The Function of the Mammal Extrinsic Tongue Musculature in the Transition from Suckling to Drinking.

The transition from suckling to drinking is a developmental pathway that all mammals take. In both behaviors, the tongue is the primary structure involved in acquiring, transporting, and swallowing the liquid. However, the two processes are fundamentally different: during suckling, the tongue must function as a pump to generate suction to move milk, whereas during drinking, the tongue moves backwards and forwards through the mouth to acquire and move water. Despite these fundamental differences, we have little understanding of how tongues role varies between these behaviors. We used an infant pig model to investigate the relationships between anatomy, physiology, and function of the tongue to examine how lingual function is modulated in the transition from infancy to adulthood. We found that while some muscles were proportionally largest at birth, others were proportionally larger at the time of weaning. Furthermore, we found variation in tongue movements between suckling and drinking along both the mediolateral and anteroposterior axes, resulting in differences in tongue deformation between the two behaviors. The extrinsic tongue muscles also changed in function differently between drinking and suckling. Genioglossus increased its activity and turned on and off earlier in the cycle during drinking, whereas hyoglossus fired at lower amplitudes during drinking, and turned on and off later in the cycle. Together, the data highlight the significant need for high neuroplasticity in the control of the tongue at a young age in mammals and suggest that the ability to do so is key in the ontogeny and evolution of feeding in these animals.

Prevalence of bovine and avian tuberculosis in camel herds and associated public health risk factors in Isiolo County, Kenya.

A cross-sectional study was conducted among 308 lactating camels selected from 15 herds from three different camel milk clusters in Isiolo County, Kenya, to determine prevalence of bovine and avian tuberculosis using Single Comparative Intradermal Tuberculin Skin test. Seventy-five (75) questionnaires were administered to pastoralists/herders, and focus group discussions were conducted among 3-5 pastoralists/herders selected from each camel herd to collect information on camel husbandry and health management practices and knowledge on tuberculosis in livestock and wildlife. An overall prevalence of bovine and avian reactors was 3.57 and 18.18%, respectively, with bovine and avian reactors for different clusters being 2.38, 3.82, and 4.48% and 25, 17.2, and 11.94%, respectively. There was significant difference (p < 0.05) in prevalence of bovine and avian reactors between different clusters. There was a negative correction (r = -0.1399) between herd size and bovine reactors, while there was a positive correlation (r = 0.0445) between herd size and avian reactors. The respondents indicated that camel herds are exposed to several risk factors like close contact with other herds or livestock or wildlife during grazing and at watering points. Pastoralists have poor knowledge on mode of infection and transmission of bovine or avian tuberculosis. The high prevalence of bovine and avian reactors and pastoralists' poor knowledge on mode of transmission signify potential risk to public health.