Drone Laying Honey Bee Workers in Queen Monitoring Cages

Techniques to monitor honey bee (Apis mellifera) egg production in cages allow researchers to study how different environmental factors contribute to reproduction. However, although the conditions required to facilitate queen egg production in a laboratory setting have been established, limited work has addressed the requirements for stimulating and monitoring worker egg laying. Here, we documented that drone laying workers will lay eggs in Queen Monitoring Cages (QMC), specialized cages designed to facilitate queen egg laying under controlled conditions. Egg production and worker mortality were compared between QMCs containing queens and those containing drone laying workers. High-definition images of the last abdominal segments of living first-instar larvae hatched from worker laid eggs and those putatively laid by queens were qualitatively compared to identify candidate characteristics to determine their sex.     

In this issue – June 2011

Computer model predictions and field observations of anthelmintic resistance in sheep · Dangers of off‐label use of barium selenate · Elbow luxation in dogs and cats · Prognosis of joint infections in adult horses · Omentalisation for mediastinal abscess in a dog · Adenoviruses in lizards     

Impact of foot-and-mouth disease on mastitis and culling on a large-scale dairy farm in Kenya

Foot and mouth disease (FMD) is a highly transmissible viral infection of cloven hooved animals associated with severe economic losses when introduced into FMD-free countries. Information on the impact of the disease in FMDV-endemic countries is poorly characterised yet essential for the prioritisation of scarce resources for disease control programmes. A FMD (virus serotype SAT2) outbreak on a large-scale dairy farm in Nakuru County, Kenya provided an opportunity to evaluate the impact of FMD on clinical mastitis and culling rate. A cohort approach followed animals over a 12-month period after the commencement of the outbreak. For culling, all animals were included; for mastitis, those over 18 months of age. FMD was recorded in 400/644 cattle over a 29-day period. During the follow-up period 76 animals were culled or died whilst in the over 18 month old cohort 63 developed clinical mastitis. Hazard ratios (HR) were generated using Cox regression accounting for non-proportional hazards by inclusion of time-varying effects. Univariable analysis showed FMD cases were culled sooner but there was no effect on clinical mastitis. After adjusting for possible confounders and inclusion of time-varying effects there was weak evidence to support an effect of FMD on culling (HR = 1.7, 95% confidence intervals [CI] 0.88-3.1, P = 0.12). For mastitis, there was stronger evidence of an increased rate in the first month after the onset of the outbreak (HR = 2.9, 95%CI 0.97-8.9, P = 0.057).

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0173-4) contains supplementary material, which is available to authorized users.     

Comparison of invasive and oscillometric blood pressure measurement techniques in anesthetized sheep,goats, and cattle

ObjectiveTo determine the level of agreement between an oscillometric (O-NIBP) and an invasive method (IBP) of monitoring arterial blood pressure (ABP) in anesthetized sheep, goats, and cattle.Study designProspective clinical study.AnimalsTwenty sheep and goats, 20 cattle weighing <150 kg body weight, and 20 cattle weighing >150 kg body weight.MethodsAnimals were anesthetized and systolic ABP (SABP), mean ABP (MABP), and diastolic ABP (DABP) were measured using IBP and O-NIBP. Differences between IBP and O-NIBP, and 95% limits of agreement (LOA) between SABP, MABP, and DABP values were assessed by the Bland–Altman method.ResultsMean difference ± standard deviation (range) between SABP, DABP, and MABP measurements in sheep and goats was 0 ± 16 (-57 to 38) mmHg, 13 ± 16 (-37 to 70) mmHg, and 8 ± 13 (-34 to 54) mmHg, respectively. Mean difference between SABP, DABP, and MABP measurements in small cattle was 0 ± 19 (-37 to 37) mmHg, 6 ± 18 (-77 to 48) mmHg, and 4 ± 16 (-73 to 48) mmHg, respectively. Mean difference between SABP, DABP, and MABP measurements in large cattle was -18 ± 32 (-107 to 71) mmHg, 7 ± 29 (-112 to 63) mmHg, and -5 ± 28 (-110 to 60) mmHg, respectively. The 95% LOAs for SABP, DABP, and MABP were -31 to +31, -19 to +44, and -19 to +34 mmHg, respectively in sheep and goats; were -37 to +37, -19 to +44, and -19 to +34 mmHg, respectively in small cattle; and were -81 to +45, -50 to +63, and -59 to +50 mmHg, respectively in large cattle.ConclusionsAgreement was poor between O-NIBP and IBP monitoring techniques.Clinical relevanceArterial BP should be monitored in anesthetized sheep, goats, and cattle using IBP.