5.2.1 Cattle production
5.2.2 Water restriction and cattle productivity
5.2.3 Other production and management studies
5.2.4 Livestock health
Relationships among milk production, milk offtake and calf growth were investigated at encampments in six madda by Nicholson (1983a) during 1981-82. Lactation curves and total milk production were quantified for 23 cows by measuring offtake and estimating milk consumption of calves from their growth, composition of milk, and assumptions concerning conversion of milk to live-weight gain (Nicholson, 1983a: pp 28-29). An equation was developed to predict calf growth based on milk intake. The equation includes the formula of Tyrrell and Reid (1965) and includes the empirical requirement of 13.6 MJ ME for a kilogram of growth for pre-ruminant calves (Roy, 1980). This equation is presented in Figure 1, Annex E. Birth dates, birth weights and growth of 133 calves were recorded at encampments in eight locations. Growth was recorded weekly by weighing calves with hanging scales from birth until 210 days of age. Data were analysed with a four-way ANOVA to detect main effects and interactions of sex, location and month and season of birth from least-squares means (Nicholson, 1983a).
Effects of household wealth, cow milking class and type of rainfall year (normal, dry or drought) were variously considered on aspects of cattle holdings and cattle production including rates and causes of calf mortality, age at first calving, calving interval, duration of lactation and milk production by Mulugeta Assefa (1990). These data were also used for economic modeling (see Section 7.3.3.4: The calf: prospects for growth acceleration) and were generated from interviews of 90 households in 1988 from 30 randomly selected encampments in Did Hara and Dubluk madda (15 each; see Figure 2.10). Wealth strata were as described in Section 4.2.4: Dairy processing and marketing. Household members provided details on lifetime production history for 482 cows. One, two or three-way ANOVAs were performed on 16 response variables (Mulugeta Assefa, 1990: pp 11 -12).
One unusual feature of the Borana pastoral system is the role of water restriction on livestock production. Labour constraints and restricted access to water and grazing, in conjunction with the relatively cool climate, have promoted a system whereby cattle may be watered once every three to four days at the height of the dry season (Alberro, 1986; D. L. Coppock, ILCA, personal observation). In a series of trials under conditions in the Ethiopian Rift Valley, Nicholson (1987a; b) studied effects of drinking frequency, extensive walking and night enclosure on various production aspects of Boran and Friesian × Boran cattle. For the drinking frequency experiment, 75 cows with new-born male calves were assigned one of one, two, or three-day watering intervals for 28 months (July 1983 to September 1985) interrupted by ad libitum watering during wet seasons for all groups. Watering frequency was thus restricted only during dry seasons (September to March) to mimic pastoral practices. Other than watering frequency, animals were treated similariy. They grazed in 90-ha paddocks and received standard health prophylaxis. Suckling was unrestricted and calves were weaned between 210 to 240 days of age.
Response variables included: (1) monthly live weights for cows, nursing calves and weaned animals; (2) a monthly condition score for mature cows; and (3) water consumption for cows by weighing animals before and after drinking. Ancillary studies included: (1) effects of treatment on milk intake of calves, measured during three 10-day periods using live weights before and after suckling as well as a tritiated water method (Coward et al, 1982); and (2) effects of treatments on dry-matter intake and digestibility for steers and cows. Intake for the steers was indirectly measured using a natural marker of indigestible acid detergent fibre (Van Soest, 1982) which was determined from forage and faeces and combined with whole faecal collections for 10 days. For cows, intake was determined under stall-feeding conditions where this marker method could be validated. Statistical analyses employed a least-squares ANOVA for feed intake experiments. Dynamics of live weight and condition scores were displayed as time-series graphs. More details are available in Nicholson (1987a; b).
Growth characteristics of over 2600 immature male cattle purchased during 1979-82 for the Sarite cooperative (see Section 1.4.5.5: development) were analysed by Nicholson (1983b). Although the concept in the southern rangelands is being phased out, the work is useful in terms of documenting variability in growth attributable to season, differing regional origin of animals and castration practices. For Group 1, monthly weights were analysed over seven months from November 1980 to June 1981. For Group 2, entry and exit weights were analysed over an average of five months from March to August 1982. Imbalances in data sets led to different analyses for both groups. Average daily gain (ADO) was analysed for Group 1 using a three-way ANOVA with least-squares means to detect effects of origin, and castration. A two-way analysis (origin × herding group) was conducted for Group 2.
Some preliminary data were collected on production performance of about 100 goats and sheep and a few camels managed at Gabra encampments near Beke Pond during average rainfall years by Belete Dessalegn (1985) and reviewed in Cossins and Upton (1987). Some aspects of these studies will be reported here.
Descriptions of management practices were conducted for cattle (Belete Dessalegn, 1983; Donaldson, 1986; Cossins and Upton, 1987; Kabaija and Little, 1987; Holden, 1988; Mulugeta Assefa, 1990; Menwyelet Atsedu, 1990), small ruminants (Belete Dessalegn, 1985; Cossins and Upton,1987) and camels (Belete Dessalegn, 1985; Donaldson, 1986). Surveys documenting presence of camels and equines in Borana encampments were conducted by Coppock and Mulugeta Mamo (1985).
Except for Mulugeta Assefa (1990: pp 34-37), who recorded information on health problems related to calf mortality during interviews on cow history, animal health was never a significant focus of research. The Southern Rangelands Development Unit (SORDU) collated data on cause of mortality for animals which received veterinary attention during 1976-1987, and these are reported here. Donaldson (1986: pp 38-40) noted causes of cattle mortality during drought including incidence of disease. Coppock (1990b) conducted a dry-season survey of the incidence of probable tick-induced damage to cow udders. This survey involved examination of 560 randomly selected cows from 63 herds at water points in the Dubluk, Medecho, Melbana and Beke Pond regions during September, 1989. Response of 24 Gabra herd owners to another questionnaire on camel production problems in the Beke Pond area (D. L. Coppock, ILCA, unpublished data) indicated disease was the most common production problem. Respondents were asked to list diseases in order of perceived importance and ranked data were analysed using Friedman's nonparametric test (Steel and Torrie, 1980). The heavy reliance on interview information, without professional necropsy or physical examinations, is a significant limitation on these results. The pastoralists demonstrated an ability, however, in naming diseases and associated symptoms consistent with those provided by local veterinary staff (Abakanou Kereyou, TLDP Animal Health Coordinator, personal communication).
Preliminary identification of some tick species common to the southern rangelands was conducted at the International Centre for Insect Physiology and Ecology (ICIPE) in Nairobi. This is reported by Nicholson (1985).
