A comparative evaluation of moringa (Moringa oleifera) and sweet potato (Ipomoea batatas) leaf hays as foraging substrates for laying hens

S S Diarra, S Rusa, N Wati, S Biloko, S Gaunalomani and M Hazeem

School of agriculture and Food Technology, Alafua Campus Samoa, PMBag Alafua, the University of the South Pacific
siakadi2012@gmail.com

Abstract

The comparative potential of moringa and sweet potato leaf hays as foraging substrates for laying hens was investigated in a 175-day experiment.

Two hundred and twenty five 126 d-old pullets were assigned to 3 foraging groups: without foraging substrate, with moringa leaf or sweet potato vine hays. Each group consisted of 5 replicates of 15 birds. Feed intake, weight gain (WG), egg weight (EW), egg mass (EM) and feed conversion efficiency (FCE) were not affected by treatment (p>0.05). Hen-day production and egg yolk pigmentation were increased (p<0.05) on the MLH but yolk pigmentation did not differ between the forage supplemented groups (p>0.05). A higher number of floor feathers was recorded on the control group (p<0.05). It was suggested that supplying Moringa oleifera leaf hay as foraging substrate in choice feeding can significantly improve the performance of laying hens in terms of egg production and yolk pigmentation and reduce the incidence of misplaced feathers on the floor.

Key words: foraging material, layer welfare, rate of lay, egg quality

Introduction

The gradual ban of conventional battery cages will increase the use of the floor system for laying hens. The incidence of feather pecking and cannibalism, a major cause of economic losses, can however, be high on the floor system. Wouw (1995) reported up to 30% mortality as a result of cannibalism in organic farming system. Beak trimming which has long been used as a tool to control feather pecking is likely to be banned on account of its welfare implication. Roughage supplementation has been reported to reduce the incidence of feather pecking and cannibalism without adverse effects on egg production and egg quality in laying hens (Steenfeldt et al 2001). These authors observed the best plumage condition in 53-week old laying hens having access to carrot, maize or barley-pea silage compared to the control group without forage. Köhler et al (2001) also reported a better plumage condition in hens given ad-libitum access to fresh grass compared to the group without. Aerni et al (2000) reported reduced incidence of feather pecking in hens fed pellet with access to foraging. Sweet potato (Ipomoea batatas) and moringa (Moringa oleifera) leaves are readily available in Samoa but their comparative use as foraging substrates for laying hens is not documented. The present study compared the effects of sweet potato (Ipomoea batatas) and moringa (moringa oleifera) leave hays as foraging substrates on egg production, egg quality traits and floor feather count of laying hens.

Materials and methods

Sources and processing of foraging materials

Leaves from moringa and 5-month old sweet potato were harvested and wilted in the sun for 24 hours to obtain moringa leaf hay (MLH) and potato vine hay (SPVH; leaves and stems) respectively with a moisture content of about 16%. The hays were analysed for proximate composition and amino acid profile (Table 1) and stored under a well-ventilated shed.

Figure 1. Harvesting leaves	Figure 2. Wilting leaves in the sun	Figure 3. Moringa leaf (above) and sweet potato vine (below) hays

Experimental birds and management

Two hundred and twenty five Shaver Brown 126 d-old pullets weighing (mean +- s.d) 1598g +- 4.3 were weighed and allotted to 15 floor pens (238 cm x 109 cm) containing 15 birds each. The birds were fed commercial layer mash (~15 5% crude protein, 11.7 MJ ME/kg, 0.5% methionine, 1% lysine, 4% Ca, and 1.1% available P) ad-libitum.The treatments consisted of a control with no foraging material and 2 groups supplemented with either MLH or SPVH. The hays were provided separately as choice in plastic trays. The lighting programme was 13 hours day light. The experiment lasted for 175 days. The experimental protocol was approved by the animal ethics committee of the University of the South Pacific.

Data collection

Data were collected on pullet growth (feed consumption, weight gain), egg performance (age at first egg, hen-day production, feed: egg), some egg external (weight, mass and per cent shell) and internal (Yolk colour, Haugh unit) qualities and floor feather count. Pullet growth, feed (including forage) intake were monitored by weighing. Egg weight was determined using a digital scale sensitive at 0.01g and egg mass (g) calculated per pen. Five eggs were selected per pen on weekly basis and broken on a glass table and albumen height taken at two locations using a spherometer. Haugh unit (HU) was calculated according to Eisen et al (1962) as HU = 100 x log (h-1.7w^0.37 + 7.6) where h is the mean albumen height (mm) and w egg weight (g). Eggshells (with membranes) were oven-dried at 60^oC overnight, weighed and per cent shell calculated as weight of dry shell dividido egg weight x 100 (Chowdhury and Smith 2001). Yolk colour was assessed using a Roche yolk colour fan graduated from 1 to 15. Floor primary feathers were collected and counted daily per pen. Data collection lasted 175 days.

Chemical analysis

Samples were analysed for proximate composition (AOAC 1990). Dry matter was determined after oven-dying samples at 103^oC overnight. Nitrogen was analysed by Kjeldahl method (ID 954.01) and crude protein calculated as nitrogen x 6.25 (feed factor). Ash was determined by burning the samples in a furnace at 500^oC. Fat, ash and crude fibre were analysed using methods ID 942.05, 920.39 and 962.09 respectively. Samples were hydrolysed in acid (6 mol/L HCl, 115^oC for 23 h) and analysed for amino acids on an ion-exchange column using a HPLC (Spackman et al 1958).

Statistical analysis

Data were analysed for ANOVA (Steel and Torrie, 1980) of the GLM of SPSS (SPSS for Windows, version 22.0; IBM Corp., Armonk, NY, USA). Feed consumption, egg production and egg quality data were collected per pen while data on body weight were collected on individual hens and related to pen. Treatment means were compared using the Least Significant Difference and significant differences reported at 5% level of probability.

Results

Chemical analysis

Moringa leaf hay (MLH) contained more crude protein, ether extract and ash but less crude fibre than sweet potato leaf hay (SPVH). With the exception of higher arginine and methionine + cysteine in MLH, the two hays were comparable in amino acid composition.

Laying performance and feather count

Performance results of the hens are presented in Table 2. The groups having access to foraging materials consumed slightly more feed than the control but treatment differences were not significant. Similarly there were no significant treatments effects on weight gain (WG), egg weight (EW), egg mass (EM) and feed conversion efficiency (FCE). A higher hen-day production (p<0.05) was recorded on the MLH group. Hen-day production did not differ (p>0.05) between the control and SPVH groups. A higher number of floor feathers was collected on the control group (p<0.05). Floor feather count did not differ between the hay supplemented groups (p>0.05).

Egg quality measurements

Egg quality data of the hens (Table 3) showed no treatment effects (P>0.05) on Haugh unit, and per cent shell but deeper yellow yolks were recorded on the MLH group compared to the control (P<0.05). Yolk colour did not differ between the hay supplemented as well as the SPVH and the control groups (P>0.05).

Discussion

Chemical analysis

The lysine and methionine contents of the sweet potato leaf meal used in this study compare with values (1.08 and 0.54% respectively) reported in ensiled (An et al 2004) but higher than the values 0.83 and 0.43% (Ly et al 2010); 0.62 and 0.26% (Farrell et al 2000) in dry sweet potato leaf meal. An et al (2003) and Ly et al (2010) harvested leaves from 60 d old sweet potato plants while Farrell et al (2000) pruned the vines at regular interval from a range of cultivars. Teguia et al (1997) also reported a lower (~ 17%) crude fibre in dry sweet potato leaf meal than the value in the present study. Differences in the age of the leaves, the cultivar, and vine: leaf ratio and processing method may all be possible factors in the variation in the composition. Edaphic and agronomic conditions which have also been reported to affect the composition of cassava leaf (Eggum 1970; Ravindran 1991) may also be reasons for variability in the composition of sweet potato leaf meal. Potato vine meal contained more NSP which was reflected in the diets as SPVM level increased. Moringa leaf hay used in this study contained more crude protein but slighter lower ME than the values (23% crude protein and 12 MJ ME/kg) reported in moringa leaf meal by Becker (1995). As earlier mentioned several factors include age of plant part, cultivar, agronomic practices and analytical procedure may all be possible reasons for the variation.

Laying performance and feather count

Feeding fibrous materials with low energy density is known to increase feed intake in poultry in an attempt to meet the energy requirement (Steenfeldt et al 2001). Although not significant, this behaviour may explain the slight increase in feed intake on the hay supplemented groups compared to the control. The composition of sweet potato vine revealed a higher fibre than moringa leaf, thus a further slight increase in feed intake on this group. The slightly higher feed intake and probably higher intake of essential nutrients may explain the higher hen-day production on the MLH supplemented birds. The reason for lower hen-day on the SPVH group was not clear but probably due to higher crude fibre and lower essential nutrients, especially amino acids in SPVH compared to MLH (Table 1). Steenfeldt et al (2001) observed no significant effect of roughage supplementation on egg production and feed efficiency. Differences in nutritional content between MLH and SPVH may further explain the improved hen-day on MLH in the present study suggesting that source and composition of foraging substrate is an important factor influencing performance. Teguia (2000) also observed differences in egg production of laying hens supplemented with different green leaves compared to the control group and attributed this to additional nutrients in the forages. The effect of roughage supplementation on the incidence of feather pecking is well documented (Hoffmeyer 1969; Aerni et al 2000; Steenfeldt et al 2001; Köhler et al 2001). Steenfeldt et al (2001) observed low incidence of feather pecking in carrot silage supplemented hens and attributed this to the lower dietary nutrient density and increased fibre content. In addition to dietary fibre the additional nutrients in MLH, especially amino acids, in the present study might have also contributed to slightly lower number of feathers on this group compared to the SPVH group. The beneficial effect of dietary essential amino acid in the prevention of feather pecking has been reported (Elwinger et al 2002; Van Krimpen et al 2005). The severity of feather pecking is reported to be age dependent with gentle feather pecking mostly in young and severe pecking in older birds (Kjaer and Søresen 1997; Huber Eicher and Sebo 2001; Rodenberg and Koene 2003). In the present study (concluded at 43weeks of age) there was no eminent sign of severe pecking yet but the higher number of misplaced floor feathers on the control could predispose to further pecking.

Egg quality measurements

All eggs were ranked AA as they had HU above the USDA (1984) value of 72. The deeper pigmentation of yolk on the hay supplemented groups was anticipated due to the carotene content of green leaves. Ravindran (1991) stated that emphasis in using leaf meal in poultry nutrition has been as a source of pigments in mixed feeds. Udedibie and Opara (1998) and Teguia (2000) also reported higher pigmentation of the yolk of hens given access to green leaves.

Conclusions

• The results suggest that supplying Moringa oleifera leaf hay as source of foraging substrate in choice feeding can significantly improve the rate of lay and reduce the incidence of misplaced feathers on the floor which might predispose to severe pecking.
  
  
• Where higher yolk pigmentation is a desirable attribute for the market these materials will improve yolk colour and reduce spending on commercial pigments and add value to this locally available raw material.

Acknowledgments

The School of Agriculture and Food Technology of the University of the South Pacific is acknowledged for providing the birds and feed.

References

Aerni V, El-Lethey H and Wechsler B 2000 Effect of foraging material and food form on feather  pecking in laying hens. British Poultry Science, 41: 16-1.

An L V, Lindberg B E F and Lindberg J E 2003 Effect of harvesting interval and defoliation on yield and chemical composition of leaves, stems and tubers of sweet potato (Ipomoea batatas) L (Lam.) plant parts. Field Crops Research, 82: 49-8.

AOAC 1990 Official Methods of Analysis 15^th edition, Washington DC.

Becker K 1995 Studies on utilization of Moringa oleifera leaves as animal feed. Institute for Animal Production in the Tropics and Subtropics vol.480.University of Hohenheim Stuttgart, p.15.

Chowdhury S R and Smith T K 2001 Effects of dietary 1,4-diaminobutane (putrescine) on eggshell quality and laying performance of hens laying thin-shelled eggs. Poultry Science, 80: 1208-214.

Eggum B O 1970 The protein quality of cassava leaves. British Journal of Nutrition , 24: 761-769.

Eisen E J, Bohren B B and McKean H E 1962 The Haugh unit as a measure of egg albumen quality. Poultry Science, 41:1461-468.

Elwinger K , Tauson R, Tufvesson M and Hartmann C 2002 Feeding of layers kept in an organic feed environment. In: 11th. European Poultry Conference, Bremen.

Farrell D J, Jibril H, Maldonada P and Manion PF 2000 A note on a comparison of the feeding value of sweet potato vines and lucerne meal for broiler chickens. Animal Feed Science and Technology,85:145-50.

Hoffmeyer L 1969 Feather pecking in pheasants - an ethological approach to the problem. Danish Review of Game Biology, 6 (1): 1-6.

Huber Eicher B and Sebo F 2001 The prevalence of feather pecking and development in commercial flocks of laying hens. Applied Animal Behaviour Science, 74 (3): 223-231.

Kjaer J B and Sørensen P 1997 Feather pecking behaviour in White Leghorns, a genetic study. British Poultry Science, 38 (4): 333-341.

Köhler B, Föhlsch J, Strube J and Lange K 2001 Influences of green forage and lighting conditions on egg quality and hen welfare. In proceedings of the 6^th European symposium on poultry welfare (Oester, H. & Wyss, C. Eds).

Ly N T H, Ngon L D, Vestegen M W A and Hendrika W H 2010 Ensiled and dry cassava leaves and sweet potato vines as a protein source in diets for growing Vietnamese Large White x Mong Cai pigs. Asian Australasian Journal of Animal Science, 23 (9): 1205-1212.

Rodenberg TB and Koene P 2003 Comparison of individual and social feather pecking tests in two lines of laying hens at ten different ages. Applied Animal Behaviour Science, 81 (2): 133-148.

Spackman D H, Stein W H and Moore S 1958 Automatic recording apparatus for use in chromatography of amino acids. Analytical Chemistry, 30: 1190-1206.

Steenfeldt S, Engberg R M and Jaer J B 2001 Feeding roughage to laying hens affects egg production, gastro-intestinal parameters and motility. Proceedings of the 13^thEuropean Symposium on Poultry Nutrition, Blankenbergen.

Steel R G D and Torrie J H 1980 Principles and Procedures of Statistics. A biometrical Approach, 2^nd edition McGraw Hills Book Co., New York, U.S.A

Teguia A, Njewe R M and Nguekouo Foyette C 1997 Effects of replacement of maize with dried leaves of sweet potato (Ipomoea batatas) and perennial peanuts ( Arcahis glabrata Benth) on the growth of finishing broilers. Animal Feed Science and Technology, 66: 283-287.

Teguia A 2000 A note on the effect of feeding local forages to commercial layers on egg production and yolk colour. Journal of Animal and Feed Sciences, 9: 391 - 396.

Udedibie A B I and Opara C C 1998 Response of growing broilers and laying hens to the dietary inclusion of leaf meal from Alchornia cordifolia. Animal Feed Science and Technology, 71: 157-164.

USDA 1984 United States Standards for Quality of Individual Shell Eggs. U.S. Department of Agriculture, Food Safety and Quality Service, Agriculture Handbook.

Van Krimpen M M, Kwakkel R P, Reuvekamp B F J, Van der Peet-Schwering C M C, Den Hartog L A and Verstegen M W A 2005 Impact of feeding management on feather pecking in laying hens. World's Poultry Science Journal, 61 (4): 663- 685.

Van Soest P J, Robertson J B and Lewis B A 1994 Methods for dietary fibre, neutral detergent and non-starch polysaccharides in relation to animal nutrition. Journal of Dairy Science, 74: 3583-597.

Wouw S V D 1995 Kannibalisme bij biolosche legkippen. Landbouw Universiteit Wageningen, Wageningen.

Received 17 July 2017; Accepted 6 August 2017; Published 1 September 2017

Go to top