Pregnancy detection and monitoring in cattle via combined foetus electrocardiogram and phonocardiogram signal processing.

BACKGROUND: Pregnancy testing in cattle is commonly invasive requiring manual rectal palpation of the reproductive tract that presents risks to the operator and pregnancy. Alternative non-invasive tests have been developed but have not gained popularity due to poor specificity, sensitivity and the inconvenience of sample handling. Our aim is to present the pilot study and proof of concept of a new non invasive technique to sense the presence and age (limited to the closest trimester of pregnancy) of the foetus by recording the electrical and audio signals produced by the foetus heartbeat using an array of specialized sensors embedded in a stand alone handheld prototype device. The device was applied to the right flank (approximately at the intercept of a horizontal line drawn through the right mid femur region of the cow and a vertical line drawn anywhere between lumbar vertebrae 3 to 5) of more than 2000 cattle from 13 different farms, including pregnant and not pregnant, a diversity of breeds, and both dairy and beef herds. Pregnancy status response is given "on the spot" from an optimized machine learning algorithm running on the device within seconds after data collection. RESULTS: Using combined electrical and audio foetal signals we detected pregnancy with a sensitivity of 87.6% and a specificity of 74.6% for all recorded data. Those values increase to 91% and 81% respectively by removing files with excessive noise (19%).Foetus ageing was achieved by comparing the detected foetus heart-rate with published tables. However, given the challenging farm environment of a restless cow, correct foetus ageing was achieved for only 21% of the correctly diagnosed pregnant cows. CONCLUSIONS: In conclusion we have found that combining ECG and PCG measurements on the right flank of cattle provides a reliable and rapid method of pregnancy testing. The device has potential to be applied by unskilled operators. This will generate more efficient and productive management of farms. There is potential for the device to be applied to large endangered quadrupeds in captive breeding programs where early, safe and reliable pregnancy diagnosis can be imperative but currently difficult to achieve.

A systematic review and meta-analysis of impact of strongyle parasitism on growth rates in young cattle.

BACKGROUND: To identify any universal impact of strongyle parasite burden on the growth rate of young cattle. METHODS: A meta-analysis and meta-regression of the relationship between differences in strongyle parasite burden between cohorts and average daily weight gain was conducted. Publications were identified from a search of databases applying PRISMA 2020 principles. Eligible studies had at least two groups of growing cattle on the same farm that were identical in composition, management and diet except for parasite exposure and were subject to body weight gain or average daily gain and faecal egg count measurements across the common growing period. The reference group had the lowest growth-period faecal egg count. A meta-regression estimated the impact of strongyle parasitism. The dependent variable was the log of the ratio of average daily gain between comparison groups and the reference group with the predictor variable as the common logarithm of the difference in average faecal egg count (plus 1) between the comparison and the reference groups. RESULTS: 26 publications containing 85 groups and 59 comparison ratios were analysed. Papers included representatives from dairy and beef industries and from pasture and feedlot production systems and from all cattle-producing continents. The comparison group average daily growth rate was 0.89 (95%CI 0.81-0.97) that of the reference group. Meta-regression identified a 0.131 linear reduction in average daily weight gain ratio for every log10 increase in the difference between comparison and reference group faecal egg count. Direction of effect was consistent across all subset analyses (continent, class of stock and production system). Whilst small faecal egg count differences between the comparison and reference groups often provided similar rates of daily weight gain, the trend was negative with most comparison groups having lower daily weight gains than their reference group. CONCLUSIONS: Strongyle parasitism of growing cattle as measured by faecal egg count is associated with reduced growth across all production systems, geographies and classes of cattle.