Formulation of appropriate strategies for long-term maintenance and use of the genetic variation within livestock species requires characterisation of animal genetic resources, to identify the variation and appropriate germplasm that is optimal for each system. Phenotypic characterisation involves carrying out baseline surveys in order to: establish identities and characteristics of individual populations (breeds/strains); determine the status of animal populations; document the full range of existing production and management systems; and compare breeds with respect to the mean and phenotypic variance of their performance and characteristics. Until we have proper information on the genotypic and phenotypic characteristics of our indigenous breeds, no rational decisions can be made regarding their utilisation and conservation.
The study was conducted in four districts, namely Makueni, Kitui, Taita Taveta and Kajiado located in the arid and semi-arid marginal lands between latitude 1° and 4°S and longitude 36° and 40°W (Figure 1). These districts receive a bimodal rainfall and a prolonged dry season. The long rains begin in March and end in May while the short rains occur between October and December in the Makueni, Kitui and Taita Taveta districts, and between November and December in the Kajiado District (ILCA 1982; Jaetzold and Schmidt 1983; Musembi 1986). The major climatic characteristics of the study area are summarised in Table 4. The inhabitants of Makueni, Kitui and Taita Taveta districts are the Kambas and the Taitas who are mainly agropastoralists. The Maasai inhabit the Kajiado District; they were originally pastoralists, but with changing economic times, have started to embrace crop farming. Livestock production systems in these areas are characterised by minimal management inputs in terms of breeding, disease control and nutrition, and are mainly traditional and subsistence oriented.
Table 4. Climatic characteristics of the study areas.
District |
AEZ1 |
Subzones2 |
Altitude (m) |
Mean annual temperature (°C) |
Mean annual rainfall (mm) |
60% rainfall reliability (mm)3 |
60% growing period reliability (days)4 | ||
1st rains |
2nd rains |
1st rains |
2nd rains | ||||||
Kitui |
3, 4, 5 |
UM 3–4 |
1340–1620 |
18.6–20.2 |
900–1050 |
300–350 |
400–490 |
105–115 |
85–105 |
LM 4 |
760–1280 |
20.9–24.0 |
700–880 |
175–243 |
315–383 |
52.5–65 |
77.5–90.0 | ||
LM 5 |
760–910 |
23.2–24.0 |
600–720 |
124–172 |
164–240 |
33–49 |
48.0–63.0 | ||
LM 6 br |
– |
– |
350–550 |
80–100 |
130–150 |
No rain-fed agriculture possible | |||
Makueni |
4–5 |
LM 4 |
1160–1280 |
21.3–22.0 |
700–850 |
190–300 |
250–350 |
55–75 |
75–85 |
LM 5 |
790–1220 |
21.6–24.0 |
600–700 |
50–160 |
150–220 |
20–40 |
45–55 | ||
LM 6 br |
– |
– |
350–550 |
80–100 |
130–150 |
No rain-fed agriculture possible | |||
Taita/ Taveta |
4–5 |
LM 5 |
790–980 |
22.4–23.5 |
480–700 |
140–250 |
120–200 |
45–75 |
<55 |
LM 6 br |
No rain-fed agriculture possible | ||||||||
L 5 |
610–790 |
23.5–24.6 |
480–680 |
140–200 |
120–210 |
40–55 |
<75 | ||
L 6 br |
No rain-fed agriculture possible | ||||||||
Kajiado |
4–5 |
– |
<1500 |
23.0–25.0 |
250–750 |
– |
– |
– |
– |
The study consisted of surveys carried out in 1992, 1998 and 1999. Two surveys were undertaken in 1992. Table 5 shows where each survey was carried out and the total number of questionnaires administered in each district. All households were chosen at random. The 1992 surveys were mainly carried out in the lower divisions of Makueni (Makindu, Kibwezi and Mtito Andei divisions) and Kajiado districts (Central, Mashuru and Loitoktok). In the 1998 survey in Kitui district, multi-level stratified sampling was used; in each division, three locations were chosen at random. In these locations, three sublocations were chosen and in each sublocation, three randomly chosen farmers were interviewed. For the 1999 survey, the three divisions with the highest concentrations of indigenous zebu were surveyed using a similar protocol to that used in the 1998 survey, with additional inclusions of the farmers with the highest and lowest numbers of livestock in each division.
Table 5. Location of each survey and total number of questionnaires administered in each district.
District |
Survey years1 | |||
1992 |
1998 |
1999 | ||
1st survey |
2nd survey |
|||
Kajiado |
X (86) |
X (60) | ||
Makueni |
X (87) |
X (106) |
X (60) | |
Kitui |
X (65) |
|||
Taita Taveta |
X (60) | |||
Structured questionnaires were used to collect information on the location of the farm, the breeds and strains kept, herd/sex structures, uses and preferences of breeds, adaptive and tolerance characteristics, breeding and management, and production and reproduction. A summary of the information collected and the classification used is given in. Given the absence of performance recording in the four districts, the productive and reproductive performance of the animals were obtained by asking farmers questions related to the reproductive cycle. Indicative milk production was obtained by asking farmers to relate yield to the number of 300-ml soft drink bottles or 0.5-litre cooking fat containers that could be filled per milking.
Depending on responses from the farmers, the collected information was classified into various classes (Appendix I). For example, the herd structures were classified into seven classes based on sex, age and whether an animal was intact or castrated. For the males, five classes were defined: adult intact males (>3 years old); adult castrates (>3 years old); young intact males (1–3 years old); young castrates (1–3 years old); and immature males (0–1 year old). For the females, only two classes were defined: adult females (>3 years old); and immature females (0–1 year old). Similarly, different uses of animals and reasons why indigenous breeds are preferred were identified. Type of mating systems applied were also identified and classified into four classes, namely: natural controlled; natural uncontrolled; artificial insemination (AI; indigenous semen); and AI (exotic semen). Responses from farmers (e.g. reasons for choosing mating systems, prevalent diseases etc.) and effects (e.g. type of birth, calving season etc.) were also identified and classified.
Data were analysed using the MEANS, GLM and FREQUENCY procedures of Statistical Analysis Systems (SAS 1993). The whole data set was divided into three subsets based on the survey years, district and on whether there were common variables in all the questionnaires. For the production data, means and standard t-test across districts and years were obtained while for the categorical data, the number of individuals in each of the defined classes was obtained using frequency counts. Tests of significance and associations (chi-square tests) across districts and years were undertaken to ascertain independence of different classification variables.
The functions performed by indigenous zebu breeds in the study area are represented in Figure 2. As can be seen, indigenous zebu breeds serve several functions that differ across and within districts. The zebu is used more as a source of draft power in Makueni (30.6%) and Kitui (24%) districts than in Taita Taveta (10%) and Kajiado (4.4%) districts. This difference can be attributed to differences in traditions between the communities inhabiting these districts. The Kamba communities that inhabit the Makueni and Kamba districts have long been known to use cattle for draft power. While the Taita Taveta and Maasai communities have learnt this quite recently; the use of cattle as a source of draft power is still very low among the Maasai tribe who regard the use of cattle for draft as a form of slavery. Draft includes activities like ploughing, planting, weeding and ridging and therefore requires strong animals that are able to endure hardship. In most cases, only male animals are used for these activities. This observation was confirmed by the results of this study, which showed that over 96% of farmers in each district preferred using male to female animals for ploughing. The situation was different when it came to using zebu cattle for transportation, in which case results depended on whether alternative forms of transport were available. Donkeys play a greater role in providing power for transport in Kitui and Kajiado than in Makueni and Taita Taveta districts. Within the study area, the importance of draft animal technology is expected to increase in the future. Land tenure regulations and inheritance patterns combined with population growth will keep farm sizes relatively small; moreover, farm sizes will increasingly be smaller than the area normally considered economically viable for cultivation using tractors.
As was expected, in all the districts, farmers kept zebu cattle for milk production for home consumption and sale. Apart from in Makueni district, farmers ranked milk production as the primary reason for keeping zebu cattle. This indicates the importance of inclusion of milk production traits in any breeding programme aimed at zebu cattle in these districts. In all the districts, cattle are a direct source of income, which is realised by exchanging cattle for cash. This in turn is used to purchase goods and services ranging from food items, clothing, medication and schooling to the purchase of breeding stock and livestock inputs for production. As more and more farmers send their children to school, the use of cattle as a source of income is bound to play an even greater role in the future.
The indigenous zebu breed is also used as a source of manure. Manure is used for different purposes in each of the districts. The proportion of respondents using manure as fertiliser, fuel or building material is shown in Figure 3. In all the districts, manure is used as fertiliser. Manure is used principally for building in Kajiado (92.5%), to a smaller extent in Taita Taveta (17.7%), but negligibly in Kitui (1.7%) and Makueni (<1%). A similar pattern was observed for use of manure as fuel. Agriculturally, given their centrality in nutrient cycling, livestock play a vital role in the development of sustainable and environmentally sound mixed crop-livestock farming systems. The use of manure for building demonstrates efficient use of an abundant and available resource by the Maasai. This may be due to the nomadic Maasai lifestyle, which does not allow for the construction of permanent houses; however, it may also be due to the fact that the Maasai are not engaged in crop production and hence there is no competition between enterprises (building vs. fertiliser).
Generally, in these study areas, zebu cattle are the major source of meat. However, Figure 2 summarises farmer’s responses as to whether their particular households slaughtered zebu cattle for home consumption. Cattle are slaughtered during specific occasions and functions such as weddings, funerals, religious and cultural festivals. For home consumption, the majority of households preferred to slaughter small ruminants and chickens, or to purchase beef from butcheries rather than to slaughter cattle.
The use of indigenous zebu cattle as multipurpose animals has been demonstrated in Ethiopia (Mukasa-Mugerwa 1981) and in Kenya (Mosi et al. 1996). This has arisen from the need to extract more than just milk and meat, in the quest to maximise output from these animals that can survive and reproduce under the harsh environmental conditions of the tropics. The development of specialised single purpose breeds, for the exclusive production of either beef or milk, is not an appropriate option for the study areas or for other areas where indigenous cattle are popular. Such livestock development activities would not attract committed farmer participation as they are targeted on single purpose milk or meat production while ignoring the farmers’ primary interest in livestock as providers of several products. Further, the bio-energetic efficiency of multipurpose livestock production would be overlooked by such developments giving rise to misplaced objectives. In a simulation study to compare different breeding objectives and schemes, Kahi (2000) reported higher profits in breeding programmes with dual-purpose objectives than in those with a single purpose objective (beef). The functions required of zebu cattle influence the traits desired by farmers from the viewpoint of genetic improvement. Therefore, the component traits need to be identified carefully before deciding what breeding or livestock development objectives should be adopted. This is the subject of Chapter 5 of this report.
Table 6 shows the proportion of respondents with a preference for each trait category. It is evident that in all districts, the indigenous breeds are preferred due to their superior adaptive capacity to the local environmental stresses, which involves their resistance to diseases and parasites. As was the case for the functions played by indigenous zebu breeds in Makueni and Kitui districts, farmers in these districts preferred these breeds as draft animals. As was expected, very few farmers preferred zebu cattle because they were better milkers, even though milk production was an important function expected of the animals (Section 3.3.1). Zebu cattle are preferred not in terms of the quantities of milk they produce, but due to their ability to provide milk under extreme conditions in which their exotic counterparts would be unable to survive, let alone produce.
Table 6. Proportion (%) of respondents with preference for each characteristic, in each district.
| District |
Farmers preferences for breeds | |||||||
Survival during droughts |
Resistance to diseases and parasites |
Better draft animals |
Ability to work for long hours |
Better milking animals |
Highly fertile |
Better carcass |
Combined criteria1 | |
Makueni |
52.55 |
21.9 |
14.6 |
8.76 |
2.19 |
– |
– |
– |
Kitui |
57.95 |
25.64 |
9.23 |
– |
– |
2.59 |
– |
3.59 |
Taita Taveta |
34.23 |
34.23 |
– |
5.41 |
16.22 |
– |
– |
9.91 |
Kajiado |
63.03 |
18.18 |
– |
– |
8.48 |
– |
6.06 |
4.26 |
The preference for indigenous breeds within the study area, may be attributed to their status as low risk, low investment animals. These breeds require no supplementation during the dry season, often subsisting on poor quality forages, and require minimal levels of veterinary care. These are the strong points of the indigenous breeds. These cattle provide the only means of survival in an environment unsuitable for any other type of land use. In their study in the Oyo State of southern Nigeria, de Jode et al. (1992) reported similar responses to those obtained in the present study. In that study, N’Dama cattle and their crosses were preferred to the exotics due to their greater resistance to diseases, wider dietary preferences, and production of better quality meat and milk.
As shown in Figure 4, the most common breeding system in Makueni, Kitui and Taita Taveta was purebreeding, while in Kajiado district it was cross-breeding. Cross-breeding was between the exotic Sahiwal and indigenous zebu breeds and it was undertaken to improve milk and beef production. Mating, in all the districts, was mainly natural uncontrolled mating and was therefore associated with parturitions distributed throughout the year. Natural controlled mating was more common than mating using AI. Most farmers were forced to allow their cattle to natural uncontrolled mating because of restricted land sizes and the lack of enough resources to demarcate the grazing grounds into paddocks to facilitate separation of male and female animals. An advantage of natural uncontrolled mating is that it allows for all year round supply of milk. Similar breeding and mating systems, and calving regimes have been observed in the southern Darfur region of Sudan (Wilson and Clarke 1975) and in the agropastoral and pastoral subsectors of Mali, Nigeria and Kenya (Maasai) (de Leeuw and Wilson 1987). In systems characterised by seasonal availability of feeds, calving throughout the year is a disadvantage, especially when calving occurs during a time when feed is scarce. At such times, the dam is put under nutritional stress leading to low milk yields, slow growth rates and low calf survival rates.
Cross-breeding was unplanned and uncontrolled, and therefore a threat to the indigenous animal genetic resources (Rege 1998). Recent reports indicate that the Maasai in Kajiado are actually asking for Sahiwals to use in cross-breeding. The zebu breeds represented in the present study have most probably had gene introgressions from other zebu types and even between themselves; these will have occurred over time through trade, social exchange and migrations. Because of the possibilities of between-and within -type gene introgression in the past generations, the zebu populations of the study area must have many alleles in common.
The majority of farmers, in all the districts, indicated that they obtained their breeding material from their own farms with selection of male animals being practised by a majority of farmers in Kajiado and Kitui, and of both sexes in Makueni and Taita Taveta districts. While the farmers practise selection of breeding animals, they do not keep records, other than those of numbers, which are committed to memory. This is similar to what was observed by Dersch (1986) in the Debre Birhan area of Ethiopia.
The basis of selection of breeding animals differed, both within and between districts. As can be seen in Table 7, both qualitative and quantitative traits were important. Much emphasis was put on milk production, body size, coat colour and horn shape for selecting breeding animals in Makueni, Kajiado and Taita Taveta districts. Large animals were preferred as they provided better draft power and higher milk yields, fetched better market prices, had better growth rates and reached market weights sooner. Brighter coloured coats were preferred most as these were considered not to attract tsetse flies and thus acted as a natural control against infection with trypanosomosis. In Kitui District, however, coat colour and horn shape were valued highly, but this could be due more to aesthetic reasons than economic considerations.
Table 7. Proportion (%) of respondents using a particular character as the basis for selection.
| District |
Basis of selection of breeding animals | ||||||
Body size |
Milk production |
Coat colour |
Horn shape |
Fertility |
Other qualitative traits1 |
Combined criteria2 | |
Makueni |
32.54 |
23.08 |
17.16 |
– |
– |
15.38 |
11.83 |
Kitui |
– |
10.84 |
33.73 |
28.92 |
– |
16.87 |
9.64 |
Taita Taveta |
30.6 |
31.34 |
11.94 |
– |
17.91 |
– |
8.21 |
Kajiado |
23.86 |
25.89 |
22.34 |
18.78 |
– |
– |
9.16 |
Coupled with the fact that most herd sizes are small, lack of records on pedigree is expected to result in intense inbreeding in these herds. Quantification of the extent of inbreeding is difficult because it requires accurate record keeping especially of the pedigree. Branding, or ear tagging or notching for identification is rare and instead identification is based on phenotypic appearances and the occasional naming of animals without any distinguishing identification marks. Lack of animal records and identification has very serious implications, as no effective selection and breeding programmes can be applied in the absence of records. Nuru and Dennis (1976) noted that the major handicap to improvement of the reproductive performance of cattle in northern Nigeria, under on-farm conditions, is the reluctance on the part of the Fulani people to keep records. Like the communities of the study area, the Fulani rely on memorised records, which over a long period may lead to inaccurate information and incorrect breeding decisions.
Poor nutrition is one of the major problems affecting livestock productivity in the tropics. This is normally reflected in reduced live weights, perpetual low animal productivity, greater age at first parturition, increased parturition intervals, prolonged nonproductive life and high mortalities. In the study area, natural pastures are the major feed resource and its utilisation is through continuous grazing. Some farmers in Kitui tether their animals. Tethering is common during the cropping season. This could be due to the shortage of herding labour as farming activities are at their peak. Moreover, tethered animals are able to obtain sufficient access to pasture during this period of the year. Tethering allows better control of animals that could otherwise stray onto other people’s farms.
Feed conservation is commonly practised in the form of crop residues (cereal straws) and hay, from native pastures. These conserved feeds are fed to animals during the dry season, to work oxen during the cropping season and to in-calf and lactating cows. Supplementation of the indigenous breeds using high energy and protein concentrates is rarely practised in the rural areas surveyed. Equally rare is the provision of mineral licks as part of cattle diets. However, animals try to exploit various natural salt deposits that exist in the grazing fields. These results agree with results obtained in Nigeria (Pullan 1979; de Jode et al. 1992) and Botswana (Rennie et al. 1977) under management systems similar to those in the study area.
The management of animal health in the study area is a very simplified practice characterised by very low levels of inputs. Castration of animals is undertaken as a normal routine. Animals are not dehorned and vaccinations, other than through government interventions, are rarely administered. In total, 34 diseases were reported to occur in the study area and these are shown in Appendix I. Figure 5 shows the diseases that appear to cause most problems in the study area. It should be noted that the overall incidence of these diseases was rather low, which could indicate low susceptibility and immuno-responsiveness to various infections. It is interesting to note that tick-borne diseases are common in all the districts. East Coast fever (ECF) was a problem in all the districts. Anaplasmosis was common in Makueni, Kitui and Kajiado. Gastro-intestinal worms were a problem in all districts, except Makueni.
The conventional control measures, such as spraying with acaricide, vaccination through government interventions, deworming, proper hygiene, use of traditional herbs and trapping of tsetse flies are being employed by farmers, although sometimes in the wrong way. For instance, approximately 4 and 6% of farmers in Makueni and Kitui districts, respectively, indicated that they sprayed their animals to prevent occurrence of FMD. In sub-Saharan Africa, there is widespread and indiscriminate application of acaricide to control ticks. This has resulted in emergence of acaricide-resistant ticks (Nolan 1990). Similarly, 2% of farmers in Makueni district applied deworming to prevent occurrence of anaplasmosis and ECF. The frequent intermingling of different groups of animals in the utilisation of common resources provides ideal opportunities for the extensive spread of infectious diseases like rinderpest, FMD, CBPP and tick-borne diseases. The exposure of livestock to wildlife, which is common in the study area, provides opportunities for infection with diseases such as trypanosomosis, ECF and anaplasmosis. Wildlife species act as the major hosts and as reservoirs for these infections.
The use of chemotherapy to control diseases has either been ineffective, unsustainable or uneconomic. Despite this, these measures are still being used in the study area to prevent occurrence of the common diseases. Genetic approaches to disease control have been suggested and should be explored for most of the tropics. In the study area, it was evident that farmers are aware that some degree of tolerance to the common diseases exists in the indigenous zebu breeds of the Makueni, Taita Taveta and Kajiado districts (Figure 6). Therefore utilisation of breeds of livestock that are considered to be disease resistant or tolerant is important to reduce the reliance on chemicals, which end up in animal products and on pastures. Breeding for resistance has attracted considerable research and development attention all over the world. A near unanimous response from farmers in all districts show that heat tolerance of indigenous zebu cattle seemed to be good.
There is a relationship between function of zebu cattle and sex structure of the herd. In districts where zebu cattle provide draft power (Makueni and Kitui), there is more emphasis on maintaining male cattle than in districts (Taita Taveta and Kajiado) focusing on milk production (Table 8). In Taita Taveta and Kajiado districts, the male to female ratio of 35:65 is similar to that noted in Sudan (Wilson and Clarke 1975) and Nigeria (Pullan 1979). In Makueni and Kitui districts, the management system tends to support similar proportions of males and females. This has also been noted in other agropastoral systems of Africa such as in Mali (de Leeuw and Wilson 1987) and Ethiopia (Mukasa-Mugerwa 1981).
Table 8. Age and sex structures of cattle herds in the study area.
| Age–sex structure | Percentage of cattle in each category by district | |||
Makueni |
Kitui |
Taita Taveta |
Kajiado | |
Males: |
46.86 |
41.78 |
36.05 |
36.08 |
Adult males (>3 years) |
13.92 |
17.99 |
8.39 |
5.46 |
Adult castrates (>3 years) |
6.27 |
5.22 |
5.56 |
11.91 |
Young intact males (1–3 years) |
9.61 |
8.90 |
11.79 |
5.66 |
Young castrates (1–3 years) |
0.98 |
0.77 |
2.57 |
4.26 |
Immatures (0–1 years) |
16.08 |
8.90 |
7.72 |
8.78 |
Females: |
53.14 |
58.22 |
63.95 |
63.92 |
Mature (>3 years) |
29.02 |
43.13 |
40.37 |
39.31 |
Young (1–3 years) |
12.16 |
8.12 |
14.04 |
12.16 |
Immature (0–1 years) |
11.96 |
6.96 |
9.55 |
12.45 |
Average herd size (numbers) |
-5.20 |
-7.95 |
-22.29 |
-53.94 |
Consistent with the findings of studies carried out elsewhere in East and South Africa (FAO 1967; Doran et al. 1979), animals over 3 years of age constitute a considerable proportion of all herds in the study area. The percentage of breeding females (range 29.02–43.13%) is considered high and could be due to the importance of milk to the households. It may also be the result of an attempt by herders to overcome the limitations imposed on herd growth by high mortalities and low conception rates. The number of adult breeding bulls in each herd gives a mating ratio of 1 bull to just under 8 breeding females, i.e. 1:2.08 for Makueni, 1:2.4 for Kitui, 1:4.8 for Taita Taveta and 1:7.2 for Kajiado. These ratios are similar to those found in the Ethiopian highlands (1:1.97) (Mukasa-Mugerwa 1981) and in migratory (1:5.9) and sedentary (1:6.9) herds in Sudan (Wilson and Clarke 1975). This is rather a high bull:breeding female ratio compared with the recommended ratio of 1:50 under natural service. The average herd sizes are small indicating that scope for within-herd selection amongst replacement cattle is small. Consequently, organisation of an efficient breeding programme using individual herds is limited.
The least squares means for production and reproduction traits in each district are presented in Table 9. For most of the traits, significant differences between districts were observed. The highest offtakes, expressed in terms of numbers, were observed in Taita Taveta and Kajiado districts. However when expressed as a proportion of the average herd size (Table 8), Makueni District had the highest offtakes while Kajiado District had the lowest. Kajiado and Taita Taveta districts are located near to Nairobi and Mombasa, respectively. This provides a readily available market for beef. This could explain the higher offtakes and larger herd sizes in these two districts compared with the other districts.
Animals in Taita Taveta District attained sexual maturity at a much younger age, which had a direct influence on the age at first calving (Table 9). The age at first calving in each district is high when compared with that of B. taurus breeds whose age at first calving is between two and three years. This is in agreement with observations from other studies involving African zebu cattle under extensive traditional management systems (Sacker and Trail 1966). Nutritional stress throughout the growth period is almost certainly the cause of this late age at sexual maturity and at first calving. Topps (1977) found that, in general, undernutrition delayed the onset of sexual maturity due to nutrition-related problems of infertility and subfertility.
The overall calving interval for the surveyed area was 16 months, with Taita Taveta District having the longest calving interval (18.5 months) and Kajiado District the shortest (13.9 months) (Table 9). Sada (1968) suggested that in N’Dama, Sokoto Gudali and West African shorthorn cattle, calving intervals shorter than 410 days (13.6 months) are very good, those of 411–460 (13.6–15.3 months) are satisfactory and those greater than 461 days (15.3 months) are unsatisfactory. On this basis, the calving intervals are satisfactory for Makueni and Kajiado and unsatisfactory for Kitui and Taita Taveta districts. Estimates of calving interval in zebu cattle range from 12.2 to 26.6 months and most are therefore unsatisfactory (Mukasa-Mugerwa 1989).
The lactation length ranged from 6.7 months in Taita Taveta to 9.8 months in Makueni (Table 9). This wide variation could be due to the difference in weaning ages of calves in the districts. Producers in Taita Taveta District wean their calves earlier than do those in the other districts. There are also relationships between the herd sizes (Table 8) in each district and the lactation lengths. In Kitui and Makueni districts, lactation length is longer than in Taita Taveta and Kajiado districts; the farmers in Kitui and Makueni districts have smaller herds and therefore milk their cows for a longer period of time to guarantee milk supply. A large herd size translates into more cows in milk at a given time and therefore the farmer can allow some of them to terminate lactation early. Similar short lactation lengths have been reported elsewhere for African cattle (Galukande et al.1962; Thorpe et al. 1980; Otchere 1984). Lactation length has a genetic basis and is a major limiter of milk production in tropical systems. Utilising the genetic variation in lactation length, therefore, can make selection gains for milk yield in tropical cattle. This can be done by selecting individuals on an optimum index of lactation yield and length, rather than on milk yield alone (Madalena 1988).
Table 9. Least squares estimates (means ± standard errors where applicable) for production and reproduction traits in each district.
Trait |
Units |
District | |||
Makueni |
Kitui |
Taita Taveta |
Kajiado | ||
Animal offtake |
no. |
3.32 ± 1.90 |
1.60 ± 1.26 |
5.98 ± 1.33 |
6.12 ± 1.33 |
Age at sexual maturity |
years |
3.33 ± 0.11 |
4.30 ± 0.13 |
3.11 ± 0.14 |
3.17 ± 0.10 |
Age at first calving |
years |
4.34 ± 0.14 |
5.30 ± 0.14 |
3.96 ± 0.16 |
4.40 ± 0.14 |
Calving interval |
months |
14.87 ± 0.93 |
16.70 ± 0.79 |
18.54 ± 0.92 |
13.92 ± 0.81 |
Lactation length |
months |
9.79 ± 0.32 |
7.98 ± 0.41 |
6.73 ± 0.47 |
6.82 ± 0.32 |
Daily milk yields | |||||
Lactation start |
kg |
2.75 ± 0.23 |
1.88 ± 0.16 |
1.76 ± 0.18 |
2.33 ± 0.23 |
Lactation peak |
kg |
3.13 ± 0.27 |
3.27 ± 0.23 |
2.39 ± 0.25 |
3.09 ± 0.27 |
Lactation end |
kg |
0.95 ± 0.11 |
1.05 ± 0.10 |
0.71 ± 0.11 |
0.93 ± 0.10 |
Lactation milk yields | |||||
Extracted |
kg |
464.52 |
410.40 |
276.74 |
362.85 |
Milked out |
kg |
1114.20 |
940.80 |
723.16 |
863.05 |
Annual milk yields1 | |||||
Extracted |
kg |
380.07 |
298.99 |
181.61 |
316.40 |
Milked out |
kg |
911.69 |
685.41 |
474.57 |
754.34 |
Culling age of breeding animals | |||||
Males |
years |
6.69 ± 0.52 |
6.90 ± 0.49 |
7.33 ± 0.54 |
8.02 ± 0.46 |
Females |
years |
11.15 ± 0.55 |
12.59 ± 0.45 |
10.55 ± 0.50 |
10.85 ± 0.45 |
Breeding efficiency2 |
% |
81.84 |
72.86 |
49.15 |
87.32 |
Productive herdlife |
years |
6.81 |
7.30 |
6.59 |
6.46 |
Lifetime production of calves |
no. |
5.50 |
5.25 |
4.27 |
5.57 |
There was a significant difference between districts in the average daily milk yields especially during the start and peak periods of lactation (Table 9). The difference in average daily milk production between the four districts may be due to differences in management, plane of nutrition and/or breeds/strains of zebu found in each of these districts. In Kajiado lactating cows are given full access to fodder banks and are watered quite frequently as compared with animals in the other districts, which depend entirely on natural pastures and crop residues.
The average daily milk yields were used to estimate the extracted (adjusted) mean daily milk yields using the following formula:
(x1y1 + x2y2 + x3y3)/(x1 + x2 + x3)
where:
y1 = milk yield at the start of lactation.
y2 = milk yield at the peak of lactation.
y3 = milk yield towards the end of lactation.
x1 = one month after parturition (no. of days).
x2 = three months after parturition (no. of days).
x3 = five months after parturition till the end of lactation (no. of days).
The extracted lactation milk yield shown in Table 9 is a function of the extracted (adjusted) mean daily milk yield and the lactation length. The milked out amount is the sum of the extracted lactation milk yield and the amount of milk consumed by the calf, which was calculated from their preweaning daily gains as suggested by Mukasa-Mugerwa (1981). The extracted lactation milk yields of the indigenous zebu cattle reported in the present study correspond with those obtained under similar conditions in other studies carried out elsewhere in Africa (Leclercq 1976; Semenye 1987; Mukasa-Mugerwa 1989). The low level of milk production by zebu cattle, while partially attributable to nutritional stress, is also an indication that they have a low frequency of genes for high production. Zebu cows have been under natural selection for productive traits for a shorter period than the B. taurus breeds. Zebus evolved in an environment where periodic famines were the rule and therefore, where the ability to survive was of greater value than the ability to produce milk at a higher level. Under traditional pastoral systems little emphasis was put on milk yield from individual cows; instead, large herds ensured an adequate milk supply for the farm family. Adaptation, hence survival was more important, and natural selection ensured that ‘hardy’ animals were the most ‘successful’.
In all the districts, female animals were culled at greater ages than the males (Table 9). This is due to the very important function they play in supplying milk to the household for subsistence and is consistent with the herd life of between 10 and 13 years reported for most African domestic cattle (Wilson 1985; Mukasa-Mugerwa 1989). The advanced culling ages of female animals depicts the ability of the animal to survive the prevalent diseases and drought periods, to withstand the rigours of long journeys in search of green pastures and water, and is an indication of its good qualities. The breeding efficiency for cows in the four districts shows that Kajiado District had the highest breeding efficiency while Taita Taveta had the lowest. Improvement in fertility of older cows following systematic culling at younger ages could be the key to high breeding efficiency in Kajiado. The lifetime production of calves estimated (productive herdlife/ calving interval in years) in this study compares favourably with the 5 calves reported for the Madagascar Zebu (Guillermo 1949) and the 5.4 calves reported for the Sudanese Kenana breed (Alim 1962).
Long reproductive life ensures a high selection differential for economic characters, providing that the cows at advanced ages are amongst the highest producers and keeping them in the herd is the best policy (Saeed et al. 1987). Increased longevity is, however, instrumental in increasing the generation interval and reducing the response to selection. Thus, the balance between individual producing ability and faster genetic gains needs to be considered in deciding the overall herd policy.
It is imperative that the second phase, which involves detailed on-farm characterisation of the management systems, production, reproduction and adaptive attributes of indigenous Small East African Zebu cattle be undertaken with the full participation of farmers. Prior to the second phase, it is important that farmers are informed of the results of the first phase through meetings organised at the farm level, so that farmers’ confidence and trust are built up to encourage future co-operation. Most previous research activities have failed to recognise this need and this has led farmers to view researchers with much suspicion, mistrust and contempt.
