Supplementation of Ziziphus spina-christi, Sterculia africana and Terminalia brownii to Abergelle kids fed hay: effects on feed intake, digestibility and post-weaning growth

Bruh Weldemariam, Solomon Melaku¹ and Berhan Tamir²

Tigray Agricultural Research Institute, P.O Box 230, Axum, Ethiopia
bruhweld@gmail.com
¹Haramaya University P.O Box 138, Dredawa, Ethiopia
²Faculty of Veterinary Medicine, AdiAbeba Unversity, P.O.Box 34, Debre Zeit, Ethiopia

Abstract

The study consisted of 7 days digestibility trial and 90 days feeding trial using 20 male Abergelle weaned kids with mean initial body weight (BW) of 11.7 ± 0.34 kg (mean± SD). The objectives were to evaluate the effect of supplementation with dried foliage of Ziziphus spina-christi (ZSC), Sterculia africana (STA) and Terminalia brownii (TBR) on feed intake, digestibility and body weight gain in natural pasture hay based feeding of Abergelle kids. The experimental design was a randomized complete block design with five replications. The dietary treatments were hay ad libitum, hay + 200 g ZSC foliage, hay + 200 g TBR foliage and hay + 200 g STA foliage on dry matter (DM) basis. Feed intake was measured daily and BW change was measured at 10 days interval throughout the experiment.

The hay contained less CP compared to ZSC, TBR and STA. Hay DM intake was higher for the control than for hay pus ZSC and hay plus STA. The intake of TBR foliage was lower compared to the other two browse species. Total DM intake was higher in supplemented animals than in the control ones. Supplementation improved CP intake which was higher for supplemented goats than the control ones. Nutrient digestibility except NDF was improved in the supplemented goats as compared to the control ones. There was higher daily BW gain in the supplemented kids than non-supplemented ones. In addition, feed conversion efficiency was improved in supplemented kids compared to the control ones. In conclusion, supplementation of dried browse foliage to Abergelle kids fed on hay during post- weaning period resulted in improved DM intake, nutrient digestibility and reversed BW loss commonly observed in the dry season in semi-arid areas. Among the browse species, supplementation with ZSC resulted in better post weaning performance of Abergelle kids.

Keywords: body weight gain, browse species, foliage, natural pasture and post- weaning

Introduction

In tropical arid regions, livestock are an important source of household livelihoods among which goats are outstanding due to adapting to the harsh environmental conditions prevalent in arid and semi- arid regions of the world. The productivity of animals maintained in resource poor environments are usually low due to seasonal fluctuations in the supply and quality of animal feeds, which could be overcome by using locally available natural resources such as the different browse species (Aregawi et al 2008). Browse species are receiving increasing attention as potential livestock forage and for re-vegetation of disturbed lands, more importantly in arid regions (Aregawi et al 2008). A number of studies have proved that the different browse species are rich in their nutrient content, have acceptable digestibility and improve performance of animals, particularly that of small ruminants (Melaku et al 2004). Fodder from browses is often available throughout the year especially, in the dry and drought periods when pastures and crop residues are depleted (Aregawi et al 2008). As a result, goat keeping in semi- arid areas depends usually on naturally grown browses. Sterculia Africana (STA), Terminalia brownii (TBR) and Zizephus spina christii (ZSC) are species of browses adapted to grow in arid and semi-arid areas and usually remain green throughout the year (Photos 1, 2 and 3).

Photo 1. Sterculia Africana	Photo 2. Terminalia brownii	Photo 3. Zizephus spina christii

Besides being available in the dry season, the browse species have a reasonable content of CP ranging between 12.7-14.7%, medium to high in vitro dry matter digestibility (IVDMD) of 66.6-80.8% and in sacco potential degradability of 86-95% (Aregawi 2006). The objective of this study was to evaluate the effect of supplementation with dried foliages of STA, TBR and ZSC on feed intake, digestibility and body weight parameters of intact Abegelle kids fed hay during the post- weaning period.

Materials and methods

Site of study

The experiment was conducted at Tanqua-Abergelle district, a semi arid district in Tigray Region of Northern Ethiopia. The study area is located at 13º 14’ North latitude and 38º 58 ’ East longitude with an average elevation of 1500 meters above sea level. Rainfall is generally very erratic in nature and the rainy season ranges from mid June to early September with an annual average precipitation of 507.5 mm. The annual maximum and minimum temperatures are 41 ºC and 24 ºC, respectively.

Experimental animals and their management

The experiment was carried out using 20 male Abergelle goats weighing 11.7±0.34 kg (mean ±SD) all with full milk teeth and purchased from local markets. The goats were drenched with anti-helminthes, sprayed against external parasites and were vaccinated against the common diseases of the area before the beginning of the experiment. In addition, animals were adapted to consumption of the dietary treatments and new environment for 15 days prior to the actual trial. Experimental goats were kept in individual pens equipped with feeding and watering troughs. Hay was given ad libitum as basal diet allowing a refusal of 25% and the supplement feeds were offered separately twice a day at 0800 and 1600 hours in equal proportions. Water and common salt were available free choice.

Experimental design and dietary treatments

A complete randomized block design with five blocks based on the initial BW of the goats and four replications was used in the study. The four-dietary treatments were randomly assigned to each animal in a block giving five animals per treatment. The supplements were offered at 200 g / head on DM basis. The treatments used in the experiment were feeding of hay (CTL), and supplementation with 200 g DM ZSC foliage (ZSC), 200g DM TBR foliage (TBR) and 200 g DM STA foliage (STA).

Feed preparation and feed intake and body weight change

Leaves and shoots of STA, TBR and ZSC were harvested by hand stripping from the browse trees on communal grazing ranges and area closures at the end of rainy season. After harvesting, the foliages were spread on plastic sheet and dried under shade. The dried foliages were collected and put into sacks and stored in well-ventilated shade until used. The basal diet consisted of mixed sward natural pasture hay. Daily feed offer and refusals were recorded for each goat to calculate daily feed intake. Samples of feed offer were collected per batch and that of refusals were collected over the experimental period for each animal and finally pooled for each treatment.

Digestibility trial

The digestibility trial was conducted after fifteen and three days of adaptation to the treatment feeds and carrying of the faeces collection bags, respectively. Total collection of feces was done for seven consecutive days. The daily fecal output of each animal was mixed thoroughly and 20% was sampled and kept in airtight plastic containers and stored at -20⁰C up to the completion of the digestibility trial. Daily feed intake of each goat was also measured during this period. At the end of the collection period, the fecal samples of each goat was partially dried at 60°C for 72 hours and then the samples were ground and stored in airtight containers pending chemical analysis. Apparent digestibility coefficient of nutrients was calculated as the proportion nutrients consumed that were not recovered in feces to total nutrient intake.

Body weight change

Initial BW of the goats was taken as mean of two consecutive weighings after overnight fasting. Subsequent BW measurements were made every 10 days after overnight fasting until the completion of the experiment. Mean daily body weight change was calculated by regressing body measurements on feeding days.

Chemical analysis

Samples of feed offer and refusal as well as feces were milled to pass through a 1 mm sieve screen size. The determination of acid detergent fiber (ADF) (index no. 973.18), DM (index no. 934.01), nitrogen (index no. 984.13), organic matter (OM) and ash (index no. 942.05) followed the procedures of AOAC (1990). The CP was calculated as N x 6.25. Neutral detergent fibre (NDF) was analyzed according to the procedure described by Van Soest et al (1991). Sulfite and a-amylase were not used as reagents in the determination of NDF. Ash corrected NDF was determined by overnight burning of the NDF in a furnace at 550°C. Sulfuric acid lignin was determined on the ADF residue. The residue of sulfuric acid lignin was ignited in a furnace at 550–600°C for three hours to determine ADF- ash.

Statistical analysis

Collected data on feed intake, digestibility and body weight change were subjected to the analysis of variance (ANOVA) using the General Linear Model procedure of SAS 1998. Treatment means were separated using Tukey HSD (Tukey Honestly Significant Difference Test).The ANOVA model used for statistical analysis was:

Y _ij = µ +αi+βj+εij,

where Y = the response variable, = overall mean, αi = treatment effect, βj = block effect and ε = the random error.

Results

Chemical composition of experimental diets

The CP contents of the browse species ranged from 145 – 194 g/ kg DM, in the order of STA >TBR >ZSC (Table 1). The NDF and ADF contents of the browse species ranged between 322 – 346 and 263 – 313 g/ kg DM, respectively. The CP content of the hay offered was marginal amounting to 66 g/ kg DM, whereas it's NDF and ADF contents were high amounting to 688 and 450 g/ kg DM, respectively. The CP content of the hay refusals was lower, but NDF and ADF levels were higher than the contents of offered hay.

Feed and nutrient intake

The non-supplemented goats had higher hay DM intake compared to those supplemented with the foliage of ZSC and STA (Table 2). However, supplementation resulted in higher total DM, OM and CP intake compared to the control treatment. Among the browse species, the intake of TBR was lower than that of ZSC and STA, but there were no differences in total DM intake. Goats supplemented with STA had higher CP intake compared to those supplemented with ZSC and TBR.

Apparent digestibility

The digestion coefficients of DM, OM, CP and ADF were higher for the supplemented goats compared to non-supplemented ones. The digestibility of NDF was similar across all treatments.

Body weight

Supplementation with ZSC and STA resulted in higher final BW compared to the control treatment. Daily BW gain was greater for all the treatments supplemented with the browse species.

Discussion

The CP content of hay used in this study was within values reported in other studies (Nega and Melaku 2009). Nevertheless, the CP content was not in the range of 70-80 g/kg DM, the desirable quantity to maintain adequate rumen microbial function and feed intake in ruminants (Van Soest 1994). On the other hand, the NDF and ADF contents of hay used in this study were high enough to limit feed intake through bulk effect and low digestibility (McDonald et al 2002). Thus, the weight loss of goats in the control treatment could be explained by the nutrient composition of the hay used. On the other hand, the different browse species used in the study contained sufficient CP and lower cell wall fiber contents similar to other reported studies (Aregawi 2006; Osuga et al 2006) and these justify their value as supplements to low quality feeds given to  goats. The lower CP and higher cell wall fiber contents in the refusals compared to the offered hay indicated that goats consumed selectively materials with better nutritive values as expected.

The non-supplemented goats consumed a relatively high quantity of hay, which is in agreement with the findings reported by Solomon et al (2008) in Sidama goats fed hay and supplemented with graded levels of concentrates. Similarly, Abdulrazak et al (2005) indicated higher hay intake in non-supplemented goats fed Rhodes grass, but total DM intake increased when supplemented with Acacia tortilis leaves and pods. This indicated that supplementation did not increase the basal diet DM intake which is in agreement with other similar studies (Solomon et al 2008). This suggests that supplement type or level may not improve intake of poor quality basal diet, but improves total DM intake and digestible DM intake as observed in this study.

The supplemented browse foliages were readily consumed in the case of ZSC and STA, whereas the pattern of consumption of TBR was variable during the experimental period leading to lower overall intake of TBR. This is expected since intake of browses depends on palatability, content of tannin as well as cell wall contents and the physiological status of the animals (Mandibaya and Chihora 1999). The low preference of goats for TBR initially might be due to the bitter taste of the plant possibly caused by anti-nutritional factors such as tannins that inhibit the utilization of nutrients through astringency, enzyme inhibition and reduced forage digestibility (Makkar 2008). Though information about the anti-nutritional content of the browses used in this study is scant, Aregawi (2006) indicated that the hydrolysable tannin content of TBR harvested in the wet season was high. Osuga et al (2006) also reported total extractable phenols and tannins of TBR to be 166 and 126 mg/g DM, respectively. The presence of such anti-nutritive factors could have contributed to the low intake of TBR foliage. Indeed, goats on this treatment encountered diarrhea that could be a symptom of digestive disturbances. The gradual increase in intake after certain period of time was probably due to physiological adaptation to the secondary plant compounds found in this browse plant. The low protein status of poor quality roughage limits voluntary intake in ruminants. In general, nutrient deficiencies that reduce the activities of rumen microorganisms are liable to reduce feed intake (McDonald et al 2002). Therefore, the low total DM intake in the non-supplemented goats was expected. The higher total DM intake due to supplementation could be attributed to the browse species supplying more nitrogen to the rumen microbes that in turn may have reduced the retention time by increasing the outflow rate and thus stimulating feed intake as suggested by Abdulrazak et al (2005). The increased digestibility coefficient of CP observed in the supplemented goats is probably due to increased supply of dietary CP compared to the control. Evidence of Beauchemin et al (1995) indicated that increased CP content due to supplementation increased CP digestibility, but had little effect on the digestibility of the other nutrients. Higher CP contents in STA and TBR did not result in better apparent nutrient digestibility compared to that observed in ZSC supplemented goats. This may imply low availability of nutrients in STA and TBR due to the presence of tannins which could inhibit nutrient digestibility. Indeed, Osuga et al (2006) reported high total extractable phenolic and total extractable tannins in TBR and low volume of gas production. The relatively low nutrient digestibility observed in the control treatment might be due to its high NDF and ADF intake from the hay, since the primary chemical components of feed that determine the rate of digestion are NDF and ADF (McDonald et al 2002). In addition, the lower digestibility observed in the control than the supplemented goats might be due to lower CP intake, since this affects microbial growth and fermentation in the rumen. Banamana et al (1990) reported that increasing CP in concentrates increased the digestibility of OM, ADF and CP.

Absence of differences in BW gain among the supplemented goats showed that the browse species possessed more or less similar feeding values, but supplementing with ZSC as source of nitrogen seems to have more relative importance in improving goat productivity. Goats fed hay alone exhibited mean BW loss of 2.9 g/day; indicating that the hay provided nutrients hardly to satisfy the maintenance requirements of the animals due to its low CP, high cell wall contents and low digestibility. In this study, the daily BW gain for the supplemented goats ranged from 12.4 - 23.8 g/day. Generally, supplementation with browse foliages appeared to improve daily BW gain of goats probably either by providing nutrient available for absorption or by enhancing microbial protein synthesis. Similarly, Abdulrazak et al (2005) reported that BW gain in browse supplemented goats was associated to sufficient supply of fermentable substrate to rumen microbes thus enhancing their growth and protein synthesis, subsequently improving availability of microbial protein in the small intestine.

Conclusions

• Supplementation of Abergelle goats with dried foliages of ZSC, TBR and STA improved feed intake, digestibility of nutrients and BW gain. The effects were more pronounced in goats supplemented with foliages of ZSC, which is an evergreen tree and usually available in arid and semi-arid rangelands. Thus, supplementation of hay with ZSC dried foliage is benefial to growing goats and possibly to other small ruminants during the dry period.

References

Abdulrazak S A, Njuguna E G and Karau P K 2005 : The effect of supplementing Rhodes grass (Chloris gayana) hay with Acacia tortilis leaves and pods mixture on intake, digestibility and growth performance of goats. Livestock Research for Rural Development. Volume 17, Article #134. Retrieved June 27, 2009, fromhttp://www.lrrd.org/lrrd17/12/abdu17134.htm

AOAC 1990 : Official methods of analysis, 15^{th ed}. AOAC, Washington DC.

Aregawi T, Melaku S and Nigatu L 2008 : Management and utilization of browse species as livestock feed in semi-arid district of North Ethiopia. Livestock Research for Rural Development. Volume 20, Article #86. Retrieved June 12, 2008, from http://www.lrrd.org/lrrd20/6/areg20086.htm

Aregawi T 2006 : Identification and nutritional characterization of major browse species as livestock feed in Abergelle Wereda of Tigray, Ethiopia. MSc Thesis, Haramaya University, Ethiopia.

Banamana M S, Oldman J D and Mowlem A 1990 : The effect of amount of protein in the concentrate on hay intake and rate of passage, diet digestibility and milk production in British Saanen goats. Journal Animal Production 51, 333-342.

Beauchemin K A, McClellad L A, Jones S D M and Ckozub G 1995 : Effect of CP content, protein degradability and energy concentration of the diet on growth and carcass characteristics of market lambs fed high concentrate diet. Canadian Journal of Animal Science 75, 387-397.

Makkar H P S 2008 : A review of the use of isotopic and nuclear techniques in animal production. Animal Feed Science Technology 140, 418-443.

Mandibaya W and Chihora R M 1999 : The nutritional value of Piliostigma thonninghii (mutukutu, monkey breed) pods as a feed supplement for communal cattle in Zimbabwe. Animal Feed Science Technology. 78, 287-295.\

McDonald P, Edwards R A, Greenhalgh J F D and Morgan C A 2002 : Animal Nutrition, 6^th edition, Pearson Educational Limited, Harlow, UK.

Melaku S, Peters K J and Tegene A 2004 : Feed intake digestive kinetics and rumen volatile fatty acids in Menz rams supplemented with Lablab purpureus or graded levels of Leucaena pallida and Sesbania sesban . Animal. Feed Science Technology 117, 61-73.

Nega A and Melaku S 2009 : Feed intake, digestibility and body weight change in Farta sheep fed hay supplemented with rice bran and/ or noug seed ( Guizotia abyssinica ) meal. Trop.ical Animal Health and Production. 41, 507-515.

Osuga I M, Abdulrazak S A, Nishino N, Ichinohe T and Fujihara T 2006 : Potential nutritive value of selected browse species from Kenya using in vitro gas production technique and polyethylene glycol. Livestock Research for Rural Development. Volume 18, Article #171. Retrieved September 2, 2009, from http://www.lrrd.org/lrrd18/12/osug18171.htm

Pond W G, Church D C and Pond K R 1995 : Basic animal nutrition and feeding, 4^th edition, John Wiley & Sons, New York.

SAS 1998 : SAS/STAT Guide to Personal Computers. Statistical Analysis System Institute Inc., North Carolina, USA, Version 7.

Solomon M, Melaku S and Tolera A 2008 : Supplementation of cottonseed meal on feed intake, digestibility, live weight and carcass parameters of Sidama goats. Livestock Science 119, 137–144.

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 Dairy Science. 74 , 3583–3597.

Received 19 January 2014; Accepted 27 July 2014; Published 5 September 2014

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