B Facultad De Ciencia Animal, Universidad Nacional Agraria, P.O. Box 453, Managua, Nicaragua

Moringa (Moringa oleifera) leaf meal as a source of protein in locally produced concentrates for dairy cows fed low protein diets in tropical areas

B. Mendieta-Araicab, R. Spörndlya, N. Reyes-Sánchezb and E. Spörndlya, ,

a Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, P.O. Box 7024, SE-750 07, Uppsala, Sweden

b Facultad de Ciencia Animal, Universidad Nacional Agraria, P.O. Box 453, Managua, Nicaragua

Received 22 June 2010;

revised 22 September 2010;

accepted 22 September 2010.

Available online 16 October 2010.

Abstract

The effect on milk yield, milk composition and ration digestibility of using Moringa leaf meal as a protein source in concentrate given to six lactating dairy cows fed a basal Elephant grass diet was tested using a changeover 3 × 3 Latin square design, replicated twice. The basal Elephant grass diet and a concentrate containing 20% soybean meal was compared with a concentrate where the soybean meal was replaced with the same amount of Moringa leaf meal. In the third diet commercially available components were used to compose an “Iso” concentrate with the same energy and protein content as the concentrate containing Moringa leaf meal. The intake of dry matter, organic matter, neutral detergent fibre and acid detergent fibre did not differ significantly between treatments and averaged 15.4, 13.9, 7.2 and 5.9 kg day− 1, respectively, while crude protein (CP) intake was higher (P < 0.001) for the soybean meal treatment compared to the other treatments, 1.7 and 1.2 kg CP day− 1, respectively. The treatments did not differ with regard to digestibility with the exception of CP digestibility, which was significantly higher in the soybean meal treatment compared with the Iso concentrate, 0.70 and 0.62, respectively. Mean daily milk yield was significantly higher (P < 0.05) when cows were given soybean meal compared with both Moringa leaf meal and the optimized concentrate, 13.2, 12.3 and 12.1 kg day− 1, respectively. There was no significant difference between treatments in either the milk composition, or the organoleptic characteristics of the milk. The conclusion is that locally produced Moringa leaf meal can, at the same protein and energy levels, successfully replace the commercial constituents in concentrate for dairy cows.

Keywords: Moringa leaf meal; Milk yield; Milk composition; Organoleptic characteristics

Article Outline

1.

Introduction

2.

Materials and methods

2.1. Location

2.2. Treatments, experimental design and management

2.3. Feed preparation

2.4. Digestibility study

2.5. Chemical analysis

2.6. Statistical analysis

3.

Results

3.1. Feed intake and apparent digestibility

3.2. Milk yield and composition

3.3. Labour requirements for Moringa leaf meal production

4.

Discussion

5.

Conclusion

Acknowledgements

References

1. Introduction

One of the most important constraints in tropical livestock production systems is underfeeding due to limitations in both quantity and quality of feed. This has been recognized by many authors ([Franziska and Baccini, 2005], [Olafadehan and Adewumi, 2009] and [Olafadehan and Adewumi, 2010]). These restrictions lead to low milk yields or growth rates which, in turn, gives low net incomes for farmers ([Olafadehan and Adewumi, 2008] and [de Leeuw et al., 1999]). This is particularly pronounced during the dry season, when natural pastures are mature and dry, and therefore have a low nutritive value. In many areas of the tropics, Elephant grass (Pennisetum purpureum) constitutes the basal diet for dairy cows ([Sarwatt et al., 2004] and [Shem et al., 2003]). However, due to the relatively low quality of Elephant grass, it is essential to provide a protein-rich feed supplement.

Dairy production in tropical areas is a complex system and cannot be seen isolated from the economical and social dimension in which the farmers live. Supplementation with conventional concentrates during the dry season is generally too costly and the levels of concentrate feeding are therefore low (de Leeuw et al., 1999). The use of concentrate or other by-products as feed supplements to dairy cows on small farms will depend on the access to cash and the price of the feeds and also the cost of transportation and availability. Therefore there is a need to find alternative low-cost supplements which can be cultivated by the dairy farmer and are available all-year around. This will allow farmers to improve the nutritional level in dairy production in the tropics and step by step improve the economy in small scale dairy production.

An important concentrate ingredient in many countries is soybean meal (SBM) which has a high crude protein (CP) content varying from 437 to 480 g kg− 1 dry matter (DM) ([Broderick et al., 1990] and [Castillo et al., 2001]) and provides a combination of amino acids that can support high milk yields ([Broderick et al., 1990] and [McDonald et al., 2002]). However, local conditions for soybean cultivation are not always favourable and in such areas it is expensive to import SBM. In tropical countries such as Nicaragua, SBM is one of the most expensive feed ingredients in concentrate feeds. During the last four years, the price of SBM has increased almost 200% (USDA, 2009) while the price of other protein-rich feeds such as peanut meal has increased only 9% (MAGFOR, 2008). In some tropical regions urea has been used as an alternative nitrogen source in ruminant diets but in many countries such as Nicaragua, urea is an imported market commodity with variable availability and price. Small farmers are reluctant to use urea because they need to purchase it on the market, availability is uncertain and it is considered difficult to use as a feed. Faced with these facts, it would be beneficial for small farmers in to replace all or part of the SBM in their concentrate mixture with a more economical protein source that could be grown locally with limited resources beside labour.

Leaf meal is a good and cheap source of protein ([Duckworth and Woodham, 1961] and [Paterson et al., 1998]). Different forage trees and shrubs, such as Chromolaena odorata (Fasuyi et al., 2005), Leucaena leucocephala (Kakengi et al., 2001), Morus alba, Azadirachta indica (Patra et al., 2003) and Acacia karroo (Mapiye et al., 2009) have been fed to goats, layers, steers and dairy cows, with good production results. However, the presence of various anti-nutritional compounds in foliage from trees and their deleterious effects in animals has also been discussed ([Ghosh et al., 2007] and [Hammond, 1995]). Largely due to the presence of anti-nutritional compounds such as mimosine, cyanogenic glycosides, condensed tannins and alkaloids, the use of forage trees and shrubs has been limited and ad libitum feeding of these forages is rarely used in livestock feeding.

Another potential protein source for livestock production is Moringa (Moringa oleifera). Although it is a widespread, drought tolerant tree with a high DM yield in the tropics (Reyes-Sánchez et al., 2006), the potential for using Moringa as animal feed is still underappreciated. It is a tree with a high CP content, varying from 179 to 268 g kg DM− 1 ([Reyes-Sánchez et al., 2006] and [Mendieta-Araica et al., 2009]), and with negligible amounts of tannins, trypsin and amylase inhibitors ([Becker, 1995], [Gidamis et al., 2003] and [Makkar and Becker, 1997]). Moringa has also been reported to be a valuable component in human food due to its adequate amino acid profile and CP content, its high level of vitamin A and its low level of anti-nutritional compounds ([Anhwange et al., 2004] and [Sánchez-Machado et al., 2009]). Due to this recent interest in Moringa, feeding trials using fresh Moringa have been performed with many types of animals such as pigs, goats and creole cows ([Ly et al., 2001], [Aregheore, 2002] and [Reyes-Sánchez et al., 2006]). Feeding fresh Moringa is convenient but there is a large variation in production over the year. Therefore, Moringa leaf meal (MLM) is an interesting product as it can be produced during periods of high yields and later used for feeding during the dry season when high quality feed resources are scarce. An important advantage with the production of Moringa leaf meal (MLM) is that the required technology is affordable and feasible even for small farmers. Moringa foliage (branches, twigs and leaves) can be obtained either from pure crop plots or live fences, cut with machete and sun-dried on a black plastic sheet placed on the ground (Olsson and Wilgert, 2007). Based on the authors' experience, the whole drying process can be completed in 72 h rendering approximately 1 kg of MLM from 10 kg fresh material. After drying, the leaves can be removed by simple threshing and the remaining small dry leaves can be crushed or ground by hand to obtain MLM.

In recent years, the interest in MLM as a diet component in animal production has received some attention by researchers who have reported promising production results in fish (Richter et al., 2003), sheep (Murro et al., 2003) and laying hens (Kakengi et al., 2007). Furthermore, in an interesting experiment performed with cross-bred dairy cows MLM was compared with cotton seed cake (CSC) as a concentrate component together with maize bran and minerals (Sarwatt et al., 2004). The cows were fed a basal Elephant grass diet together with one of three concentrate mixtures. Moringa leaf meal substituted 43, 73 and 100% of the CSC in these mixtures. The cows that were fed higher proportions of MLM yielded significantly more milk indicating that MLM is an interesting feed resource in dairy cow diets.

However, the number of dairy cow experiments with MLM is limited (Sarwatt et al., 2004) and it is therefore interesting to study the potential of MLM as an alternative protein source for milk production further, and explore the labour requirements for small scale on-farm production of MLM. Therefore, the aim of this study was to evaluate how MLM compares to commercial concentrate constituents with regard to milk yield, milk composition and ration digestibility and to estimate the work needed to produce MLM under small scale farming conditions.

2. Materials and methods

2.1. Location

The experiment was carried out during the dry season at Santa Ana Farm in Masaya, Nicaragua, located at 13°29´16.5″ N and 60°55´10″ W. The average annual temperature in Masaya is 26.6 °C and the mean annual rainfall is 1361.3 mm, with a marked dry season (November–May).

2.2. Treatments, experimental design and management

A basal Elephant grass diet with a concentrate containing 20% SBM was tested against the same basal diet with a concentrate where the SBM was replaced with the same amount of MLM on weight basis. In the third experimental diet, commercially available components (including SBM) were used to compose an “Iso” concentrate with the same energy and protein content as the concentrate containing MLM.

The concentrate mixtures used in the three experimental treatments are presented in Table 1. The SBM concentrate had the same composition as concentrates commonly used in the dairy industry of Central America. In the MLM concentrate, the SBM was replaced by MLM on weight basis. The Iso concentrate had the same energy and protein content as the MLM concentrate but contained the cheapest available commercially ingredients instead.

Table 1. Proportions of feedstuffs in % wet weight in the concentrate mixtures.

Full-size table

MLM: moringa leaf meal, SBM: soybean meal.

View Within Article

The experiment was designed as a Changeover 3 × 3 Latin Square, as described by Patterson and Lucas (1962), replicated in two orthogonal Latin squares. Each experimental period consisted of 2 weeks for treatment adaptation and 2 weeks of data collection with regard to milk yield and feed intake. The last week of each period was used to estimate digestibility.

Six dairy cows from the farm herd, in their second or third lactation and weighing 467 ± 22 kg were used in the trial. The cows were in their fourth week of lactation at the start of the experiment. All of the cows were treated according to EC Directive 86/609/EEC for animal experiments. The animals were loose confined in individual, well-ventilated stalls with concrete floor which was covered with rubber mats during faecal collection periods. Before the start of the trial, the cows were injected with Vitamin A (625,000 IU), Vitamin D3 (125,000 IU) and Vitamin E (125 IU); treated against external and internal parasites and vaccinated against anthrax. Water was provided ad libitum and the cows had access to a commercial mineral supplement with Ca, P, Mg and trace elements.

The feed allotment was planned to fulfil the protein requirement (NRC, 2001) of CP for the SBM diet when adopting the DM intake of 3.2 of body weight recommended in the region ([Hazard, 1990] and [Romero and González, 2004]). Sixty percent of the expected DM intake was given as roughage in the form of Elephant grass and the remaining 40% was given as one of the three concentrates. These proportions represent approximately those usually used by dairy farmers in the Central American region (Castro Ramírez, 2002; Vélez, 1997). Roughages were offered individually in separate feed troughs twice per day, at 07:00 h and 17:00 h. The concentrates were fed individually during milking, at 05:00 h and 16:00 h. The DM content of Elephant grass was determined twice per week using a microwave oven according to the procedure described by Undersander et al. (1993).

The offered amounts of feed and occasional refusals were weighed daily and sampling of feeds was performed as follows. One kilogram of offered roughage per cow per day was collected and immediately frozen at − 18 °C. After every period the frozen samples of offered feed for each cow were thawed and pooled into one sample per period for chemical analysis. The occasional refused feed was individually sampled and frozen immediately at − 18 °C. At the end of each experimental period these individual samples of refusals were thawed and sent to a laboratory for chemical analysis. From each concentrate in the experiment 1 kg from every delivered batch was collected for analysis, giving a total of three samples per concentrate corresponding to the three periods in the experiment.

The cows were hand-milked and at each milking the yield was weighed and recorded. From each cow and milking a sample of 100 ml was collected and immediately refrigerated at 4 °C. Milk samples from each cow were pooled into one sample per week during the data collection period and then analyzed for fat and protein content, the same milk sample procedure was used for the organoleptic test.

2.3. Feed preparation

The branches with leaves and soft twigs used for the production of MLM were collected from M. oleifera trees in the experimental area by cutting every 45 days. They were then sun-dried for 24 h before the partially dried leaves were removed by threshing and then sun-dried again approximately 48 h on black plastic sheets. The dried leaves were finely ground in a hammer mill, packed in sacks and stored in a well-ventilated storeroom. During the production of MLM for the experiment, the amount of fresh material harvested and the amount of MLM produced was weighed. Furthermore, the work used for harvesting Moringa and the amount of work used in the drying process was registered.

The other concentrate ingredients were purchased in the local market and the experimental concentrate mixtures (Table 1) were produced at the Feed Concentrate Plant of the National Agrarian University, Nicaragua. Before the start of the experiment, the field with Elephant grass (P. purpureum) was divided into several plots that were harvested at regular intervals before experimental start. This was done to enable regrowth cuts at similar intervals with the objective to harvest at approximately 45 days regrowth throughout the experiment. During the experiment, the elephant grass was harvested daily at 46 ± 3 days regrowth and offered fresh to the cows, chopped into pieces of approximately 2 cm using a tractor mounted forage chopper.

2.4. Digestibility study

Every day during the last week of each period, all the faeces from each cow were collected manually. During the collection period cows were supervised 24 h daily and any time when a cow adopted the defecation position a shovel was put under her tail to collect the faeces and avoid contamination from urine and dirt from the stall floor. Thereafter, the faecal material was put into a large, individually marked container for the cow and covered with a lid to avoid evaporation. Once daily, the faecal contents in the containers of each cow were weighed and thoroughly mixed. Five percent of the daily faecal contents from each cow was then taken as a subsample and frozen. When the collection was complete, the subsamples were thawed and mixed together into one homogeneous sample per cow and period. Approximately 300 g of the mixture from each animal was then taken as a faecal sample. The results of the chemical analysis of faeces and feed were used together with intake data to estimate apparent digestibility.

2.5. Chemical analysis

The samples of offered feed, refused feed and faeces were dried at 60 °C and ground through a 1 mm sieve before analysis. Ash and DM were analyzed using AOAC (1990) procedures. The CP content was determined using the Kjeldahl method (AOAC, 1984). Neutral detergent fibre and ADF were analyzed as described by Van Soest et al. (1991). The apparent digestibility coefficient for DM was calculated by comparing the dietary intake of constituents and the amounts recovered in faeces. Nitrogen content in the milk was determined using the Kjeldahl method and milk protein content was calculated as N × 6.38. Milk fat was determined using the Babcock method (Pereira, 1988), while total solids and casein were analyzed according to AOAC (1984) procedures. An organoleptic evaluation of the milk was performed by an experienced panel of 15 persons. A triangle difference test (Witting de Penna, 1981) was applied using a milk sample with normal sensory characteristics (colour, smell and taste) as standard.