Milk production from the indigenous Malawi goat

R.A. Cooper,¹ J.A. Kirk,¹ L. Kamwanja² and J. Banda²

¹ Seale-Hayne Faculty of Agriculture, University of Plymouth
Newton Abbot TQ12 6NQ, United Kingdom
² Bunda College of Agriculture, University of Malawi
Box 219, Lilongwe, Malawi

Abstract
Rationale
Materials and methods
Results
Discussion
Conclusions
References

Abstract

In a 2x2 factorial trial involving 80 does kept under traditional management, the milking potential of the indigenous Malawi goat was determined and the effects of supplementary feeding examined. Feeding was based on grazed indigenous pasture, largely Hyparrhenia spp only and with supplementation of 250±10 g maize bran daily. Does were separated from their kids each evening at housing and hand milked before turn out. Kiddings occurred between duly 1991 end April 1992. Milk yields from 25±3 days postpartum varied between 1.5 and 61 litres per lactation and lactation length between 13 and 252 days. Lactation patterns were similar, with peaks of 270±99 ml on day 26 for supplemented animals and 259±99 ml on day 19 for controls but a significant interaction between date of kidding and supplementation was noted. Does kidding in August had higher yields (31.6±17.5 vs 21.2±13.66 litres for supplemented and unsupplemented does, respectively) than those of does kidding in March (17.7±7.5 vs 9.1±5.7 litres, P<0.05). Mean daily yields for supplemented does were 191 ml over weeks 1-10 and 139 ml over weeks 1-20. For control animals the equivalent figures were 158 and 104 ml. Reproductive performance was not affected by milking, with kidding to first oestrus intervals of 110±57 days for the milked does and 80±52 days for unmilked does. Anoestrus period was not affected by supplementation. Most kid mortality occurred in the first 30 days and was not influenced by milking or level of supplementation. There was no effect of doe treatment upon kid growth to 28 weeks, when live weights were 7.25±0.87 kg, 7.63±0.75 kg, 6.75±0.66 kg and 7.33±0.6 kg for the unmilked and unsupplemented; unmilked and supplemented; milked and unsupplemented, and milked supplemented animals, respectively. It is concluded that with minimal modification of traditional husbandry methods the indigenous Malawi goat may be milked daily without detriment to her or her offspring.

Rationale

It has been estimated that in some areas of Malawi the incidence of malnutrition in children under the age of five years may be as high as 70%. The problem is particularly severe in those children who have been weaned off breast milk and who are now required to rely largely on 'phala' (maize meal gruel). In many areas of the world milk is seen as being of special benefit to such children, providing high quality protein and high levels of minerals, especially calcium and vitamins, in a very palatable form. For some, the most usual source of that milk is the cow but for many, it is the goat. In excess of 60 million goats are currently being milked world-wide, producing nine million tonnes of milk annually (FAO 1990). Many of these milking goats are to be found in Africa, especially in the Arabic-speaking countries to the north while, despite the presence of large numbers of goats in sub-Saharan Africa, the practice of milking them is uncommon in the area. Malawi is a good example of this situation.

Estimates of the number of goats in Malawi vary between one million (Zerfas, personal communication) and 1.6 million (Government of Malawi 1988) and yet, with the exception of a few areas, these goats are not milked. There does not appear to be any custom or taboo prohibiting the drinking of goat milk (Chimwaza 1982) and in a recent survey Banda (1992a) showed that goat milk was acceptable to many people and was, indeed, preferred to that of the cow or the sheep.

The aim of the project reported here was therefore to examine the potential of the indigenous Malawi goat as a milk producer, when managed under a system as similar as possible to that practised in the villages, and in particular to answer the following questions:

1. How much milk, per day and per lactation is one doe capable of producing when milked once a day?

2. What effect does the removal of this milk have on the survival and growth rate of the goat kids?

3. Is it possible, by supplementing "bush" grazing with maize bran, to increase milk yields economically?

Materials and methods

This trial was undertaken at Bunda College of Agriculture, University of Malawi, during 1991-92. In order to mimic traditional management as far as possible animals grazed unimproved grassland as their main forage source but during the dry season they had access to maize stover in fields and to tobacco gardens. Animals were brought in from grazing before dusk and turned out immediately after milking each morning. Housing was constructed of blue-gum poles and chain-link fencing under galvanised iron roofing. Individual pens were approximately 4x4 m and each housed 10-14 does and their kids. Water was available in the pens overnight. Half of the animals involved (n = 40) were offered a supplementary feed of 250±10 g of maize bran daily, fed in the pen each morning before turnout. Half of the animals in each group were milked once daily in the morning. These animals were removed from their kids each evening at housing and penned separately. The following morning each doe was hand-milked before being rejoined with her kid(s) for the day's grazing. Milking began 25±3 days after kidding and usually continued until yield fell below 50 ml/day for three consecutive days. Does which lost their kid(s) were removed from the trial. Thus the effective trial design was a 2x2 factorial with two levels of supplementation and two levels of milking.

Animals were blocked by week of kidding, beginning on 1 July 1991 and allocated to treatment within block, according to litter size. Milking continued until September 1992 and a total of 50 lactations were recorded. Milk yield for each doe was measured daily and all oestruses and matings recorded. Does were weighed regularly and all mortalities were noted.

Results

Reproduction

Data for the period July 1991 to June 1992 are given in Table 1. Kiddings took place in most months of the year. Overall kidding rate was 142 live births/100 does kidding. There was no relationship between doe live weight and number of kids born (the overall correlation being 0.1).

Overall kid mortality averaged 33.5% of live births. Few triplets were born but mortality was high, at 58.3%. For single and twins mortality was 30.4% and 35%, respectively.

The majority of deaths took place within the first 30 days after birth, that is, before hand milking had begun, and were spread throughout the year with no significant time-of-year effect. Treatment of dam had no effect on kid mortality. Numbers dead were 33 from milked does vs 43 from the unmilked and 33 from supplemented does vs 42 for the unsupplemented.

In the does, post-partum anoestrus was very variable, ranging from 22 to 214 days. There was a trend for longer anoestrus in milked goats (110±57 days) than in the unmilked (80±52 days) but the differences were not significant. There was also a tendency for does kidding in the dry season to have longer anoestrus than those kidding in the rains. Level of supplementation had no effect on anoestrus period.

Table 1. Kidding performance of Malawi does, July 1991-June 1992.

Variable		Month of kidding												Total
		Jul	Aug	Sept	Oct	Nov	Dee	Jan	Feb	Mar	Apr	May	Jun
Type of kidding (number)
	Single	9	9	14	4	2	11	2	8	13	9	-	-
	Twin	4	10	13	1	4	4	1	6	3	3	-	-
	Triplet	-	1	-	-	-	1	-	1	-	-	-	1
Does kidding (number)		13	20	27	5	6	16	3	15	16	12	-	1	134
Kids born alive (number)		17	32	40	6	10	22	4	23	19	15	-	3	191

Milk production

Milk production per doe was extremely variable with yields ranging from 1.5 to 61 litres per lactation. Does that had very low yields often did not reach the bottom limit of 50 ml per day and the decision was taken to stop milking them. Lactation length was thus extremely variable, ranging from 13 days for the very low yielders to 252 days for the better animals.

Total lactation yields were not significantly affected by supplementation. Data, broken down by month of kidding and by lactation period, are given in Table 2, with weekly yield totals shown in Table 3. Overall, patterns of lactation were not different between treatments with peak daily yield from supplemented animals reaching 290±99 ml at 26 days from commencement of milking (range 140-500 ml) while equivalent figures for unsupplemented does were 259±99 ml at 19 days (range 80-450 ml). Supplemented does milked for longer than controls (147±54 days vs 117±47 days). There was an interaction between level of supplementation and month of kidding (Figure 1). For does kidding in August supplementation had no effect on yield or persistency. For does kidding in February/March, with much of their lactation after the end of the rainy season, supplementation led to longer lactations and significantly higher yields (17.7±0.7 vs 9.1±1.5 Iitres, P<0.05). There was no relationship between doe live weight at kidding and subsequent milk yield. The correlation coefficients were 0.42 for supplemented animals and 0.33 for controls. The overall linear regression equation was y = -18 +57w (where w = doe live weight in kg).

Kid growth

The live weights of kids, by age and treatment, are given in Table 4. The kids from supplemented does were consistently heavier than those of unsupplemented animals while those from unmilked animals were heavier than those from milked ones from the 8th to the 28th week of age but none of these differences were significant. Mortality rates were not affected by treatment

Table 2. Lactation performance (means±SE) of Malawi does.

Variable	Dietary treatment
	Period	Supplement (n=20)	Control (n=20)
Yield by month of kidding (litres)	August	31.6±17.5	21.2±13.6
	September	17.7±12.0	15.6±10.9
	February/March	17.7±7.s	9.1±5.7
Yield by lactation period (litres)	Weeks 1-10	13.4±5.0	11.1±5.7
	Weeks 1-20	19.4±9.4	14.5±9.6
	Overall	21.2±13.2	15.0±11.0
Mean lactation length (days to <50ml/day)		119±54	90±47

Table 3. Mean weekly performance (ml±SE) of Malawian does by dietary treatment and month.

Week	Supplemented			Unsupplemented
	August	September	February/March	August	September	February/March
1	1406±246	1564±539	1502±497	1586±562	1393±562	1312±581
2	1148±162	1619±528	1276±483	1394±484	1158±381	1298±484
3	1250±111	1727±629	1538±390	1472±484	1109±361	1251±580
4	1338±155	1572±511	1526±401	1551±618	1200±519	1192±620
5	1274±54	1543±587	1491±415	1417±361	1313±719	1118±680
6	1397±267	1465±566	1500±462	1309±584	1360±619	996±432
7	1407±470	1474±654	1157±378	1735±645	1213±486	867±601
8	1377±459	1387±752	1065±300	1643+516	1144±422	782±431
9	1425±487	1351±573	1137±362	1376±468	1189±540	698±540
10	1425±487	1466+684	1122±338	1548±642	1108±497	533±179
11	1387±502	1307±650	1066±329	1418±642	895±350	411±276
12	1262±588	1302±707	1135±284	1550±731	849±441	-
13	1227±581	1226±781	950±225	1213±559	896±375	-
14	1252±616	1176±807	876±249	1152±618	829±320	-
15	1189±617	1123±847	944±146	1111±667	690±173	-
16	980±546	1177±863	805±157	1244±461	549±225	-
17	832±501	1010±720	-	985±523	499±265	-
18	760±302	1045±764	-	951±315	546±195	-
19	601±193	932±588	-	775±293	688±140	-
20	664±201	542±573	-	739±285	517±24	-

Discussion

The performance of goats in this trial was similar in all respects to that reported elsewhere. In terms of reproduction, overall kidding rate was higher than the 109% reported by Reynolds (1979) and the 103% of Karua (1988). Kid growth rates, thought somewhat disappointing, were in line with the 42 g/day reported by Zerfas and Stotz (1987) and the 47 g/day of Karua, despite the amounts of milk removed. The quality of milk from the Malawi goat is high. Banda (1992b) reports an analytic composition of 5.3% protein, 6.7% butterfat and 4.7% lactose, figures similar to those found in the West African Dwarf goat (Akinsonyu et al 1977) and the South African Boer goats (Raats et al 1983) but significantly higher than those of 'exotic' milking goats. Two hundred millilitres of this milk would thus provide 10.5 g high quality protein, 13.5 g fat and 250 mg calcium. Such amounts would go a long way towards improving the diet of children drinking this milk and the nutritive value would not be impaired by the boiling which would be necessary before its use. It should, however, be noted that the overall mineral composition of goat milk is such that it is unsuitable for children below one year of age.

Conclusions

It is concluded that while yields vary considerably it is possible, with minor modifications to traditional husbandry practices, and at a small cost, to produce usable amounts of milk from the indigenous Malawi goat; removing this milk does not have any adverse effects on the doe or her offspring, and the milk so obtained is capable of contributing significantly to the diets of children aged between one and five years in the households in which the goats are kept.

Figure 1. Mean milk yield per week by month of kiding (dl).

Table 4. Weights (mean ± SE kg) of kids born in year 1991-92 by age and treatment group.

Age (wks)	Treatment
	Non-milked		Milked
	Non-supplemented	Supplemented	Non-supplemented	Supplemented
Birth	1.88±0.125	1.88±0.08	1.78±0.07	2.00±0.11
4	3.00±0.102	3.14±0.09	3.06±0.03	3.18±0.24
8	3.42±0.46	3.60±0.19	3.17±0.11	3.59±0.20
12	4.17±0.36	4.50±0.79	3.96±0.18	4.32±0.29
16	4.83±0.22	5.19±0.65	4.55±0.27	5.05±0.29
20	5.58±0.46	5.88±0.59	5.25±0.37	5.73±0.36
24	6.25±0.76	6.56±0.58	5.88±0.52	6.39±0.42
28	7.25±0.87	7.63±0.55	6.75±0.66	7.33±0.60
52	14.00±1.73	13.67±3.76	13.25±1.03	15.67±0.88

Acknowledgements

The help and encouragement of the Principal and all the staff at Bunda College is gratefully acknowledged. This work was funded by the Natural Resources Institute of the UK Overseas Development Administration.

References

Akinsonyu O.A., Mba A.V. and Olubajo F.O. 1977. Studies on the milk yield and composition of West African Dwarf goats. Journal of Dairy Research 44:57-62.

Banda J.W. 1992a. Acceptability of goat's, sheep's and cows' milk in Malawi. Journal of Consumer Studies and Home Economics 16:129-138.

Banda J.W. 1992b. Genotypic and Seasonal Influences on Milk Yield and Composition of Sheep and Goats in Malawi. PhD thesis, University of Giessen, Germany.

Chimwaza B. 1982. Food and Nutrition in Malawi. PhD thesis, Queen Elizabeth College, London, UK.

FAO (Food and Agriculture Organization of the United Nations). 1990. Quarterly Bulletin of Statistics 3(4). FAO (Food and Agriculture Organization of the United Nations), Rome, Italy.

Government of Malawi. 1988. National Sample Survey of Agriculture. Government Printer, Zomba, Malawi.

Karua S. 1988. Reproductive performance of indigenous Malawi goats under traditional management. Mimeo. Goat Development Workshop, Bikika, Zimbabwe.

Raats J.G., Wilke P.I. and Du Toit J.E.J. 1983. Effect of age and litter size on milk production in Boer goats. South African Journal of Animal Science 13:240-243.

Reynolds L.I. 1979. Breeding performance and growth rates of indigenous Malawi goats. Bunda College of Research Bulletin 10:90-100.

Zerfas H.P. and Stotz D. 1987. An Account of On-farm Goat Research. Malawi-German Livestock Development Programme Working Paper 6. Malawi-German Livestock Development Programme, Lilongwe, Malawi. 8 pp.