Citation of this paper

Effects of replacing concentrate feed by probiotic fermented soya waste in the diet on feed consumption, nutrient digestibility, nitrogen retention and rumen parameters of growing goats

Truong Thanh Trung¹ and Nguyen Binh Truong^2,3

¹ Can Tho University, Can Tho, Vietnam
tttrung@ctu.edu.vn
² An Giang University, An Giang, Vietnam
³ Vietnam National University Ho Chi Minh City, Vietnam

Abstract

This study aimed to determine the proportion of probiotic fermented soya waste in the diet on feed intake, nutrient digestibility, rumen parameters and nitrogen retention of goats. The difference in treatments was probiotic fermented soya waste (FSW) levels replacing concentrate at 0, 25, 50, 75 and 100% (dry matter basic) corresponding to FSW0, FSW25, FSW50, FSW75 and FSW100, respectively. A result as dry matter intake tended to be low in FSW100 (p>0.05) but crude protein consumption was not different (p>0.05) among treatments. Although the digestibility of FSW100 was higher than FSW0 for DM, OM and CP it was not different in this study. The pH, NH₃ and VFAs at 0h and 3h were similar (p>0.05) among treatments. However, nitrogen retention had an increasing tendency followed by the increasing of the ratio of FSW in the diet from 6.98 to 7.59, 7.85, 7.45, 7.28 g/goat/day corresponding to FSW0, FSW25, FSW50, FSW75 and FSW100. Therefore, probiotic soya waste fermentation could replace concentrate and at the ration replacement of 50% was the best for utilization in goats in terms of feed utilization and profits.

Keywords: digestibility, feeds, small ruminants

Introduction

Local feed utilization is very important for animal production. It helps farmers have a good income from the low price of feed sources. Soya waste is popular in the Mekong Delta and it is a good feed supplement for ruminants. However, soya waste will bad smell for 2 to 3 days. Moreover, Rahman et al (2014) suggested that feed costs can be reduced by replacing commercial concentrate pellets with soya waste in the diet of goats. Nowadays, feed fermentation is a new way to slow down greenhouse in the world. Some articles on feed fermentation such as supplementing yeast-fermented broken rice in goats (Nguyen Thi Thu Hong et al (2023), supplementing the diet of growing cattle with yeast-fermented rice reported by Nguyen Van Thu et al (2022). Therefore, this study hypothesizes that the difference in the proportion of soya waste fermentation (FSW) and concentrate could not affect feed intake, nutrient digestibility, rumen environment and nitrogen retention of goats.

Materials and methods

Location

The experiment was conducted at Cam Nhung farm in Thoi Hoa ward, O Mon district, Can Tho city, Vietnam from December 2022 to April 2023.

The chemical composition of experimental diets was analyzed at laboratory E205 of the Faculty of Animal Sciences, Agriculture University of Can Tho University.

Animals and experimental design

Five female (Boer x Bach Thao) goats with an average live weight of 14 kg were arranged in a 5×5 Latin square experiment), including five treatments and five periods with each period lasting for 21 days. Five treatments were five levels replacing concentrate by FSW in the diet: 0, 25, 50, 75 and 100% corresponding to FSW0, FSW25, FSW50, FSW75 and FSW100 treatments, respectively. Concentrate, FSW and Operculina turpethum were fed to animals first, they were then received ad libitum of Pennisetum purpureum. Experimental goats were fed a diet of 5.5g CP/kg body weight/day with a DM intake of 3.5%/body weight.

Table 1. Dietary formula of experimental goat in the first period (Average live weight goat = 13 kg)
Feedstuff, g fresh form	FSW0	FSW25	FSW50	FSW75	FSW100

Fermented probiotic soya waste	0	317	633	950	1267
Mixed concentrate feed	250	188	125	63.0	0
Operculina turpethum	1000	1000	1000	1000	1000
Pennisetum purpureum	600	600	600	600	600
DM/BW, %	3.5	3.5	3.5	3.5	3.5
gCP/kg BW	5.5	5.5	5.5	5.5	5.5

The mixed concentrate feed (MCF) used in the experiment had a CP content of 17.6% and ME of 12.3MJ/kgDM mixed from rice bran (38%), broken rice (36%) and extraction soybean meal (25 %), salt (1%) and vitamin and mineral premix (1kg/200kg of feed). The fermented probiotic soya waste has a CP content of 18.8% and ME 12.0 MJ/kgDM with the following formula: soya waste 96%, extraction soybean meal 1.7%, broken rice 1.7%, mineral and vitamin 0.1% and probiotic 0.5%. Mix all ingredients well and put in a tightly covered container to ferment anaerobically for the third day and feed to the goats. Diets were daily monitored to make sure that the goat’s exact consumed ratios were as experimental designed.

MCF and FPSW were weighed and mixed daily before feeding the animals. Feed ingredients of probiotics are shown in Table 2.

Table 2. The composition in 100g probiotic product (BIO – Pharmachemie company)
Item	Unit

Lactobacillus acidophilus	2 x 10⁹CFU
Bacillus subtilis	2 x 10⁹CFU
Saccharomyces cerevisiae	2 x 10⁹CFU
Aspergillus oryzae	2 x 10⁹CFU
Vitamin A	100.000 UI
Vitamin D3	15.000 UI
Folic acid	10 mg
Nicotinamide	200 mg
Vitamin B1	25 mg
Lactose, Dextrose just enough	100g

Measurements

Daily feed intakes, nutrient digestibility, nitrogen retention and weight gain were measured and calculated.

Feed offered, refusals and feces were analyzed for dry matter (DM), organic matter (OM), crude protein (CP) and Ash contents according to the procedures of AOAC (1990). However, neutral detergent fiber (NDF) and acid detergent fiber (ADF) were analyzed by the procedure of Van Soest et al (1991).

This study had four periods. Each experimental period was 21 days including 14 days for adaptation and 7 days for sample collection of feces. Apparent DM, OM, CP, EE, NDF and ADF digestibility were employed according to McDonald et al (2010).

Rumen fluid was collected for determination of pH, total volatile fatty acids (VFAs) and ammonia (N-NH₃). The samples were taken before feeding (0h) and after feeding (3h) in the morning in the middle of each period by using a stomach tube. Rumen fluid was immediately measured for pH using a portable pH (EcoTestr pH2, Eutech – Singapore). Rumen VFAs were determined by the procedure of Barnet and Reid (1957). Rumen ammonia concentration was determined by distillation and titration with the Kjeldahl method (AOAC, 1990). The protein solubility (PS) was determined by the method of Whitelaw and Preston (1963).

The total urine of experimental goats was taken and acidified using H₂SO ₄ solution for the determination of nitrogen as described by AOAC (1990).

The goats were weighed on two consecutive days at the beginning and end of each experimental period.

Statistical analysis

The data were analyzed using the ANOVA Linear Model (GLM) of Minitab Reference Manual Release 20. (Minitab, 2021). Then for the paired comparison of two treatments, the Tukey test was used in this study (p<0.05).

Results

Chemical composition of feeds

The chemical compositions of feeds were shown in Table 3.

Table 3. Chemical composition of feeds (% DM basis) used in the experiment
Feed	DM, %	% in DM
Feed	DM, %	OM	CP	PS	NDF	Ash

Fermented probiotic soya waste	17.4	95.8	18.8	5.71	31.9	4.25
Mixed concentrate feed	87.9	94.4	17.6	3.80	40.2	5.62
Operculina turpethum	14.2	90.0	16.8	1.97	51.3	9.99
Pennisetum purpureum	16.7	87.1	10.2	1.52	59.5	12.9
DM: dry matter, OM: organic matter, CP: crude protein, PS: protein solubility, NDF: neutral detergent fiber

Feed and nutrient intakes

The results are presented in Table 4 for feed intake and nutrient consumption.

Table 4. Effect of soya waste fermentation on feed and nutrient intakes of goat
Item	FSW0	FSW25	FSW50	FSW75	FSW100	SEM	p

Feeds intake, gDM/animal/day
Soya waste fermentation	-	91.3^d	183^c	256^b	344^a	10.49	0.001
Concentrate	334^a	251^b	167^c	83.5^d	-	11.78	0.001
Operculina turpethumvines	165	163	164	161	163	1.376	0.325
Pennisetum purpureum	97.1^a	79.8^ab	68.7^ab	52^ab	48.3^b	10.63	0.038
Nutrient intake, gDM/animal/day
DM	596	584	584	553	555	14.58	0.202
OM	548	540	541	514	518	13.13	0.315
CP	96.3	96.6	98.5	95.2	97.0	2.006	0.835
PS	17.4^d	19.1^cd	21.1^bc	21.8^ab	23.6^a	0.452	0.001
PS/CP, %	18.0^e	19.7^d	21.4^c	22.8^b	24.2^a	0.110	0.001
NDF	276^a	261^ab	251^abc	229^bc	222^c	7.577	0.001
FSW0, FSW25, FSW50, FSW75 and FSW100 as the proportion of soya waste fermentation replaced concentrate at 0, 25, 50, 75 and 100% (DM basic).DM: dry matter, OM: organic matter, CP: crude protein, NDF: neutral detergent fiber. ^{a, b, c}values with different superscript letters within one row are significantly different at the level of 5%.

Digestibility

The result of Table 5 shows the nutrient digestibility and digestible nutrient of goats.

Table 5. Apparent nutrient digestibility and digestible nutrient of goats in different treatments
Item	FSW0	FSW25	FSW50	FSW75	FSW100	SEM	p

Nutrient digestibility, %
DM	78.8	81.5	79.6	80.5	82.1	1.463	0.526
OM	79.4	82.1	80.4	81.4	82.9	1.396	0.463
CP	76.7	79.6	78.8	80.5	80.2	1.743	0.581
NDF	77.0	78.2	77.5	75.9	77.8	2.104	0.947
Digestible nutrient, g/animal/day
DM	456	464	455	438	446	13.42	0.702
OM	423	432	426	412	421	12.17	0.835
CP	71.8	75.2	76.2	75.5	76.4	2.399	0.671
NDF	205^a	197^ab	189^ab	170^b	167^b	7.487	0.015
FSW0, FSW25, FSW50, FSW75 and FSW100 as the proportion of soya waste fermentation replace concentrate at 0, 25, 50, 75 and 100% (DM basic).DM: dry matter, OM: organic matter, CP: crude protein, NDF: neutral detergent fiber. ^{a, b, c}values with different superscript letters within one row are significantly different at the level of 5%.

Rumen parameters of experimental goat

Rumen parameters of the experimental goat are shown in Table 6.

Table 6. Rumen pH, N-NH₃ and total volatile fatty acids (VFAs) concentrations of goat in this study
Item	FSW0	FSW25	FSW50	FSW75	FSW100	SEM	p

pH
0 h	6.27	6.21	6.93	6.99	6.96	0.397	0.450
3 h	6.68	6.66	6.63	6.56	6.60	0.050	0.453
*N–NH ₃ (mg/100ml)*
0 h	30.9	28.4	27.7	26.4	24.0	2.492	0.433
3 h	33.7	34.0	33.7	29.9	24.0	2.851	0.483
**VFAs (m mol/ml)**
0 h	73.6	76.3	71.3	80.6	69.5	6.822	0.800
3 h	85.5	101	103	94.1	86.2	7.449	0.356
FSW0, FSW25, FSW50, FSW75 and FSW 100 as the proportion of soya waste fermentation replaced concentrate at 0, 25, 50, 75 and 100% (DM basic).^{a, b, c}values with different superscript letters within one row are significantly different at the level of 5%.

Nitrogen retention and daily weight gain

Daily nitrogen retention and weight gain of goats in different treatments are shown in Table 7.

Table 7. Nitrogen retention and daily weight gain of goats in the present study.
Item	FSW0	FSW25	FSW50	FSW75	FSW100	SEM	p

Nitrogen (N), g/animal/day
N _intake	14.9	15.1	15.4	15.0	15.3	0.290	0.719
N _fecal	3.44	3.04	3.23	2.89	3.06	0.260	0.634
N _urine	4.51	4.43	4.34	4.64	4.94	0.472	0.908
N _retention	6.98	7.59	7.85	7.45	7.28	0.446	0.709
N_retention /N_{intake, %}	47.2	50.2	51.0	49.9	47.6	3.028	0.863
N _intake /W^0.75	1.53	1.60	1.58	1.59	1.59	0.056	0.932
N_retention /W^0.75	0.73	0.80	0.80	0.78	0.76	0.055	0.810
Body weight change, g/animal/day
Initial_{body weight}, kg	19.6	19.7	19.0	19.2	19.6	0.271	0.351
Final _{body weight}, kg	21.4	22.4	22.0	21.4	21.6	0.449	0.458
DWG, g	86.0	132	141	105	96.0	20.20	0.295
FSW0,FSW25,FSW50,FSW75 and FSW100 as the proportion of soya waste fermentation replaced concentrate at 0, 25, 50, 75 and 100% (DM basic). N: nitrogen, DWG: daily weight gain. ^{a, b, c} values with different superscript letters within one row are significantly different at the level of 5%.

Figure 1. Effect of replacing rice bran/broken rice with fermented soya waste

Discussion

The feed chemical compositions were shown in Table 3. The results revealed that the CP of fermented soya waste (Photo 4) was 18.8% higher than concentrate (17.6%, Photo 3). The CP content of Operculina turpethum vines and Pennisetum purpureum was 16.8% and 10.2%, respectively. The NDF of Pennisetum purpureum in this study was lower than reported by Rusdy (2016) about 63.9-75.4%.

The results in Table 4 indicate that the DM intake of FSW0 (596 g/animal/day) was higher than FSW25, FSW50, FSW75 and FSW100 treatments (584, 584, 553 and 555 g/animal/day, respectively). However, it was not different (p>0.05) among treatments. Similarly, the CP consumption was not different among treatment groups (p<0.05). It was 96.3, 96.6, 98.5, 95.2 and 97.0 g/animal/day corresponding to FSW0, FSW25, FSW50, FSW75 and FSW100 treatments. The CP intake in the present study was found to be comparable to the results of Rahman et al (2020) who reported that the total feed intake tended to decrease as the quantity of soya waste consumed increased in goats.

The nutrient digestibility and digestible nutrients of experimental goats are shown in Table 5. The nutrient digestibility of DM, OM and CP tended to increase (p>0.05) followed by increasing soya waste fermentation. The DM digestibility was 78.8, 81.5, 79.6, 80.5 and 82.1 % corresponding to FSW0, FSW25, FSW50, FSW75 and FSW100, respectively. Similarly, The CP digestibility was 76.7, 79.6, 78.8, 80.5 and 80.2%, respectively (FSW0, FSW25, FSW50, FSW75 and FSW100, respectively). The result of CP digestibility was nearly to the findings of Nguyen Thi Kim Dong and Nguyen Van Thu (2020) who concluded that the CP digestibility of different protein sources on feed supplements in goats was about 85.0-87.5%.

In general, rumen pH values, N-NH₃ and VFAs concentrations at 0h and 3h after feeding of the goats (Table 6) were not different (p>0.05) among treatments. The pH values at 3h after feeding were lower than those at 0h, while the concentrations of N-NH₃ and VFAs at 3h after feeding were higher than those at 0h. According to Chanjula et al (2022) pH of goats was about 6.57-6.74 and Gunun et al (2023) reported that it was 7.1-7.2. The results indicated that there was no significant effect of dietary soya waste fermentation replacing concentrate on the rumen parameters of goats.

Nitrogen intake of goats was similar (p>0.05) among treatments and ranged from 14.9 to 15.3 g/animal/day. The nitrogen retention (g/animal/day) had a trend of increasing with the rise of dietary soya waste fermentation levels and it was 6.98, 7.59, 7.85, 7.45 and 7.28 g/animal/day corresponding to FSW0, FSW25, FSW50, FSW75 and FSW100, respectively. The daily weight gain (g/animal) of experimental goats was similar (p>0.05) among the treatments. Rahman et al (2020) reported that the daily weight gain of growing crossbred goats was 73.2 - 93.7 g/animal/day.

In short, soya waste fermentation replacing concentrate in the diet of goats was not different (p>0.05) in feed intake, nutrient digestibility, nitrogen retention and weight gain. Nutrient consumption tended to decrease from FSW0 to FSW100. However, the increasing ratio replacement of FSW was increased for nutrient digestibility, nitrogen retention and average weight gain.

Conclusion

A level of 50% soya waste fermentation replacing concentrate in the diet could be properly recommended to implement performance studies in goats for applications in terms of better by-product utilization, reasonable growth rate.

References

AOAC (Association of Official Analytical Chemists) 1990 Official methods of analysis (15th edition). Washington, DC, 1: 69-90.

Chanjula P, So S, Suntara C, Prachumchai R and Cherdthong A 2022 Efficiency of Feed Utilization, Ruminal Traits and Blood Parameters of Goats Given a Total Mixed Diet Ration Containing Extracted Oil Palm Meal. Veterinary Sciences, 9(11), 612. Link: https://doi.org/10.3390/vetsci9110612

Gunun P, Cherdthong A, Khejornsart P, Wanapat M, Polyorach S, Kaewwongsa W and Gunun N 2023 Replacing Concentrate with Yeast-or EM-Fermented Cassava Peel (YFCP or EMFCP): Effects on the Feed Intake, Feed Digestibility, Rumen Fermentation and Growth Performance of Goats. Animals, 13(4), 551. Link: https://doi.org/10.3390/ani13040551

McDonald P, Edwards R A, Greenhalgh J F D, Morgan C A, Sinclair L A and Wilkinson R G 2010 Animal Nutrition (7^th edition). Longman Scientific and Technical. N.Y. USA.

Minitab 2021 Minitab reference manual release 20.3, Minitab Inc.

Nguyen Thi Kim Dong and Nguyen Van Thu 2020 Effects of dietary protein sources on feed and nutrient intake, digestibility and rumen parameters of growing Bach Thao goats. Journal of Animal Science and Technology, 108 (February, 2020): 43-49. Link: https://vcn.org.vn/xuat-ban/tap-chi-khoa-hoc-cong-nghe-chan-nuoi-so-108-thang-02-2020-journal-of-animal-science-and-technology-vol-108-february-2020

Nguyen Thi Thu Hong, Nguyen Thi Ngoc Trang and Le Tran Minh Hieu 2023 Effects of a supplement of yeast-fermented broken rice on nitrogen retention and methane emissions in growing goats fed Para grass (Brachiaria mutica). Livestock Research for Rural Development 35 (5) 2023, #47. Link: https://www.lrrd.org/lrrd35/5/3547hong.html

Nguyen Van Thu, T R Preston and Leng R 2022Supplementing the diet of growing cattle with yeast-fermented rice (YFR) increased the production of rumen propionate, decreased emissions of methane and improved growth and feed conversion. Livestock Research for Rural Development 34 (12) 2022 #113. Link: https://www.lrrd.org/lrrd34/12/34113thuv.html

Rahman M M, Abdullah R B, Wan Khadijah W E, Nakagawa T and Akashi R 2014 Feed intake and growth performance of goats fed with Napier grass and oil palm frond supplemented with soya waste. Journal of Applied Animal Research, 43(3), 256-260. Link: http://dx.doi.org/10.1080/09712119.2014.963095

Rahman M M, Abdullah R B, Mat K B, Ishigaki G, Nor M M and Akashi R 2020 Replacement of soybean meal with levels of inclusion of soya waste in the diet of growing goats. Tropical animal health and production, 52, 3085-3090. Link: https://doi.org/10.1007/s11250-020-02330-6

Rusdy M 2016 Elephant grass as forage for ruminant animals. Livestock Research for Rural Development, 28: Article #49. Link: http://lrrd.cipav.org.co/lrrd28/4/rusd28049.html

Van Soest P J, Robertson J B and Lewis B A 1991 Methods for dietary fiber, neutral detergent fiber and non-starch polysaccharides in relation to animal nutrition. Journal of Dairy Science, 74: 3583-3598. Link: https://doi.org/10.3168/jds.S0022-0302(91)78551-2

Whitelaw F G and Preston T R 1963The nutrition of the early-weaned calf. III. Protein solubility and amino acid composition as factors affecting protein utilization. Animal Science, 5, 131-145.