Moringa stenopetala Leaves and Cafeteria Leftover as Nonconventional Supplements in the Diets of Local Gamo Sheep: Nutrient Utilization, Growth Performance and Economic Efficiency

ABSTRACT

Background

Strategic supplementation of unexploited, cheap, less competitive and easily accessible protein sources of nonconventional origin was considered as a feasible alternative way to mitigate protein deficiency in poor‐quality feeds during periods of feed scarcity

Objective

To determine the comparative effects of supplementing Moringa stenopetala and cafeteria leftovers on nutrient uptake, weight gain and economic viability in local Gamo sheep.

Method

A total of 20 yearling lambs were used in four treatments with five replicates in randomized complete block design. The treatments included grass hay (GH) + 125 g concentrate mix (CM) for treatment 1 (T1), GH + 125 g CM + 300 g Moringa stenopetala leaves (MSL) (T2), GH + 125 g CM + 300 g cafeteria leftover (CLO) (T3) and GH + 125 g CM + 150 g MSL + 150 g CLO (T4). A 90‐day feeding trial was followed by a 10‐day digestibility investigation. The study used SAS 9.0 for data analysis, Duncan multiple range test for mean separation and partial budget analysis for financial feasibility testing.

Results

With better responses in T4 followed by T2, T3 and T1, supplementation significantly improved total DM, nutritional intakes and apparent digestibility (p < 0.001). The two nonconventional supplements resulted in an average daily gain of 44.00 g (T2) and 25.33 g (T3) when independently and 54.33 g (T4) concurrently. Blended supplementation of the nonconventional feeds had better marginal returns (2.21) than when MSL (1.96) and CLO (1.34) were supplemented solely.

Conclusion

For smallholders having plenty of cafeteria leftovers and M. stenopetala leaves, feeding blends of the ingredients is more profitable than feeding solely. Conversely, provided that they are comparably available, sole supplementation of M. stenopetala to growing animals is more advantageous to get improved animal performance and obtain better economic returns than sole supplementation of cafeteria leftovers.

For smallholders having plenty of cafeteria leftovers and M. stenopetala leaves, blended feeding of the ingredients is more profitable than their exclusive feeding.

Provided that they are comparably available, sole supplementation of M. stenopetala is more advantageous and profitable than sole supplementation of cafeteria leftovers.

1. Introduction

In Ethiopia, sheep are the second most important and numerous species, next to cattle. Most of these sheep are distributed across various agro‐ecological zones of the nation (CSA 2020). They are dominantly kept by smallholders in the highlands and lowlands for immediate cash income, food (milk and meat) and non‐food products such as manure, skin and wool. Besides, sheep are used as a source of savings, and have social and economic importance to the producers (Habtamu 2015). In spite of the large population of sheep and the great role of sheep both to the livelyhood of resource‐poor farmers and the national economy at large, the current level of on‐farm productivity in the smallholder production system is low. Inadequate and low‐quality feed, lack of effective and sustainable breeding programs and absence of institutional and policymakers’ commitments were among the main constraints challenging the sheep production industry of Ethiopia (Abraham et al. 2016; FAO 2018).

Natural pasture, crop residues and aftermath share more than 60% of the feed resource bases for sheep in Ethiopia (FAO 2018; Seyoum et al. 2018). Contrary to their largest share as feed sources, the aforementioned feed types were frequently reported to be deficient in protein, energy and mineral sources, being incapable even to satisfy the maintenance needs of the animals. So, animals depending on such feeds were observed to have retarded growth and productivity (McDonald et al. 2010; Mekuanint and Girma 2017; Gelgelo et al. 2017). Improving the quality of the roughage feeds through supplementation with nutritious conventional concentrates of either energy or protein source was among the suggested technical strategies to tackle the nutritional incapabilities of the roughage feed resources (CSA 2020; Hailecherkos et al. 2021). However, the commercial concentrate feeds, comprised of especially grains and oil seeds, are expensive and highly valued as human food. Therefore, the provision of cereal origin supplements to farm animals brings unnecessary competition between human beings and the farm animals (Ayenew et al. 2012). Moreover, agro‐industrial by‐products are inaccessible and unaffordable to smallholder farmers; hence, alternative supplementary feedstuffs produced on‐farm other than commercial concentrates are very essential. In this regard, strategic supplementation of unexploited, cheap, less competitive and year‐round available and easily accessible protein sources of nonconventional origin was considered as a feasible alternative way to mitigate protein deficiency in poor‐quality feeds during periods of feed scarcity (Lamrot et al. 2018).

According to FAO (2018), Ethiopia has a huge potential of non‐conventional feeds available across various corners of the country, which could be harnessed and utilized for their livestock feed potential. Moringa stenopetala leaf foliage and food wastes were among the main ones (Aberra et al. 2015; Tesfaye et al. 2016). There is a growing, massive generation of cafeteria food leftover from Ethiopian public higher education institutions, hospitals, hotels, restaurants and other catering providers that could be diverted into economic opportunities. Converting cafeteria food leftovers into livestock feed is an alternative and feasible option to reduce feed cost, enhance livestock productivity and reduce environmental and health impacts. However, available research works on the feeding value of dried cafeteria food leftovers have been inclined towards non‐ruminant animals, especially pigs and poultry (Tesfaye et al. 2016; Asmamaw and Dinberu 2015; Ebrahim 2023). Among the very few feeding experiments done with supplementation of CLO for ruminants, some were designed by mixing CLO and conventional concentrates giving more emphasis to effect on feed digestibility (Hassen et al. 2022) while others were concerned on partial replacement of differentially processed CLO for commercial concentrate (Tadele et al. 2025). Hence, the information on sole feeding of food wastes to ruminants and their effect is still desirable. Besides, the relative effect of feeding M. stenopetala leaf (MSL) foliage and cafeteria leftovers (CLO) on nutrient utilization and animal performance and its economic feasibility is also not yet investigated. Therefore, the current study was conducted to evaluate the comparative effects of supplementing M. stenopetala leaves (MSLs) and CLO on nutrient uptake, growth performance and economic viability in local Gamo sheep.

2. Materials and Methods

2.1. Description of the Study Area

This study was conducted at the university's research and teaching farm. The study area is located at 447 km from Addis Ababa and found at an elevation of 1285 m.a.s.l with an average yearly temperature of 21°C, a wind speed of 6 km/h and an air humidity of 87%. The area receives 800–1200 mm of rainfall annually, and it has an average of 18°C, 26°C and 37°C of minimum, medium and maximum temperature, respectively. Moreover, the area was geographically located between 6°1′ 60 N latitude and 37°32′ 60 E longitude. The study area has some comfortably humid months, and slightly dry months in the opposite season (Kibru et al. 2021).

2.2. Experimental Animals and Their Management

Twenty healthy male yearling local Gamo sheep were obtained from a local market for an average body weight of 18.92 ± 0.38 (mean ± SD) kg. Dentition and owner information were used to estimate the age of the animals. To acclimate to the habitat and for a health check, the animals were isolated for 21 days at the experimental site. The animals were dewormed to prevent internal parasites and sprayed to prevent exterior parasites throughout this time. They were also given vaccinations against pasteurellosis and anthrax. Individual pens with a separate feed and watering trough were employed to house the animals. The experimental animals were identified by their ear tags.

2.3. Feed Preparation and Feeding

Natural pasture Grass hay was harvested at 50% flowering from the study area; air dried and hand chopped into the size of 3–5 cm for easy feeding then stored under a shade to maintain its quality. MSL were collected; trimmed from its twigs and then shade dried on a plastic sheet for 4–6 days. During the drying process, regular turning of leaves was done to ensure uniform drying. Fresh CLO was obtained from the university student cafeteria. The main constituents of student's CLO were Enjera (major food in Ethiopia) mainly made of teff (Eragrostis tef), bread mainly made of wheat (Triticum aestivum) and sauce (wot in Amharic) mainly made from onion, berbere (pepper and spices mixture), vegetable oils, lentil (Lens culinaris) and pea (Pisum sativum) cooking. Potential food items that would lead to fungal development such as Pasta and Macaroni were excluded by preliminary observation because it will take too much time to dry. The student's CLO was collected and sun‐dried by sparsely spreading on canvas. Every day it was hand‐stirred to facilitate better drying, for removal of moisture and reduce moulding. Every evening, the ingredients were put indoors to minimize re‐absorption of moisture. It took 6–8 days to dry the whole student's CLO, which was used for the entire experimental period. After drying the required amount for the entire experiments, the dried CLO was coarsely grounded in mill for the animal to be easily consumed and then stored in sacks until required for formulation of the experimental rations. To offset the low protein content of the basic diet and create a ration satisfying, at least, the experimental sheep's maintenance requirements, commercial concentrate mixture was purchased from an animal feed processing business. In the morning, the basic feed, water and mineral licks were all freely available. Throughout the course of the trial, the rejection % was modified every 4 days based on the refusal of the previous day. The concentrate mix (CM) was given to each animal individually once a day in the morning in the feeding bucket whereas the nonconventional supplements were given to the animals in two equal parts each day at 8:00 AM and 4:00 PM. All of the experimental feeds (the grass hay, the two nonconventional supplements and CM) were provided individually in separate feeding troughs. The rejected grass hay was gathered and weighed every morning prior to offering the morning meal. Over the course of the 90 feeding days, samples of offers from all the diets and refusals from straw were gathered, weighed, bulked and subsampled for laboratory analysis.

2.4. Experimental Design and Treatment

The experiment was conducted in randomized complete block design (RCBD) with four dietary treatments and five blocks. The initial body weights (IBW) of sheep were determined by taking the mean of the two consecutive weighing on the same day of the start of the feeding trial after overnight fasting. Based on their IBW, the animals were then divided into four groups of five animals to have five animals per each treatment (Table 1). Diet compositions of the experimental animals were prepared assuming 2.5% of live body weight intake per day and a minimum of 7% CP requirement for maintenance (NRC 2007). All treatment groups received a supplement of 125 g of CM to complement the low protein content of baseline diet. The treatment diet composition was as indicated below.

TABLE 1.

Diet Composition of the Feeding Experiment.

Treatment	Grass hay	CM (g)	MSL (g)	CLO	Total supplement (g)
1	Ad libitum	125	—	—	125 (Control)
2	Ad libitum	125	300	—	425
3	Ad libitum	125	—	300	425
4	Ad libitum	125	150	150	425

Note: Concentrate mix = wheat bran + maize + Noug Seed cake (2:1:1).

Abbreviations: CLO, cafeteria leftover; CM, Concentrate mix; MSL, M. stenopetala leaves.

2.5. Measurements and Data Collection

2.5.1. Feed Intake, Body Weight Changes and Feed Conversion Efficiency

After 21 days of acclimatization to the experimental site, the animals were fastened overnight before the start of the feeding trial, and their initial weight was determined by averaging the results of two separate measurements. Before the start actual data collection for the feeding experiment which lasted for 90 days (Marten et al. 1989), the animals were allowed to adapt the experimental diets for a period of 15 days. Every day, samples of the feed that was presented and rejected were taken and stored in plastic pails after being weighed, recorded and stored for each animal individually. Each animal's refuse samples, which were taken every 10 days for each treatment, were bulked up and pooled according to the treatments. The difference between the feed that was offered and rejected was utilized to compute daily DM or nutrient intake. At intervals of 10 days during the trial period, body weight measurements were taken (Kinder 2016). Average daily gain (ADG) was measured as the difference between final and IBW divided by the number of feeding days, whilst weight gain was calculated as the difference between final and IBW (Akbulut et al. 2013). The ratio of a unit of body weight growth to the number of units of feed consumed was used to calculate feed conversion efficiency (FCE) (Brown et al. 2001).

$$\mathrm{FCE}=\frac{\mathrm{Body}\mathrm{weight}\mathrm{gain}\mathrm{in}\mathrm{g}/\mathrm{day}}{\mathrm{DM}\mathrm{intake}\mathrm{in}\mathrm{g}/\mathrm{day}}$$

2.5.2. Apparent Nutrient Digestibility

Following feeding trial, digestibility test was conducted with all of the animals in each treatment. To prepare the lambs for carrying faecal collection bags throughout the digestibility study, they were harnessed for 3 days. Each animal then underwent seven days of faeces collection. The faecal output per animal was collected and weighed each morning before offering the morning meal. After weighing the daily total faeces voided by each animal, the faeces were thoroughly mixed and a sub sample of 20% was taken to form a single weekly composite faecal sample for each animal. Composite samples per animal were stored in airtight plastic bags in deep freezer at −20°C. The composite faecal samples were thawed and thoroughly mixed for each animal and a sub‐sample was taken for chemical analysis. To create a single weekly composite faecal sample for each animal, a sub‐sample of 10% of the daily faecal excretion was obtained and pooled across the collection period (Galyean 2010). In airtight polyethylene bags, dried samples of meals, refusals and faeces were stored for chemical analysis after being pulverized to pass a 1 mm filter. Finally, digestibility of each nutrient was calculated using the following equation (Galyean 2010):

$$\begin{array}{ccc}& & \mathrm{Digestibility}\mathrm{of}\mathrm{DM}\mathrm{or}\mathrm{Nutrient}\left(\%\right)\hfill \\ & & =\frac{\mathrm{DM}\mathrm{or}\mathrm{nutrient}\mathrm{intake}-\mathrm{DM}\mathrm{or}\mathrm{nutrient}\mathrm{in}\mathrm{feces}}{\mathrm{DM}\mathrm{or}\mathrm{nutrient}\mathrm{intake}}\times 100\hfill \end{array}$$

2.6. Chemical Analysis

Determination of DM, OM, Ash and CP were done according to methods of AOAC (2000)]. NDF, ADF and ADL were determined using their standard procedures (Van soest and Robertson 1985).

2.7. Statistical Analysis

Analysis of variance (ANOVA) in SAS 9.0 was used to examine the data. Duncan Multiple Range Test was to separate means significantly differing among each other at p < 0.05. The statistical model used to analyse the data was:

$${\mathrm{Y}}_{ijk}=\mu +{\alpha }_i+{ß}_j+{\epsilon }_{ijk}$$

where Y_ijk = is the response variable; μ, is the overall mean; α_i = is treatment effect, β_j , is the block effect, Ɛ_ijk = is the random error.

The power analysis was conducted for the ANOVA procedure employed in this study (Table 2). The effect size of the present study (0.595–1.00), which was presented as partial Eta squared, was in the category of maximum range (Serdar et al. 2021), underlining that, the significant difference observed among groups was due to the real difference between treatment but not by sudden. On the other hand, the observed power for this experiment was in the range of 0.961–1.00. According to Serdar et al. (2021), a high observed power (e.g., above 80%) indicates a strong likelihood of detecting an effect if one exists, while a low observed power (e.g., below 50%) suggests the study may have been underpowered, potentially missing a true effect. Accordingly, the present study was powerful enough to detect the real difference that practically exist among the treatment groups.

TABLE 2.

Power analysis of the ANOVA procedure (between‐subjects effects).

Source	Variable	Degree of freedom	Significance	Partial Eta Squared	Observed Power
Treatment	Hay DMI	3	< 0.001	0.999	1.000
	TDMI	3	< 0.001	1.000	1.000
	TOMI	3	< 0.001	1.000	1.000
	TCPI	3	< 0.001	0.999	1.000
	TNDFI	3	< 0.001	0.999	1.000
	TADFI	3	< 0.001	0.998	1.000
	DC DM	3	< 0.001	0.908	1.000
	DC OM	3	< 0.001	0.880	1.000
	DC CP	3	< 0.001	0.969	1.000
	DC NDF	3	0.002	0.595	0.961
	DC ADF	3	< 0.001	0.958	1.000
	FBW	3	< 0.001	0.930	1.000
	BWG	3	< 0.001	0.999	1.000
	ADG	3	< 0.001	0.999	1.000
	FCE	3	< 0.001	0.999	1.000

Abbreviations: ADG, average daily gain; BW, body weight; BWG, body weight gain; DCADF digestibility coefficient acid detergent fibre; DCDM, digestibility coefficient of dry matter; DCNDF, digestibility coefficient of neutral detergent fibre; DCOM, digestibility Coefficient of organic matter; DMI, Dry matter intake; FCE, feed conversion efficiency; TADF, total acid detergent fibre intake; TCPI, Total crude protein intake; TDMI, total dry matter intake; TNDFI, Total neutral detergent fibre intake; TOMI, total organic matter intake.

2.8. Partial Budget Analysis

Economic feasibility of the feeding experiment was tested by partial budgeting. A due attention was given to major costs disregarding labour, housing and veterinary costs which were common for all treatments under consideration (Soha 2014). Purchasing and selling prices of all animals was recorded so that total return (TR) was calculated as difference of the two prices. Experienced sheep market dealers assisted estimation of selling prices. Net return (NR) generated by M. stenopetala or CLO supplementation was the amount of money left when total variable costs (TVC) are subtracted from the TRs. All costs related to feed preparation, that is, purchasing, transportation and processing for MSL and processing and transportation for CLO, were added to the TVC. The change in NR (∆NR) was computed as difference between change in TR (∆TR) and change in TVC (∆TVC); where; ∆TR is TR of the given supplemented treatment minus TR of the control treatment (T1) and ∆TVC is TVC of supplemented treatment minus TVC of the control. The marginal rate of return (MRR), which is the measures of the NR on additional capital invested on feeding of the nonconventional supplements, M. stenopetala or CLO, to the animals, expressed as percentage, was calculated as ratio of change in net income (∆NI) to ∆TVC multiplied by 100.

3. Results

3.1. Chemical Composition of Experimental Feeds

The chemical compositions of the experimental diets used in the experiment are indicated in Table 3.

TABLE 3.

Chemical composition of experimental feeds.

		Chemical Composition, % DM
	DM%	OM	CP	Ash	NDF	ADF
Feed Ingredient
Hay	91	81.14	5.97	9.86	65.66	33.89
MSL	90.2	78.95	27.12	11.25	19.8	11.62
CLO	91.4	84.08	13.25	7.32	22.7	12.05
CM	90.5	79.61	18.58	10.89	30.25	18.75
Grass Hay Refusals
T1	88.25	78.23	4.35	10.02	66.15	34.45
T2	89.02	78.89	4.14	10.13	67.02	33.98
T3	88.45	79.40	4.02	9.05	66.57	35.07
T4	88.35	79.38	3.93	8.97	65.85	34.22

Abbreviations: ADF, acid detergent fibre; CLO, Cafeteria leftover; CM, Concentrate mix; CP, crude protein; DM, dry matter; MSL, Moringa stenopetala leaves; NDF, neutral detergent fibre; OM, organic matter; T1, Hay Ad libitum + 125 g Concentrate mix (CM); T2, Hay Ad libitum + 125 g CM + 300 g Moringa stenopetala leaves (MSL); T3, Hay Ad libitum + 125 g CM + 300 g Cafeteria leftover (CLO); T4, Hay Ad libitum + 125 g CM + 150 g MSPL + 150 g CLO.

The DM content of all of the experimental feeds used in the present study does not show as such wider and diverse variations. On the other hand, the CP values showed distinctive variability with the highest observation in MSLs followed by CM and CLO while the basal dies (Grass hay) had the least CP of all. The NDF and ADF composition of the experimental feeds exhibited a consistent pattern such that, the highest values were noted for the grass hay while the least values were observed in MSL. Moreover, the grass hay refusals had relatively lower CP and OM composition but moderately higher fibre fractions as compared to their offered mate.

3.2. Nutrient Intake

The daily nutrient intake of intact yearling local Gamo sheep fed grass hay supplemented with MSLs and CLO was presented in Table 4.

TABLE 4.

Daily nutrient intake of intact yearling local Gamo sheep fed grass hay supplemented with M.stenopetala leaves and Cafeteria leftover.

	T1	T2	T3	T4	SEM	Significance
Hay DMI	371.67d	405.96b	380.11c	421.50a	4.57	< 0.0001
TDMI	496.67d	830.96b	805.11c	846.50a	33.04	< 0.0001
TOMI	401.09d	665.76b	660.17c	686.06a	26.19	< 0.0001
TCPI	45.41d	128.82a	85.67c	108.94b	7.12	< 0.0001
TNDFI	281.85d	363.77b	355.49c	378.32a	8.56	< 0.0001
TADFI	149.39d	195.88b	188.41c	201.79a	4.69	< 0.0001

Note: Means in the same row with different superscript letters are significantly different.

Abbreviations: DMI, dry matter intake; SEM, standard error of the mean; T1, Hay Ad libitum + 125 g Concentrate mix (CM); T2, Hay Ad libitum + 125 g CM + 300 g Moringa stenopetala leaves (MSL); T3, Hay Ad libitum + 125 g CM + 300 g Cafeteria leftover (CLO); T4, Hay Ad libitum + 125 g CM + 150 g MSPL + 150 g CLO; TADFI, Total acid detergent fibre intake TCPI, total crude protein intake; TDMI, total dry matter intake; TNDFI, total neutral detergent fibre intake; TOMI, total organic matter intake.

In the current investigation, supplementation had a significant (p < 0.001) impact on the daily nutritional consumption of the experimental animals. T4 had a significantly higher (p < 0.001) consumption of total hay and nutrients compared to the other treatments followed by T2 and T3 while T1 scored the lowest response in terms of hay and nutrient intake. Intake of OM and the detergent fibre fractions also showed a similar pattern of variability stated among all treatments. All of the treatment meals in the current investigation had significantly different CP intake records (p < 0.001) from one another. It exhibited the pattern that, the CP intake of T2 > T4 > T3 > T1.

3.3. Apparent Digestibility of Nutrients

Table 5 below shows how readily DM and nutrients were assimilated by intact yearling local Gamo sheep fed grass hay supplemented with MSLs and CLO. In the current investigation, supplementation had a significant impact (p < 0.01) on digestibility of DM and all of the nutrients. T4 had a higher DM digestibility as compared to the other treatments. While T1 scored the lowest response in terms of DM digestibility, T2 and T3 showed intermediate values comparable with each other. The digestibility of OM, CP and ADF significantly vary among the treatments (p < 0.001) in the way that the digestibility records of T4 > T2 > T3 > T1. The mean NDF digestibility values observed for the experimental animals in this study can be categorized in to two distinguishable groups, with the higher (p < 0.01) record for T4 and T2 and lower comparable records for T3 and T1.

TABLE 5.

Apparent nutrient digestibility (%) of intact yearling local Gamo sheep fed grass hay supplemented with M. stenopetala leaves and Cafeteria leftover.

	Treatments
Parameter	T1	T2	T3	T4	SEM	Significance
DM	55.81c	61.21b	60.93b	63.08a	0.65	< 0.0001
OM	68.44d	73.49b	71.09c	75.27a	0.63	< 0.0001
CP	62.97d	77.30b	73.88c	82.23a	1.6	< 0.0001
NDF	60.85b	63.48a	61.51b	63.97a	0.39	0.002
ADF	54.58d	62.19b	57.19c	63.79a	0.87	< 0.0001

Note: Means in the same row with different superscript letters are significantly different.

Abbreviations: ADF, acid detergent; CP, crude protein; DM, dry matter; NDF, neutral detergent fibre; OM, organic matter; SEM, Standard error of the mean; T1, Hay Ad libitum + 125 g Concentrate mix (CM); T2, Hay Ad libitum + 125 g CM + 300 g Moringa stenopetala leaves (MSL); T3, Hay Ad libitum + 125 g CM + 300 g Cafeteria leftover (CLO); T4, Hay Ad libitum + 125 g CM + 150 g MSPL + 150 g CLO.

3.4. Body Weight Parameters and FCE

The body weight parameters and FCE of intact yearling local Gamo sheep fed grass hay supplemented with MSLs and CLO were presented in Table 6. With the exception of IBW, the animals’ body weight parameters and FCE in this experiment demonstrated a significantly considerable difference (p < 0.001) from one another.

TABLE 6.

Body weight parameters and feed conversion efficiency of intact yearling local Gamo sheep fed grass hay supplemented with M. stenopetala leaves and Cafeteria leftover.

	Treatments, mean
Parameter	T1	T2	T3	T4	SEM	SL
Initial BW (Kg)	18.82	18.86	19.01	19.01	0.085	NS
Final BW (Kg)	20.57d	22.82b	21.29c	23.89a	0.31	< 0.0001
BWG (Kg)	1.75d	3.96b	2.28c	4.89a	0.29	< 0.0001
ADG (g/d)	19.44d	44.00b	25.33c	54.33a	3.22	< 0.0001
FCE (ADG/TDMI)	0.039c	0.053b	0.031d	0.064a	0.0029	< 0.0001

Note: Means in the same row with different superscript letters are significantly different.

Abbreviations: ADG, average daily gain; BW, body weight; BWG, body weight gain FCE, feed conversion efficiency; NS, non‐significant; SEM, standard error of means; T1, Hay Ad libitum + 125 g Concentrate mix (CM); T2, Hay Ad libitum + 125 g CM + 300 g Moringa stenopetala leaves (MSL); T3, Hay Ad libitum + 125 g CM + 300 g Cafeteria leftover (CLO); T4, Hay Ad libitum + 125 g CM + 150 g MSPL + 150 g CLO.

In the present study, a consistent pattern of variability was observed for all of the body weight parameters (FBW, BWG and ADG) of the experimental animals such that, the values of T4 were higher than T3 followed by T2 while T1 had the least value of all. On the other hand, the treatments exhibited a beat different pattern of variability in their FCE records that the observations of T4 > T2 > T1 > T3 (p < 0.001).

3.5. Correlations Between Nutrient Intake, Digestibility and Body Weight Parameters

The correlation patterns between nutrient intake, digestibility and body weight parameters of intact yearling local Gamo sheep fed grass hay supplemented with M. stenopetala leaves and CLO were depicted in Table 7.

TABLE 7.

Correlation between nutrient intake, digestibility and body weight parameters of intact yearling local Gamo sheep fed grass hay supplemented with M. stenopetala leaves and Cafeteria leftover.

	DMI	OMI	CPI	NDFI	ADFI	DMD	OMD	CPD	NDFD	ADFD	BWG
OMI	0.99 ***	1
CPI	0.89 ***	0.88 ***	1
NDFI	0.99 ***	0.98 ***	0.89 ***	1
ADFI	0.99 ***	0.98 ***	0.92 ***	0.99 ***	1
DMD	0.93 ***	0.91 ***	0.82 ***	0.95 ***	0.95 ***	1
OMD	0.82 ***	0.78 ***	0.83 ***	0.86 ***	0.87 ***	0.84 ***	1
CPD	0.93 ***	0.90 ***	0.87 ***	0.96 ***	0.97 ***	0.91 ***	0.91 ***	1
NDFD	0.59 **	0.56 *	0.69 **	0.64 **	0.66 **	0.63 **	0.63 **	0.69 **	1
ADFD	0.80 ***	0.76 ***	0.88 ***	0.85 ***	0.86 ***	0.81 ***	0.93 ***	0.90 ***	0.78 ***	1
BWG	0.74 ***	0.69 ***	0.83 ***	0.81 ***	0.82 ***	0.79 ***	0.91 ***	0.89 ***	0.76 ***	0.97 ***	1
ADG	0.74 ***	0.69 ***	0.83 ***	0.81 ***	0.82 ***	0.79 ***	0.91 ***	0.89 ***	0.76 ***	0.97 ***	1.00 ***

Abbreviations: ADG, average daily gain; ADFD, acid detergent fibre digestibility; ADFI, acid detergent fibre intake; BWG, body weight gain; CPD, crude protein digestibility; CPI, crude protein intake; DMD, dry matter digestibility; DMI, dry matter intake; NDFD, neutral detergent fibre digestibility; NDFI, neutral detergent fibre intake; OMD, organic matter digestibility; OMI, organic matter intake.

^* p < 0.05.

^** p < 0.01.

^*** p < 0.001.

All of the nutrient intake and digestibility parameters had a significant and positive correlation with each other (p < 0.05) and body weight parameters as well (p < 0.001). Except NDF digestibility, which had moderate correlation with DM intake (r = 0.59) and OM intake (r = 0.56), all of the rest parameters had strong correlations (p > 0.60) with each other. On the other hand, a perfect positive correlation (p = 1.00) was observed between ADG and BWG of the experimental animals.

3.6. Partial Budget Analysis

The partial budget analysis of intact yearling local Gamo sheep fed grass hay supplemented with MSLs and CLO was indicated in Table 8 In the present study, the NR of treatments differed from each other in such a way that, the returns of T4 > T2 > T3 > T1.

TABLE 8.

Partial budget analysis of intact yearling local Gamo sheep fed grass hay supplemented with M. stenopetala leaves and Cafeteria leftover.

Parameters	T1	T2	T3	T4
Number of Animals	5	5	5	5
Purchasing price per Sheep (ETB)	1411	1402	1416	1444
Total Hay consumed (Kg/head)	33.45	36.54	34.21	37.94
Total MSL consumed (Kg/head)	0	27	0	13.5
Total CLO consumed (Kg/head)	0	0	27	13.5
Total CM consumed (Kg/head)	11.25	11.25	11.25	11.25
Feed costs
Cost of basal diet (ETB/head)	133.8	146.16	136.84	151.76
Cost of CM (ETB/head)	168.75	168.75	168.75	168.75
Cost of MSL (ETB/head)	0	135	0	67.5
Cost of CLO (ETB/head)	0	0	54	27
Total variable cost (ETB/head)	1713.55	1851.91	1775.59	1859.01
Gross Return (selling price)(ETB)	3150	3550	3300	3650
Total return (ETB)	1739	2148	1884	2206
Net return (ETB)	25.45	296.09	108.41	346.99
ΔTVC	—	138.36	62.04	145.46
ΔNR	—	270.64	82.96	321.54
MRR (ratio)		1.96	1.34	2.21

Abbreviations: CLO, Cafeteria leftover; CM, Concentrate mix; ETB, Ethiopian Birr; MRR, marginal rate of revenue; MSL, Moringa stenopetala leaves; T1, Hay Ad libitum + 125 g CM; T2, Hay Ad libitum + 125 g CM + 300 g MSL; T3, Hay Ad libitum + 125 g CM + 300 g CLO; T4, Hay Ad libitum + 125 g CM + 150 g MSPL + 150 g CLO; ΔNI, change in net income; ΔTVC, change in total variable cost.

4. Discussion

4.1. Chemical Composition of the Experimental Feeds

Livestock feed resources having crude protein content less than 12% were categorized as low protein sources while those having CP between 12% and 20%, and above 20% were identified as, medium, and high protein source feeds, respectively (Lonsdale 1989). Accordingly, among the feeds used in this experiment, MSLs could be considered as a high protein source feeds while CLO and the CM were considered as a medium protein source feeds and the grass hay could be marked as a low protein source feed. On the other hand, the high CP content of MSLs indicates their high potential as a protein supplement diet for poor‐quality roughage feed. According to the argument of Van soest (1994), a minimum of 7.5% CP is needed for optimum microbial activity and ensure satisfactory feed intake in animals at any stage of growth and physiological state. Then, it follows that, the lower CP content of the grass hay used in this study would lead to lower voluntary feed intake, less digestibility and an inability to meet the animals’ maintenance needs when given exclusively.

The slightly higher content of fibre fractions and lower composition of CP in treatment refusals as compared to those of grass hay offered counterpart could be associated with preferential feeding habit of the animals selectively consuming the most nutritious segments and refusing the most fibrous components. Depending on their NDF contents, roughage feeds could be classified as good quality when they have NDF content of less than 45% on DM basis and categorized as medium and low‐quality roughages if they have NDF content of 45%–65% and greater than 65%, respectively (Singh and Oosting 1992). As a result, the grass hay employed as a basal diet in the current investigation could be qualified as a low‐grade roughage whereas all the rest experimental diets fall under the feed category of good quality. The NDF content of natural grass hay observed in this study (65.66%), was comparable to the 66.08% NDF reported by Gebregiorgis et al. (2012), lower than Grass hay NDF values of 70.8% that was reported by Sisay et al. (2019) but considerably higher than 58.60% NDF of a grass hay reported by Hailecherkos et al. (2021). Besides, the ADF contents of grass hay in the present study (33.89%) were lower than 50.98% and 50.2% ADF reported by Desta et al. (2017) and Shashie et al. (2017), respectively but substantially higher than 25.7% ADF of grass hay reported by Aberra et al. 2015). The observed disparity in the nutritional properties of different grass species could be associated with either the inherent nature of each species, harvesting stage, variation of soil fertility crop grown, the amount of fertilizer applied, the stage of crop harvested or morphological and anatomical differences among grass species, edaphic or other environmental factors (Asrat et al. 2015; Horst et al. 2020).

The CP contents of MSLs observed in the present study (27.12) was comparable with the reports of Kebede et al. (2024) (27.26%), lower than 29.5% reports of Aberra et al. (2015), but prominently higher than 7%–11.9% CP contents reported by Abuye et al. (2003). The variations in CP composition value of MSLs reported by different authors could be associated with the age of harvest, soil type and fertility, proportion of leaf and stem and agro‐ecological zone where trees are growing (Horst et al. 2020; Gobena et al. 2022). In agreement with the present study, Nagasa (2015) and Tesfaye et al. (2016) reported a similar DM content of 91.20% for CLO. The same authors also reported a common CP value of 9.00% for CLO which was lower than the observations of the present study (13.25%). On the other hand, a CP value reported by Asmamaw and Dinberu (2015) (17.60%) for the same ingredient was by far higher than the results of the present investigation (13.25%). The observed discrepancy in crude protein composition of CLO among different research works could be qualified by differences in food type, methods of food preparation, moisture contents and processing methods (Mosebework et al. 2018).

4.2. Nutrient Intake

All of the supplemented treatments had significantly higher nutrient intake values over the control one. This boldly qualifies the positive and measurable influence of supplementation on nutrient uptake of the growing animals. The intake records of T4 were observed to be higher consistently in all of the intake variables considered in the present study. This could also indicate comparative advantage of blended feeding of the two nonconventional supplements (M. stenopetala and CLO) over their exclusive supplementation. On the other hand, M. stenopetala constituting treatment (T2) had relatively higher nutrient intake values over the sole CLO constituting treatment (T3), implying substantial advantage of M. stenopetala supplementation over the CLO. The nutrient uptake values of the experimental animals in the present study were actually in line with the nutrient composition of the experimental feeds, especially protein. As reported by McDonald et al. (2010), nutritional protein supplementation is known to enhance intake by increasing the supply of nitrogen to the rumen microbes, which increases the microbial population and efficiency, enabling an increased rate of breakdown of the digest, which in turn increases feed intake. The positive influence of nonconventional feed supplementation of nutrient uptake of experimental animals was a very common observation (Tesfaye et al. 2016; Negasa 2015; Kebede et al. 2024).

The total dry matter intake of the supplemented treatments in the present study (805–846 g/day) was higher than the reports of Mulat (2006) and Teklu et al. (2018) who noted dry matter intake records of 480–498 g/day and 671.7–754.3 g/day for local lambs fed on finger millet straw basal diet and different levels of concentrate supplements and for Arsi‐Bale sheep fed on Faba bean straws with concentrate respectively. Conversely, the animals in T3 of the present study (805.11 g/day) had comparable total DM intake values (809.3 g/day) reported by Worknesh and Getachew (2018) for Dorper × Afar F1 sheep fed on Rhodes grass hay supplemented with alfalfa, lablab and Leucaena leucocephala and concentrate mixtures. The observed disparities in dry matter intakes could be accredited to breed and body weight conditions of the experimental animals as well as the environmental condition, diet composition and quality of the experimental feeds (McDonald et al. 2010).

4.3. Apparent Digestibility of Nutrients

The significant variability in nutrient digestibility of the experimental animals could be associated with the differences in nutrient composition of the experimental diets. As reported by McDonald et al. (2010), the digestibility of a feed is influenced by the composition of other feeds consumed with it and the associative effects could be negative or positive. The same authors also noted that addition of dietary nutrients like protein in the supplement increases protein availability to rumen microorganisms to speed up the digestion process. Similarly, Foster et al. (2009) argued that the CP content of feeds is important to increase the microbial population in the rumen to support optimum ruminal activity. Therefore, the higher digestibility values of T4 over the rest treatments could be justified by the collective advantage that the animals feeding the particular treatment could get from M. stenopetala, cafeteria left over and the CM. On the other hand, animals in T1 had lowest digestibility records of all treatment diets. This could be adhered to the influence higher content of fibre fractions in the basal diet. According to the arguments of Okunade et al. (2014) low to moderate fibre contents of feedstuffs advocate their potential nutritive value, since fibre plays a significant role in voluntary intake and digestibility, supporting intestinal movement, proper rumen function and promoting dietary efficiency. The variability pattern in nutrient digestibility patterns of the present experimental diets was consistent with the observations of Kebede et al. (2024) who argued that, a statistically variable nutrient digestibility enhancing effect of the treatment diets of black head Ogaden lambs directly mirrors the protein content and nutrient utilization efficiency of the respective treatments.

Contrary to the present study, Bonsi et al. (1995) and Yeshambel et al. (2012) reported non‐significant difference in the apparent digestibility of nutritive parameters among the supplemented and control treatments in Menz sheep and Washera lambs supplemented with nonconventional supplements respectively. Besides, the dry matter digestibility coefficients of the supplemented groups in the present study (60.93%–63.08%) was lower than the dry matter digestibility coefficients of both Kafa sheep (66.60%–68.60%) and Arsi Bale sheep (65%–70%) reported by Worku et al. (2015) and Bekele et al. (2013). This disparity in the effect of nonconventional supplements on nutrient digestibility could be qualified by the types and amounts of supplements used and variability in the nutritive values of the respective supplements.

4.4. Body Weight Change and FCE

The observed variability in the body weight parameters of the local Gamo sheep in the present study was consistent with the nutrient consumption and digestibility patterns of the respective treatments. In accordance with the observations of the present study, Kebede et al. (2024) reported that, disparity in body weight gain and ADG of black head Ogaden lambs supplemented with a nonconventional supplement, Commelina species, was a direct reflection of the total DM and OM intake and digestibility seen in the treatment groups. All of the experimental treatments in the present study were observed to display a positive change consistently throughout the experimental period. This could be attributed to the dry matter digestibility of the treatment diets used in this experiment (55.81%–63.08%). Because, it is well established that, animals feeding on a feed with dry matter digestibility of 42%–45% could secure their maintenance needs and display an increased trend in their body weight parameters (McDowel 1988). The observations of Abraham et al. (2016) that disclosed non‐significant effect of air‐dried foliage of African wild olive and red thorn supplementation on growth performance of Tigray highland sheep; and the report of Gezahegn (2019) that testified non‐significant effect of supplementation with nonconventional supplements on FCE of Bonga lambs were in contrary to the observations of the present study. Differences in nutritional qualities of feed types employed in experiment or variability in feed converting efficiency of the experimental animals could justify the noted discrepancy in the observations of the present study and those of the other scholars.

The ADG of the supplemented local Gamo sheep observed in the present study (41.22 g/day) was lower than the ADG of blackhead Ogaden lambs supplemented with Commelina species (47.78 g/day) (Kebede et al. 2024) but higher than ADG of Farta sheep fed urea‐treated rice straw supplemented with graded levels of dried Sesbania sesban leaves (22.99 g/d) reported by Lamrot et al. (2018). Differences in nutritive quality, diet composition or breed type could contribute to the discrepancies in the reports of different researchers (McDonald et al. 2010).

4.5. Correlations between Nutrient Intake, Digestibility and Body Weight Parameters

In agreement with the observations of the present study, Shitaneh et al. (2021) reported that, the intake and digestibility of total DM, CP, OM and NDF of Gumuz lambs supplemented with cowpea (Vigna unguiculata) hay and noug seed (Guizotia abissynica) cake were positively and strongly correlated (p < 0.001) with each other and ADG. According to the authors, the positive correlation between these factors indicates the enhanced fermentation and passage rate, which leads to improved intake because of the dietary treatments. Similarly, Mekonnen et al. (2019) also argued that an increased in DM intake leads to increased DM digestibility of the ration and improved body weight changes of animals. Moreover, the positive significant correlation observed between the nutrient intake digestibility and body weight parameters of local Gamo sheep observed in the present study was also supported by observations of Adugna et al. (2020) and Hailecherkos et al. (2021), who underlined that CP intake was positively correlated with intake of DM, OM and CP and OM and CP digestibility and ADG of Gumuz and Washera lambs respectively.

4.6. Partial Budget Analysis

In the present study, T4 returned better profit of all treatment. The growth data shows a slight positive change in T1 and NR of 25.45 ETB per head. This could imply a measurable impact of the commercial concentrate on the body weight change and return of the animals beyond sustaining the maintenance requirement of the animals. All supplemented treatments of the present study generated a positive MRR value and the records suggests that an additional one unit of ETB cost increment per animal resulted in one ETB and additional 1.96, 1.34 and 2.21 ETB benefit for T2, T3 and T4, respectively. This could imply that, for smallholder farmers having plenty of CLO and MSLs in their localities, feeding mixtures of the ingredients to growing animals they have at their farm is more profitable than feeding the ingredients solely. On the other hand, among the two conventional supplements, provided that they are comparably available, sole supplementation M. stenopetala to growing animals is more advantageous to get improved animal performance and obtain better economic returns than sole supplementation of CLO.

5. Conclusions

M. stenopetala was marked as a high protein source feed whereas the CM and the CLO used in the present study were distinguished as medium protein source feeds having a promising potential to enhance nutrient utilization and growth performance in growing animals. Supplementation considerably increased the experimental animals’ total DM and nutritional consumption. Sole conventional supplement comprised treatments demonstrated considerably higher intake response than the control group but lower feed intake improvement than their combined treatment. Similar findings were made for the experimental animals’ body weight measurements and feed digestibility. The CP intake of the experimental treatment followed the trend that the intake of T2 > T4 > T3 > T1. Whereas the intake of the rest nutritional parameters and digestibility of OM, CP and ADF varied among the treatments in the way that the values of T4 > T2 > T3 > T1. The present investigation underlined a meaningful variation between daily gains acquired by control treatments (19.44 g/day), that of the meals containing sole M. stenopetala (44.00 g/day) and CLO (25.33 g/day) as well as their combined treatment (54.33 g/day). In conclusion, for smallholder farmers having plenty of CLO and MSLs in their localities, feeding mixtures of the nonconventional ingredients to growing animals they have at their farm is more profitable than feeding the ingredients solely. On the other hand, among the two conventional supplements, provided that they are comparably available, sole supplementation M. stenopetala to growing animals is more advantageous to get improved animal performance and obtain better economic returns than sole supplementation of CLO.

Author Contributions

Addisu Barango: conceptualization; methodology; writing – original draft. Yisehak Kechero: supervision; writing – review and editing. Kebede Gelgelo: supervision; writing – review and editing.

Funding

The authors have nothing to report.

Ethics Statement

The animal study was reviewed and approved by Arba Minch University Animal Research Ethics Review Committee (Approval Number AMU/AREC/2/2017).

Conflicts of Interest

The authors declare no conflicts of interest.

Barango, A. , Kechero Y., and Gelgelo K.. 2026. “ Moringa stenopetala Leaves and Cafeteria Leftover as Nonconventional Supplements in the Diets of Local Gamo Sheep: Nutrient Utilization, Growth Performance and Economic Efficiency.” Veterinary Medicine and Science 12, no. 1: e70772. 10.1002/vms3.70772

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.