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Selection response from a two-tier nucleus breeding scheme using the current Kenyan breeding goal was compared with an alternative that also accounts for protein yield (PY) and mastitis resistance (MR). The economic value for PY was estimated using a bio-economic model. For mastitis resistance, like other disease resistance traits, the economic value cannot be estimated with profit equations because they have multi-fold effects on input and output, which affects profitability. Therefore, selection index methodology was used. Somatic cell count (SCC) was used as an indicator trait for MR. The ZPAN computer program was used to model the breeding schemes and evaluate response to selection. The alternative breeding goal, which included PY and MR, realized additional KES358.48, 613.55, and 613.65 in annual genetic gain, returns and profit per cow per year, respectively, compared with the current breeding goal. Economic values for PY and MR were KES778.99 and -2364, respectively. Relative economic values for milk yield (MY, kg), fat yield (FY, kg), protein yield (PY, kg), MR, calving interval (CI, days), preweaning daily gain (DG, g/day), postweaning daily gain (PDG, g/day), live weight (LW, kg), preweaning survival (SR1, %), postweaning survival (SR2, %), and length of productive life (PLT, days) were 23 689.80, 4 146.77, 34 665.50, -992.88, 33.66, 62.40, 159.80, 391.94, 987.04, 4 474.37, and 7.56, respectively. This implies that including milk quality traits such as PY in the breeding goal would optimize response to selection in dairy cattle production. Keywords: breeding objective, economic values, genetic evaluation, milk quality, traits, udder health

Dairy cattle farming in developing countries is mainly by resource poor smallholder farmers. Intensification of production within smallholder production systems is being driven by increasing demand for animal products. Current intensification is driven by importation of high-input high-output genotypes. This puts in question the sustainability of these resource constrained systems under harsh environmental conditions. Sustainability of production systems can be defined as long-term resilience and productivity. We use deterministic simulations to compare the impacts of three criteria to define breeding objectives i.e., economic, desired gains and non-market value, on annual genetic and monetary gains in production (market) and functional (non-market) traits for a small-sized nucleus genomic selection breeding program under developing country conditions. Market traits considered were milk yield (MY) and mature body weight (MBW). Non-market traits were calving interval (CI) and production lifetime (PLT). Fat yield (FY) was also considered a non-market trait as it had no market value. With the economic objective, traits were weighted on economic values. Weights for desired gains and non-market (NM) values were derived iteratively. Economic objectives placed highest emphasis on MY with very little gains in non-market traits but had the highest returns on investment. For desired gains objective, maximal achievable gains in PLT, CI and FY were lower than the indicated desired gains. The non-market value objective achieved the best compromise between gains in MY and other traits. We conclude that non-market value objectives can be applied to direct selection towards more robust genotypes but with loss in monetary gain. Breeding robust genotypes can contribute to sustainable intensification in developing small-holder dairy systems. However, for such objectives to be satisfactory, a sound criterion is required to determine declines in genetic gains for market traits that are acceptable by producers.

This study aims to determine the genetic and phenotypic parameters of net feed efficiency (NFE) traits namely Residual feed intake (RFI), residual gain (RG), and residual intake and gain (RIG) along the growth curve of indigenous chicken in Kenya. Feed intake and body weight data was collected on 107 experimental birds on a daily and weekly basis, respectively from 77 days to 140 days of age. Random regression sire model was used for analysis, fitting Legendre polynomials as basis function. Sex, hatch group and interaction between sex and cluster constituted fixed effects in the model while additive genetic and permanent environmental effects were fitted as random variables. A heteroscedastic residual variance was modelled by grouping the test period into nine classes. The orders of polynomial fit for additive genetic and permanent environmental effects in the model were 4 and 5; 3 and 4; and 5 and 5; for RFI, RG and RIG, respectively. The additive genetic variances for RFI and RG were higher at the beginning of the trajectory but declined as the test period progressed while their respective phenotypic and permanent environment variances increased with age. Consequently, moderate (0.34) and high (0.77) heritability estimates for RFI and RG, respectively, were observed during the early test period and thereafter decreased to 0.03 for RFI and 0.01 for RG. Additive genetic variance for RIG increased across the test period while phenotypic and permanent environment variances declined. This resulted in high estimates of heritability and permanent environmental variance as a proportion of phenotypic variance of 0.69 and 0.98, respectively, at the extremes of the trajectory. At mid-point of test period, low estimates of heritability and permanent environmental variance as a proportion of phenotypic variance of 0.13 and 0.19, respectively were observed. The heritability estimates indicate possible selective breeding for NFE given the moderate estimates (0.23–0.34) for RFI, moderate to high estimates (0.30–0.77) for RG and high estimates (0.49–0.98) for RIG. However, caution has to be taken when selecting for RG and RIG given the extreme heritability estimates resulting from statistical and biological factors. Genetic correlations were high to moderate and positive (0.99 to 0.32) between records at early and mid-ages (77–105 days), but high and negative (−0.99 to −0.45) between early (77 days) and late ages (112–140 days). Selection for NFE at growth inflection point (77 days) would result in a favourable correlated response at point of maximum growth (105 days) but would be associated with unfavourable response at point of asymptotic growth (140 days) as birds are approaching sexual maturity. Given the high standard errors for the genetic parameters estimates in this study, there is need for further analyses prior to selection for feed efficiency indigenous chicken.

Characterization of indigenous chicken (IC) production systems in Rwanda was conducted from November 2015 to January 2016 with the aim of understanding socio-economic characteristics, management of IC, production parameters, feed resources, and constraints faced by farmers rearing IC. A survey involving 206 households was carried out in 5 districts with the highest populations of IC using structured questionnaires. Data were analyzed using SAS software. The results showed that the majority of respondents (62.4%) were males and 37.6% were females. The majority of respondents (83.6%) had formal education. All family members were involved in the chicken husbandry practices. However, women (78%) were highly responsible for IC management activities. The family size averaged 5 persons (ranging 2 to 13) per household. Land was privately owned by farmers (84%) with a mean holding of 0.87 ha per household. The production system was mainly extensive with minimum provision of supplementary feeds. Chickens were being housed in separate houses at night and mating was uncontrolled. Breeding and replacement stocks were mainly sourced from the hatching of eggs using broody hens (60.68% of respondents). There were no vaccination programs, and ecto- and endo-parasites control was done when need arose. Egg production, income generation, meat production, and production of breeding stock were the main reasons of keeping IC. The first 3 main challenges facing IC production were diseases outbreaks, lack of investment capital, and predators. Others challenges, such as feed shortage, thieves, fluctuation of market price, lack of information on poultry rearing, and lack of chicken houses, also were mentioned. The IC production constraints mentioned need urgent mitigation measures to sustain utilization of IC against the changing climatic and economic conditions. Therefore, individual, public institution, and non-governmental organization efforts are required to develop sustainable breeding objectives directed to functions of IC and production challenges faced in the systems.

In this study, indigenous chickens were collected from eight different regions in Kenya and kept at InCIP-Egerton University. These were studied using eighteen microsatellite markers to determine genetic variation. Statistics related to genetic variation were estimated using GenALEx6. Mean percentage polymorphic loci (PPL) was 96.71% and 4% genetic variance ( p ≥ 0.003) was seen between the eight populations. MCW0123 marker had the highest genetic variance of 13% among populations ( p ≥ 0.003) at 95% CI. Mean He ranged from 0.351 ± 0.031 (SIB) to 0.434 ± 0.022 (BM) with a grand mean He of 0.399 ± 0.011 across the populations using the microsatellite markers. Nei’s genetic distance ranged from 0.016 (SIB and WP) to 0.126 (NR and SIB). DARwin6.501 analysis software was used to draw the population dendrogram and two major population clusters were observed, also seen with PCoA. This study found a lot of genetic variation and relatedness within and among populations. Based on the phylogenetic tree result, it is concluded that the clustering of the chicken populations in the present study is not based on geographical proximity. The microsatellite markers used in this study were suitable for the measurement of the genetic biodiversity and relationship of Kenyan chicken populations. These results can therefore serve as an initial step to plan the conservation of indigenous chickens in Kenya.

In developing countries minimal and erratic performance and pedigree recording impede implementation of large-sized breeding programs. Small-sized nucleus programs offer an alternative but rely on their economic performance for their viability. We investigated the economic performance of 2 alternative small-sized dairy nucleus programs [i.e., progeny testing (PT) and genomic selection (GS)] over a 20-yr investment period. The nucleus was made up of 453 male and 360 female animals distributed in 8 non-overlapping age classes. Each year 10 active sires and 100 elite dams were selected. Populations of commercial recorded cows (CRC) of sizes 12,592 and 25,184 were used to produce test daughters in PT or to create a reference population in GS, respectively. Economic performance was defined as gross margins, calculated as discounted revenues minus discounted costs following a single generation of selection. Revenues were calculated as cumulative discounted expressions (CDE, kg) × 0.32 (€/kg of milk) × 100,000 (size commercial population). Genetic superiorities, deterministically simulated using pseudo-BLUP index and CDE, were determined using gene flow. Costs were for one generation of selection. Results show that GS schemes had higher cumulated genetic gain in the commercial cow population and higher gross margins compared with PT schemes. Gross margins were between 3.2- and 5.2-fold higher for GS, depending on size of the CRC population. The increase in gross margin was mostly due to a decreased generation interval and lower running costs in GS schemes. In PT schemes many bulls are culled before selection. We therefore also compared 2 schemes in which semen was stored instead of keeping live bulls. As expected, semen storage resulted in an increase in gross margins in PT schemes, but gross margins remained lower than those of GS schemes. We conclude that implementation of small-sized GS breeding schemes can be economically viable for developing countries.

We tested hypothesis that inclusion of the disease resistance indicator traits in a dairy goats’ breeding goal would result to increased profitability of smallholder farmers. Deterministic simulation was used to compare responses for breeding schemes without (Scheme I) and with (Schemes II, III and IV) disease resistance in the breeding goal. Faecal egg count (FEC) and somatic cell score (SCS) were used as the indicator traits for helminthosis and mastitis in goats, respectively. We also investigated the effect of risk aversion among the smallholder farmers on response to selection. The breeding structure consisted of a two-tier closed nucleus system, with recording and genetic evaluations being undertaken in the nucleus. Breeding schemes differed on the number of traits in the selection criteria and number of records used to estimate breeding values. In Scheme I, traits in the breeding goal included milk yield (MY), live weight (LW), average daily gain (ADG), doe mature weight (DMW), number of kids weaned (NKW) and survival rate (SR). Scheme II was similar to Scheme I, but included records of FEC and SCS measured immediately after weaning and during early lactation, respectively. Scheme III was similar to II, but with additional information on SCS recorded at mid-lactation, while Scheme IV was similar to III with more SCS information recorded in late-lactation. Our findings indicate that schemes that included disease resistance indicator traits in the selection criteria (Schemes II, III and IV) were 28, 24 and 19%, respectively superior in profitability to Scheme I. Profitability for Scheme II was 3.5 and 7.6% higher than for Schemes III and IV, respectively. The response to selection was maximized when the nucleus consisted of 4–5% of the does’ effective population size and 20% of them were phenotyped for SCS. High risk aversion tended to result in low profits. This suggests that use of economic values obtained using low risk aversion models could overestimate the economic worth of a breeding program especially in smallholder production systems where farmers are risk averse.

espanolSe llevo a cabo un analisis genealogico con datos de 18 315 animales nacidos entre 1949 y 2008 con el fin de cuantificar la variabilidad genetica de la poblacion Sahiwal en Kenya. Los intervalos generacionales por la via paterna fueron mayores que por la via materna y aumentaron con el paso del tiempo, desde aproximadamente 4 a 16 anos. Esto ultimo se debio al uso de machos viejos para la cria en las dos ultimas franjas de anos y al cese del testaje de la progenie en el ano 2000. El nivel medio de endogamia en el ultimo periodo de tiempo estudiado fue del 1.2 por ciento. La variabilidad genetica de la poblacion, determinada en base a estadisticas del origen de los genes, disminuyo a lo largo de los anos. El ratio entre el numero efectivo de fundadores y los fundadores fue de 0.06, lo cual muestra una contribucion desigual de los fundadores a la poblacion de referencia. Sin embargo, desde la poblacion fundadora, los ancestros contribuyeron equitativamente, tal como refleja el ratio fe/fa de 0.94, que tambien podria deberse a una falta de seleccion eficaz en esta poblacion. El ratio fg/fa de 0.63 indico una perdida de variabilidad genetica ocurrida por deriva genetica en la poblacion Sahiwal keniana. El pequeno numero de ancestros (16) responsable del 50 por ciento de la variacion total en la poblacion de referencia hace pensar en un uso excesivo de un reducido numero de animales como progenitores a lo largo de varias generaciones. Tambien el hecho de que el ratio fg/fe sea menor que el ratio fa/fe confirma la perdida de variabilidad genetica en la poblacion por deriva genetica mas que por cuellos de botella. En consecuencia, la estrategia reproductiva para la poblacion Sahiwal en Kenya deberia incorporar herramientas que equilibren la tasa de ganancia genetica y la tasa futura de endogamia. Palabras clave: tamano efectivo de poblacion, genealogia, diversidad genetica, endogamia, contribucion optima EnglishPedigree analysis using genealogical information of 18 315 animals born between 1949 and 2008 was done to quantify genetic variability of the Sahiwal population in Kenya. Generation intervals for sire pathways were longer than dam pathways and increased over year periods, from about 4–16 years. The later was due to use of old bulls for breeding in the last 2 year groups and cessation of progeny testing in the year 2000. Average inbreeding level in last year period studied was 1.2 percent. Genetic variability of the population as assessed based on gene origin statistics decreased over the years. The ratio of effective number of founders to founders of 0.06 showed unequal contribution of founders to the reference population. However, since the founding population, ancestors contributed equally as shown by the ratio of fe/fa of 0.94, which could also be due to lack of effective selection in this population. The ratio of fg/fa of 0.63 indicated genetic loss of genetic variability occurred through genetic drift in the Kenyan Sahiwal population. The small number of ancestors (16) that accounted for 50 percent of the total variation in the reference population suggested overuse of a small number of some animals as parents over generations. The smaller ratio of fg/fe compared with fa/fe also confirms loss of genetic variability in the population by genetic drift than bottlenecks. Therefore the breeding strategy for the Sahiwal population in Kenya should incorporate tools that balance rate of genetic gain and the future rate of inbreeding. Keywords: effective population size, genealogy, genetic diversity, inbreeding, optimum contribution francaisUne analyse genealogique a ete realisee avec les donnees de 18 315 animaux nes entre 1949 et 2008 dans le but de quantifier la variabilite genetique de la population Sahiwal au Kenya. Les intervalles generationnels ont ete plus longs sur la voie paternelle que sur la voie maternelle et se sont allonges au cours des annees, d’environ 4 ans a 16 ans. Ceci a ete du a l’utilisation de vieux mâles pour la reproduction dans les deux dernieres periodes d’annees et a l’arret du controle de la descendance en l’an 2000. Le niveau moyen de consanguinite dans la derniere periode etudiee a ete de 1.2 pour cent. La variabilite genetique de la population, evaluee au moyen de statistiques sur l’origine des genes, a diminue au fil des annees. Le rapport entre le nombre effectif de fondateurs et les fondateurs a ete de 0.06, ce qui met en evidence une contribution inegale des fondateurs a la population de reference. Cependant, depuis la population fondatrice, les ancetres ont contribue equitablement, comme reflete par le rapport fe/fa de 0.94, qui pourrait aussi etre du a un manque de selection efficace dans cette population. Le rapport fg/fa de 0.63 indique une perte de variabilite genetique causee par derive genetique dans la population Sahiwal du Kenya. Le faible nombre d’ancetres (16) expliquant 50 pour cent de la variation totale dans la population de reference suggere l’utilisation excessive en tant que parents d’un petit nombre d’animaux au cours de plusieurs generations. De meme, le fait que le rapport fg/fe soit inferieur au rapport fa/fe confirme la perte de variabilite genetique dans la population par derive genetique plutot que par goulots d’etranglement genetique. Par consequent, la strategie de selection pour la population Sahiwal au Kenya devrait integrer des outils permettant d’equilibrer le taux de gain genetique et le taux futur de consanguinite. Mots-cles: taille effective de la population, genealogie, diversite genetique, consanguinite, contribution optimale

A deterministic simulation model was used to test the hypothesis that utilization of untested juvenile bucks could be an alternative to old buck strategy in dissemination of superior genetic materials in dairy goats breeding program. We compared the genetic and economic gains realised when the untested juvenile and old bucks were used to disseminate genetic materials in a two-tier closed and open nucleus breeding systems. In the untested juvenile buck strategy, 95 and 70% of nucleus and commercial does, respectively, were mated to the untested juvenile bucks. In the old buck strategy, all the females in the nucleus and 70% of commercial does were mated by old bucks from the nucleus. In the open nucleus system, 20% of the does born in the commercial sector were recruited into the nucleus to produce nucleus does of does. Utilization of untested juvenile bucks realised 5.92 and 7.30% more annual returns and profitability per doe, respectively compared to old buck strategy. The old buck strategy, however, outperformed untested juvenile buck strategy by 23.37 and 14.85% in total annual genetic gain in closed and open nucleus breeding systems, respectively. Comparison between closed and open nucleus breeding systems demonstrated that open nucleus systems are superior to closed nucleus systems both in genetic and economic response. These findings therefore demonstrate that untested juvenile bucks could be an alternative to old buck strategy when economic viability of the breeding program is the main focus. There is, however, need to strike a balance between economic and genetic gains in the breeding program.

Previous genetic and economic evaluation of beef cattle breeding programmes have used genetic and phenotypic parameter estimates obtained in different studies. Such parameters are heterogeneous because they are obtained from different locations, using different sample sizes and estimation methods. The consequence of using such parameters is underestimation or overestimation of potential genetic gains, leading to wrong investment decisions. The objective of the current study was to estimate consensus genetic and phenotypic parameter estimates for beef cattle in the tropics. Meta-analysis of productive, reproductive, adaptation and disease resistance traits was done to obtain weighted traits means, heritabilities, and genetic and phenotypic correlations. Estimates from 208 means, 119 direct and 50 maternal heritability, 42 direct genetic and maternal genetic correlations, 136 genetic and 93 genetic and phenotypic correlations, respectively, were used. A random effect model was used to include the variances within and between studies. Unweighted average direct heritability estimates ranged from 0.26 to 0.32, 0.08 to 0.40, 0.14 to 0.34, 0.18 to 0.67 and 0.30 to 0.35 for growth, reproduction, disease resistance, adaptation and carcass traits, respectively. Weighted heritability estimates for birth weight, weaning weight and yearling weight ranged from 0.18 to 0.26, while those for reproduction traits ranged from 0.02 to 0.09. Weighted maternal heritability estimates for growth traits ranged from 0.07 to 0.11. Carcass, disease resistance and adaptation traits were the least studied despite their great economic importance to beef production in the tropics. Direct maternal heritability estimates for birth, weaning and yearling weights were 0.26, 0.24 and 0.18, while the corresponding maternal heritability estimates were 0.07, 0.11 and 0.08, respectively. Genetic and phenotypic correlations for body weights ranged from 0.43 to 0.88 and 0.32 to 0.80, respectively. Yearling weight and final weight had the highest genetic correlation (0.88). The genetic correlations between body weights and growth rates were moderate to high (0.37 to 0.79). Weaning weight was negatively correlated with post-weaning daily gain (-0.12). Disease resistance traits had low to negative genetic correlations with body weight and growth rate traits (-0.06 to 0.01). Some traits reviewed in the current study were not given a lot of attention, and therefore more focus is required on disease resistance, adaptation and carcass traits. In spite of these limitations, the weighted parameter estimates reported here can be used to add value to beef cattle improvement programmes in the tropics.

It was reasoned that technologies that increase the reproductive rate of males and females in dairy cattle would realize higher responses to selection. The authors tested this hypothesis using deterministic simulation of breeding schemes that resembled those of dairy cattle in Kenya. The response to selection was estimated for four breeding schemes and strategies. Two breeding schemes were simulated, based on artificial insemination (AI) and multiple ovulation and embryo transfer (MOET) reproductive technologies. The strategies were defined according to the use of conventional semen (CS) and X-chromosome-sorted semen (XS). The four strategies therefore were AI with CS (AI-CS) and XS (AI-XS), and MOET with CS (MOET-CS) and XS (MOET-XS). The four strategies were simulated based on the current dairy cattle breeding goal in Kenya. A two-tier closed nucleus breeding programme was considered, with 5% of the cows in the nucleus and 95% in the commercial. Dissemination of superior genetic materials in the nucleus was based on all four breeding strategies, while in the commercial only the AI-CS strategy was considered. The strategies that increased the reproductive rates of both males and females (MOET-CS and MOET-XS) realized 2.1, 1.4, and 1.3 times more annual genetic gain, return and profitability per cow, per year, respectively, than strategies that increased the reproductive rates only of males (AI-CS and AI-XS). The use of CS or XS, however, did not affect response to selection in the two schemes. The findings demonstrate that reproductive technologies such as MOET maximize response to selection in dairy cattle breeding. Keywords: artificial insemination, conventional semen, deterministic simulation, multiple ovulation and embryo transfer, X-chromosome-sorted semen

Summary This study evaluates the effect of certified organic production on poverty in smallholder production systems. Data was collected from cross sectional survey of local market-oriented peri-urban vegetable and rural honey producers in Kenya. Poverty was measured using the multidimensional poverty methodology and endogenous switching probit model used to assess the effect of certified organic production on multidimensional poverty. Findings were that certified producers were less likely to be multidimensional poor compared to their counterfactual case of not participating in organic certification schemes. Additionally, noncertified producers would be less likely to be poor if they were to participate in organic certification production.

SummaryData on breeding management, breed and trait preference for pigs were collected from smallholder farmers in Kiambu and Kakamega Counties of Kenya. The production systems evaluated were semi-intensive and extensive and depicted varying pig production intensities, production objectives, pig performances as well as farmers’ breed and trait preferences. The perception of the importance of traits was evaluated to obtain a more balanced objective view on production and/or breeding objectives. The data collected were analysed through computation of indices, which represented a weighted average of all rankings of a particular trait. In the semi-intensive system, preference for performance traits such as size, growth rate and body weight, scored the same index (0.181), followed by the reproduction trait – prolificacy (0.161). In the extensive system, the indices for these traits were 0.187, 0.183, 0.163 and 0.106, respectively. Spearman's non-parametric rank correlations were calculated for ranking of traits of economic importance to indicate the directional effects and plausible trade-offs between traits. In the semi-intensive system, correlations were moderate between growth rate and both size and weight. In the extensive system, correlations were moderate for growth rate with both size and body weight. Appropriate breeds that suit the divergent production systems need to be identified and utilized based on performance and adaptability to ensure efficient resource use.

The aim of the current simulation study was to maximize the amount (kg) of high value meat arising from surplus males and females per kilogram of the goat population and, maximize weight gains to turnoff age. Subsequently, the study aimed to decrease turnoff age, maximization of reproduction rates and minimization of the mature weight of does in the low-input livestock production system in Kenya. Three crossbreeding systems and a synthetic breed development were evaluated, namely; (a) straight breeding system that utilized pure Small East African goat (SEAG) where parental lines were maintained to generate the desired terminal crosses, (b) three-breed crossbreeding system that utilized SEAG as pure breed, Galla goat (GG) as the first cross sire breed, and Improved Boer goat (IBG) as the terminal sire, (c) two-breed rotational crossbreeding system where the SEAG and IBG were purebreds, and (d) synthetic breed development system utilizing SEAG × IBG. The HotCross crossbreeding simulation software was used to assess the predicted performance of the different goat breed crosses under conditions of agro ecological zones (AEZ) V and VI. A model was developed to compare these crossbreeding systems, and showed the optimum numbers required in each stage of a cross to maximize production. In the AEZ V, it was found that the three-breed terminal system gave 18.2 kg (76%) improvement over straightbreds per doe mated per year. The multi-breed composite realized 20.4 kg (86%) improvement over pure SEAG. In the AEZ VI, it was found that the three-breed terminal system gave 10 kg (64%) improvement over straightbreds per doe mated per year. The multi-breed composite realized 14.6 kg (94%) improvement straightbreds per doe mated per year. The two-breed rotation was worse than the multi-breed composite in both environments. This implies that in low-input livestock production system, a multi-breed composite may be the crossbreeding system of choice, so long as supportive infrastructure is put in place.

Data on breeding practices and traits of economic importance for the indigenous chicken (IC) were collected through personal interviews using structured questionnaires and direct observations of chicken management practices. The study was conducted from November 2015 to January 2016 in Rwamagana, Rulindo, Ruhango, Kicukiro and Muhanga districts of Rwanda. Data were collected and analysed through computation of indices, which represented a weighted average of all rankings of a specific trait. Spearman’s non-parametric rank correlation was calculated for ranking of traits of economic importance to indicate the directional effects. The results on chicken ecotypes and their attributes showed that prolificacy, mature weight, disease tolerance, egg number and heat tolerance were highly preferred. The dwarf ecotype was most abundantly reared (38.84%) and considered to be significantly smaller and to have poorer growth rate, but to have better prolificacy than other indigenous chicken ecotypes. Selection of breeding cock and hen was based on disease tolerance, body weight at sexual maturity, body size and growth rate. In addition, for hen, mothering ability and egg fertility (Fer) were considered. Indices for the traits perceived by farmers as of primary economic importance were egg yield (0.093), disease tolerance (0.091), high growth rate (0.089), prolificacy (0.088), high body weight (0.087) and egg fertility (0.083). The most important traits considered by the marketers were body weight (BW), disease tolerance (Dtol), plumage colour (Pcol), egg yolk colour (EYC), meat quality (MQ), growth rate (GR) and egg yield (EY) whereas for consumers, meat quality, egg yolk colour, egg yield, body weight and growth rate were considered. Among traits perceived as important by farmers, a positive and significant correlation was found between BW and GR and Fer. Correlation was moderate for BW and prolificacy, drought tolerance (Drtol), Dtol and EYC. BW was negatively correlated with temperament (Temp), heat tolerance, Pcol and egg shell colour (ESC). Regarding marketers and consumers’ preference rank correlation, positive and significant correlation was between BW and GR and MQ. As such, appropriate ecotypes (indigenous chicken) which have these characteristics need to be identified and utilised more based on their performance and adaption to the environment conditions to ensure efficient IC production.

Context In the present study we assessed the use of average relationship as a means to control future rates of inbreeding in small cattle closed nucleus and its effect on genetic gain for milk yield as a means of managing genetic variability in livestock improvement programs. Aim The aim was to strike an ideal balance between genetic gain and loss of genetic variability for Sahiwal population. Methods A total of 8452 milk yield records of Sahiwal cows from National Sahiwal Stud, Kenya, were used to estimate breeding values and 19315 records used to estimate average relatedness of all individuals. The estimated breeding values and genetic relationships were then used to optimise individual genetic contributions between the best two males and the top 210 females in 2000–2008-year group, as well as between the best four, six and eight males and top, 420, 630 and 840 females based on estimated breeding values for lactation milk yield. Weights on genetic merit and average relationship considered in this study were (1, 0), (1, −300), (1, −500), (1, −1000) and (0, −1). Key results When the best sires were selected and used for mating disregarding average relationship with their mates i.e. (0, –1), genetic gain of up to 213 kg was realised accompanied by a rate of inbreeding per generation of 4%. Restricting average relationship alone i.e. (0, –1), resulted in a future rate of inbreeding of 1.6% and average merit of 154 when top two sires were used for breeding. At the same restriction level but using eight top sires, the rate of inbreeding per generation was 0.9% accompanied by an average merit of 128.2 kg. Controlling average relationship between mates resulted in increased genetic variability i.e. lower rate of inbreeding though average merit declined. Conclusion A rate of inbreeding per generation of

SummaryThe study investigated the genetic make-up of different ecotypes of indigenous chickens (ICs) in Kenya based on major histocompatibility complex (MHC)-linked and non-MHC microsatellite markers. Blood samples were collected from eight regions (48 birds per region) of Kenya: Kakamega (KK), Siaya (BN), West Pokot (WP), Turkana (TK), Bomet (BM), Narok (NR), Lamu (LM) and Taita-Taveta (TT) and genotyped using two MHC-linked and ten non-MHC markers. All MHC-linked and non-MHC markers were polymorphic with a total of 140 alleles, of which 56 were identified in MHC-linked markers. Mean number of alleles (Na and Ne), private alleles, heterozygosity and genetic distances were higher for MHC-linked markers compared with non-MHC markers. Thead hocstatistic ΔK detected the true numbers of clusters to be three for MHC-linked markers and two in non-MHC markers. In conclusion, Kenyan ICs belong into two to three genetically distinct groups. Different markers systems have different clustering system. MHC-linked markers divided ICs into three mixed clusters, composing of individuals from the different ecotypes whereas non-MHC markers grouped ICs into two groups. These IC ecotypes host many and highly diverse MHC-linked alleles. Higher allelic diversity indicated a huge amount of genetic variation in the MHC region of ICs and supported their reputation of being hardy and resistant to diseases.

Summary Genetic improvement of farm animals encompasses both mating and selection for desired traits and indigenous chicken genetic resources are no exception. In Kenya, previous attempts to genetically improve indigenous chicken involved cross-breeding scheme by utilizing cockerels and pullets of exotic breeds with the local indigenous chicken. This scheme was complimented with farmer training on good management practices and vaccination for disease control. The scheme was partially successful with improved performance in the crossbreds that declined with subsequent generations. Failure of the programme to meet stakeholder’s expectation led to its’ termination. The current attempt through the Smallholder Indigenous Chicken Improvement Programme has initiated an holistic and comprehensive approach to analysing the entire indigenous chicken actors and avert the causes of previous failures. The programme has genetically and phenotypically characterized the chicken; established reference/base population collected from different ecotypes/counties, established the breeding goals and designed breeding programmes that best suit the Kenyan stakeholders. The on-station research has reported variation on production traits, determined heritability estimate on growth. Current and ongoing research is focused on molecular characterization, selection for improved immune response, carcass quality, eggs production, growth and adaptation traits. The research is also concerned with conservation of these genetic resources.

Selection and production environments may differ in level of management. In production environment, the majority of animals may have, especially in tropical environments, lower milk production due to inadequate feed intake and other constraints associated with flat or decreasing lactation curves. Holstein–Friesian herds in Kenya were separated in selection environment (SENV) and production environment (PENV), respectively herds that contributed breeding males or not to the population. Legendre polynomials with two to five coefficients were fitted to 57,071 daily lactation records of 5931 heifers, to model genetic and permanent environmental lactation curves and to evaluate whether daily variances differed across the environments. Daily additive genetic variances declined from onset to the end of lactation, while permanent environmental variances were larger at both extremes of lactation. Daily additive genetic and permanent environmental variances were on average 66.7% and 9.7%, respectively, higher in the SENV than in the PENV. Average daily heritability estimates were 0.27±0.01 (SENV) and 0.16±0.01 (PENV). Three random regression coefficients (RRCs) for additive genetic and four for permanent environment component with homogeneous residual variance for the SENV and heterogeneous for the PENV best captured the genetic and permanent environment variability. However, a model fitting three RRCs for both additive genetic and permanent environment effect selected the same set of bulls as the more complex models (rank correlations 0.985 (SENV) and 0.980 (PENV)). Re-ranking of sires EBVs occurred between SENV and PENV (rank correlation 0.18 for sire EBVs of 305 day milk yield).

Postnatal mortality (PM) of calves is an economically important trait, because a high mortality rate of calves decreases farm income and significantly increases production costs. In spite of the economic importance of PM, genetic studies on PM have been scarce for Japanese Black cattle. The objectives of this study were to estimate the direct and maternal heritability for PM using a Bayesian threshold model with Gibbs sampling in Japanese Black cattle. The original data consisted of 43 723 records of animals born from January 2005 to June 2006. Four binary traits of mortality were considered: D1-14, D15-60, D61-180 and D1-180 with numbers indicating the period of risk in days after birth. Direct heritabilities for PM ranged from 0.12 to 0.31 and maternal heritabilities for PM were lower than the direct heritabilities and ranged from 0.02 to 0.16. Direct genetic correlations between D1-14 and D15-60, between D15-60 and D61-180, and between D1-14 and D61-180 were 0.501, 0.689 and 0.062, respectively. Direct genetic correlations of birth weight with D1-14, D15-60, D61-180 and D1-180 were 0.089, 0.482, 0.434 and 0.394, respectively. These results indicated that different genes were responsible for early and late PM and early PM (D1-14) can be genetically reduced without influencing birth weight.

Open nucleus dairy cattle breeding schemes (ONBS) in developing countries are advantageous due to lower operational costs. However, genotype by environment interaction (GE) between the selection (SE) and production environment (PE) should be considered. Records of 5468 cows, daughters of 251 sires with at least a first lactation record between 1990 and 2007, were used to establish whether Holstein-Friesian populations in the SE and PE in Kenya were genetically similar through use of common sires. The effect of diverse sire origins on 305-day milk yield (305-day MY), age at first calving (AFC) and calving interval (CI) in the two environments was also evaluated. Environmental sensitivity of the traits was assessed using records of daughters of common sires. Genetic similarity indices between the two environments and between female progeny groups of Kenyan born sires and those from Europe and USA and Canada were 0.46, 0.31 and 0.39, respectively. Sire origin was significant (P

Economic values for production traits (milk yield, MY, g; 12-month live weight, yLW, kg; consumable meat percentage, CM, %) and functional traits (mature doe live weight, DoLW, kg; mature buck live weight, LWb, kg; kidding frequency, KF; pre-weaning survival rate, PrSR, %; post-weaning survival rate, PoSR,%; doe survival rate, DoSR, %; and residual feed intake, RFI, kg) were estimated using profit functions for the Small East African goat. The scenario evaluated was a fixed flock size, and the resultant economic values (Kes per doe per year) were 34.46 (MY), 62.35 (yLW), 40.69 (CM), 0.15 (DoLW), 2.84 (LWb), 8.69 (KF), 17.38 (PrSR), 16.60 (PoSR), 16.69 (DoSR) and -3.00 (RFI). Similarly, the economic values decreased by -14.7 % (MY), -2.7 % (yLW), -23.9 % (CM), -6.6 % (DoLW), -98 % (LWb), -8.6 % (KF), -8.2 % (PrSR), -8.9 % (PoSR), -8.1 % (DoSR) and 0 % (RFI) when they were risk rated. The economic values for production and functional traits, except RFI, were positive, which implies that genetic improvement of these traits would have a positive effect on the profitability in the pastoral production systems. The application of an Arrow-Pratt coefficient of absolute risk aversion (λ) at the level of 0.02 resulted in a decrease on the estimated economic values, implying that livestock keepers who were risk averse were willing to accept lower expected returns. The results indicate that there would be improvement in traits of economic importance, and, therefore, easy-to-manage genetic improvement programmes should be established.

The indigenous chicken (Gallus gallus domesticus) genetic resources (IC) comprise more than 80% of the overall poultry population in rural villages despite their low productivity. However, a holistic approach that increases productivity without increasing production costs or leading to loss of biodiversity is presently limited. Conversely, in most developing countries, there is almost no organizational structure for breeding programmes for improving and conserving IC. These locally adapted IC can only be conserved in the most rational and sustainable way by ensuring that they are functional part of different production systems. Their conservation should be through utilisation if they are to be of any benefit to the poor rural households. This discussion focuses on five very relevant questions that need to be answered if the conservation of IC is to be effective and sustainable: What, why and how should we conserve, who are the stakeholders and what are their roles in conservation efforts?

Dairy cattle breeding programs in developing countries are constrained by minimal and erratic pedigree and performance recording on cows on commercial farms. Small-sized nucleus breeding programs offer a viable alternative. Deterministic simulations using selection index theory were performed to determine the optimum design for small-sized nucleus schemes for dairy cattle. The nucleus was made up of 197 bulls and 243 cows distributed in 8 non-overlapping age classes. Each year 10 sires and 100 dams were selected to produce the next generation of male and female selection candidates. Conception rates and sex ratio were fixed at 0.90 and 0.50, respectively, translating to 45 male and 45 female candidates joining the nucleus per year. Commercial recorded dams provided information for genetic evaluation of selection candidates (bulls) in the nucleus. Five strategies were defined: nucleus records only [within-nucleus dam performance (DP)], progeny records in addition to nucleus records [progeny testing (PT)], genomic information only [genomic selection (GS)], dam performance records in addition to genomic information (GS+DP), and progeny records in addition to genomic information (GS+PT). Alternative PT, GS, GS+DP, and GS+PT schemes differed in the number of progeny per sire and size of reference population. The maximum number of progeny records per sire was 30, and the maximum size of the reference population was 5,000. Results show that GS schemes had higher responses and lower accuracies compared with other strategies, with the higher response being due to shorter generation intervals. Compared with similar sized progeny-testing schemes, genomic-selection schemes would have lower accuracies but these are offset by higher responses per year, which might provide additional incentive for farmers to participate in recording.

This paper uses data from a survey of 186 dairy households in two divisional administrative zones in the Kenya highlands to establish the dominant milk marketing channel based on net returns. Cumulative density function results show that, the private channel dominates over all the other channels except at the 0.8 probability level of choice where the cooperative channel dominates overall. Although most smallholder farmers in Kenya market milk through the traditional channel, the net returns that would accrue from their enterprise if they used the traditional and cooperative channels is still considerably higher. It is however apparent that the traditional channel is being replaced, albeit slowly, giving rise to the need of a policy to breach the quality gap between the traditional and the modern channels by making popular training and certification programs for small scale milk traders and processors.

Dairy cattle industries contribute to food and nutrition security and are a source of income for numerous households in many developing countries. Selective breeding can enhance efficiency in these industries. Developing dairy industries are characterized by diverse production and marketing systems. In this paper, we use weighted goal aggregating procedure to derive consensus trait preferences for different producer categories and processors. We based the study on the dairy industry in Kenya. The analytic hierarchy process was used to derive individual preferences for milk yield (MY), calving interval (CIN), production lifetime (PLT), mature body weight (MBW), and fat yield (FY). Results show that classical classification of production systems into large-scale and smallholder systems does not capture all differences in trait preferences. These differences became apparent when classification was based on productivity at the individual animal level, with high and low intensity producers and processors as the most important groups. High intensity producers had highest preferences for PLT and MY, whereas low intensity producers had highest preference for CIN and PLT; processors preferred MY and FY the most. The highest disagreements between the groups were observed for FY, PLT, and MY. Individual and group preferences were aggregated into consensus preferences using weighted goal programming. Desired gains were obtained as a product of consensus preferences and percentage genetic gains (G%). These were 2.42, 0.22, 2.51, 0.15, and 0.87 for MY, CIN, PLT, MBW, and FY, respectively. Consensus preferences can be used to derive a single compromise breeding objective for situations where the same genetic resources are used in diverse production and marketing circumstances.

This study aims to investigate the influence of non-genetic factors on feed efficiency in indigenous chicken. Residual feed intake (RFI), residual gain (RG) and residual intake and gain (RIG) were used as measures of feed efficiency. Feed intake and body weight data were collected on 107 experimental birds on a daily and weekly basis, respectively, from ages 11 to 20 weeks. A general linear model was fitted to determine the effect of sex, cluster, genotype and hatch group on mean performance and to assess temporal variation across clusters. The overall mean performance for daily gain (ADG), daily feed intake (ADFI), weekly metabolic body weight (MBW), RFI, RG and RIG was 10.38 g/day, 133.01 g/day, 164.12 g/day, 0.00 (±14.23), 0.00 (±1.83) and 0.00 (±14.64), respectively. Sex significantly influenced variation in ADG and RG while hatch group influenced all traits except ADFI. Cluster and genotype had no effect on the traits. Interaction between sex and cluster significantly influenced ADFI, RFI and RIG. There was a significant temporal variation within and among clusters resulting in re-ranking of the phylogenetic groups in efficiency across the test period. Results indicate that growth and feed efficiency traits are influenced by non-genetic factors which should be accounted for, to reduce bias and improve accuracy of performance evaluations in the indigenous chicken.

A bio-economic model was developed to evaluate the utilisation of indigenous chickens (IC) under different production systems accounting for the risk attitude of the farmers. The model classified the production systems into three categories based on the level of management: free-range system (FRS), where chickens were left to scavenge for feed resources with no supplementation and healthcare; intensive system (IS), where the chickens were permanently confined and supplied with rationed feed and healthcare; and semi-intensive system (SIS), a hybrid of FRS and IS, where the chickens were partially confined, supplemented with rationed feeds, provided with healthcare and allowed to scavenge within the homestead or in runs. The model allows prediction of the live weights and feed intake at different stages in the life cycle of the IC and can compute the profitability of each production system using both traditional and risk-rated profit models. The input parameters used in the model represent a typical IC production system in developing countries but are flexible and therefore can be modified to suit specific situations and simulate profitability and costs of other poultry species production systems. The model has the capability to derive the economic values as changes in the genetic merit of the biological parameter results in marginal changes in profitability and costs of the production systems. The results suggested that utilisation of IC in their current genetic merit and production environment is more profitable under FRS and SIS but not economically viable under IS.

Poultry production and in particular indigenous chicken (IC) production has been recognised as an avenue to improve livelihoods of the rural households. Previous attempts to improve their productivity have had little success due to, among others, lack of a holistic approach in solving the constraints and dissemination of inappropriate technologies given the production circumstances and market dynamics. Marketing as a constraint is often blamed for the failure of interventions to improve livelihoods, despite lack of saturation for IC products at local and national levels and the increasing demand for the same. This paper highlights the past improvement attempts and suggests strategies to improve IC productivity and thereby improve the livelihood of the rural households which are the custodians of these genetic resources. It is concluded that there is potential for improvement of IC production in Kenya given the available genetic and physical resources. However, a holistic strategy that increases productivity without increasing production costs or leading to loss of biodiversity must be developed. Such a strategy must take into account the various uses of the IC in a rural household.

This study estimated economic values (EVs) for disease resistance traits for dairy/crossbred goats in Kenya. The traits mean somatic cell count (SCC, cells/μl) and faecal worm egg count (FEC, epg) were taken as indicator traits for the most prevalent diseases in the smallholder farms i.e., mastitis and helminthiosis, respectively. Economic weights were objectively assigned to these indicator traits in a selection index such that the overall gains in the breeding objective traits were maximised. Four options for calculating EVs for SCC and FEC were considered. Option 1, response from single trait selection was set equivalent to index response for the trait. Option 2, response from single trait selection was set equivalent to maximum gains achievable. Option 3, level of FEC/SCC was set to zero; and option 4, response in FEC/SCC was set to the minimum gains achievable. In all the options, EVs with/without risk for breeding objective traits 12-month live weight (LW-kg); ADG, average post-weaning daily gain (ADG-g); DMY, average daily milk yield (DMY-kg) were used. For each production trait selected for improvement, a less positive response in the traits FEC and SCC would be desirable. Maximum negative EVs were achieved at a point where the response in SCC was set at zero (option 3) while EVs for SCC were zero when response for DMY was maximised (option 2). In addition, considerable differences in EVs for SCC were obtained when EVs with/without risk were used. Similar results were also observed for FEC when LW was the objective of improvement. However, more positive EVs for FEC were estimated relative to ADG and DMY. The results confirm that there is a scope to incorporate disease resistance traits in a breeding program with objective of reducing disease incidences and the costs of disease control.

The economic values for productive (egg number, average daily gain, live weight, and mature weight) and functional (fertility, hatchability, broodiness, survival rate, feed intake, and egg weight) traits were derived for three production systems utilizing indigenous chicken in Kenya. The production systems considered were free-range, semi-intensive, and intensive system and were evaluated based on fixed flock size and fixed feed resource production circumstances. A bio-economic model that combined potential performances, feeding strategies, optimum culling strategies, farmer's preferences and accounted for imperfect knowledge concerning risk attitude of farmers and economic dynamics was employed to derive risk-rated economic values. The economic values for all the traits were highest in free-range system under the two production circumstances and decreased with level of intensification. The economic values for egg number, average daily gain, live weight, fertility, hatchability, and survival rate were positive while those for mature weight, broodiness, egg weight, and feed intake were negative. Generally, the economic values estimated under fixed feed resource production circumstances were higher than those derived under fixed flock size. The difference between economic values estimated using simple (traditional) and risk-rated profit model functions ranged from -47.26% to +67.11% indicating that inclusion of risks in estimation of economic values is important. The results of this study suggest that improvement targeting egg number, average daily gain, live weight, fertility, hatchability, and survival rate would have a positive impact on profitability of indigenous chicken production in Kenya.

The objective of this paper was to estimate the farmers� preferences based on the non-market traits in selection, breeding and conservation of indigenous chicken. The study was carried out in four selected counties of Kenya. Data were collected using structured questionnaires with the use of multi-attribute elicitation techniques applied to 450 rural households. Conjoint analysis through an ordered probit model was used to analyse the data. The study identified traits preferred by the farmers based on their current low-input production circumstances. Using these traits, indigenous chicken can be selected for higher productivity and performance while retaining their diversity and adaptability. In general, the determination of the importance of various attributes elucidates to the stakeholders some valuable aspects that would assist them in overcoming some of the major constraints of indigenous chicken production in rural areas and at the same time provides vital information for selection, conservation and development of breeding programmes.

SUMMARYThe objective of the present study was to determine the optimal culling strategy in relation to biological and economic efficiency (BE and EE, respectively) and annualized net revenue (AN) in the Japanese Black cow–calf production system with special reference to the beef quality of culled cows. The herd model focused on two ways of mating: one-mating trial system (ONE) and continuous-mating trial system (CON). ONE assumed that heifers that fail to conceive are culled and cows that fail to conceive are culled at weaning of their calves, while CON assumed that mating continues until all females theoretically conceive. Least square means of carcass data of Japanese Black cows collected from a cooperative farm in Japan were used to estimate the carcass price of a cow by parity and Beef Marbling Standard (BMS) number. The simulation, assuming the current production situation in Japan, indicated that sales of culled cows accounted for 0·10–0·20 of total sales and was an important element in total production. Comparisons between ONE and CON showed that production efficiency in the current situation is higher in CON. The BE, EE and AN were higher in CON than in ONE. The two economic indicators were less sensitive to changes in annual discount rate but highly sensitive to changes in female calf price and BMS number of cows, indicating the importance of considering fluctuations in calf price and potential quality of culled cows’ carcasses when estimating the economically optimal parity of culling. The three indicators derived different optimal solutions even in the same mating trial systems, stressing the importance of choice of production indicators when determining the culling strategy and evaluating animal production.

Studies on Sahiwal cattle genetic resources in the tropics have mainly concentrated on evaluating their performance levels, with only a few published reports describing the breed characteristics. The aim of this study was to critically examine the existing breeding and conservation programmes for Sahiwal cattle in the tropics, focusing on Pakistan, India and Kenya as the core regions of development. The study was based on review of both published and unpublished literature highlighting shortcomings and strengths in the existing strategies, and opportunities for improvement and conservation. The Sahiwal breed is utilized for dairy and beef production under smallholder dairy, pastoral extensive and ranching production systems, both as pure-breds or cross-breds. The necessary components to strengthen the breeding programmes such as performance recording, genetic evaluation and artificial insemination (AI) facilities exist to differing degrees. Breeding and conservation efforts benefit from the technical and financial support from government research institutions which also provide incentives to enhance participation in the programmes. However, breeding goals are rather informal and only defined in terms of high-production levels with functional traits largely ignored. There is need for participatory identification of breeding and production goals, and structured cooperation of the small herds, so as to accommodate the specific contributions of the breed in future breeding and conservation programmes.

Indigenous chicken (IC) and their production systems were characterized to understand how the whole system operates for purposes of identifying threats and opportunities for holistic improvement. A survey involving 594 households was conducted in six counties with the highest population of IC in Kenya using structured questionnaires. Data on IC farmers' management practices were collected and analysed and inbreeding levels calculated based on the effective population size. Indigenous chicken were ranked highest as a source of livestock income by households in medium- to high-potential agricultural areas, but trailed goats in arid and semi-arid areas. The production system practised was mainly low-input and small-scale free range, with mean flock size of 22.40 chickens per household. The mean effective population size was 16.02, translating to high levels of inbreeding (3.12%). Provision for food and cash income were the main reasons for raising IC, whilst high mortality due to diseases, poor nutrition, housing and marketing channels were the major constraints faced by farmers. Management strategies targeting improved healthcare, nutrition and housing require urgent mitigation measures, whilst rural access road network needs to be developed for ease of market accessibility. Sustainable genetic improvement programmes that account for farmers' multiple objectives, market requirements and the production circumstances should be developed for a full realization of IC productivity.

The Sahiwal breed has been used for upgrading the East African Zebu (EAZ) for improved milk production and growth performance in the southern rangelands of Kenya. Main users of this breed are Maasai pastoralists. Until now, there has been no deliberate effort to understand why these pastoralists specifically prefer to keep Sahiwal genetic resources as well as which traits are considered important by them and what is the underlying reason for this. However, this information is regarded vital for further development of the breed. A survey was conducted between May and October 2009 among Maasai pastoralists in Kajiado and Narok counties in the Southern part of Kenya, and private ranches and government farms to identify production objectives and breeding goals of Sahiwal cattle producers. Sahiwal genetic resources were mainly kept for domestic milk production and for revenue generation through milk sales and live animals. To a limited extent, they were kept for breeding and also for multiple objectives that included insurance against risks and social functions. Production aims were influenced to varying extents by various household and farmer characteristics. Sahiwal cattle and their crosses were generally perceived to be better with respect to productive traits and fertility traits when compared to the EAZ. However, the EAZ was rated higher with respect to adaptation traits. The breeding objective traits of primary importance were high milk yield and big body size, good reproductive efficiency and relatively good adaptation to local production conditions. Performance and functional traits are important breeding goals that play a major role in fulfilling the multiple production objectives. This forms the basis for the optimisation of a breeding programme for sustainable utilisation to meet the needs of Sahiwal cattle producers.

This paper aimed at evaluating closed and open nucleus schemes for Boran cattle based on genetic and economic merits of three alternative breeding programmes; 1) breeding programme closed to the members of the Boran Cattle Breeders Society aimed at improving growth (ENTIRE), 2) expanded breeding programme managed by the ENTIRE but incorporating the trait preferences of low-input farmers aimed at improving growth and adaptation (EXPO) and 3) breeding programme for the low-input farmers aimed at improving adaptation, growth and milk production (LOW). Within ENTIRE, two options were considered; option 1 included breeding objectives and selection criteria derived from the recommendation for ENTIRE (ENTIRE1) and option 2 included breeding objectives and selection criteria derived from the recommendation for the EXPO breeding programme but without extra recording for packed cell volume (ENTIRE2). Sensitivity analysis of the programmes to changes in nucleus size (5%, 10% and 25%), gene contribution to commercial herds (25%, 50% and 70%) and degree of opening the nucleus (10%, 20% and 30%) were performed. The ENTIRE1 within closed nucleus programme obtained overall monetary genetic gain of US$1.16 1 and profit amounting to US$5.36 and for ENTIRE2, the monetary genetic gain and profit rose to US$2.01 and US$11.10, respectively. The open nucleus posted higher values than the closed nucleus for monetary genetic gain (US$1.46) for ENTIRE1 but had a lower profit (US$5.02). This was a general trend in the alternative programmes. Moving from ENTIRE (growth) to EXPO (growth and adaptation) resulted in the drop in sale weight gain by almost 2 kg, but a gain of 20% in packed cell volume. The LOW posted a negative gain for milk yield of − 1.1 kg. Restrictions on growth and adaptation on the breeding objective allowed for moderate positive gains in milk. The nucleus size of 25%, genetic contribution to commercial herds of 70% and degree of opening the nucleus of 10% were most profitable. When extra recording for packed cell volume was applied in the commercial herds in EXPO, no additional benefits accrued. The trade-offs for ENTIRE due to incorporation of adaptation traits as well as the feasibility of the alternative breeding programmes are critically discussed.

The objective of this study was to define breeding objectives and consequently determine optimum crossbreeding levels for goats in the smallholder production systems. Profits and economic values (EVs) were estimated for four genotypes namely (a) original stock or local goat breeds with 0% German Alpine blood level (OS), (b) F1 with 50% German Alpine blood level (F1), (c) first backcross with 75% German Alpine blood level (B1) and (d) second backcross with 87.5% German Alpine blood level (B2). The EVs were estimated for average daily milk yield (DMY, kg), average post-weaning daily gain (ADG, kg), number of kids weaned (NKW), mature weight (MW, kg) and 12-month live weight (LW, kg). Profitability in Kenyan Shilling (KES) without risk was optimal (KES 6038.02) for the B1 genotype. Economic values without risk for most traits were highest for the F1 genotype, i.e., KES 64.85 (ADG), 24.02 (NKW), −27.55 (MW) and 84.51 (LW). There was, however, a 23% reduction in profits in the F1 genotype. It was evident that crossbreeding would improve the profitability of the smallholder farms, but not beyond the 75% grade level. A similar trend was observed when risk was incorporated. Differences in profitability with and without risk were less than 0.005% for all the genotypes. However, differences in EVs were large, ranging from −28% to +19%; DMY had the largest differences. Therefore, incorporation of risk in estimation of EVs for traits of importance is necessary. This study has also demonstrated that crossbreeding to a higher grade level is not necessarily compensated for by a high performance in most traits. Therefore, a crossbreeding program targeting B1 (75%) crossbreds would be desirable for implementation in the smallholder production systems.

The aim of this study was to evaluate the effect of the cluster ecotype and the part of chicken on nutritional composition, and functionality of sarcoplasmic and myofibrillar proteins that are most relevant to the technological features of chicken meat. Over 50 chickens from each ecotype cluster purchased, slaughtered and the meat stored under refrigeration at -20oC and later on transferred in cooler box on ice and flown to South Africa, at the Durban University of Technology. Protein fractions were extracted with a cocktail of Sodium Chloride buffer (50mM NaCl, 50mM Tris HCl; 75mM DTT and 1mM EDTA at pH 7) and quantified by Bradford method. One dimensional Sodium Dodecyl Polyacrylamide Gel Electrophoresis (SDS PAGE) was applied to separate protein fractions. Emulsifying capacity, emulsifying stability, solubility, and in vitro digestibility were determined on the total protein isolates. Significant differences in band expressions were recorded for the myofibrillar and the sarcoplasmic proteins. The three ecotypes had high quality proteins with all the limiting and essential amino acids at concentrations higher than FAO/WHO recommended daily allowance for adults and children. Distinct protein bands at larger molecular weight proteins >100 kDa, corresponding to Myosin Heavy Chain, medium fractions 75 kDa and 45 kDa and even lower molecular weight fraction

Data consisting of 8922 weight records from 2642 Dorper sheep from 20 to 380 days of age spanning 1981–1996 were used to model the growth trajectory using random regression (RR) and estimate genetic parameters. The independent variables were orthogonal (Legendre) polynomials of age at weighing and orders of fit up to 3 were considered. Analyses were carried out fitting sets of RR coefficients due to direct and maternal additive genetic and environmental effects, and heterogeneous error variances. Direct additive genetic variance increased steadily along the trajectory from 0.9 at 20 days of age to 2.44 at 380 days of age. Maternal additive genetic variance increased steadily along the trajectory from 0.13 to 2.92. Direct permanent environmental effect variances increased steadily from a value of 0.66 at 20 days to 2.13 at 380 days of age. Maternal permanent environmental variances declined from 0.87 at 20 days of age to 0.01 at 200 days of age followed by an increase to 0.87 at 380 days. Direct genetic heritability estimates declined sharply from 0.13 at 20 days to 0.07 at 80 days of age then fluctuated thereafter. Maternal genetic heritability estimates increased along the trajectory up to 320 days of age after which it declined slightly. The genetic and phenotypic correlations decreased with increasing lag in time between the weights. The Dorper sheep growth was adequately modeled using RR models despite the limited data. This study has demonstrated the possibility of application of RR models for routine genetic evaluation of Dorper sheep in Kenya.

Animal recording in Kenya is characterised by erratic producer participation and high drop-out rates from the national recording scheme. This study evaluates factors influencing efficiency of beef and dairy cattle recording system. Factors influencing efficiency of animal identification and registration, pedigree and performance recording, and genetic evaluation and information utilisation were generated using qualitative and participatory methods. Pairwise comparison of factors was done by strengths, weaknesses, opportunities and threats-analytical hierarchical process analysis and priority scores to determine their relative importance to the system calculated using Eigenvalue method. For identification and registration, and evaluation and information utilisation, external factors had high priority scores. For pedigree and performance recording, threats and weaknesses had the highest priority scores. Strengths factors could not sustain the required efficiency of the system. Weaknesses of the system predisposed it to threats. Available opportunities could be explored as interventions to restore efficiency in the system. Defensive strategies such as reorienting the system to offer utility benefits to recording, forming symbiotic and binding collaboration between recording organisations and NARS, and development of institutions to support recording were feasible.

SUMMARYAnimal recording is an interactive process that involves several practices. The efficiency of the process is essential to ensure the utility of outcomes necessary for sustainable participation. Most evaluation approaches define efficiency in economic terms. Animal recording systems lack outputs of direct economic benefits; hence, efficiency evaluation based on utility derived from the records would be more laudable. In that case, a system is considered efficient when outcome-utility-dependent participation is sustained. Approaches for evaluating efficiency based on the utility of outputs are, however, unavailable. The current study presents an approach for evaluating the efficiency of animal recording based on output utility using the institutional analysis and development framework. The approach evaluates efficiency by incorporating institutional issues influencing the operations of the system and its outcomes. It considers animal recording as an action arena with various actors in three action situations, namely: animal identification and registration, pedigree and performance recording and animal evaluation and information utilization. The variables include the positions occupied by actors, their actions, the outcomes associated with the actions, the level of control over choice, available information and the cost and benefits of engagement. As an interactive process, animal recording has rules that order relationships between actors. It also exists within a biophysical system and community whose attributes, combined with the rules, influence the actions and outcomes of recording. These are evaluated by looking at rule formation structures, enforcement and compliance and the level of interaction between the recording system and other biophysical characteristics and the community for their effects on outcomes, their utility and sustainability of recording. Participatory tools, Stakeholder matrix and Venn diagrams are used to identify the variables, quantify their interactions and link them to outputs. The applicability of the approach is tested using a case where information systems are imperfect. The approach successfully identifies missing actors within the action arena, poor rule conformance due to weak enforcement agencies and the absence of rules that govern outcomes and ensure the utility of outcomes as hindrances to the utility of recording and hence the efficiency of the system. It may therefore be used to evaluate the efficiency of systems whose outputs do not have a direct market value and in situations where quantitative market information is scarce.

Summary The objective of this study was to develop a method to optimize the selection and mating decisions based on genotypic information with overlapping generations by applying mate selection algorithm. In this study, differential evolution algorithm was used to optimize numbers of mating between genotypes and the optimal numbers of males and females selected from each genotype over planning horizon. This method assumed a single biallelic QTL (Q and q) and was applied to a simple situation in a herd of pigs as an example. Four dominance degrees of gene: recessive, additive, complete-dominance and over-dominance were considered. For all dominance degrees, the frequency of the favourable allele in males selected for replacement increased rapidly. In contrast, the frequency of favourable allele in females selected for replacement increased more gradually. The superiorities in cumulative discounted performance (CDP) when the initial allele frequency was 0.5 over a case when the frequency was 0.05 over the planning horizon were greatly affected by dominance degrees. The CDP superiorities ranged from 24% for an over-dominant QTL to 91% for a recessive QTL.

This paper reviews breeding technologies vital for breeding programme development in Sub-Saharan Africa while considering indigenous cattle genetic resources for beef production. The importance of beef cattle is highlighted, given the globally and regionally growing demand for meat and the fact that Sub-Saharan Africa is home to a large population of indigenous cattle – for which, however, few examples of successful breeding programmes exist. Examples are analysed, including the N'Dama pure breeding programme in western Africa, the Boran improvement programme in eastern Africa, Nguni cattle breeding in southern Africa and the Ankole cattle of Uganda. The characteristics of livestock production systems, livestock breeds and socio-political aspects of Sub-Saharan Africa have largely inhibited successful breeding technology transfer from developed countries. Technological adjustments and the increasing consideration of target group involvement in livestock breeding programmes may offer better possibilities for raising production by breeding in low-input and medium-input livestock production systems. Livestock keepers can be differentiated into breeder groups and commercial groups. Breeder groups are important targets for genetic improvement programmes via community-based genetic improvement organizations. Breeding programmes are suggested for Sub-Saharan Africa within the concept of regional genetic improvement programmes controlled by breed societies, government and national agricultural research systems.

Genetic and phenotypic parameters were estimated for lamb growth traits for the Dorper sheep in semi-arid Kenya using an animal model. Data on lamb growth performance were extracted from available performance records at the Sheep and Goats Station in Naivasha, Kenya. Growth traits considered were body weights at birth (BW0, kg), at 1 month (BW1, kg), at 2 months (BW2, kg), at weaning (WW, kg), at 6 months (BW6, kg), at 9 months (BW9, kg) and at yearling (YW, kg), average daily gain from birth to 6 months (ADG(0-6), gm) and from 6 months to 1 year (ADG(6-12), gm). Direct heritability estimates were, correspondingly, 0.18, 0.36, 0.32, 0.28, 0.21, 0.14, 0.29, 0.12 and 0.30 for BW0, BW1, BW2, WW, BW6, BW9, YW, ADG(0-6) and ADG(6-12). The corresponding maternal genetic heritability estimates for body weights up to 9 months were 0.16, 0.10, 0.10, 0.19, 0.21 and 0.18. Direct-maternal genetic correlations were negative and high ranging between -0.47 to -0.94. Negative genetic correlations were observed for ADG(0-6)-ADG(6-12), BW2-ADG(6-12), WW-ADG(6-12) and BW6-ADG(6-12). Phenotypic correlations ranged from 0.15 to 0.96. Maternal effects are important in the growth performance of the Dorper sheep though a negative correlation exists between direct and maternal genetic effects. The current study has provided important information on the extent of additive genetic variation in the existing flocks that could now be used in determining the merit of breeding rams and ewes for sale to the commercial flocks. The estimates provided would form the basis of designing breeding schemes for the Dorper sheep in Kenya. Implications of the study to future Dorper sheep breeding programmes are also discussed.

The objectives of this study were to estimate the environmental and additive and non-additive genetic effects on lactation curve and lactation parameters of crosses of Holstein (H), Brahman (B) and Brown Swiss (BS) in Olancho region in Honduras. The data consisted of 54,517 milk yield records from 192 dual-purpose crossbred cows lactating from 2000 to 2005 at the Universidad Nacional de Agricultura de Honduras (UNA). The lactation curve and lactation parameters of interest were the scaling factor to represent yield at the beginning of lactation ( a ), the factor associated with the inclining ( b ) and declining ( c ) slopes of the lactation curves, and the milk yield at initial day of lactation ( MY 20 ), peak milk yield ( MY max ), day at peak milk yield ( t max ), and the total milk yield ( TM ) per lactation, respectively. The incomplete gamma function (Wood function) was used to estimate lactation curve and lactation parameters from daily milk records of H × B, H × BS and BS × B crossbred cows. The environmental, additive and non-additive genetic effects on lactation curve and lactation parameters were estimated using Dickerson and Kinghorn models. The coefficients of determination of fitness of Wood's function ( R 2 ) ranged from 80% to 97% with an average of 93%. The lactation curve of the crossbred cows was similar to those reported for dairy cows grazing in the tropics. Lactation parameters such as MY max , t max and TM were significantly ( P MY max and TM indicate that one of the milk yield parameters could be used as a selection criterion to improve either one or both traits. Despite the fact that both genetic models showed similar patterns, the absolute value of the parameters varied. For both models, individual additive genetic breed effect for H breed were significant ( P TM than the BS breed. In the Dickerson model, highly positive significant ( P TM for H×BS and BS×B crosses was found. The Kinghorn model did not show significant effects of dominance on this parameter. The estimate of recombination effect for all crosses involving B breed were negative and significant ( P

Increasing population pressure, land scarcity and diminishing production resources are promoting goat production in the tropics. Dairy goat breeding (DGB) projects have been implemented by development agencies, governments and the private sector with the objective of improving the dairy merits genetically through crossbreeding with exotic genotypes. The performance of these projects is still a cause for concern. Therefore, sustainable dairy goat breeding forces various stakeholders to re-orient their breeding goals, strategies and design of breeding programmes towards a sustainability perspective. This paper highlights a set of key requirements for establishing sustainable dairy goat breeding programmes. Conclusions are drawn based on the lessons learnt from numerous examples of DGB projects in East and Central Africa keeping sustainability concerns insight to inform on-going and future projects.

The influence of major genes for crested-head (Cr), frizzle-feather (Fr) and naked-neck (Na) on body weights and growth patterns of indigenous chickens reared intensively was investigated and compared with normal-feather (na) gene. Birds were individually weighed at hatch and every two weeks up to 30 weeks of age. Growth patterns were modelled using the Gompertz-Laird function. The genes influenced body weights and growth patterns at various ages. The Cr gene had significant (P < 0.05) negative effects on body weights (between 52.2 g and 112.3 g) from 18 weeks onwards and low absolute growth rate from 10 to 22 weeks than na, but higher initial specific growth and maturation rates than the Na gene. The Fr gene had significant negative effects on body weights (between 28.2 g and 75.1 g) from 8 to 16 weeks than na, but a higher relative growth rate than Cr from 12 to 16 weeks. The Na gene had significant negative effects on body weights (between 24.7 g and 134.6 g) from 8 weeks onwards than na. It was concluded that Frfr and Nana genotypes are not ideal for cool environments in Kenya and indigenous chicken genotypes have varied growth potentials and patterns that can be improved to increase production.

This study evaluates the provision of services; veterinary services (VS), extension services (ES), marketing services (MS), performance recording (PR), monitoring and evaluation of dairy goat breeding activities (ME) and provision of water (WT) and determines the effectiveness of applying these services in dairy goat production systems in Kenya. A household survey was conducted with 311 farmers participating in three dairy goat projects (Dairy Goat Association of Kenya (DGAK), Higher Education Links-Egerton University Community Dairy Goats Project (HEL-EUCDGP) and Heifer Project International (HPI)) to assess farmers' willingness to pay for provision of these services. Ranking these services revealed that MS was the most important service in priority order for goat keepers. Farmers with and without experience were willing to pay significantly more for provision of VS. Variables such as satisfaction with project activities, system of production, social benefits, flock size, participation in the projects, farm visits, market linkage and information, and experiences on the services significantly influenced willingness to pay (WTP). The decision to pay or not was not necessarily affected by those not willing to pay because of the inter-linkage probabilities with the ability to pay. Projects should take a broader responsibility of providing these services or link farmers to agents to provide the services. The poor farmers should be supported in a cost-sharing manner to avoid undesirable practises or the services left to those who can afford to pay.