in the earlier published article (Prasad et al., 2019). Whereas, the decreasing trend of does milk production in its lactation limited the weight gain of kids in the natural system of rearing.

Significantly (P<0.05) higher dressing percentage in case of T₂ kids might be due to adequate availability of required nutrients for development of muscle mass. The dressing percentage increases with increasing slaughter weight (Bonvillani et al., 2010). Whereas, Sarker et al., (2015) found higher dressing percentages (P<0.05) in whole milk fed kids than in milk replacer groups. They attributed their results to higher gut fill associated with earlier rumen development in milk replacer fed kids than the whole milk consumed group.
       
The mean weights of non-carcass components like liver, kidney, heart, spleen, testicles, blood yield, head yield, skin, hind feet, fore feet, lung and trachea were significantly (P<0.01) higher in T₂, due to the higher slaughter weight compared to T₁ as presented in Table 3. Information on yield of non-carcass components of animals is important, where they are more valuable for the households especially in developing countries like India. The live weight of the animals majorly influences the yield of non-carcass components.
 

 
Meat quality characteristics
 
The values of meat quality characteristics are presented in the Table 4. The pH values of meat from both the groups did not differ significantly. The cooking loss, shear force and colorimeter values like L* and a* were significantly (P<0.01) different in the meat samples of kids fed broiler goat concentrate diet than control group.
 

       
The Meat which has an ideal ultimate pH (pH <5.8) results in acceptable meat tenderness and colour (Yalcintan et al., 2018). The pH values were lower than the ultimate pH values for goat meat reported by Kannan et al., (2001) which was above 6.
       
Meat color is an important parameter influencing consumer preference of purchasing and it is well known that animal diet could strongly affect meat color (Priolo et al., 2001). Yalcintan et al., (2018) also reported significant influence of kids live weight on all chromometer values (L*, a*, b*, hue angle, chroma), the lightness of meat tends to decrease, while redness value tends to increase as live weight increases. Lower L* values in T₂ indicated that the meat obtained was darker than T₁. The higher positive a*, b* value in T₂ indicated that the meat obtained from the kids in T₂ was dark reddish yellow compared to T₁.  This could be due to direct influence of the diet and slaughter weight of the kids. Ryan et al., (2007) reported similar results among the goats fed range diets, where they had lower a*, b*, hue angle, chroma and marbling scores. They also stated that the concentrate diet is necessary to improve color and marbling of the muscles. Thus, broiler goat production system positively influenced the colour of chevon as the consumer put importance on colour as an indicator of meat quality (Kadim and Mahgoub, 2012).
       
Cooking losses from chevon is important because the water that remains in the cooked product is the major contributor to the juiciness of that product. Cooking losses of goat meat will be usually closer to 35% or above (Webb et al., 2005). The higher cooking loss (%) for the meat samples in T₁ indicated that the meat of un-weaned kids had more water content as the limited fat content of meat possibly intensifies cooking losses (Lawrie, 1998). This was contradictory to the report of Ryan et al., (2007), who stated that “chops from concentrate fed goats had greater cooking loss compared to range fed goats”. Whereas, Moreno-Indias et al., (2012) reported that the dietary treatment has no effect on the cooking loss of the goat meat.
       
The significantly (P<0.01) higher shear force values of meat samples in T₂ indicated that the meat samples of T₂ was having good meat consistency than T₁ due to better development of structural biomass of the muscles in broiler goat concentrate fed group. Argüelloet_al(2005) reported lower shear force values and higher water holding capacity in the meat of kids suckling on the dam. Whereas, Ryan et al., (2007) didn’t found differences between the meat samples of kids fed varying levels of concentrates in their diet.

The male goat kids reared under broiler goat production system produced higher body weight. The meat quality characteristics of goat kids is influenced by the production systems and the type of diet offered. Compared to the natural system of rearing, broiler goat production system increased carcass characteristics and chevon produced was tender with less cooking loss. The broiler goat production system could produce chevon in shorter time period with more gain and better quality. 

The authors are grateful to Kerala Veterinary and Animal Sciences University, Wayanad, Kerala for providing facilities and funding this project.