Dietary Crude Protein and Total Digestible Nutrient on The Performance of Boerka Goats Male Growing Phase

Boerka goat is the best meat type goat. Feed quality is one of the biggest factors that affect productivity, so it is necessary to know in advance the need for nutrients. The purpose of this study was to determine the dietray of crude protein (CP) and Total Digestible Nutrients (TDN) in efficient feed for the production of Boerka goats male growing phase. This study was designed in a completely randomized design, consisting of six combination feed treatments with six replications. Namely: 1 (CP 13.00% and TDN 63.10%); 2 (CP 13.03% and TDN 65.07%); 3 (CP 13.00% and TDN 70.00%); 4 (CP 15.00% and TDN 62.69%); 5 (CP 15.12% and TDN 65.00%); 6 (CP 15.00% and TDN 70.00%). The observed variables were feed consumption, feed consumption ratio (FCR), nutrient digestibility (dry matter, organic matter, crude protein) and average daily gain (ADG). Results of this study show that the balanced of CP and TDN has no significant effect on consumption and FCR. However, it was significantly different for digestibility and ADG. Feed treatment (CP 13.03% and TDN 65.07%) obtained the higher digestibility of DM and OM (71.49 and 70.5%), while the highest CP digestibility was treated with CP 15.05% and TDN 62.69% (71.59%). The ADG response of Boerka goats with CP 13.03% and TDN 65.07% was the good results (144.90 g head -1 day -1 ) while the lowest response was on CP 13.08% and TDN 63.10%. It is concluded that the dietray of CP 13.03% and TDN 65.07% is a recommended of Boerka goat male growing phase.


Background
Boerka goat is small ruminant that have good characteristics as meat goats and have potential as superior goat breeds (Richard, 2011;Elieser et al. 2012). The young male of Boerka goat is a feeder that can be used as seeds that can produce meatproducing livestock, in that phase the need for feed (quality and quantity) must be fulfilled with the aim of spurring growth in order to achieve maximum body weight when used as a stud goat or cut according to size, with its biological level (Ginting and Fera, 2008).
Feed is the biggest factor affecting livestock productivity. Growing goats need energy for life, growth, muscle movement, and synthesis of new tissues (Arthur et al. 2011;Moroz and Samorukov, 2020). Feed conditions, such as insufficient quality and quantity, lead to low livestock productivity, as indicated by a slow growth rate and low body weight. One of the efforts that can be done to increase the productivity of young male Boerka goats is to provide good feed with sufficient nutrient content. The availability of nutrients in the right amount, composition and at the right time greatly affects the level of livestock productivity (Sampurna, 2013;Rohayati, 2019).
Crude protein (CP) and Total Digestible Nutrients (TDN) or energy are nutrients that are needed. Lack of energy in livestock rations can reduce rumen function and reduce the efficiency of protein use and inhibit livestock growth. Protein deficiencies include anorexia, decreased growth rate, decreased or unbalanced N, decreased feed efficiency, decreased serum protein concentration, anemia, fat accumulation in the liver, edema (in some cases), decreased birth weight, decreased milk production, decreased enzyme synthesis and certain hormones (Chakeredza et al. 2008;FAO, 2012).
The availability of energy in the ration consumed is very important for livestock, because it can affect the efficiency of protein use in synthesizing body tissues (Charles and Glen, 2017). Protein availability is one of the nutritional components needed by young livestock for growth. Feed protein that enters the rumen will initially undergo proteolysis by protease enzymes into peptides, then hydrolyzed into amino acids which are then rapidly deaminated into ammonia (Sok et al. 2017;Suryani et al. 2020). The presence of protein and energy in the feed will be used by rumen microbes for cell protein synthesis and in the rumen it acts as a digester of crude fiber feed and as a source of protein for the landlady.
The balance of energy and protein is important because it can affect the dynamics of the microbial fermentation process in the rumen (Castillo et al. 2014). Microbes need an energy source for growth, generally only use carbohydrates. The carbohydrates are needed as a source of carbon atoms (C) to form the structural framework of rumen microbial protein (Ginting, 2005). Proteins that are degraded (deaminated), in addition to releasing ammonia (NH3) groups, will produce carbon chain groups which can also be substrates in the rumen microbial fermentation process. Synchronous proteinenergy ratio will show optimal fermentation efficiency, in this case the feed energy used for the process will be optimal as well. So it is necessary to study how much energy can be utilized by livestock fed with different CP and TDN balances.
Synchronization between energy and protein availability in the rumen, apart from increasing microbial activity, can also increase rumen microbial protein synthesis and livestock performance. The results of research by Martawidjaja et al. (1999) reported that feeding with higher protein and energy levels resulted in higher dry matter consumption, protein and energy in goats. Based on these problems, a study is needed on how much protein and energy needs in efficient feed for the productivity of male Boerka goats in the young phase.

Materials and Methods
This activity was carried out in the laboratory and experimental cage Indonesian Goat Research Station, Deli Serdang Regency, North Sumatera. The study was conducted for six months using Boerka goats male growing phase at the age of five months. A total of 36 male Boerka goats (mean live weight 11.2 ± 1.33 kg) were randomly placed in individual cages and given a basic diet of 3.8% of body weight based on dry matter (NRC, 1981). Water is given freely (adlibitum). Basic feed is given for two weeks with the aim that the goats can adapt to the form of feed that will be given during the observation period. The goats were randomized to get one of the six treatment feeds that had been prepared. The treatment feed provided consisted of two levels of crude protein content and three levels of Total Digestible Nutrients. There were six combinations of feed treatments in this study (Table 1). Feed treatment is given in a single feed (3.8% of life weight), and adjusted every two weeks so that it is in line with the life necessities  The parameters observed are consumption, feed consumtion ratio (FCR), nutrient digestibility (dry matter, organic matter, protein) and life weight changes. Consumption data were obtained from the difference between giving and the rest feed every day. The feed samples were analyzed proximately, with the AOAC method (1995), while the Energy Content is used by Adiabatic Bomb Calorimeter (Gallenkamp Autobomb). Digestibility values were carried out using the method of Tillman et al. (1991). To determine changes in live weight, goats were weighed every two weeks before being fed in the morning.

Statistical Analysis
The study was conducted in a completely randomized design (Gomez and Gomez, 1984) with six treatments (feed composition) and six replications. All data obtained were analyzed with correlation analysis with SPSS version 16.0 program. Significant differences among treatment means were tested using Duncan's multiple range test (DMRT) at the 5% level of.

Results and Discussion Consumption, feed consumption ratio and digestibility
The value of consumption, FCR and digestibility (dry matter, organic matter, crude protein) for six treatment combinations of feed with different energy and protein content given as a single feed to goats is shown in Table 3.
The effect of balances CP and TDN on treatment feed on dry matter (DM) consumption and FCR of young male Boerka goats was not significantly different (P>0.05). Average consumption is 105.90 g head -1 day -1 . Numerically, the highest level of consumption was found in goats fed with P1 TDN2 (1119.55 g) and the lowest was in P1 TDN1 (986.40 g) treatment, almost comparable to the study of Rochana et al. (2020), with a balance of 12% protein and 60% TDN can consume 973.26 g head -1 day -1 dry matter. The level of feed consumption in this study was moderate and did not affect the value of the obtained FCR (average 8.44).  Mathius et al. (2002) 74.40% used young PE goats with different protein and energy balances. Differences in acid detergent fibers may cause differences in the level of digestibility. The feed component in this study using palm fronds is a component of the ration containing lignin and is known to be unable to be broken down/digested by rumen microorganisms. As a consequence the digestibility of DM will be affected (Van Soest, 1982;Yanti et al. 2004

Average daily gain
The effect of several of feed treatment on the average daily gain of Boerka goats male growing phase is presented in Figure 1. The value of Average daily gain (ADG) above shows that the lower of TDN content consumed, the lower the response that can be shown by goats in the form of ADG. However, data obtained on Boerka goats showed that all feed treatments gave a fairly good response to the appearance. The average of ADG obtained was 136.81 g head -1 day -1 , ranging from 130.21-144.90 g head -1 day -1 . The results of this study is higher compared to those reported by Rochana et al. (2020), the balance of 16% protein and 65% TDN obtained ADG of 114.28 g head -1 day -1 . Mathius et al. (2002) reported that young male PE goats obtained an average of 86.40 g head -1 day -1 . While research by Nugroho et al. (2013) obtained 73.86 g using a 16% PK balance and 66% TDN in the feed.
The results obtained in Figure 1 show that the P1 TDN2 feed treatment obtained the highest ADG yield, significantly different (P<0.05) from the P1 TDN1 treatment. The results of statistical tests showed that there was no significant difference in the treatment of P1 TDN3, P2 TDN1, P2 TDN2, and P2 TDN3. The response of young Boerka goats with a protein balance of 13.03% and TDN of 65.07% was sufficient to obtain very good results on ADG. Meanwhile, the lowest response occurred in goats that received treatment with low TDN levels (63.10%). Goats that received treatment with a high protein level of 15.00% and high TDN of 70.00% in this study numerically did not show optimal results even though they were not significantly different from low protein 13.03% and medium TDN (65.07%).
The Average daily gain obtained in this study is also known to have a relationship with a high level of feed digestibility. The digestibility of feed (DM, OM and CP) in the P1 TDN2 treatment was high compared to other treatments, each obtaining 71.49, 70.5, 70.92% (Table 3). Each of these relationships follows the ADG equation, the higher the consumption and digestibility of the feed, the higher the ADG obtained. This results in more nutrient intake which will be used for livestock growth (Ayuningsiha et al. 2018). Meanwhile, ruminants that experience a lack of protein and energy result in loss of body weight and have an impact on reproductive failure (Olson et al. 1999). The rate of degradation of carbohydrates as a source of energy and protein feed in the rumen can have a major influence on the final product of fermentation and livestock performance (Russel et al. 1992). If substance N is degraded faster than the energy source (TDN), then the ammonia resulting from the degradation of compound N will be transferred to the liver, and then recycled to the digestive tract (a small portion) and most of it is lost with urine secretion. On the other hand, if the amount of available energy exceeds the availability of N, the microbial growth and efficiency of rumen fermentation decreases. If feed degradation is slow, consumption will be depressed and some nutrients cannot be fermented optimally in the rumen (Ginting, 2005). Therefore, it is necessary to balance protein and energy in the ration.

Conclusion
The effect of dietray crude protein and TDN has no significant effect on consumption and FCR. However, it gave a good response to the value of feed digestibility and average daily gain. Feed treatment with CP 13.03% and TDN 65.07% obtained the highest digestibility of DM (71.49%) and OM (70.5%), and gave the best performance for ADG (144.90 g head -1 day -1 ). Thus, the treatment level of CP 13.03% and TDN 65.07% can be recommended for the use of male Boerka goat male feed in the growing phase.