Comparative reproductive performance of Saanen and Toggenburg bucks raised under tropical environment.

The objective of this study was to evaluate the effect of breed and age on scrotal measurements and semen characteristics of Saanen and Toggenburg bucks raised under extensive system in the tropic. The study was conducted using Toggenburg and Saanen bucks; the bucks were allocated into two different groups based on breed and age in 2 × 2 factorial completely randomized design. The body weight was determined using a hanging weighing scale expressed in kilogrammes (kg). Scrotal circumference and scrotal length were measured using metal measuring tape. Semen characteristics evaluated were volume, consistency, mass activity and progressive motility, live sperm cells, normal morphology and spermatozoa concentration. The current study found that breed of bucks had no influence on body weight, scrotal circumference, scrotal length, volume, mass activity, progressive motility, live sperm cells and sperm morphology. The study also found that Toggenburg bucks had higher semen consistency and spermatozoa concentration as compared with Saanen bucks. Therefore, it can be concluded that Toggenburg bucks can produce high number of total spermatozoa and as a result higher semen doses for artificial insemination purposes. Further studies with more number of animals are recommended.

Prevalence of hepatitis B virus infection and uptake of hepatitis B vaccine among healthcare workers, Makueni County, Kenya 2017.

BACKGROUND: Hepatitis B virus (HBV) is a vaccine-preventable infection that can spread in healthcare setting. Data on HBV infections and vaccine in African healthcare workers (HCWs) are limited. We estimated HBV infection prevalence, hepatitis B vaccination status and identified factors associated with vaccination in one Kenyan county. METHODS: Randomly selected HCWs completed a questionnaire about HBV exposure and self-reported immunization histories, and provided blood for testing of selected HBV biomarkers to assess HBV infection and vaccination status: HBV core antibodies (anti-HBc), HBV surface antigen (HBsAg) and HBV surface antibodies (anti-HBs). Prevalence odds ratios (OR) with 95% confidence intervals (95% CI) were calculated to identify factors associated with vaccination. RESULTS: Among 312 HCWs surveyed, median age was 31 years (range: 19-67 years). Of 295 blood samples tested, 13 (4%) were anti-HBc and HBsAg-positive evidencing chronic HBV infection; 139 (47%) had protective anti-HBs levels. Although 249 (80%) HCWs received ≥1 HBV vaccine dose, only 119 (48%) received all three recommended doses. Complete vaccination was more likely among those working in hospitals compared to those working in primary healthcare facilities (OR = 2.5; 95% CI: 1.4-4.3). CONCLUSION: We recommend strengthening county HCW vaccination, and collecting similar data nationally to guide HBV prevention and control.

Farmers' breeding practices and traits of economic importance for indigenous chicken in RWANDA.

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.

Characterization of indigenous chicken production systems in Rwanda.

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.

Prevalence of hepatitis C virus and its genotypes among a cohort of drug users in Kenya.

BACKGROUND: Prevalence of hepatitis C virus and that of its main genotypes varies between the worlds geographic regions. The risk factors for infection with HCV include blood transfusion, tattoing and injecting drug use. OBJECTIVES: To examine the prevalence of HCV and determine its main genotypes among a cohort of drug users in Kenya. DESIGN: A laboratory based study. SETTING: Hepatitis research laboratory in the Centre for Virus Research at the Kenya Medical Research Institute, Nairobi. SUBJECTS: Three hundred and fourteen male and 19 female intravenous and non-intravenous drug users aged between 15-55 years. RESULTS: Seventy four (22.2%) out of 333 samples tested positive for anti-HCV. Sixty nine out of the 74 serum samples were assayed for HCV RNA and 38 (55.5%) were positive. The RNA positive samples were further subjected to sequencing and 19 (73%) of the samples were classified as genotype 1a, while seven (27%) samples were classified as genotype 4. Genotypes 2, 3, 5 and 6 were not identified in this study. CONCLUSIONS: These results demonstrate a high HCV infection prevalence among this cohort of drug users (22.2%) as compared to that of the general population, which is estimated to be 0.2-0.9%. The study also confirms the presence of at least two major genotypes among Kenyan drug users (genotypes 1 and 4).

Genetic and phenotypic parameters and annual trends for milk production and fertility traits of the Sahiwal cattle in semi arid Kenya.

Data comprising 7211 lactation records of 2894 cows were used to estimate genetic and phenotypic parameters for milk production (lactation milk yield, LMY and lactation length, LL) and fertility (calving interval, CI; number of services per conception, NSC and age at first calving, AFC) traits. Genetic, environmental and phenotypic trends were also estimated. Variance components were estimated using univariate, bivariate and trivariate animal models on based restricted maximum likelihood procedures. Univariate models were used for each trait, while bivariate models were used to estimate genetic and phenotypic correlations between milk production and fertility traits and between LMY, LL, CI and NSC within each lactation. Trivariate models were used in the analysis of LMY, LL, CI and NSC in the first three lactations. Heritability estimates from the univariate model were 0.16, 0.07, 0.03, 0.04 and 0.01 for LMY, LL, CI, AFC and NSC, respectively. The heritability estimates from trivariate analysis were higher for milk production traits than those from univariate analyses. Genetic correlations were high and undesirable between milk production and fertility traits, while phenotypic correlations were correspondingly low. Genetic trends were close to zero for all traits, while environmental and phenotypic trends fluctuated over the study period.

Genetic and phenotypic parameters for test day milk yield of Sahiwal cattle in the semi-arid tropics.

A total of 19 376 test day (TD) milk yield records from the first three lactations of 1618 cows daughters of 162 sires were used to estimate genetic and phenotypic parameters and determine the relationship between daily milk yield and lactation milk yield in the Sahiwal cattle in Kenya. Variance components were estimated using animal models based on a derivative free restricted maximum likelihood procedure. Variance components were estimated using various univariate and multi-trait fixed regression test day models (TDM) that defined contemporary groups either based on the year-season of calving (YSCV) or on the year-season of TD milk sampling (YSTD). Variance components were influenced by CG which resulted in differences in heritability and repeatability estimates between TDM. Models considering YSTD resulted in higher additive genetic variances and lower residual variances compared with models in which YSCV was considered. Heritability estimates for daily yield ranged from 0.28 to 0.46, 0.38 to 0.52 and 0.33 to 0.52 in the first, second and third lactation, respectively. In the first and second lactation, the heritability estimates were highest between TD 2 and TD 4. Genetic correlations among daily milk yields ranged from 0.41 to 0.93, 0.50 to 0.83 and 0.43 to 86 in the first, second and third lactation, respectively. The phenotypic correlations were correspondingly lower. Genetic correlations were different from unit when fitting multi-trait TDM. Therefore, a multiple trait model would be more ideal in determining the genetic merit of dairy sires and bulls based on daily yield records. Genetic and phenotypic correlations between daily yield and lactation yields were high and positive. Genetic correlations ranged from 0.84 to 0.99, 0.94 to 1.00 and 0.94 to 0.97 in the first, second and third lactations, respectively. The corresponding phenotypic correlation estimates ranged from 0.50 to 0.85, 0.50 to 0.83 and 0.53 to 0.87. The high genetic correlation between daily yield and lactation yield imply that both traits are influenced by similar genes. Therefore daily yields records could be used in genetic evaluation in the Sahiwal cattle breeding programme.