Citation of this paper

Effect of supplementation with mixtures of Acacia tortilis pods or groundnut haulm and maize grain on weight gains of Abergelle goats

Desta Tekle and Teferi Aregawi¹

Abergelle Agricultural Research Center, PO Box 44, Abyi Adi, Tigray, Ethiopia
destate14@gmail.com
¹ Tigray Agricultural Research Institute, PO Box, 492, Mekelle, Tigray, Ethiopia

Abstract

The study was conducted in Tanqua Abbergelle district, Ethiopia with the objective of evaluating the effect of supplementation of maize/ Acacia tortilis pods or maize/groundnut haulm to Abergelle goats having access to native browse trees. The experimental design was a randomized block with eight replications (separate farms) of three treatments: browse alone or supplemented (445 or 500 g/day) with mixtures of Acacia tortilis pods (30%) and maize grain (70%) or groundnut haulm (65%) and maize grain (35%), respectively. Live weight gains were increased from 21 g/d on browse alone to 61 and 63 g/d for goats that were supplemented.

Key-words: browsing, local resources, on-farm research, trees

Introduction

Goat rearing is the major livestock activity in Tanqua Abergelle district of northern Ethiopia. But, the productivity of the goats is challenged by feed shortages (Yami 2008). The major feed resources in Tanqua Abergelle district are crop residues (mainly from cereal crops) and natural grazing/browsing (Gebremariam and Belay 2016).

It was observed that in Tanqua Abergelle district, potentially accessible feed resources such as Acacia tortilis pods and groundnut haulms are underutilized. Therefore, this study was conducted with the objective to evaluate the effect of supplementation of maize/Acacia tortilis pods or groundnut haulms and maize grain on growth performance of Abergelle goats having access to native browse trees.

Materials and methods

Study site

The experiment was conducted at Hadinet village in Tanqua Abbergelle district, Tigray region, Ethiopia. The district is located at latitude 13° 27′ 49″ N and longitude 39° 2′ 12″ E with elevation 1450 masl. Its annual mean rainfall is between 400 and 600 mm while its mean temperature is between 28 and 42 °C (ARD 2012). The farming system is mixed crop-livestock production. The major livestock in the area are goats, sheep, cattle, poultry and donkeys, while the major crops include sorghum, groundnut, cowpea, maize, Teff, barley and sesame.

Farmer selection

Eight interested farmers each provided three male yearling Abergelle goats which were normally managed by free grazing of pastures dominated by native browse trees. The goats were treated against internal and external parasite using anti-helminthes and ivermectin, respectively and vaccinated against ovine pasteurellosis, the most common disease in the area. The goats were allowed to feed on indigenous browse species likeZiziphus spina-christi, Balanites aegyptiaca, Acacia a seyal, Acacia amara, Terminalia brownie and Dichrostachys cinerea as their basal diet and also accessed fresh water near their browsing site (Photo 1).

Photo 1. The grazing area dominated by browse trees

Experimental design and treatments

The study was a randomized block design with three treatments and eight replications (farms). The treatments were: browse alone or supplemented (445 or 500 g/day) APMG [mixtures of Acacia tortilis pods (30%) and maize grain (70%)]; and or GHM [mixture of groundnut haulm (65%) and maize grain (35%)], respectively. The three goats on each farm had free access to browse trees (Photo1) from early morning to late afternoon when they were kept in individual pens to receive the supplements (2 goats) or none (one goat). The supplements were given in equal portions at 14:00 and 20:00 h for 15 and 90 days of adaptation and experimental feeding trial, respectively.

The Acacia tortilis pods, and groundnut haulms were collected mainly from area enclosures and cultivated land in Tanqua Abergelle district, respectively. Subsequently, they were air-dried under shade. The maize grain was purchased from the local market. All the feed ingredients were crushed to smaller and similar particle size for easy of mixing. The supplements were distributed to each of the selected participants.

The weight of each goat was taken at the beginning of the experiment and then fortnightly, after an overnight fast. Live weight gains were determined from the linear regression of live weigh (Y) on days in the experiment (X).

Chemical analysis

The dry matter, ash and N content of the supplements were analyzed using the procedures outlined by AOAC (1990). Neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) contents were done according to the method described by Van Soest et al (1991).

Data analysis

The data were subjected to analysis of variance (ANOVA) using the general linear model procedure of SAS version 9.0 (SAS 2004). The statistical model was

Yij= μ + τi + βj + εij, where: Yij= response variable; μ= overall mean; τi= effect of treatment i; βj= effect of block j and εij= random error.

Results and discussion

Composition of experimental feeds

The pods of Acacia tortilis were richer in protein but with higher ADF and ADL than the groundnut haulm (Table 1).

Table 1. Chemical composition of experimental feeds (g/kg DM except for DM which is on air-dry basis)
	DM	OM	CP	NDF	ADF	ADL

Acacia pods	906	946	187	398	354	43
Groundnut haulm	911	874	114	384	187	27.5
Maize grain	880	929	98	107	43.8	8.1
Acacia torilis pods + maize	889	934	124	194	137	19
Groundnut haulm + maize	900	893	109	287	137	21

Supplement intake and live weight change

The supplements were completely consumed (Table 2). Live weight gains were increased from 21 to 63 and 60 g/d by supplementation with no difference between the two supplements (Figure 1).

Table 2. Body weight change of browsing Abergelle goats supplemented with mixtures of Acacia tortilis pods (AP) or groundnut haulm (GH) and maize grain (MG)
	Treatments			SEM	p
	Browsing	APMG	GHMG	SEM	p

Supplement CP, g/d		124	109
Supplement DM, g/d		445	500
Initial wt, kg	17	16.9	16.7	0.602	0.426
Final wt, kg	18.9^b	22.6^a	22.1^a	0.629	<0.0001
Weight gain, g/d	21.3^b	63.1^a	60.4^a	1.34	<0.0001
^abc means in the same row with different superscript differ at p<0.0001

Figure 1. Growth rates of Abergelle goats on browsing only or supplemented with Acacia
tortilis pods-maize grain (APMG) or groundnut haulm-maize (GHMG)

Conclusion

Acacia tortilis pods and groundnut haulm mixed with maize grain were equally effective as supplements to natural browse tree grazing increasing the growth rates of Abergelle goats to 60 and 63 g/day compared with 20 g/d on traditionally managed native browse trees alone.

Acknowledgements

The authors acknowledge the Tigray agricultural research institution for funding the research.

References

AOAC 2005 Official methods of analysis. 18^th edition, Association of Official Analytical Chemists, Washington, DC.

Gebremariam T and Belay S 2016 Livestock feed resources utilization practices in Tanqua-Abergelle district of Tigray, northern Ethiopia. Tropical Animal Health and Production, 48(6):1183-1190.

OoARD 2012 Tanqua-Abergelle Office of Agriculture and Rural Development annual report, Yechilla, Tigray, Ethiopia.

SAS 2004 SAS/STAT Guide to personal computers, release 9.0. Statistical Analysis System Institute. Inc., NC. North Carolina, USA

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. Symposium: Carbohydrate methodology, metabolism, and nutritional implications in dairy cattle. Journal of Dairy Science, 74, 3583-3597.

Yami A 2008 Nutrition and feeding of sheep and goats. In. Yami A and Merkel RC (Eds.), Sheep and goat production handbook for Ethiopia. Addis Ababa, Ethiopia. pp.104-159.