Raising rabbits were done by people in developing countries, especially in rural areas being one of the solutions to sufficient animal protein of farmers in addition, also aims to increase the income of farmers. This is partly that raising rabbit is not needing a wide area and capital needed is relatively small (Nuriyasa, 2012).  The failure of the farmers in raising rabbit at present is because of farmers knowledge about rabbit nutrition is not enough (Nuriyasa et al., 2013).

Coffee pulp is a waste of harvest coffee agro industry. The fact that currently coffee pulp is regarded as rubbish and  only  a  few  farmers  use  coffee   pulp   as   organic fertilizer. Coffee pulp is often regarded as cause of environmental pollution because it is sprinkled around the coffee plants that cause the growth of fungi. Utilization of coffee pulp as rabbit diet can increase the value coffee pulp.

Bio fermentation for the coffee pulp could improved nutrient value of these by product, increased digestibility coefficient and reduced the pollutant gas which is important to create sustainable agriculture (Dubey, 2006). Mastika (2013) reported one of the alternatives for the cheap and competitive feed is through the utilization of agriculture waste. One of the wastes that can be used as animal feed is coffee pulp that has a high nutrient content, low price and it is available with lower production costs.

The coffee pulp production is very important for animal feed and the availability is 4,118.24 ton/ha of coffee plantation. Using Aspergillus niger in coffee pulp fermentation, the protein content could be increased from 9.94 to 17.81%, and crude fiber content decreased from 18.74 to 13.05% (Lestari et al., 2005). The study of Parwati et al. (2008) found that the fermented coffee pulp using A. niger could replaced rice bran utilization up to 5% in the diet and had no ad versed effect on performance of kampong chicken. Guntoro et al. (2004) has recommended that the level of coffee pulp utilization for pig and chicken diet is 10 to 15% respectively. Due to limitation of information about the utilization of fermented coffee pulp on rabbit nutrition especially the local rabbit, this experiment was carried out.

Rabbit

A total of 80 local rabbits with the average body weight 258.50 g ± 1.08 g were used in this experiment.

Cage of the rabbit

In this experiment, a total of 40 battery cages measuring 70 cm length, 50 cm width and 45 cm height following the recommendation of (Schiere, 1999) were used.

Feed and drinking water

The feed used in the experiment composed of yellow corn, fish meal, rice brand, copra meal, soy bean meal, elephant grass, cassava meal, fermented coffee pulp, coconut oil and bone meal. Feeds were composed of the same protein and calorie content which contain 16% CP and 2.500 kcal/kg (Nuriyasa et al., 2014). Feed was given in crumble form and drinking water was ad lib.

Hematological responses

Observation of hematological variables consist of hemoglobin (%), erythrocytes (10⁶/ µl), leukocyte (10³/ µl), hematocryte (%), glucose (mg/100 ml), triglyceride  (mg/100 ml) and Cholesterol (mg/100 dl) following the method of Bivin and King (2012). Anti frozen blood used is lithium heparin (Xiangmei, 2008), hematologic analysis performed in Bina Medika laboratory, Denpasar.

Body composition

Calculation of energy and protein retention in the body of rabbits follows the formulation of Fernandez and Fraga (1996). Briefly, the rabbit samples were taken at 17 week old. The fresh body from each treatment was chopped, ground using meat grinder, then the ground meat were mixed thoroughly. Four samples from each treatment were taken for calorie and protein determination. Energy content of the carcass was determined using bomb calorimeter  and Kejelldhal apparatus for protein determination. Energy and protein concentration of diets, feces and empty bodies was measured with adiabatic bomb calorimeter and Kejelldhal apparatus (Xiccato et al., 1999).

Performance

Feed and water consumption were calculated each week by deduction of the feed and water given for one week. Before measurement rabbit was fasted for 12 h. Feed conversion ratio was calculated from feed consumption divided by weight gain at 12 weeks.

Carcass

Data carcass was carried out following the method of Alhaidary et al. (2010).  Briefly, rabbit sample was killed at 84 days aged, as recommended by Owen and Owen (1981). All data were recorded, tabulated, and analyzed using analysis of variance. Whenever significantly differences among treatment were found, analysis will continue using Duncan’s Multiple Range Test (Steel and Torrie, 1980).

Rabbits given R3 consumed diet, had weight gain and feed conversion lower than other treatments. Rabbits given R3 and R4 consumed higher protein (P<0.05) than the ones given R2, R1 and R0 respectively. Sweet taste of diet R3 and R4 made the rabbits to consumed more fed so protein consumption was also more. This result is supported by Mc Nitt et al. (1996). Diets R0, R1, R2, R3 and R4 have no effect on the protein content of the feces. Rabbit given diet R3 had protein retention of 0.55g/day higher (P<0.05) than those given R4 (0.53 g/day), R2 (0.50 g/day), R1 (0.52 g/day) and R0 (0.53 g/day), respectively.  Growth rate and feed efficiency with higher protein retention is also reported in the body, this finding confirmed the result reported by Nuriyasa et al. (2014). Rabbits offered diet R3 have significant (P<0.05) final body weight and weight gain compared to those given diet R4, R2, R1 and control diet (Table 3). Bio fermentation process had increased the nutrient availability and digestibility of the coffee pulp (Dubey, 2006). 

Krisnan (2002) stalled that Aspergillus niger caused decreased tannin content of feed stuff. Rabbit fed diet R3 had higher body weight. This finding is in line with the report of Nuriyasa et al. (2014). He postulated that the best growth rate is due to higher retention of energy and protein on body of rabbit. Feed conversion of the rabbit fed diet R3 was significantly (P<0.05) lower compared to other treatment.  This is due to hematological response in rabbit fed diet R3 so they grew faster than other treatments.

Jorgensen et al. (1997) stated that better metabolism has strong effect of crude fiber content of diets especially for non ruminant nutrition.  The laboratory analysis showed that diet R3 had the lowest crude fiber (11.96%) compared to other diets such as control that had 12.13%, diet R1, R2 and R4 were 12.72, 13.38 and 12.96%, respectively. This is in line with the report of Nuriyasa et al. (2014). Rabbit given diet R3 at 70 days age had carcass weight, carcass percentage  and  carcass  length significantly (P<0.05) higher than those fed other diets. This is due to the fact that the feed consumption and growth rate of the rabbit fed diet R3 were significantly (P<0.05) higher than those getting other treatments (Table 3). Jorgensen (1997) has stated that crude fiber content of diet had increased the digestibility of diets so nutrient could be absorbed well and finally causing carcass weight, carcass percentage, carcass length higher than other diet.   

From the result of the experiment it can be concluded that rabbits containing 10% of fermented coffee pulp had performance carcass and hematological better than other treatments. Energy retention of the rabbit given diet R3 (55.20 kcal/day) are higher than those given diet R4 (53.77 kcal/day), R2 (53.83 kcal/day), R1 (51.56 kcal/day) and R0 (52.90 kcal/day), respectively.  Protein retention of the rabbit given diet R3 (0.55 g/day) were higher than the rabbits given R4 (0.53 g/day), R2 (0.50 g/day), R1 (0.52 g/day) and R0 (0.53 g/day), respectively.

The authors have not declared any conflict of interests.

The authors wish to thank the Indonesian government through Udayana Community Service (LPPM), who gave financial support to complete this study. Thanks to the Faculty of Animal Husbandry, Udayana University and Faculty of Post Graduate Study who had provided equipment and research facilities during this study.