Cattle In Kenya Research Articles

BoLA-6*01301 and BoLA-6*01302, two allelic variants of the A18 haplotype, present the same epitope from the Tp1 antigen of Theileria parva

We have recently shown that the BoLA-A18 variant haplotype (BoLA-6*01302) is more prevalent than the BoLA-A18 haplotype (BoLA-6*01301) in a sample of Holstein/Friesian cattle in Kenya. These MHC class I allelic variants differ by a single amino acid polymorphism (Glu97 to Leu97) in the peptide-binding groove. We have previously mapped an 11-mer peptide epitope from the Theileria parva antigen Tp1 (Tp1214–224) that is presented by BoLA-6*01301. Crystal structure data indicates that Glu97 in the MHC molecule plays a role in epitope binding through electro-static interaction with a lysine residue in position 5 of the epitope, which also functions as an additional anchor residue. In contrast to expectations, we demonstrate that the amino acid substitution in BoLA-6*01302 does not divert the CTL response away from Tp1214–224. The two MHC molecules exhibit similar affinity for the Tp1 epitope and can present the epitope to parasite-specific CTLs derived from either BoLA allelic variants. These data confirm that this BoLA polymorphism does not alter Tp1 epitope specificity and that both allelic variants can be used for Tp1 vaccine studies.

Characterisation of recent foot-and-mouth disease viruses from African buffalo (Syncerus caffer) and cattle in Kenya is consistent with independent virus populations.

BackgroundUnderstanding the epidemiology of foot-and-mouth disease (FMD), including roles played by different hosts, is essential for improving disease control. The African buffalo (Syncerus caffer) is a reservoir for the SAT serotypes of FMD virus (FMDV). Large buffalo populations commonly intermingle with livestock in Kenya, yet earlier studies have focused on FMD in the domestic livestock, hence the contribution of buffalo to disease in livestock is largely unknown. This study analysed 47 epithelia collected from FMD outbreaks in Kenyan cattle between 2008 and 2012, and 102 probang and serum samples collected from buffalo in three different Kenyan ecosystems; Maasai-Mara (MME) (n = 40), Tsavo (TSE) (n = 33), and Meru (ME) (n = 29).ResultsAntibodies against FMDV non-structural proteins were found in 65 of 102 (64%) sera from buffalo with 44/102 and 53/102 also having neutralising antibodies directed against FMDV SAT 1 and SAT 2, respectively. FMDV RNA was detected in 42% of the buffalo probang samples by RT-qPCR (Cycle Threshold (Ct) ≤32). Two buffalo probang samples were positive by VI and were identified as FMDV SAT 1 and SAT 2 by Ag-ELISA, while the latter assay detected serotypes O (1), A (20), SAT 1 (7) and SAT 2 (19) in the 47 cattle epithelia. VP1 coding sequences were generated for two buffalo and 21 cattle samples. Phylogenetic analyses revealed SAT 1 and SAT 2 virus lineages within buffalo that were distinct from those detected in cattle.ConclusionsWe found that FMDV serotypes O, A, SAT 1 and SAT 2 were circulating among cattle in Kenya and cause disease, but only SAT 1 and SAT 2 viruses were successfully isolated from clinically normal buffalo. The buffalo isolates were genetically distinct from isolates obtained from cattle. Control efforts should focus primarily on reducing FMDV circulation among livestock and limiting interaction with buffalo. Comprehensive studies incorporating additional buffalo viruses are recommended.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-015-0333-9) contains supplementary material, which is available to authorized users.

Foot and Mouth Disease Sero-prevalence in Cattle in Kenya

A cross sectional study was conducted on serum from 39 counties in Kenya in order to determine the prevalence of foot and mouth disease in bovine species. The study utilized serum samples at Foot-and-Mouth Disease (FMD) laboratory including Somali Ecosystem Rinderpest Eradication Coordination Unit (SERECU) project collected in the year 2010. From the serology results, the national prevalence of foot and mouth disease in bovines was 52.5% (CI = 95). Of the 3709 samples subjected toNonstructural protein (NSP) enzyme linked immunosorbent assay (ELISA) screening test, 1,947 of those were interpreted as positive representing 52.5% (1947/3709) while the other 1,762 samples turned negative representing 47.5% (n = 1,762). There was significant association between seropositivity and age groups (p = 0.002) and vaccination status (p = 0.048) but no association between the seropositivity and sex (p = 0.063). Key words: Cattle, foot and mouth disease (FMD), Kenya, seroprevalence.

Historical Perspective on Agroterrorism: Lessons Learned from 1945 to 2012

This article presents a historical perspective on agroterrorism cases from 1945 until 2012. The threat groups and perpetrators associated with bio- and agroterrorism are clustered into several groups: apocalyptic sects, lone wolves, political groups, and religious groups. We used open-source information, and 4 biological agroterrorism cases are described: (1) in 1952, Mau Mau poisoned cattle in Kenya by using a plant toxin from the African milk bush plant; (2) in 1985, the USDA claimed that Mexican contract workers were involved in deliberately spreading screwworm (Cochliomyia hominivorax) among livestock; (3) in 2000, Palestinian media reported that Israeli settlers released sewer water into Palestinian agricultural fields; and (4) in 2011, a person was sentenced to prison after threatening US and UK livestock with the deliberate spread of foot-and-mouth disease virus. All 4 cases can be assigned to political groups. These cases have not attracted much attention in literature nor in the public media, and the credibility of the sources of information varies. We concluded that agroterrorism has not been a problem during the period studied. Lessons learned from the few cases have generated awareness about the fact that nontypical biological weapons and non-high-risk agents, such as African milk bush, screwworm, and sewer water, have been used by attackers to influence local decision makers. This review will be useful in improving future preparedness planning and developing countermeasures.

Concomitant fungal and <i>Mycobacterium bovis</i> infections in beef cattle in Kenya

Bovine tuberculosis is an important zoonosis and accurate diagnosis is important for its surveillance. Post-mortem diagnosis may, however, be compromised by lesions caused by other pathogens. In an investigation on its prevalence in slaughter cattle in Kenya, Mycobacterium bovis and dimorphic fungi were inadvertently identified separately or concurrently in tuberculous lesions. Beef carcasses were inspected for lesions in two abattoirs in Nairobi. Tissues with lesions were collected and transported to the laboratory. Smears of lesions were stained by acid-fast procedure and examined microscopically. Lesions were cultured in Löwenstein-Jensen (LJ) and in BBL™ Mycobacterium growth indicator tubes (MGIT) media. Mycobacteria isolates in LJ medium were identified by DNA typing. Smears of BBLTM MGIT cultures were acid-fast stained and examined microscopically. Tissue sections were stained with periodic acid-Schiff reagent before examination. Of the 929 carcasses examined, 176 had granulomatous lesions. Dimorphic fungi were detected as acid-fast negative cells in 58 (32.9; 33.5%) of the lesion smears, either alone (29.0; 16.4%) or concurrently with acid-fast bacilli (29.0; 16.4%). The fungi were also detected in some BBL TM MGIT-culture smears and lesioned tissue sections. The fungi were identified, by means of cellular morphology, as Paracoccidioides brasiliensis and Blastomyces dermatitidis. A total of 64 isolates of mycobacteria were recovered in LJ medium, 19 of which were identified as M. bovis. The present report documents native P. brasiliensis infections outside the presumed endemic region and B. dermatitidis infections in a livestock animal. The findings further indicate the importance of dimorphic fungi as a differential diagnosis of bovine tuberculosis in the region.

Bluetongue and Epizootic Haemorrhagic Disease virus in local breeds of cattle in Kenya

The presence of bluetongue virus (BTV) and Epizootic Haemorrhagic Disease virus (EHDV) in indigenous calves in western Kenya was investigated. Serum was analysed for BTV and EHDV antibodies. The population seroprevalences for BTV and EHDV for calves at 51weeks of age were estimated to be 0.942 (95% CI 0.902–0.970) and 0.637 (95% CI 0.562–0.710), respectively, indicating high levels of circulating BTV and EHDV. The odds ratio of being positive for BTV if EHDV positive was estimated to be 2.57 (95% CI 1.37–4.76). When 99 calves were tested for BTV and EHDV RNA by real-time RT-PCR, 88.9% and 63.6% were positive, respectively. Comparison of the serology and real-time RT-PCR results revealed an unexpectedly large number of calves that were negative by serology but positive by real-time RT-PCR for EHDV. Eight samples positive for BTV RNA were serotyped using 24 serotype-specific real-time RT-PCR assays. Nine BTV serotypes were detected, indicating that the cattle were infected with a heterogeneous population of BTVs. The results show that BTV and EHDV are highly prevalent, with cattle being infected from an early age.

Productivity in different cattle production systems in Kenya

Cattle are kept as an important source of livelihood in many Kenyan farming households whilst also having cultural and social value. A review was undertaken to estimate productivity in the three main Kenyan cattle production systems: small-scale dairy and meat; small-scale dairy; and large-scale dairy and meat. Data on production parameters were collected through a systematic literature search of electronic databases for peer reviewed and grey literature. The parameters included were reproductive rates, mortality rates and yields. Prices for livestock and livestock products were estimated from markets. The data were used to estimate net output from cattle using the Livestock Productivity Efficiency Calculator (LPEC), a deterministic steady state model which measures productivity as net output per megajoule (MJ) of metabolisable energy (ME). The estimated net outputs per livestock unit year(-1) were USD 146.6, USD 215.1 and USD 84.8 in the large-scale dairy and meat, small-scale dairy and meat and small-scale dairy systems, respectively. Milk production contributed significantly to net output in all systems and was 91.8 % of total output in small-scale dairy. Cattle sales had the highest contribution to net output in large-scale dairy and meat system (45.1 %). Sensitivity analysis indicated that output was most affected by milk yield, age and weight at maturity and parturition rate. The productivity differences between the production systems call for more detailed research on the constraints to the production systems such as diseases, and to describe the benefits that farmers and society would obtain from disease control and improved management.

Prevalence of bovine tuberculosis in slaughter cattle in Kenya: a postmortem, microbiological and DNA molecular study

A study to determine the presence and prevalence of bovine tuberculosis in slaughter cattle in Kenya was carried out in two abattoirs from July to November 2009. Routine postmortem meat inspection was performed on a subpopulation of 929 cattle selected randomly from among 4,984. Carcases were inspected for gross tuberculous lesions which were then examined for acid-fast bacilli, (AFB), cultured for isolation of mycobacteria and the isolates characterised by DNA molecular analysis. Of the carcases examined, 176 (18.95 %, 95 % CI) had lesions suggestive of tuberculosis. AFB were observed in 63/176 of the lesioned cattle and mycobacteria were isolated from 64 of them. The isolates were identified as Mycobacterium bovis (19/64), Mycobacterium tuberculosis, (2/64) and mycobacteria other than tuberculosis (43/64). The prevalence of M. bovis by molecular analysis was 2.05 % (95 % CI). This study documents for the first time the presence of bovine tuberculosis among slaughter cattle in Kenya. There is therefore a need to formulate and implement control programmes in order to minimise transmission among animals and to humans. Isolation of M. tuberculosis from cattle underscores the risk tuberculous humans pose to animals.

Application of DNA markers in parentage verification of Boran cattle in Kenya

Boran cattle provide livelihood to thousands of households in the arid and semiarid lands of Kenya. Due to their superior adaptive and productive traits in comparison to other breeds of cattle, they have also become a popular choice for breeders in Eastern and Southern Africa. Continued genetic improvement of the breed is important, and therefore accurate performance and pedigree records are required. One hundred seventy-eight pedigree records and blood samples of four Boran stud herds were evaluated for accuracy of parentage allocation using 11 microsatellite markers recommended by ISAG for parentage verification. The panel of the 11 microsatellite markers was found to be highly polymorphic (PIC of 0.6901) with a combined probability of exclusion of 0.9997. The dam misidentification was low ranging between 0% and 5% for the herds tested. The estimated rate of mispaternity however ranged between 4.3% and 80% among the four stud herds, and more than 50% of the offspring of some herds were misidentified. The high rate of mispaternity will have a negative impact on the response to selection. The use of DNA markers for parentage assignment will improve the accuracy of the pedigree records of Boran stud cattle in Kenya and contribute to more accurate selection of superior animals.

Infection of cattle in Kenya with Brucella abortus biovar 3 and Brucella melitensis biovar 1 genotypes

Brucella melitensis biovar 1 was isolated from bovine milk samples from a herd in central Kenya, and Brucella abortus biovar 3 was isolated from aborted fetus materials and vaginal discharge fluids from cattle in central and eastern provinces of Kenya. All infections including those with B. melitensis were in cattle with reproductive problems kept in mixed herds indicating that cross infection occurs from small ruminants. Multiple-locus variable-number tandem repeat analysis genotyping revealed a close molecular homology of the B. melitensis isolates with an isolate from Israel and a close homology of the B. abortus isolates with an isolate from Uganda indicating that these genotypes have a wide geographic distribution. Infection of cattle with B. melitensis may complicate the control of brucellosis in this country.

Sahiwal cattle in semi-arid Kenya: genetic aspects of growth and survival traits and their relationship to milk production and fertility

The aim of this study was to estimate genetic and phenotypic parameters for growth and survival traits of Sahiwal cattle in Kenya and determine their relationship to milk production and fertility. Performance records of 5,681 animals were obtained from the National Sahiwal Stud and the traits considered were: birth weight (kilogrammes), weaning weight (kilogrammes), pre-weaning average daily gain (grammes per day), post-weaning average daily gain (grammes per day), yearling weight (kilogrammes), mature weight at 36 months (kilogrammes), pre-weaning survival rate (SR), post-weaning survival rate (PSR), lactation milk yield (kilogrammes), age at first calving (days), and calving interval (days). The data was analysed using univariate and bivariate animal model based on restricted maximum likelihood methods, incorporating all known pedigree relationship among animals. The additive direct effects were more pronounced than maternal genetic effects in early and in post-yearling growth performance. The additive genetic variance and heritabilities were low for SR and PSR. The correlation between direct additive genetic and maternal genetic effect were negative for pre-yearling traits. Genetic and phenotypic correlations among growth traits and between growth and milk yield were positive, whilst those between growth and fertility were weak and negative. Correlations between survival and growth were generally low and positive. The estimates obtained in this study provide the necessary technical parameters for evaluating alternative breeding programmes and selection schemes for sustainable improvement of Sahiwal cattle.

Modelling of lactation curves of dairy cows based on monthly test day milk yield records under inconsistent milk recording scenarios

The objective of this study was to describe the lactation curve of dairy cattle in Kenya using a suitable lactation function in order to facilitate inclusion of partial lactations in national dairy cattle evaluation and to assess the effect of data characteristics on lactation curve parameters. Six functions were fitted to test day (TD) milk yield records from six parities of Ayrshire, Guernsey, Holstein Friesian, Jersey and Sahiwal cattle. Five datasets: DS-1 (12-TD dataset with randomly missing records), DS-2 (10-TD dataset without missing records), DS-3 (10-TD dataset with randomly missing records), DS-4 (7-TD dataset, with only TD 4 to 10 records) and DS-5 (7-TD dataset, with TD 1 to 4, 6, 8 and 10 records) depicting various recording circumstances were derived to assess the effects of data characteristics on lactation curves and to assess the feasibility of reducing the number of TD samples per lactation. The fit of the functions was evaluated using adjusted R2 and their predictive abilities were compared using mean square prediction error, percentage of squared bias and the correlation between the predicted and actual milk yield. These criteria plus the changes in the parameters of curve functions and their associated standard errors were used in determining the effects of data characteristics on lactation curves. The mechanistic functions of Dijkstra (DIJ) and Pollott (APOL), and the incomplete gamma function of Wood (WD) had the highest adjusted R2 > 0.75. The APOL function was eliminated due to convergence failures when analysis of individual lactations within breeds was carried out. Both DIJ and WD had good predictive ability, although DIJ performed slightly better. Convergence difficulties were noted in some DIJ analysis where data were limiting. Missing records, especially at the beginning of a lactation, greatly influenced parameters a and b of the functions. It also resulted in estimates with large standard errors. Missing records in later lactation hardly affected the parameter estimates. The WD and DIJ functions showed superior fit to the data. The WD function demonstrated higher adaptability to various data characteristics than DIJ and could be used in situations where animal recording is not consistently practised and where recording of animal performance is routinely practised. DIJ function had high data requirements, which restricts it to dairy systems with consistent recording, despite easy physiological interpretation of its parameters. The number of TD per lactation could be reduced by minimising sampling frequency in the later lactation while maintaining the monthly sampling frequency in early lactation.

Use of SNP genotyping to determine pedigree and breed composition of dairy cattle in Kenya

High levels of inbreeding in East African dairy cattle are a potential concern because of use of a limited range of imported germplasm coupled with strong selection, especially by disease, and sparse performance recording. To address this, genetic relationships and breed composition in an admixed population of Kenyan dairy cattle were estimated by means of a 50K SNP scan. Genomic DNA from 3 worldwide Holstein and 20 Kenyan bulls, 71 putative cow-calf pairs, 25 cows from a large ranch and 5 other Kenyan animals were genotyped for 37 238 informative SNPs. Sires were predicted and 89% of putative dam-calf relationships were supported by genotype data. Animals were clustered with the HapMap population using Structure software to assess breed composition. Cows from a large ranch primarily clustered with Holsteins, while animals from smaller farms were generally crosses between Holstein and Guernsey. Coefficients of relatedness were estimated and showed evidence of heavy use of one AI bull. We conclude that little native germplasm exists within the genotyped populations and mostly European ancestry remains.

Economic evaluation of breeding strategies for improvement of dairy cattle in Kenya

Cost-benefit analysis using net present value (NPV) as the economic evaluation criterion was used to investigate the economic merits of four breeding strategies used for genetic improvement of dairy cattle in Kenya. The breeding strategies were evaluated over a 25-year period. The costs involved in setting up and running each strategy were obtained from large-scale dairy cattle farms, and government and private institutions involved in genetic improvement of dairy cattle. Only benefits from genetic improvement were considered. The impact on NPV due to changes in genetic and economic parameters was investigated. The ranking of the breeding strategies greatly differed with genetic ranking. Among the local selection programs, a strategy utilizing young bulls, sons of local bulls, was more profitable than one utilizing old progeny tested bulls. Continuous semen importation was not an economically viable alternative. The strategy utilizing young bulls progeny of imported bulls (PIB) was only viable if imports were from countries which are >2.00 SD in genetic merit above the local dairy cattle population. The ranking of strategies was not sensitive to changes in genetic parameters but to economic parameters. The use of local semen from young bulls progeny of local proven bulls is recommended. Alternatively, PIB can be utilized but the semen will have to be imported from countries which are >2.00 SD above the local dairy cattle population or the cost of imported semen should be < or = US$40 per straw.

Genetic evaluation of breeding strategies for improvement of dairy cattle in Kenya

A deterministic approach was used to compare breeding strategies utilizing local and imported semen for improvement of dairy cattle in Kenya. The local selection programs considered were a closed progeny testing scheme (CPT) and a young bull system progeny of local bulls (PLB). The continuous semen importation (CSI) and young bull system progeny of imported bulls (PIB) were the strategies based on imports. The breeding strategies were compared on the basis of selection response. The effect of genetic correlation (r(g)) and initial differences in genetic merit between the two populations was also examined. The CSI and PIB strategies ranked above CPT by, correspondingly, 35.1% and 25.0% when the r(g) between Kenya and the USA was assumed to be one. At a r(g) of 0.58, imports from countries which are 1.50 standard deviation (SD) above the local population were superior to CPT but equal to PLB. This means that if CSI is to be used at a r(g) of 0.58, then only semen from countries which are >1.50 SD should be imported. At a r(g) of 0.70 and with an initial genetic difference of 1.25 SD, the economic responses in CSI and PLB were equal. This indicates that semen importation is only justified when genotype-environment interaction is >0.70. It is concluded that wholesale importation of semen as a means of achieving sustainable genetic progress in Kenya is a less optimal solution and there is the need for an effective local selection program.

A nested PCR assay exhibits enhanced sensitivity for detection of Theileria parva infections in bovine blood samples from carrier animals

Theileria parva causes East Coast fever, an economically important disease of cattle in sub-Saharan Africa. We describe a nested polymerase chain reaction (nPCR) assay for the detection of T. parva DNA in cattle blood spotted onto filter paper using primers derived from the T. parva-specific 104-kDa antigen (p104) gene. The sensitivity of this assay was compared to a previously described p104-based PCR and also the reverse line blot (RLB) technique, using serial dilutions of blood from a calf with known T. parva piroplasm parasitaemia. The relative sensitivities of the three assays were 0.4, 1.4 and 4 parasites/microl corresponding to blood parasitaemias of 9.2 x 10(-6)%, 2.8 x 10(-5)% and 8.3 x 10(-5)%, respectively. The three assays were applied to samples from two calves infected with the T. parva Muguga stock. Parasite DNA was consistently detectable by the two p104 PCR assays until 48 and 82 days post-infection, respectively, and thereafter sporadically. RLB detected parasite DNA in the two infected calves until days 43 and 45. Field samples from 151 Kenyan cattle exhibited 37.7% positivity for T. parva by regular p104 PCR and 42.3% positivity using p104 nPCR. Among 169 cattle blood samples from Southern Sudan, 36% were positive for T. parva using nPCR. The nPCR assay represents a highly sensitive tool for detection and monitoring of asymptomatic carrier state infections of T. parva in the blood of cattle.

White Wolves Can Stand the Heat

T. M. Anderson et al. report that wolves of the northwestern forest in North America are dark in comparison to the wolves of the tundra (“Molecular and evolutionary history of melanism in North American gray wolves,” Reports, 6 March, p. [1339][1]). Anderson et al. suggest in passing that the dark coats might better hide preying wolves in the forest. An alternative adaptive explanation is that in the summer, a black tundra wolf could overheat. A study by Finch and Western provides evidence of the temperature-related consequences of coat color among pastoralists' cattle in Kenya ([ 1 ][2]). Finch and Western showed experimentally that black Boran Zebu cattle in the sun became hotter than did white cattle and that across Kenya, as heat stress increased, the proportion of dark cattle in herds decreased. They also found that herders report more dark than light cattle dying during droughts at low altitude. Finch and Western related the variation in color to the social system of the Kenyan herders. Some of them divide themselves into clans according to the preferred color of their cattle, and the preference correlates adaptively with the usual heat stress of the clans' home ranges. 1. [↵][3] 1. V. A. Finch, 2. D. Western , Ecology 58, 1384 (1977). [OpenUrl][4][CrossRef][5][Web of Science][6] [1]: /lookup/doi/10.1126/science.1165448 [2]: #ref-1 [3]: #xref-ref-1-1 View reference 1 in text [4]: {openurl}?query=rft_id%253Dinfo%253Adoi%252F10.2307%252F1935090%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [5]: /lookup/external-ref?access_num=10.2307/1935090&link_type=DOI [6]: /lookup/external-ref?access_num=A1977ES71000015&link_type=ISI

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

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

Direct and maternal (co)variance components and genetic parameters for growth and reproductive traits in the Boran cattle in Kenya

Direct and maternal (co)variance components and genetic parameters were estimated for growth and reproductive traits in the Kenya Boran cattle fitting univariate animal models. Data consisted of records on 4502 animals from 81 sires and 1010 dams collected between 1989 and 2004. The average number of progeny per sire was 56. Direct heritability estimates for growth traits were 0.34, 0.12, 0.19, 0.08 and 0.14 for birth weight (BW), weaning weight (WW), 12-month weight (12W), 18-month weight (18W) and 24-month weight (24W), respectively. Maternal heritability increased from 0.14 at weaning to 0.34 at 12 months of age but reduced to 0.11 at 24 months of age. The maternal permanent environmental effect contributed 16%, 4% and 10% of the total phenotypic variance for WW, 12W and 18W, respectively. Direct-maternal genetic correlations were negative ranging from -0.14 to -0.58. The heritability estimates for reproductive traits were 0.04, 0.00, 0.15, 0.00 and 0.00 for age at first calving (AFC), calving interval in the first, second, and third parity, and pooled calving interval. Selection for growth traits should be practiced with caution since this may lead to a reduction in reproduction efficiency, and direct selection for reproductive traits may be hampered by their low heritability.

First report of Cryptosporidium deer-like genotype in Kenyan cattle

The objective of the study was to identify Cryptosporidium genotypes from feces collected from urban and peri-urban dairy cattle in Nairobi, Kenya, in order to determine their zoonotic potential. DNA was extracted from 34 samples that were diagnosed positive by the modified Ziehl–Neelsen technique. Two Cryptosporidium isolates examined at the 18S rRNA locus were identified as the deer-like genotype by DNA sequencing. As public health officials are facing the difficult decision whether to allow urban livestock production because of its economic benefits and a livelihood asset to the urban communities, or to ban it for its public health risks, the finding of non-zoonotic genotypes in a smallholder dairy system has significant public health as well as economic implications that merit further investigation.