The cattle population in Mauritius amounts to about 35,000 head, made up of various breeds. Of this, approximately 7,000 are females of producing age. The cattle industry in general can be described as being a low input system. The local cattle are called Creole; they are Bos taurus type and of medium size, 300–450 kg adult weight, polled and humpless. They are predominantly white or white-brown with dun, black or brown characteristic spots (Bennie, 1956). Cross-breeding programmes, using AI and bulls, have resulted in various levels of Friesian-Creole crosses. Other exotic breeds and their crosses exist in smaller numbers.
The small farms in the villages consist of 1–4 cows per household. These cows have a milk yield of 1200–1500 litres per lactation, short lactations (225–250 days), long calving intervals (15–18 months) and they first calve at 3–3 1/2 years of age. The cows are hand-milked twice a day, generally before sunrise and at sunset. All cattle are kept indoors and fodder is brought to them. The stables vary from very simple ones built of poles with a thatched roof to improved ones with concrete walls and a roof of iron sheets.
The traditional practice of cowkeepers (small cattle owners in the villages) is to feed their cows mainly on sugar cane tops, which are abundant during the sugar cane harvest season (June to November), together with some selected grasses and crop residues. During the rest of the year, they feed a mixture of various grasses, creepers, shrubs, twigs and crop residues; these forages are available in varying amounts all the year round. Most of them are highly fibrous and contain 4–12% crude protein in dry matter. All forages are collected free from the neighbourhood and none are cultivated, at the cowkeeper level, for use as cattle feed.
Socio-economic importance of cowkeepers
The cowkeepers form an important socio-economic group as they supply about 95% of the fresh milk produced in the country. This is equivalent to about 12% of the total consumption of milk which amounts to about 90 million litres per year (fresh milk and imported milk powder). Cattle rearing in the village smallholdings is a family business and generally a part-time activity. This makes the business a flexible one in the sense that, depending on circumstances, the smallholder can add or sell one or two head of cattle quite easily. This is perhaps one important factor contributing to the fact that, despite the recent wave of industrialisation with its accompanying migration of labour from agriculture to the factories, the cowkeeper community has continued to be in business, although their number has decreased compared to a couple of decades ago. The cowkeeping tradition is still present in the rural areas and people still like to invest in this family business. There is a continuing demand for fresh milk both in the urban and rural areas.
In 1971, the Milk and Meat Project (FAO) diagnosed that lack of supplementation limited milk production. However, it was not specified whether it was energy or protein in the supplement that was important, and the basal diet of cane tops and grasses was not evaluated. This FAO study also proved technically that milk yield could be increased considerably by better feeding and management.
Recent research findings (Ma Poon et al., 1977 Gaya et al., 1982), obtained by the Ministry of Agriculture on Government farms, pointed out that one important limiting factor regarding milk production was the role of appropriate supplements which can stimulate consumption and utilization of roughages rather than depress roughage intake.
On the basis of these findings, the need was felt to further investigate the milk production potential of cows in the country. As the cows in the village smallholdings make a major contribution to the national production of fresh milk, it was decided, within the context of a project funded by the UNDP, to carry out the on-farm research described here in these smallholdings. This was decided because it was possible to have access to a large number of pregnant cows (experimental units) in a relatively short time and at almost no cost in the villages, whereas it would have been very difficult to obtain similar facilities on state farms.
The objectives of this study were to:
ORGANIZATION OF ON-FARM TRIAL
The Animal Nutritionist was the team leader. The Extension Officer organized the evening meetings with the cowkeepers. Extension Assistants residing in the villages made daily visits to the farms and helped in data collection. They travelled on bicycles. Notebooks were kept at the cowkeepers' homes for recording animal weights, milk production, fodder offered, etc. The Veterinary Officer looked after the health of the cows and assessed pregnancy.
This consisted of a van for transporting staff, concentrates and an electronic cattle scale; a bathroom scale to measure birth weight of calves; a spring balance to measure the quantity of forage; and a kitchen scale for concentrates and minerals.
A chemistry laboratory was available for chemical analysis of feedstuffs and cannulated animals for nylon bag study of forages.
The cowfeed had 17% crude protein and was made up of 30% cane molasses, 30% cottonseed cake (or groundnut cake), 5% wheat bran, 11.5% rice bran, 20% maize, 1% common salt and 2.5% calcium carbonate. Cottonseed cake had 44% crude protein and was fed together with a mineral supplement of 15 g common salt and 50 g calcium carbonate per day. It was chosen for comparison with cowfeed because the Ministry proposed to use it later as a straight protein supplement, thus sparing mixing and transport costs.
The cowkeepers fed their cows forages ad libitum according to normal practice. Regular visits, 3 times per week, were made to the cowkeepers' farms and observations were made of management practices and animal behaviour associated with the supply and consumption of fodder. Measurements were made of total feed intake on 30% of the total number (88) of cows participating in the project.
The cane tops were first separated into two fractions, sheath bundle and leaf blade, with a large knife before analysis. For nylon bag work, two mature Friesian × Creole steers fitted with permanent rumen cannulae were used. They were fed a mixture of 20 – 25 kg Setaria sphacelata and Ischmaemum aristatum and 1 kg cottonseed cake plus minerals.
Choice of cows
Cowkeepers who were willing to participate in the project voluntarily registered their names at their local Extension Office. When their cows were seven months pregnant, they started to receive the concentrates. Each cow was alloted in turn to either the cowfeed or cottonseed cake treatment.
Table 1 summarises the pattern of feeding the supplements which were given in two feeds daily.
|7th month (kg/d)||2||1|
|8th and 9th month (kg/d)||3||1|
|Lactation (kg/l milk)||0.5||0.25|
The amount of cowfeed fed was twice that of cottonseed cake, because it had less than half the amount of protein as compared to cottonseed cake. Supplementation started at the end of pregnancy to make sure all the cows participating in the trial had adequate nutrition for fetal growth and lactation.
Management of calf
Only one aspect of the traditional management of the cowkeeper was interfered with during this study; anyone who used to allow his calf to suckle its dam was required to feed it from a bucket from the 7th day after calving until weaning at three months. This was necessary to measure total milk yield accurately.
The trial was conducted in 2 different climatic areas, with 3000 and 1450 mm rain per year respectively. The mean milk production of the cows (all breeds together) on the two types of supplement is summarized in Table 2. Milk composition was determined from monthly morning milk samples.
|Wet uplands||Dry Northern Area||Significance|
|Milk production (kg)|
|301 day lactation||3023||2871||2538||2649||P<.05||NS|
|Mean fat (%)||4.08||4.57||4.31||4.61||NS||NS|
|Mean protein (%)||3.41||3.58||3.47||3.40||NS||NS|
There was no significant difference between cowfeed and cottonseed cake in terms of milk yield. However, supplementation increased milk production by about 1400 kg per lactation, compared to the traditional yield of about 1200 – 1500 kg. Supplementation also prolonged lactation from the national mean of 225–250 days to 301 days. The lactation curves (Boodoo et al., 1988a) were of the classical shape with peak lactation (14.7 and 11.3 litres/day, for the wetter and drier areas respectively) occurring in the second month. The upland cows produced significantly more milk but there were no significant differences in milk fat and in milk protein due to the different areas and concentrates.
The effect of breed on milk production
The cows were classified on the basis of their phenotypic appearance into (1) the local breed, Creole (23 cows), (2) Creole × Friesian (47 cows) and (3) Friesian (18 cows). Table 3 summarises their milk production data. There were no significant differences in total milk production between breeds. These yields compare with national yields of up to 1500 kg for cows receiving little or no supplement and imply a response to supplementation.
Effect of harvest season on milk production
The average milk production of cows calving during the sugar cane crop season (June to November) was 2950 ±92 kg and was significantly (p<0.001) higher than the average for cows calving outside the cropping season (December to May) which was 2705 ±76 kg. There was not a statistically significant interaction between area and time of calving on the total milk production per lactation.
|Uplands||301 days||2788 (232)||2958 (115)||2899 (176)|
|Peak1||13.0 (0.2)||14.5 (0.4)||13.0 (0.8)|
|Northern Area||301 days||2889 (216)||2536 (124)||2459 (156)|
|Peak1||12.1 (0.4)||12.4 (0.6)||10.3 (0.7)|
1 Mean daily production in the 2nd month of lactation
OBSERVATIONS ON THE INTAKE OF FORAGES
The cane tops that were collected by the cowkeepers did not include any flowering ones. In addition, the cowkeepers carefully selected the cane tops and discarded the very mature ones. From those selected, the outer older leaves and all dry ones were discarded. Some cowkeepers had the habit of chopping off and discarding about a third of the leaf blade at the tapering end when they were collecting their bundle of cane tops in the field.
The cows' eating behaviour, as noted during the farm visits, was confirmed in numerous interviews with the cowkeepers. The cows consistently started to consume the cane tops at the sheath bundle end. They consumed the whole of the sheath bundle portion first, then started to eat the leaf blade (Figure 1). They consumed only part of the leaf blades on both sides of the midrib. It was estimated that from one third to one half of the leaf blade was thus consumed.
It was observed in the wet uplands that Ischaemum aristatum (herbe d'argent) generally formed the bulk of the fodder that was given to cows during the sugar cane inter-crop season whereas other assorted forages, singly or mixed, were given in small amounts of a few kilograms per cow. In the drier area, Plantago lanceolata, Digitaria didactyla, Stenotaphrum dimidiatum and young cane regrowths (about 50 cm high) generally formed the bulk of the fodder in the inter-crop season. A few kilograms of other assorted forages, singly or mixed, were also given to the cows.
Figure 1. Sheath bundle and leaf blade fraction of cane top.
The sheath bundle fraction had a lower dry matter and crude protein content (19.3% and 5.5% respectively) than the leaf blade (31.3 and 7.3%) or the assorted forages (23.1 and 9.7% respectively). The crude protein content of the assorted forages and crop residues (9.7%) was quite interesting. The leguminous forages contained up to 14% crude protein (Table 3).
|Dry Matter||Crude Protein||Crude Fibre|
|1. Leaf blade*||(23)||31.3||0.9||(25)||7.3||0.4||(22)||32.9||0.8|
|2. Sheath bundle*||(23)||19.3||1.0||(24)||5.5||0.3||(22)||31.9||0.5|
|3. Assorted forages and crop residues||(49)||23.1||1.0||(49)||9.7||0.5||(15)||31.0||1.2|
|Range for assorted forages etc.|
* These fractions were prepared from one original big bundle (about 7kg) of cane tops.
Rate of degradation in nylon bag
Results of the nylon bag study of the various types of forages are shown in Table 4. These data show that the sheath bundle fraction degraded much faster than the leaf blade at all the time intervals studied. On the other hand, the sheath bundle and assorted forages show remarkably similar DM degradabilities from the 16, 24, 48 and 72 hour incubations. The rate and extent of degradation supports the view that the sheath bundle and assorted forages are good quality roughages in this environment. Their potential degradability is approximately 26% higher than that of the leaf blade.
|Incubation Time (h)|
1These 18 samples were a random selection from 49 original ones.
Table 5 summarizes the data on forage consumption, liveweight and DM intake.
|Wet uplands||Dry Area|
|Cane tops||Mixed grasses||Cane tops||Mixedgrasses|
|Surplus feed (% of amount eaten)||58.9%||18.9%||40.3%||27.2%|
|Liveweight of cows (kg)||342||353||364||311|
The cows were offered forages ad libitum such that the surplus amounted to 19–58% of the amount eaten, especially sugar cane tops which are abundant during the harvest season. This surplus gave them plenty of scope to select the best parts and this resulted in a high intake of fodder dry matter (about 3.7% of body weight).
DISCUSSION AND CONCLUSION
Cottonseed cake provided slightly more protein than cowfeed at the levels used. However, cowfeed, because of its molasses content would have provided more energy than cottonseed cake. It is therefore interesting to note that similar levels of milk were obtained with these two supplements, which point to protein being the primary nutrient limiting milk production under these conditions.
The traditional practice of selectively feeding a variety of forages has sound scientific basis. With time, the cowkeepers have developed an appreciation of forage quality. The present data show that the rate and extent of degradability of the sheath bundle fraction of cane tops and the assorted forages are the basis for good milk production in the villages, compared to the larger systems of production where there is less attention to forage selection.
The local Creole breed has sufficient potential for milk production, given the climate and the resources available on village smallholdings in Mauritius. There would therefore appear to be no advantage to be gained from the importation of exotic breeds for milk production.
Bennie, J.S.S. 1956. The Mauritius Creole breed of Milch Cow. Empire Journal of Experimental Agriculture. 24 (95).
Boodoo, A.A., 1988a Ramjee, R., Hulman, B., Dolberg, F. and Rowe, J.B. The effect of supplements of cowfeed and cottonseed cake on milk production in Mauritian villages. Paper presented at seminar Milk and Beef Production in Mauritius, Division of Animal production, Ministry of Agriculture, Fisheries and Natural Resources. June 7 –8, 1988.
Boodoo, A.A., 1988b Ramjee, R., Hulman, B., Dolberg, F. and Rowe, J.B. Evaluation of the basal forage diet of village cows. In: Milk and Beef Production in Mauritius, loc. cit.
Boodoo, A.A., Ramjee, R., Hulman, B., Dolberg, F. and Rowe, J.B. 1989 The response of Creole, Friesian and Friesian cross cows to concentrate supplementation on village smallholdings in Mauritius. Animal Production. In press.
FAO. 1971 Milk and Meat Project. FAO, Mauritius. Working reports Nos. 1, 5 and 17.
Gaya, H., Hulman, B. and Preston, T.R. 1982 The value for milk production of different feed supplements: Effect of cereal protein concentrate, poultry litter and oilseed meal. Tropical Animal Production 7: 134–137.
Ma Poon, L.K., Delaitre, J.C. and Preston T.R. 1977 The value for milk production of supplements of mixtures of final molasses, bagasse pith and urea, with and without combinations of maize and groundnut cake. Tropical Animal Production 2: 148– 150.