Research Article

High-Quality Forage and Palm Concentrate Concerning Milk Production in Etawa Crossbreed Goats

Arief1*, Roni Pazla2

1Department of Animal Production Technology, Faculty of Animal Husbandry, Andalas University. Jl. Raya Limau Manis Campus, Padang, West Sumatra, Indonesia; 2Departemen of Nutrition and Feed Technology, Faculty of Animal Husbandry, Andalas University. Jl. Raya Limau Manis Campus, Padang, West Sumatra, Indonesia.

Received | September 19, 2023; Accepted | October 09, 2023; Published | November 06, 2023

*Correspondence | Arief, Department of Animal Production Technology, Faculty of Animal Husbandry, Andalas University. Jl. Raya Limau Manis Campus, Padang, 25163, Indonesia; Email: aarief@ansci.unand.ac.id

Citation | Arief, Pazla R (2023). High-quality forage and palm concentrate concerning milk production in etawa crossbreed goats. Adv. Anim. Vet. Sci., 11(11):1810-1816.

DOI | https://dx.doi.org/10.17582/journal.aavs/2023/11.11.1810.1816

ISSN (Online) | 2307-8316

Copyright: 2023 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

INTRODUCTION

Forages and concentrates are essential components for optimal milk production and quality in dairy goats. However, in Indonesia, there are challenges concerning the provision of forages and concentrates within the community. The community only knows natural grass as a source of forage, while its availability is limited due to the limited growing areas as a result of housing construction, road development, highways, and other infrastructure development. The concentrate is a strengthening feed whose price is quite high on the market, so farmers cannot afford to buy it in large quantities.

Mirasolia diversifolia (Md), Indigofera zoolingeriana (Iz), and Gliricidia sepium (Gs) are high-quality forages that have not been widely utilized and cultivated by dairy goat farmers. The crude protein content of these forages is 21.75 (Pazla et al., 2023a), 27.01 (Badarina et al., 2023), and 19.11% (Adrizal et al., 2021), respectively. When compared with field grass, which contains only 7-11% crude protein (Elihasridas et al., 2023a), Md, Iz, and Gs possess the capacity to enhance dairy goats performance. This potential is attributed to their high crude protein content. Crude protein is degraded by rumen microbes into ammonia (NH3) (Antonius et al., 2023; Pazla et al., 2023b; Zain et al., 2023). NH3 is essential for rumen microbes to synthesize their body proteins (Synthesis of proteins by microorganisms) (Pazla et al., 2018a; Putri et al., 2019, 2021). Microbial protein plays a crucial role as a nutrient that enhances both milk production and quality (Rosmalia et al., 2022; Sari et al., 2022).

Palm concentrate (PC) is an alternative to commercial concentrates with high prices. It is derived from palm kernel cake, a by-product of the palm oil processing industry. The use of PC as a substitute for the company’s concentrate has the potential to sustain both the production and quality of milk in Etawa crossbreed goats (Arief et al., 2018a, b, 2020, 2023a; Arief and Pazla, 2023). The mixture Md with napier grass in etawa crossbreed goat ration can optimize digestibility and milk production (Pazla et al., 2022). Arief and Pazla (2023) reported milk quality of etawa crossbreed goat can optimize with the mixture Gs and palm concentrate in the ration. The use of a mixture of Md, Iz, and Gs with PC for the Etawa crossbreed goat has not been previously studied. We aimed to evaluate the effectiveness of combining high-quality forages such as Md, Iz, and Gs with PC in the Etawa crossbreed goat ration.

MATERIALS AND METHODS

Research site

Ration trials on Etawa crossbreed goats were performed at Toni Farm livestock company in Payakumbuh City, West Sumatra. The feed ingredients, feces, fat, and milk lactose content analysis was performed at the Payakumbuh Polytechnic Laboratory, West Sumatra.

Research materials

We employed 16 Etawa crossbreed goats with an average weight of 60±1.31 kg. These dairy goats are in their second lactation. The goats were placed in individual pens equipped with feeding and drinking facilities.

The research ration consisted of forage and concentrate. The forage used includes company forage, Md, Iz, and Gs, while the concentrate consists of both company concentrate (CC) and palm oil concentrate (PC). The ratio of forage and concentrate is 60:40. Forage and concentrate were given separately. The concentrate was administered twice daily, in the morning and the afternoon. On the other hand, forage was provided three times a day: In the morning, during the afternoon, and in the evening. PC is produced from a blend of palm kernel meal, bran, corn, and minerals. The chemical structure of the feed components comprising the ration is presented in Table 1. The structure and chemical analysis of the ration are presented in Table 2.

Experimental design

We employed an experimental approach utilizing a fully randomized design, which consisted of four dietary treatments and four repetitions as follows: T1 (Control): 60% company ration + 40% company concentrate, T2: 60% (Md+Gs) + 15% CC +25% PC, T3: 60% (Iz+Gs) + 15% CC +25% PC, and T4: 60% (Md+Iz) + 15% CC +25% PC.

 

Table 1: Chemical composition of feed ingredients.

Chemical Composition (%)	Feedstuff
	CF	Md	Iz	Gs	PC	CC
Dry Matter	26.03	23.13	21.24	21.42	93.06	30.67
Organic Matter	87.93	84.65	92.41	94.85	94.07	94.33
Crude Protein	25.43	25.07	25.29	19.11	12.53	08.32
Crude Fiber	28.02	22.62	12.87	19.75	19.05	20.37
Crude fat	2.73	1.62	3.64	2.98	3.50	5.82
TDN	56.46	56.72	61.42	66.07	77.54	78.26
NFE	31.75	35.34	40.51	53.01	58.99	59.82
Ash	12.07	15.35	07.59	05.15	5.93	5.67

 

Total digestible nutrient (TDN), Nitrogen free extract (NFE), Mirasolia diversifolia (Md). Indigofera zoolingeriana (Iz), Gliricidia sepium (Gs), Palm concentrate (PC), Company forages (CF), Company concentrates (CC)

 

Table 2: Ratio composition and chemical composition of treatment rations.

Feedstuff	Treatments (% DM)
	T1	T2	T3	T4
Company Forages	60	0	0	0
Ms	-	40	-	30
Gs	-	20	15	-
Iz	-	-	45	30
Pc	-	25	25	25
CC	40	15	15	15
Total	100	100	100	100
Chemical Composition
Dry Matter	27.89	31.40	30.64	31.18
Organic Matter	90.49	90.50	93.48	90.79
Crude Protein	18.59	18.23	18.63	19.49
Crude Fiber	24.96	20.82	16.57	18.47
Crude Fat	3.97	2.99	3.83	3.33
TDN	65.18	67.03	68.67	66.57
NFE	42.98	48.46	49.90	46.48
Ash	9.51	9.50	6.52	9.22

 

Dry matter (DM), Mirasolia diversifolia (Md), Indigofera zoolingeriana (Iz), Gliricidia sepium (Gs), Palm concentrate (PC), Company forages (CF), Company concentrates (CC).

 

Statistical analysis

The data underwent analysis of variance, and IBM SPSS version 21 software was employed for this purpose. Treatment distinctions were evaluated through the application of the Duncan Test at a significance level of 5% (Steel and Torrie, 2002).

The measured parameters included ration consumption (crude fat, crude fiber, and NFE), the digestive efficiency of food substances (crude fat, crude fiber, and NFE), dairy production, milk fat, and lactose content. The food substances were assessed through the AOAC method (AOAC, 2016). Milk fat and lactose content were determined using Lactoscan Pro 201. Milk production (FCM) was calculated based on the method described by Mavrogenis and Papachristoforou (1988).

Where; FCM = fat-corrected milk production (at 4% fat); M= the weight of milk in Kg; f = the amount of fat present in milk.

Research period

This research comprises three phases: A 14-day adaptation phase, a 14-day initial phase, and a 5-day data collection phase. The adaptation phase aims to get the goats used to eating the new ration. The initial phase aimed to eradicate the influence of the previous ration, while the collection phase was used to determine milk production, ration consumption, feces collection, and the digestibility of nutrients and milk quality. Ration consumption was calculated by weighing the difference between the quantity of food provided to the livestock with the residual amount. Fecal samples, comprising 10% of the total feces, were then sun and oven-dried at 60°C/48 h. Subsequently, the stool samples were analyzed for their chemical composition based on AOAC (2016).

 

Table 3: Feed Intake of The Treatment Ration.

Parameters (kg/day)	Treatment
	T1	T2	T3	T4
Crude Fat Intake	0.072	0.059	0.067	0.076
Crude Fiber Intake	0.371	0.409	0.328	0.454
Nitrogen-Free Extract Intake	0.782	0.953	0.934	0.989

 

RESULTS and Discussion

Consume crude fats, crude fibers, and nitrogen-free extract (NFE)

The consumption of crude fiber, crude fat, and NFE in the diet of lactating Etawa crossbreed goats is presented in Table 3. The treatments showed no significant effects on the consumption of crude fiber, crude fat, and NFE. The mixture of Md, Iz, and Gs forages with PC can match the consumption of forages and company concentrates.

Digestibility of crude fiber, crude fat, and nitrogen free extract (NFE)

The digestibility of crude fiber, crude fat, and NFE is presented in Figures 1, 2, and 3. The treatments showed significant (P<0.05) differences in the digestive ability of crude fat, crude fiber, and NFE. The highest digestive ability of crude fiber and crude fat was found in T3.

 

 

 

The digestibility of crude fat and crude fiber among treatments T1, T2, and T4 showed no significant differences. The T4 exhibited the highest NFE digestibility, whereas treatments T1, T2, and T3 demonstrated no significant differences.

Milk production

Milk production (FCM) for each treatment is presented in Figure 4. The treatments showed insignificant (P<0.05) differences in milk production. The replacement of company rations with a combination of forages and PC successfully maintained milk production. Although there was no statistical significance, T3 yielded the highest milk production, whereas T4 had the lowest milk production.

 

 

 

Milk fat and lactose content

The milk fat and lactose content of the treated milk are presented in Figures 5 and 6. The treatments showed insignificant differences in the fat and lactose content of the milk. Replacing company rations with a combination of forages and PC maintained milk fat and lactose levels. Although not statistically significant, T3 produced the highest milk fat content and the lowest lactose.

Consumption of crude fats, crude fiber, and NFE

The nonsignificant differences between the ration treatments were attributed to the level of palatability and livestock preferences for the given rations being consistent. Pazla et al. (2018b) and Jamarun et al. (2023), have stated that feed ingredients’ palatability directly influences attractiveness and can stimulate livestock appetite. Aroma, texture, and odor significantly impact the taste. Considering our results, it is evident that the provided ration possesses an aroma, texture, and odor that enhances livestock appetite. Arief and Rizqan (2023b) discovered that the consumption of crude fat, crude fiber, and NFE did not differ in the Etawa cross-breed goat ration containing field grass, Md, cassava, and PC, with consumption values of 0.07 kg/d, 0.51 Kg/d, and 1.11Kg/d, respectively. The forage-to-concentrate ratio of 60:40 in the feed also leads to consistent livestock consumption. Disparities in the forage and concentrate ratio within the ration will result in differences in the amount of ration consumed by livestock (Pazla et al., 2023c). In addition, the four treatments were prepared with nearly identical protein and energy balances, ensuring nearly identical nutritional quality. Febrina et al. (2017) and Marquest et al. (2022) have affirmed that ration consumption is influenced by feed quality and digestibility level.

Digestibility of crude fats, crude fiber, and nitrogen free extract

Significant differences in the digestive ability of crude fiber, crude fat, and NFE were attributed to the influence of the nutrient composition of the feeds, specifically the crude fiber and NFE content, and the capacity of rumen microbes to break down feed. The highest digestive ability of crude fat and crude fiber was found in the T3, which included rations containing IZ and Gs forage along with PC. The T3 contained a lower crude fiber value than the other treatments. Crude fiber acts as a limiting factor for rumen microbes in the degradation of feed and its conversion into an energy source (Jamarun et al., 2017a, b, c; Pazla et al., 2020; Elihasridas et al., 2023b). The highest NFE content in T3, at 49.90%, also greatly facilitates the development of rumen microbes. NFE is a carbohydrate fraction easily metabolized by rumen microbes (Pazla et al, 2023d). The higher the NFE value, the more significant its contribution to energy production and milk quality. The fat content across treatments remained within the tolerance limits for rumen microbes. Rumen microbes are disturbed in digesting crude fat when the fat content exceeds 5% (Makmur et al., 2019; Jamarun et al., 2020). The high digestibility of ration fat in T3 was due to an increase in the rumen microbial population, a result of the low crude fiber content and high NFE content in T3. While the digestibility of NFE in T4 is indeed higher than that in T3, the levels of NFE in T4 are lower than in T3, resulting in nearly equal total NFE digestion between T4 and T3. In the T4 treatment, rumen microbes are believed to degrade more of the NFE content in the ration, leading to optimal digestibility.

Milk production

Milk production, which showed no significant variation among treatments, can be attributed to nearly identical feed quality factors. The rations were prepared with proteins that showed minimal variation between treatments. The energy content (TDN) also exhibited minor differences. This study found almost identical availability of protein and energy, resulting in no discernible differences in milk production. However, Figure 4 reveals that the T3, comprising a ration containing Iz, Gs forage, and PC, achieved the highest FCM milk production. The quantity of digested food substances, such as crude fat and crude fiber, was also highest in the T3, leading to optimal milk production in this treatment.

The consumption of the same ration was the primary reason for the absence of differences in milk production between treatments. Larson (1979) states that milk production relies heavily on blood nutrients associated with the efficiency of the consumed food. The milk production (FCM) produced in this study closely resembled that reported by Arief et al. (2023b), ranging from 1.22 to 1.41 Kg with rations comprising field grass, Md, and PC. However, it was lower than that documented by Pazla et al. (2022), which ranged from 0.51 to 0.54 kg with a ration consisting of palm fronds, Md, and elephant grass. This variation can be attributed to the differences in the type of ration provided.

Milk fat and lactose content

The fat and lactose content of the milk, which did not differ between the ration treatments, was a result of the nearly identical quality of the rations provided. Feed consumption was nearly identical in each treatment, ensuring that the nutritional intake for milk fat and lactose formation remained consistent. However, the T3 exhibited a higher fat value than the other treatments. This condition occurred due to the high digestibility of crude fiber and crude fat at T3. The digestibility of crude fiber and crude fat closely correlates with milk fat value. Arief et al. (2023b) identified a correlation between milk fat content and the digestive ability of crude fiber and crude fat. Crude fiber, when fermented by rumen microbes, produces acetic acid, a fundamental component in milk fat formation (Despal et al., 2021a, b). Optimal degradation of crude fiber in the rumen results in elevated acetate levels, consequently increasing milk fat content (Florendo et al., 2018; Fatmawati et al., 2022). The consistent milk fat content across the treatments resulted from the equal ratio of forage and concentrate in the rations. The ratio of concentrate in the ration greatly affects the fat content of milk. Milk fat content will decrease if the ratio of concentrate in the ration is raised (Schmidely and Sauvant, 2001).

The lowest milk lactose value was found in T3. This is very natural because milk fat is the opposite of milk lactose. Milk lactose binds with water. When the milk has a high lactose level, it will have a higher water content, whereas if the milk has a low lactose level, it will contain less water but a higher fat content. Milk lactose is synthesized from the NFE substance, which is transformed into propionic acid in the rumen. Propionic acid is taken up from the rumen wall and transformed into glucose in the liver. Glucose enters the mammary gland cells and is converted into lactose (Sondakh et al., 2017). The quality of milk is determined by the fat content contained in the milk. The quality of the milk improves as its fat content increases. In this study, the milk’s fat and lactose content meet the criteria for premium milk quality as defined by the Thai Agricultural Standard (2008).

CONCLUSIONS and Recommendations

Providing a mixture of Md, Iz, and Gs forage with PC to Etawa crossbreed goats balanced the FCM milk production of the company. The three ration formulations can serve as a foundation for dairy goat farmers in providing nutrition to their livestock.

ACKNOWLEDGEMENT

Thank you to LPPM Andalas University for funding this research through the Superior Applied Research Scheme, Research Cluster-Accelerated Publication, with contract number: T/3/UN16.19 Pangan PTU-KRP2GB-Unand/2023. Also, I extend my gratitude to the leadership of Toni Farm for providing research facilities and laboratory assistants at Payakumbuh Politani University.

NOVELTY Statement

This study introduces a new ration formulation for Etawa-breed dairy goats, incorporating high-quality forages and palm oil concentrates. This combination optimizes the milk production of Etawa crossbreed goat milk.

AUTHOR’S CONTRIBUTION

ARIEF designed the research concept and provided field supervision, while Roni Pazla conducted in-vivo research, performed laboratory analysis, analyzed the data, and drafted the document.

Ethical statement

This study has obtained ethical approval from the Faculty of Medicine at Andalas University regarding the use of animals in research experiments with number: 115/ UN.16.2/KEP-FK/2023.

Conflict of interest

The author affirms that there are no conflicts of interest regarding the research or publication of this manuscript.

REFERENCES

Adrizal, Pazla R, Sriagtula R, Adrinal, Gusmini (2021). Assessment of local forage nutrition potential for ruminant feeding in the Payo agro-tourism area, Solok City, West Sumatra, Indonesia. Earth Environ. Sci., 888: 1-5. https://doi.org/10.1088/1755-1315/888/1/012055

Antonius, Pazla R, Putri EM, Negara W, Laia N, Ridla M, Suharti S, Jayanegara A, Asmairicen S, Marlina L, Marta Y (2023). Effectiveness of herbal plants on rumen fermentation, methane gas emissions, in vitro nutrient digestibility, and population of protozoa. https://doi.org/10.14202/vetworld.2023.1477-1488

AOAC (2016). Official methods of analysis of the association of analytical chemists. Virginia, USA: Association of Official Analytical Chemists, Inc.

Arief, Jamarun N, Pazla R, Satria B (2018a). Production and quality of Etawa raw milk using palm oil industry waste and Tithonia diversifolia plants as an early Feed. Int. J. Dairy Sci., 13: 15-21. https://doi.org/10.3923/ijds.2018.15.21

Arief, Sowmen S, Pazla R, Rizqan (2018b). Production and quality of Etawa raw milk using palm oil industry waste and paitan plants as an early Feed. Pak. J. Nutr., 17(8): 399-404. https://doi.org/10.3923/pjn.2018.399.404

Arief, Sowmen S, Pazla R, Rizqan (2020). Milk production and quality of Etawa crossbreed dairy goat that given Tithonia diversifolia, corn waste and concentrate based palm kernel cake. Biodiversitas, 21(9): 4004-4009. https://doi.org/10.13057/biodiv/d210910

Arief, Pazla R (2023). Milk production and quality of etawa crossbred goats with non-conventional forages and palm concentrates. Am. J. Anim. Vet. Sci., 18(1): 9-18. https://doi.org/10.3844/ajavsp.2023.9.18

Arief, Pazla R, Jamarun N, Rizqan (2023a). Production performance, feed intake and nutrient digestibility of Etawa crossbreed dairy goats fed tithonia (Tithonia diversifolia), cassava leaves and palm kernel cake concentrate. Int. J. Vet. Sci., 12(3): 428-435. https://doi.org/10.47278/journal.ijvs/2022.211

Arief, Pazla R, Rizqan JN (2023b). Influence of tithonia diversifolia, cassava and palm concentrate combinations on milk production and traits in etawa crossbred. Adv. Anim. Vet. Sci., 11(4): 568-577. https://doi.org/10.17582/journal.aavs/2023/11.4.568.577

Badarina I, Dwatmadji, Rapelino R (2023). In vitro digestibility and rumen pH of diet comprised by different levels of Indigofera zollingeriana and Pennisetum purpureum. E3S Web Conf., 373(01): 1-5. https://doi.org/10.1051/e3sconf/202337301009

Despal D, Sari LA, Permana IG, Zahera R, Anzhany D (2021a). Fibre feeds impact on milk fatty acids profiles produced by smallholder dairy farmers. Int. J. Dairy Sci., 16: 98-107. https://doi.org/10.3923/ijds.2021.98.107

Despal D, Anzhany D, Permana IG, Toharmat T, Zahera R, Rofiah N, Nuraina N, Hamidah AH (2021b). Estimation of milk fatty acids health index as milk value added determinant using FT-NIRS. Am. J. Anim. Vet. Sci., 16: 335-344. https://doi.org/10.3844/ajavsp.2021.335.344

Elihasridas, Erpomen, Pazla R (2023a). Substitution of field grass with yam straw to nutrient digestibility in vitro. Indonesian J. Anim. Sci., 25(2): 246-254. https://doi.org/10.25077/jpi.25.2.246-254.2023

Elihasridas, Zain M, Pazla R, Sowmen S, Aini Q (2023b). In vitro Digestibility of ammoniated aromatic supplemented lemongrass waste. https://doi.org/10.17582/journal.aavs/2023/11.8.1368.1376

Fatmawati M, Suwanti L, Hambarrukmi W, Sukesi L, Novianto E, Wahyutyas K (2022). A comparative study among dairy goat breeds in Lumajang and Malang (East Java, Indonesia) based on milk organoleptic and milk composition. Biodiv. J. Biol. Divers., 23. https://doi.org/10.13057/biodiv/d230616

Febrina D, Jamarun N, Zain M, Khasrad (2017). Effects of using different levels of oil Palm Fronds (FOPFS) fermented with Phanerochaete chrysosporium plus minerals (P, S and Mg) instead of Napier grass on nutrient intake and the growth performance of goats. Pak. J. Nutr., 16(8): 612-617. https://doi.org/10.3923/pjn.2017.612.617

Florendo PDC, Sharma SR, Vfellner V (2018). Cattle rumen microorganisms hydrolysis for switchgrass saccharification, volatile fatty acids and methane production. Int. J. Agric. Technol., 14: 31-43.

Jamarun N, Zain M, Arief, Pazla R (2017a). Effects of calcium, phosphorus and manganese supplementation during oil palm frond fermentation by phanerochaete chrysosporium on laccase activity and in vitro digestibility. Pak. J. Nutr., 16(3): 119-124. https://doi.org/10.3923/pjn.2017.119.124

Jamarun N, Zain M, Arief, Pazla R (2017b). Effects of calcium (Ca), phosphorus (P) and manganese (Mn) supplementation during oil palm frond fermentation by Phanerochaete chrysosporium on rumen fluid characteristics and microbial protein synthesis. Pak. J. Nutr., 16: 393-399. https://doi.org/10.3923/pjn.2017.393.399

Jamarun N, Zain M, Arief, Pazla R (2017c). Populations of rumen microbes and the in vitro digestibility of fermented oil palm fronds in combination with Tithonia (Tithonia diversifolia) and elephant grass (Pennisetum purpureum). Pak. J. Nutr., 17: 39-45. https://doi.org/10.3923/pjn.2018.39.45

Jamarun N, Pazla R, Arief, Yanti G (2020). Chemical composition and rumen fermentation profile of mangrove leaves (Avicennia marina) from West Sumatra, Indonesia. Biodiv. J. Biol. Div., 21. https://doi.org/10.13057/biodiv/d211126

Jamarun N, Pazla R, Arief, Elihasridas, Yanti G, Sari RWW, Ikhlas Z (2023). The impact of mangrove (Rhizophora apiculata) leaves hay and fermented Tithonia diversifolia on intake, nutrient digestibility and body weight gain of goat. Adv. Anim. Vet. Sci., 11(9): 1441-1450. https://doi.org/10.17582/journal.aavs/2023/11.9.1441.1450

Larson BL (1979). Biosynthesis and secretion of milk protein: A review. J. Dairy Res., 46: 161. https://doi.org/10.1017/S002202990001699X

Makmur M, Zain M, Marlida Y, Khasrad, Jayanegara A (2019). Fatty acids composition and biohydrogenation reduction agents of tropical forages. Biodiversitas, 7: 1917-1922. https://doi.org/10.13057/biodiv/d200718

Marques RO, Gonçalves HC, Meirelles PRL, Ferreira RP, Gomes HFB, Lourençon RV, Brito P, Cañizares GIL (2022). Production, intake, and feeding behavior of dairy goats fed alfalfa via grazing and cassava. Rev. Brasil. Zoot., 51: e20210102. https://doi.org/10.37496/rbz5120210102

Mavrogenis AP, Papachristoforou CHR (1988). Estimation of the energy value of milk and prediction of fat corrected milk yield in sheep and goats. Small Rumin. Res., 1(3): 229-236. https://doi.org/10.1016/0921-4488(88)90051-X

Pazla R, Jamarun N, Zain M, Arief (2018a). Microbial protein synthesis and in vitro fermentability of fermented oil palm fronds by Phanerochaete chrysosporium in combination with tithonia (Tithonia diversifolia) and elephant grass (Pennisetum purpureum). Pak. J. Nutr., 17: 462-470. https://doi.org/10.3923/pjn.2018.462.470

Pazla R, Zain M, Ryanto HI, Dona A (2018b). Supplementation of minerals (phosphorus and sulfur) and Saccharomyces cerevisiae in a sheep diet based on a cocoa by-product. Pak. J. Nutr., 17(7): 329-335. https://doi.org/10.3923/pjn.2018.329.335

Pazla R, Jamarun N, Agustin F, Zain M, Arief, Cahyani NO (2020). Effects of supplementation with phosphorus, calcium, and manganese during oil palm frond fermentation by Phanerochaete chrysosporium on ligninase enzyme activity. Biodiversitas, 21: 1833-1838. https://doi.org/10.13057/biodiv/d210509

Pazla R, Jamarun N, Zain M, Arief, Yanti G, Masdia EM, Chandra RH (2022). Impact of Tithonia diversifolia and Pennisetum purpureum-based ration on nutrient intake, nutrient digestibility, and milk yield of Etawa crossbreed dairy goat. Int. J. Vet. Sci., 11(3): 327-335.

Pazla R, Putri EM, Jamarun N, Negara W, Khan FA, Zain M, Arief A, Yanti G, Antonius A, Priyatno TP, Surachman M, Darmawan IWA, Herdis H, Marlina L, Asmairicen S, Marta Y (2023a). Pretreatment of Mirasolia diversifolia using Lactobacillus bulgaricus at different dosages and fermentation time: Phytic acid concentration, enzyme activity, and fermentation characteristics. South Afr. J. Anim. Sci., 53(3): 429-437.

Pazla R, Zain M, Despal, Tanuwiria UH, Putri EM, Makmur M, Zahera R, Sari LA, Afnan IM, Rosmalia A, Yulianti YI, Putri SD, Mushawwir A, Apriliana RA (2023b). Evaluation of rumen degradable protein values from various tropical foliages using in vitro and in situ methods. Int. J. Vet. Sci., 12(6): 860-868.

Pazla R, Jamarun N, Elihasridas, Arief, Yanti G, Ikhlas Z (2023c). The impact of replacement of concentrates with fermented tithonia (Tithonia diversifolia) and avocado waste (Persea americana miller) in fermented sugarcane shoots (Saccharum officinarum) based rations on consumption, digestibility, and production performance of Kacang goat. Adv. Anim. Vet. Sci., 11(3): 394-403. https://doi.org/10.17582/journal.aavs/2023/11.3.394.403

Putri EM, Zain M, Warly L, Hermon (2019). In vitro evaluation of ruminant feed from West Sumatra based on chemical composition and content of rumen degradable and rumen undegradable proteins. Vet. World, 12(9): 1478–1483. https://doi.org/10.14202/vetworld.2019.1478-1483

Putri EM, Zain M, Warly L, Hermon (2021). Effects of rumen-degradable-to-undegradable protein ratio in the ruminant diet on in vitro digestibility, rumen fermentation, and microbial protein synthesis. Vet. World, 14(3): 640–648. https://doi.org/10.14202/vetworld.2021.640-648

Rosmalia A, Permana I, Despal (2022). Synchronization of rumen degradable protein with non-fiber carbohydrate on microbial protein synthesis and dairy ration digestibility. Vet. World, 15: 252-261. Retrieved from https://www.doi.org/10.14202/vetworld.2022.252-261, https://doi.org/10.14202/vetworld.2022.252-261

Sari RM, Zain M, Jamarun N, Ningrat RWS, Elihasridas, Putri EM (2022). Improving rumen fermentation characteristics and nutrient digestibility by increasing rumen degradable protein in ruminant feed using Tithonia diversifolia and Leucaena leucocephala. Int. J. Vet. Sci., 11(3): 353-360. https://doi.org/10.47278/journal.ijvs/2021.121

Schmidely P, Sauvant D (2001). Fat content yield and composition of milk in small ruminants: Effects of concentrate level and addition of fat. Prod. Anim. Paris- Inst. Natl. Res. Agron. 14: 337-354. https://doi.org/10.20870/productions-animales.2001.14.5.3760

Sondakh E, Kalele JAD, Ratulangi FS (2017). The use of coconut pulp as a feed substrate to methanogenesis inhibitor in in vitro rumen fluid fermentation. J. Indonesian Trop. Anim. Agric., 42: 202. https://doi.org/10.14710/jitaa.42.3.202-209

Steel PGD, Torrie JH (2002). Prinsip dan prosedur statistika suatu pendekatan geometrik. (Terjemahan B. Sumantri). PT Gramedia. Jakarta.

Thai Agricultural Standard (2008). TAS 6006-2008. Raw Goat Milk. National Bureau of Agricultural Commodity and Food Standards, Ministry of Agriculture and Cooperatives. ICS 67.100.01. Published in the Royal Gazette, Vol. 125, Section 139 D. Thailand. http://extwprlegs1.fao.org/docs/pdf/tha166272.pdf

Zain M, Despal, Tanuwiria UH, Pazla R, Putri EM, Amanah U (2023). Evaluation of legumes, roughages, and concentrates based on chemical composition, rumen degradable and undegradable proteins by in vitro method. Int. J. Vet. Sci., 12(4): 528-538. https://doi.org/10.47278/journal.ijvs/2022.218