Abstract: Objective: This study was set up to increase the productivity of Kacang goats using fish meal and soybean meal (containing relatively high ruminally undegradable protein) in the ration. Materials and Methods: Twelve kacang goats, 1-1.5-year-old, 17.84+1.57 kg were used in this study. A completely randomized design was used with 3 different rations: NG (control) = Natural grass, FM = Total Mixed Ration (TMR) containing fish meal and SBM = Total mixed ration containing soybean meal. The rations contained 15% of crude protein and 1% of the mineral mix, except for NG. Water and feed were provided ad libitum. Data were analyzed by analysis of variance using the SPSS statistics software version 19. Results: The growth of FM goats (ADG = 59.03 g) and SBM goats (ADG = 80.06 g) were higher than that of NG goats (ADG = 27.22 g). However, the slaughter weight, carcass weight and dressing percentage of goats fed TMR containing soybean meal (SBM) were the highest among all of the treatments with having the lowest of non-carcass (%). The meat, bone and fat of SBM carcass are also the highest among others. The chevon fat content of goats fed Natural Grass (NG) was the highest, while other physical and chemical properties of chevon were relatively the same. Conclusion: It can be concluded that the use of fish meal and soybean meal in the ration improved the performance of local kacang goats. In fact, soybean meal in the ration can improve the productivity and carcass products of kacang goats better than fish meal.
INTRODUCTION
The numbers of goats slaughtered in Central Java, Indonesia were more than sheep, namely 764,645 goats and 333,318 sheep1. This is because chevon is preferable meat for health conscious people because of the nutritious and healthy product. It has low fat and low cholesterol content2, containing 19.6-20.7% of meat protein3. These conditions have stimulated people to raise goats. The number of goats reared by farmers in Central Java, Indonesia as much as 3,461,409 heads, whereas sheep were only 533,616 heads4.
Kacang goat is one of animal genetic resources of goats in Indonesia5 which can adapt to the environmental conditions, especially well adapted to traditional management6 and prolific7. Elieser et al.8 stated that most farmers in the rural area of Indonesia raise kacang goats. Farmers raise goats traditionally (grazed during the day and housed at night fed roughage without concentrate) so that the productivity is low. Adiwinarti et al.9 reported low productivity of grazing kacang goat that produced only 5.66 kg of carcass weight (38.79% of the slaughter weight). The average daily gain of grazing kacang goats was only 3.20 g10. Therefore, many efforts have to be done to increase the productivity of local goats. This study was set up to increase the productivity of kacang goats using fish meal and soybean meal (containing relatively high ruminally undegradable protein) in the ration. Beside investigating the performance of the goat, the quality of meat is also important to study for health conscious consumer’s information.
MATERIALS AND METHODS
Twelve kacang goats, 1-1.5 year-old (the incisors have erupted 1), with the initial body weight of 17.84+1.57 kg (CV = 8.80%) were used in this study and arranged with a completely randomized design. The goats were fed by 3 different rations: NG (control) = Natural grass, FM = Pennisetum purpureum (30%)+Gliricidia leave (30%)+concentrate with fish meal and SBM = Pennisetum purpureum (30%)+Gliricidia leave (30%)+concentrate with soybean meal. The ration was made Total Mixed Ration (TMR) containing 15% of crude protein (Table 1) and 1% of the mineral mix, except for NG. The goats were dewormed with 1.5 mL per head of valbendasol given orally and 0.5 mL per head of intermectin (Interchemie, Holland) administered sub-cutaneously. Water and feed were provided ad libitum. The goats were adapted for 5 weeks and treatment periods for 14 weeks.
| Table 1: | Feed ingredients and nutrients content in the ration |
Parameters observed were the goat’s growth, carcass traits, physical and chemical properties of meat. The growth was recorded by weighing the bucks weekly and the average daily gain was calculated from linear regression of weekly weights (14 weeks). The bucks were fasted for 12-15 h with free access to fresh water and then were weighed before being slaughtered for carcass observation. Carcass traits included dressing percentage and the weight and percent of carcass composition (meat, fat and bone). Chevon quality was accessed in the Bicep femoris muscles. Chevon quality observed were physical quality included pH, water-holding capacity/WHC, cooking loss and tenderness using warner-bratzler shear force values11 and chemical quality included water, fat, protein content and collagen in meat using near infrared spectroscopy (NIRS)12. Data were analyzed by analysis of variance using the SPSS statistics software version 19.
RESULTS AND DISCUSSION
Growth of kacang goats fed ruminally undegradable protein: The growth of kacang goats fed ruminally undegradable protein (fish meal and soybean meal) was higher (p<0.01) than those fed natural grass. This indicated that the performance of kacang goats improved by feeding ration containing fish meal and soybean meal. The average of daily gain of FM goats (59.03 g) was lower (p<0.01) than those of SBM goats (80.06 g), but it was higher (p<0.01) than that of NG goats (ADG = 27.22 g). However, the slaughter weight of goats fed TMR containing soybean meal (SBM = 25.56 kg) was the highest (p<0.01) among all of the treatments (NG = 20.65 and FM = 20.59 kg) because the growth of SBM goats was also the highest than others (Fig. 1).
| Fig. 1: | Growth of kacang buck fed natural grass, total mixed ration containing fish meal and soybean meal (SBM) |
| Table 2: | Slaughter weight, carcass weight, carcass and non-carcass percentage |
| A,BMeans in the same column without common letter are different at p<0.01, a,bMeans in the same column without common letter are different at p<0.05 |
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| Table 3: | Carcass components and the percentages |
| A,BMeans in the same column without common letter are different at p<0.01, a,bMeans in the same column without common letter are different at p<0.05 |
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Figure 1 shows that in the first 5 weeks, the growth of FM goats was lower than NG and SBM goats, afterward, SBM goats grew significantly higher than those of NG and FM goats while NG and FM growth were relatively the same. The weight gains were highest for SBM goats and lowest for NG goats. Those were exactly reflected by the differences in Dry Matter Intake (DMI). The DMI of SBM goats (707.48 g) was higher than those of NG goats (502.17 g) and FM goats (597.86 g), but the DMI of NG goats were relatively the same as FM goats. Low DMI in NG goats might be caused by the high content of crude fiber (Table 1) as reported by Ukanwoko and Okehielem13 that high crude fiber content caused low feed intake, low total weight gain and poor performance of West African dwarf bucks. However, low DMI in FM goat might be caused by the low palatability of the ration. Kacang goats did not like the ration containing fish meal. This finding is in line with Addulah et al.14 study that reported kacang buck preferred ration containing 0% of fish meal.
Dry matter intake of NG goats (25.59 g kg–1 b.wt. day–1) was lower than those of FM goats (31.16 g kg–1 b.wt. day–1), SBM goats (32.93 g kg–1 b.wt. day–1) and Aryanto et al.15. Aryanto et al.15 stated that DMI of kacang goat fed ad libitum reached 29.42 g kg–1 b.wt. day–1. However, the DMI of FM and SBM goats was higher than those of kacang goats reported by Aryanto et al.15.
The ADG of kacang goats fed natural grass ad libitum (27.22 g) in this study was higher than those of grazing kacang goats (3.20 g) reported by Adiwinarti et al.10. The ADG of kacang goats fed TMR containing soybean meal (SBM = 80.06 g) was higher than those of kacang goats reported by Restitrisnani et al.16, but lower than those of kacang goats reported by Addulah et al.14. Restitrisnani et al.16 reported kacang goats having ADG of 23.5-69.4 g and Addulah et al.14 reported kacang goats fed fish meal having ADG of 77.5-101.6 g.
Carcass traits: The carcass weight and dressing percentage of goats fed TMR containing soybean meal (SBM) were also the highest among all of the treatments with having the lowest of non-carcass (%) (Table 2). The high carcass weight was influenced by slaughter weight (Table 2) and the growth rate of the goat. The slaughter weight and carcass weight of SBM goats were higher (p<0.01) by 4.95 and 3.47 kg over NG and 5.01 and 3.03 kg over FM, while the slaughter weight and carcass weight of NG and FM were relatively the same (p>0.05). This finding is in line with the previous study of Johnson et al.17 that reported heavier carcasses having a correlation to heavier ending weights of the goats.
The Dressing Percentages (DP) of this study were lower than those of kacang goats reported by Naser18 and Gafar et al.19. Dressing percentage of kacang goat reported by Naser18 was 47.4-51.6%. Gafar et al.19 reported kacang goats fed palm oil decanter cake having DP of 53.3-56.7%. However, this finding was similar to Hutama20 that reported DP of kacang goat was 46.7%. In fact, DP of this research was higher than those of Sumardianto et al.21 study (DP: 40.86%).
The meat, bone and fat of SBM carcass was also the highest (p<0.01) among others and those of NG and FM carcasses were relatively the same (Table 3). This finding is in line with Never22 that reported carcass composition was affected by carcass weight. However, the percentages of meat, fat and bone were similar (p>0.05) among all of the treatments. The averages of meat, fat and bone percentages were 71.28, 7.73 and 20.99%. It indicated that higher carcass produced higher meat, fat and bone proportionally (Fig. 2).
| Fig. 2: | Carcass components of kacang goats fed Natural Grass (NG), TMR containing Fish Meal (FM) and soybean meal (SBM) |
| Table 4: | Physic-chemical properties of chevon from kacang buck fed ruminally undegradable protein |
| A,BMeans in the same column without common letter are different at p<0.01, a,bMeans in the same column without common letter are different at p<0.05 |
|
The meat+fat-bone ratios of all treatments were similar (p>0.05) that having averages of 3.83. These results were better than Sumardianto et al.21 that reported kacang bucks producing 3.49 kg of meat (63.2%), 0.546 kg of fat (9.70%), 1.57 kg of bone (28.02%) and 2.60 meat-bone ratio. However, Sebsibe et al.23 reported that the meat-bone ratio of Ethiopian goats fed concentrates (4.03-5.01) was higher than those of kacang goats in this study.
Physic-chemical properties of chevon: The physical properties of chevon included pH, water-holding capacity/WHC, cooking loss and tenderness using Warner-Bratzler shear force values were relatively the same among all of the treatments (Table 4). The pH of the kacang buck meat (6.04) was relatively high compared to those of Ethiopian goats meat (pH: 5.61-5.94)23 and Indian goats meat (pH: 5.63-5.79)1. However, Pratiwi et al.24 also reported high pH value of Australian Feral goats 20-40 kg that was about 5.8-6.0 and Judge et al.25 also stated that a high post mortem animal pH was around 6.5-6.8. Meats from goat usually have ultimate pH that is higher than mutton26. The ultimate pH variation was influenced by energy metabolism during post mortem25,26 and antemortem handling26.
The increasing of pH value will increase WHC and decrease cooking loss1,25,27. The WHC of kacang goats in this study (39.9%) was higher compared to Indian goat (WHC: 22.9-24.01%)1, but lower than Egyptian Baladi goat (WHC: 68.8%)28. Therefore, the cooking loss of Egyptian baladi goat (27.9%) was lower than this study (37.9%). The cooking loss in this study was relatively similar to Indian goat (36.2-38.6%)1 but lower than Australian feral goats 20-30 kg (31.1-46.4%)24.
Tenderness of kacang goat in all of the treatments was not significantly different (p>0.05) because the collagen content in all treatments was also similar. The average of tenderness and collagen content in this study were 6.79 kg cm–2 and 1.91%. The high collagen content will cause the meat less tender29. The tenderness value of Kacang goat was relatively similar to Indian goat (5.8-6.5 kg cm–2)1, but higher than Egyptian baladi goat (4.83 kg cm–2)28. Goat meats were reported to be tougher than mutton26.
The chevon fat content of goats fed Natural Grass (NG) was the highest (p<0.05) than other treatments. This condition might be caused by the increasing of protein in the ration of FM and SBM. The higher protein content in FM and SBM rations than those in NG (Table 1) were suspected causing the decrease of fat content that was in agreement with Soeparno30. While other chemical properties of chevon were relatively the same (p>0.05) in all of the treatments. The fat content of kacang buck was lower than that of castrated etawah crossbred (8.36%) and castrated boer crossbred (8.98%)31.
Water content of kacang goat meat (72.05%) was relatively similar to that of kacang goat meat reported by Mirdhayati et al.32: 73.8-74.5%, Indian goat meat reported by Das and Rajkumar2: 72.4-74.08%, however, it was lower than meat of Australian Feral goats 20-30 kg reported by Pratiwi et al.24: 76.0-77.3%, refined white breed kid reported by Pieniak-Lendzion et al.33: 76.5-78.03%. Pratiwi et al.24 stated that heavier goat meats contained less water content than skinnier goat meats.
The average of protein content in kacang chevon was 21.9% that was higher than in refined white breed kid (19.1-20.8%)33 in Etawah crossbred goat (17.131 and 19.6-20.7%2) and also in boer crossbred goat (17.9%)31. However, it was lower than protein content in kacang chevon reported by Mirdhayati et al.32: 23.2-23.5%. Judge et al.25 reported that lean meat contained 19.0-23.0% of protein content.
CONCLUSION
It can be concluded that the use of fish meal and soybean meal in the ration improved the performance of local kacang goats. In fact, soybean meal in the ration can improve the productivity and carcass products of kacang goats better than fish meal.
SIGNIFICANCE STATEMENTS
| • | Kacang goats usually are raised traditionally by grazing during the day and housed at night, fed roughage without concentrate, so that the productivity is low |
| • | This study was set up to improve the performance of local goats using ruminally undegradable protein feeds (fish meal and soybean meal). Natural grass was used for control, because farmers usually provide natural grass for the goat, but in this study the grass was provided ad libitum |
| • | Kacang goats did not like the palatability of concentrate containing fish meal, therefore, the rations were made total mixed rations |
| • | Total mixed rations containing fish meal and soybean meal can improve the productivity and carcass product of kacang goats |
ACKNOWLEDGMENTS
The authors gratefully appreciate to the Directorate of Higher Education, Ministry of Education, the Republic of Indonesia for Doctoral Program Scholarship (BPP-DN) and Research Grant "Penelitian Unggulan Universitas Gadjah Mada". Appreciation is also expressed to "Kacang goats research team" that has assisted for data collection.