Identification systems and selection criteria for small ruminants among pastoralist communities in northern Kenya: prospects for a breeding programme.

Data on animal identification systems and selection criteria for sheep and goats were collected from the Rendille and Gabra communities in northern Kenya. These were then analysed through computation of indices, which represented a weighted average of all rankings of a particular trait or identification system. The three most important records kept were castration (index = 0.224), dates of birth (0.188) and entries into the flock (0.185). Identification was done through ear notching (0.409), branding (0.248), and coat colour of the animals (0.150). Characteristics with index >or=0.200 were considered more important and included big body size (Rendille, 0.260; Gabra, 0.251) and milk yield (Rendille, 0.206) for the buck's dam. Big body size (Rendille, 0.264; Gabra, 0.245) and offspring quality (Rendille, 0.252; Gabra, 0.265) were considered important attributes for the buck's sire. Important qualities for the ram's dam were big body size (Rendille, 0.246; Gabra, 0.216), offspring quality (Rendille, 0.200; Gabra, 0.235), fat deposition (0.233) among the Rendille and drought tolerance (0.246) among the Gabra. For the rams' sire, big body size (Rendille, 0.235; Gabra, 0.233), offspring quality (Rendille, 0.200; Gabra, 0.235) and fat deposition (Rendille, 0.203; Gabra, 0.220) were considered important. The results from this study imply that pedigree and performance recording have been practiced through own intricate knowledge and that pastoralists have deliberate selection criteria. This information is the cornerstone in the establishment of appropriate breeding programmes in the slowly changing pastoral systems.

Economic contribution and viability of dairy goats: implications for a breeding programme.

To augment the incomes of smallholder farmers in Kenya and consequently improve their nutrition and income, many development organisations and policy makers are increasingly promoting dairy goat farming. Among the key organisations supporting the initiative is Heifer Project International-Kenya (HPIK). However, the economic contribution and viability of dairy goats under the HPIK project have not been studied so far. The aim of the present study was to determine the contribution of dairy goats to household income and the performance of the dairy goat enterprise using gross and net margins from dairy goat farming as an indicator of economic viability. A survey covering 71 farmers was carried out in the Coast, Nyanza, and the Rift Valley provinces of Kenya using a set of pre-tested structured and semi-structured questionnaires. Results showed that, on average, the dairy goat enterprise contributed, correspondingly, about 15.2% and 4.8% to the total livestock and overall household income and was viable. Differences in gross and net margins across agroecological zones were attributed to milk prices. Despite the existence of non-viable enterprises in two of the provinces, the few present suggest the possibility of obtaining reliable incomes from the enterprise. Redoubling of effort or re-orientation of production to match the local and external requirements would, however, be necessary. Costs and revenues were similar across the agroecological zones. Farmers with positive gross margins had better milk and stock sales and vice versa. The success of a dairy goat enterprise is attributed to location and good management. Besides, farmers' awareness of the market demands within and outside the community is important in establishing production goals and may be crucial to achieving a positive gross margin.

Genetic and phenotypic parameters and annual trends for growth and fertility traits of Charolais and Hereford beef cattle breeds in Kenya.

This study estimated genetic and phenotypic parameters and annual trends for growth and fertility traits of Charolais and Hereford cattle in Kenya. Traits considered were birth weight (BW, kg), pre-weaning average daily gain (ADG, kg/day) and weaning weight (WW, kg); calving interval (CI, days) and age at first calving (AFC, days). Direct heritability estimates for growth traits were 0.36 and 0.21; 0.25 and 0.10; 0.23 and 0.13 for BW, ADG and WW in Charolais and Hereford, respectively. Maternal heritability estimates were 0.11 and 0.01; 0.18 and 0.00; 0.17 and 0.17 for BW, ADG and WW in Charolais and Hereford, respectively. Direct-maternal genetic correlations ranged between -0.46 and 1.00; -0.51 and -1.00; -0.47 and -0.39 for BW, ADG and WW in Charolais and Hereford, respectively. Genetic correlations ranged from -0.99 to unity and -1.00 to unity for growth and fertility traits respectively. Prospects for improvement of growth and fertility traits exist.

Analysis of production objectives and breeding practices of dairy goats in Kenya.

Production objectives and breeding practices of smallholder households participating in dairy goat breeding projects were analysed in relation to their ability to bring about sustainable genetic improvement in the dairy goat flocks in Kenya. A stratified survey involving 311 goat keepers in 4 project sites was used. This employed both qualitative and quantitative research methods to get a holistic view of dairy goats, and take into account the full array of contributions of dairy goats to the smallholder households. Milk production and sales of breeding stock were high priority functions for the objective to create a financial buffer. The breeding objective traits that farmers perceived as being of primary importance were milk yield, growth rate, body size, fertility and disease tolerance. There were logical trade-offs in the choice of these traits by farmers. Female dairy goats were mainly culled due to old age, poor fertility, small body size and poor health. Farmers did not place a large significance on unsatisfactory milk performance when culling female goats, mainly due to the very small production size and the high demand existing for breeding animals. Factors affecting milk yield and flock size presented satisfied a P<0.1 significance level. The performance levels of dairy goats were mainly influenced by breeding strategies and the resource availability at the farm level. The optimisation of genotype x environment interactions remains the biggest challenge given the objectives set by the farmer.

Breeding goals for the Kenya dual purpose goat. II. Estimation of economic values for production and functional traits.

Economic values for production traits (milk yield, MY, kg; 12-month sale weight, LW, kg; consumable meat percentage, CMP) and functional traits (doe live weight, DoWT, kg; number of kids weaned, NKW; kidding frequency, KF; kidding rate, KR, %; doe weaning rate, DoWR, %; doe survival rate, DoSR, %; post-weaning survival rate, PoSR, %; pre-weaning survival rate, PrSR, % and; residual feed intake of yearlings, RFIgamma, kg and does RFId, kg) were estimated for the Kenya Dual Purpose goat (KDPG) for systems under two bases of evaluation. The production systems included smallholder low-potential (SLP), smallholder medium-potential (SMP) and smallholder high-potential (SHP), while the bases of evaluation considered were fixed flock-size and fixed feed resource. Under both bases of evaluation, economic values were highest in SMP apart from the economic values for feed intake-related traits (RFIy and RFId). In SMP, the economic values under fixed flock-size scenario were KSh 71.61 (LW), 20.90 (MY), 45.20 (CMP), 13.68 (NKW), 3.61 (KF), 6.52 (KR), 12.39 (DoWR), 22.96 (DoSR), 22.87 (PoSR), 13.18 (PrSR), -2.76 (RFIy) and -3.00 (RFId). The corresponding economic values under fixed feed resources scenario were KSh 73.28, 29.39, 45.20, 16.91, 4.76, 9.45, 13.84, 25.67, 25.15, 16.19, -2.76 and -3.00. Generally in all production systems, economic values for most traits were higher under fixed feed resource than under fixed flock-size scenario. In all systems, the economic values for most of the traits were sensitive to changes in prices of feed, milk and meat. The positive economic values for most traits under fixed flock-size scenario and fixed feed resource indicates that a unit increase in genetic merit for the traits would have a positive effect on the profitability of the systems.

Breeding goals for the Kenya dual purpose goat. I. Model development and application to smallholder production systems.

A deterministic model was developed and applied to evaluate biological and economic variables that characterize smallholder production systems utilizing the Kenya Dual Purpose goat (KDPG) in Kenya. The systems were defined as: smallholder low-potential (SLP), smallholder medium-potential (SMP) and smallholder high-potential (SHP). The model was able to predict revenues and costs to the system. Revenues were from sale of milk, surplus yearlings and cull-forage animals, while costs included those incurred for feeds, husbandry, marketing and fixed asset (fixed costs). Of the total outputs, revenue from meat and milk accounted for about 55% and 45%, respectively, in SMP and 39% and 61% in SHP. Total costs comprised mainly variable costs (98%), with husbandry costs being the highest in both SMP and SLP. The total profit per doe per year was KSh 315.48 in SMP, KSh -1352.75 in SLP and KSh -80.22 in SHP. Results suggest that the utilization of the KDPG goat in Kenya is more profitable in the smallholder medium-potential production system. The implication for the application of the model to smallholder production systems in Kenya is discussed.

Evaluation of the efficiency of alternative two-tier nucleus breeding systems designed to improve meat sheep in Kenya.

A deterministic approach was used to genetically and economically evaluate the efficiency of five two-tier nucleus breeding systems for meat sheep in Kenya. The nucleus breeding systems differed in terms of whether the system was closed or open, in the type of animals that were involved in the movement of genetic superiority and in the number of selection pathways in each system. These systems were compared under four alternative breeding objectives based on monetary genetic gain and profit per ewe. The first objective simulated a situation where the flock size cannot be increased due to non-feed related constraints (FLOCK). The second specifically assumed that the flock size is restricted due to limited amount of feed resources (FEED). The third and fourth objectives assumed that sheep performed only tangible roles (TR) and both tangible and intangible roles (IR) in the production system respectively. Monetary genetic gains were highest for all objectives in an open nucleus system with a certain proportion of commercial-born ewes being introduced in the nucleus while at the same time utilizing young rams from the nucleus to breed sires and dams for the nucleus and commercial sector (ONyre). Utilizing young rams in a closed nucleus system for the dissemination of superior genes resulted in higher annual monetary genetic gain than utilization of old rams. Profit per ewe was significantly higher for FLOCK and IR in ONyre. In a closed system that allowed for downward movement of dams from the nucleus to the commercial sector to breed sires and dams, profit per ewe was highest for FEED and TR. The success of a nucleus breeding system should also focus on the profitability and logistics of establishing it. The implication of these results on the choice of two-tier nucleus breeding systems for the improvement of meat sheep is discussed.

Economic values for resistance to gastrointestinal helminths in meat sheep in Kenya.

Economic values for resistance to gastrointestinal (GI) helminths in meat sheep were estimated based on previously published genetic and phenotypic parameters in a selection index objectively optimizing gains on yearling weight (YW). A two-trait index of YW and faecal egg count (FEC) were considered when accounting only for tangible roles of sheep production using individual records for index calculation (scheme 1) or including individual, sire, dam and male paternal half-sib information (scheme 2). Schemes 3 and 4 were similar to schemes 1 and 2, respectively, but accounted for both tangible and intangible roles of sheep production. Economic values within each scheme were estimated for five breeding objectives as follows: (i) index response in YW equals response from single trait selection, (ii) index response in YW is maximum, (iii) the level of FEC was held constant, (iv) A predetermined response of -0.22 (x1000) eggs per gram was assumed and (v) Monetary value of response in FEC is minimum. All estimated economic values were negative, and were Kenya Shillings (KSh) -34.90 (US dollar -0.50), 0.00, -92.20 (US dollar -1.32), -153.31 (US dollar -2.19) and -47.90 (US dollar -0.68), respectively, for options 1-5 in scheme 1. In all schemes the breeding options ranked 4, 3, 5 and 1 in descending order; however, options 1 and 5 exchanged positions in schemes 2 and 4. Economic values were responsive to changes in heritability of FEC and genetic correlation between the two traits. The magnitude of the economic values reflects the importance of including resistance to GI helminths in the breeding objectives for meat sheep in different production systems.

Evaluation of closed adult nucleus multiple ovulation and embryo transfer and conventional progeny testing breeding schemes for milk production in tropical crossbred cattle.

The potential benefits of closed adult nucleus multiple ovulation and embryo transfer (MOET) and conventional progeny testing (CNS) schemes, and the logistics of their integration into large-scale continuous production of crossbred cattle were studied by deterministic simulation. The latter was based on F1 (Bos taurus x Bos indicus) production using AI or natural mating and MOET, and continuous F2 production by mating of F1 animals. The gene flow and the cumulative discounted expressions (CDES) were also calculated. Both schemes had 8, 16, 32, or 64 dams with 2, 4, 8, 16, or 32 sires selected. In the MOET nucleus scheme (MNS), the test capacity was 1, 2, 8, or 16 offspring, and the number of matings per dam per year was 1, 2, or 4. A scheme of 8 sires with 64 dams and a test capacity of 4 female offspring per dam per year resulted in an annual genetic gain (in phenotypic standard deviation) of 0.324 and 0.081 for MNS and CNS, respectively. In the MNS, there was substantial genetic gain with a relatively small number of animals compared with a CNS. The F1 had the highest, and the F2 scheme the lowest CDES. However, a very large number of B. indicus females would be required in the F1 scheme. This scheme may not be practical under conditions in developing countries. The F2 scheme was logistically attractive because it produces its own replacements, and the number of B. taurus females required would be easy to attain. Accompanying technical and financial constraints of nucleus schemes should be addressed before applying them.

Influence of production circumstances and economic evaluation criteria on economic comparison of breeds and breed crosses.

The ranking of genotypes (i.e., breeds and breed crosses) for economic performance depends on the production circumstances of the herd and the criteria for economic evaluation. In this study, the effects of evaluation criteria and production circumstance are quantified using data from the literature on six genotypes. The economic evaluation criteria measured at herd level included lifetime profit and lifetime profit expressed per day of calving interval, per day of productive lifetime, per day of total herd life, per unit of milk, and per unit of feed energy. Four production circumstances were studied; these circumstances included constraints on the output of milk and on herd use of concentrates, roughages, and both concentrates and roughages. Profit was determined based on the sale of milk, calves, cull cows, and heifers and the expenses incurred for concentrates and roughages, animal deaths, milking time, interest, and other inputs. Results indicate that production circumstances and evaluation criteria largely influence the ranking of genotypes and, therefore, the outcome of economic comparisons. The genotype that ranks the best under a certain criteria and circumstance ranks differently when these situations are altered. In economic comparisons of genotypes aimed at offering recommendations for implementation in smallholder dairy production systems in the tropics, the choice of the evaluation criteria should be determined by the limitation or constraint that characterizes the area where the genotypes are to produce or are currently producing. For example, for situations in which feed availability is limiting, genotypes should be ranked on total profit per unit of feed energy.