Production performance
The production performance of female Kacang goats fed with chemically and biologically treated durian fruit husk with different urea levels is presented in Table 2. The analysis of variance (ANOVA) results indicated that there was no significant interaction (P>0.05) between the administration of chemically and biologically processed durian fruit husk with different levels of urea on the variables of weight gain, dry matter intake, protein intake, feed utilization efficiency, feeding duration, rumination duration, resting duration and feeding frequency in the female Kacang goats. Similarly, the administration of durian fruit husk using different processing methods did not have a significant effect (P>0.05) on dry matter intake, feeding duration, rumination duration, rest duration and feeding frequency. However, the administration of durian fruit husk with different levels of urea had a significant effect (P<0.05) on the weight gain of the female Kacang goats.
The least significant difference (LSD) test results revealed that the weight gain, crude protein intake, protein utilization efficiency and feed utilization efficiency of goats fed biologically processed durian fruit husk were significantly higher compared to those fed chemically processed durian fruit husk. The higher weight gain, crude protein intake, protein utilization efficiency and feed utilization efficiency when goats were fed biologically processed durian fruit husk can be attributed to the superior quality of the feed compared to chemically processed durian fruit husk. The biological processing of feed ingredients enhances their quality through the involvement of microorganisms before animal consumption. This process is closely related to the functions of microorganisms during processing, as they are capable of breaking down complex compounds into simpler forms, particularly fiber components that often limit feed utilization in animals. Consequently, this improvement in feed quality directly enhances weight gain and nutrient utilization efficiency in animals.
The most essential nutrients for Kacang goats in cell formation and cell size enlargement are proteins, which contribute to weight gain. However, it is important to note that goats do not directly digest the whole proteins. Instead, protein undergos a process of breakdown by microorganisms through fermentation in the rumen.
The absence of effect on dry matter intake, feeding duration, rumination duration, resting duration and feeding frequency due to the administration of processed durian fruit husk can be related to the bulk characteristics of the forage consumed by Kacang goats. Additionally, the contents of the digestive tract remain in the reticulorumen for a significant period, approximately 70-90 hours, while the digestion of consumed feed primarily occurs within the rumen
(Tyagi et al., 2022).
The Least Significant Difference (LSD) test results indicated that the weight gain of goats fed durian fruit husk with 1.0% urea was significantly lower (P<0.05) compared to those fed with 2.5% and 5.0% urea levels. However, no significant difference in weight gain was observed between goats fed with 2.5% and 5.0% urea levels. The higher weight gain found in the goats fed processed feed with 2.5%-5.0% urea levels is caused by the availability of ammonia and VFA for rumen microbial growth, which help in the digestion of consumed feed. This is consistent with
McDonald et al., (2010) finding that urea in animal feed quickly dissolves and hydrolyzes into ammonia by rumen bacteria. Protein degradation in the rumen produces ammonia, VFA and CO
2, where ammonia is utilized as an N source for microbial protein growth, while VFA is utilized by the animal’s body for growth and CO
2 is expelled out.
Physiological condition
The physiological conditions (functional status and hematological values) of female Kacang goats fed chemically and biologically processed durian fruit husk with different levels of urea are presented in Table 3. The analysis of variance (ANOVA) test revealed that there was no significant interaction (P>0.05) between the administration of chemically and biologically processed durian fruit husk with different levels of urea on the physiological status (body temperature, respiratory rate and pulse rate) and hematological values (white blood cell count, red blood cell count, hemoglobin level and hematocrit value) in the Kacang goats. Similarly, the administration of durian fruit husk using different processing methods did not have a significant effect (P>0.05) on the physiological status (body temperature, respiratory rate and pulse rate) and hematological values (white blood cell count, red blood cell count, hemoglobin level and hematocrit value) of the Kacang goats. Additionally, the different levels of urea in durian fruit husk did not have a significant effect (P>0.05) on the functional status (body temperature, respiratory rate and pulse rate) and hematological values (white blood cell count, red blood cell count and hemoglobin level), except for the hematocrit value in the Kacang goats.
The results of this study indicate that the physiological status (body temperature, respiratory rate and pulse rate) and hematological parameters (white blood cell count, red blood cell count, hemoglobin level and hematocrit value) obtained from the goats fall within the normal range. The physiological condition (functional status and hematological values) of goats fed durian fruit husk processed using different methods and urea levels did not disrupt their physiological well-being. This suggests that both chemical and biological processing methods, with urea levels up to 5.0%, can be tolerated by goats for their normal activities. These findings are supported by
Bata et al., (2022), who revealed that the use of 5% urea in the fermentation process of rice straw was found to improve the digestibility of dry matter and organic matter without inducing negative effects. Similarly,
Puga et al., (2001) demonstrated that the utilization of 5% urea in the processing of agricultural waste enhanced the performance of rumen microorganisms in sheep.
The least significant difference (LSD) test results indicated that the hematocrit values of goats fed with 5% urea (L3) were significantly (P<0.05) higher compared to those fed with 1% urea but did not differ significantly from the values observed in goats fed with 2.5% urea (L2). However, there was no significant difference in hematocrit values between goats fed with 1% and 2.5% urea levels. The increasing levels of urea administration indicate an elevation in erythrocyte volume, indicating the availability of protein sources in red blood cell formation. Erythrocytes are essential components of the blood responsible for transporting oxygen and carbon dioxide. Erythrocytes are composed of approximately 60% water and 40% protein, which forms heme. Each erythrocyte contains 400 million hemoglobin molecules and constitutes 95% of the dry weight
(Hess and D’Alessandro, 2022).
Carcass and non-carcass
The results of the observations on slaughter weight, weight and percentage of carcass and non-carcass edible parts in female Kacang goats fed durian fruit husk processed using different chemical and biological methods and urea levels are presented in Table 4. The analysis of variance (ANOVA) showed that there was no significant interaction (P>0.05) between the administration of durian fruit husk processed using different chemical and biological methods and urea levels on the carcass weight, carcass percentage, non-carcass weight and percentage, internal non-carcass weight and percentage, external non-carcass weight and percentage and edible non-carcass weight and percentage on the Kacang goats. Similarly, the administration of durian fruit husk using different processing methods did not have a significant effect (P>0.05) on carcass weight, carcass percentage, external non-carcass percentage and non-carcass edible weight and percentage on the Kacang goats. Additionally, the durian fruit husk with different urea levels did not have a significant effect (P>0.05) on carcass weight, carcass percentage, external non-carcass weight and percentage and non-carcass edible weight and percentage. However, it had a significant effect on non-carcass weight and percentage and internal non-carcass weight and percentage in female Kacang goats.
The least significant difference (LSD) test results revealed that the percentage of non-carcass and the weight and percentage of internal non-carcass parts in goats fed 5% urea (L3) were significantly higher compared to those fed 1% urea (L1) and 2.5% urea (L2). However, no significant differences were observed between the 1% and 2.5% urea levels. The similar weights and percentages of carcasses in this study may be attributed to the similar quality of the feed provided in each treatment. Conversely, the increasing levels of urea resulted in increased non-carcass and internal non-carcass components, indicating possible fat deposition along the goat’s digestive tract. Growing goats in Indonesia requires a dietary protein content of 12-14% and a DE (digestible energy) of 2.8 Mcal.
A sufficient quantity and quality of feed cannot alter the genetically small body size of animals. However, providing inadequate feed quantities will not lead to optimal weight gain and carcass growth aligned with the genetic potential of each animal, such as a high growth rate and carcass percentage, among others
(Lutfi et al., 2022). The quality or nutritional value of feed can influence the amount of feed consumed by livestock. The quality of feed consumed by livestock can also affect the carcass percentage.
Rohana et al., (2020) stated that protein and energy are crucial elements for growth processes and a high-protein and high-energy diet can lead to significant weight gain.
Based on the results of this study, the carcass weights for each treatment ranged from 16.92 to 18.15 kg, resulting in little variation in non-carcass edible weight and percentage. This agrees with the finding by
Clinquart et al., (2022) that factors influencing carcass production in animals include breed, age, sex, growth rate, slaughter weight and nutrition. The percentage of non-carcass edible components that can be consumed can be calculated by dividing the weight of non-carcass edible components by the carcass weight and multiplying by 100%. The results of this study indicated that the treatments increased the percentage of non-carcass edible components that could be consumed.