Background: The use of artificial insemination (AI) has great potential to improve smallholder dairy herds in Africa, however poor success and, in some situations, high costs in Kenya, have been discouraging. Effective AI requires accurate oestrus detection and the measurement of progesterone (P4) can be used to indicate oestrus as well as non-pregnancy. A cow-side progesterone lateral flow test, P4 Rapid, was evaluated as an aid to detect oestrus and non-pregnancy in Kenyan dairy cows, and assessed for association with AI efficiency. Methods: A total of 527 cows were enrolled in the study, from two counties in central and southern Kenya. Cattle in the test group (n = 308) were presented when suspected to be in oestrus and tested with the P4 Rapid (low P4 = oestrus, medium P4 = inconclusive, high P4 = not in oestrus/pregnant). Cattle with low P4 were inseminated. Cattle in the control group (n = 219) were inseminated when oestrus behaviour was detected i.e. standard practice. Results: Of the total P4 Rapid tests performed (n = 745), 1.5% were inconclusive, with the true accuracy of the test between 87-97%. Conception rates were not significantly higher in the test group (83.9%) compared to the control group (77.9%). Abortion rates were not significantly different between the control (9.5%) and test groups (8.2%). In the test group, 6.2% (19/308) cows showed a medium or high P4 level on day 0 and nine of these were subsequently found to have been already pregnant. Conclusions: The data indicated that the P4 Rapid test can be a useful tool to assist farmer decision-making in the confirmation of correct timing for AI, and importantly may avoid unnecessary inseminations in pregnant animals, thus reducing the risk of AI-induced abortion.

doi: 10.1093/af/vfaa002 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. © Mrode, Ekine Dzivenu, Marshall, Chagunda, Muasa, Ojango, and Okeyo Feature Article Phenomics and its potential impact on livestock development in low-income countries: innovative applications of emerging related digital technology

In vitro embryo production (IVEP) has been used to improve of cattle genotypes in many parts of the world. However IVEP is not without some challenges. Oocyte developmental competence is a key area affecting IVEP and it is associated with the glucose 6 phosphate dehydrogenase (G6PDH) activity and follicle size. Ovarian follicular dynamics differ between B. indicus and B. taurus, which may influence oocyte competence. This study sought to evaluate the effect of follicle size on G6PDH activity and oocyte developmental competence in the Boran (African Zebu breed) cattle using brilliant cresyl blue (BCB) staining. Oocytes were collected from Boran cows at slaughter, their follicles were measured and classified into 3 groups; 1-3mm, >3-6mm and >6mm in diameter. Cumulus oocytes complexes (COC) were exposed to BCB stain for 1 hour and observed for cytoplasmic coloration. Those that retained the blue coloration (BCB positive) were deemed competent (low activity of G6PDH) while those that did not have any cytoplasmic coloration (BCB negative) were deemed incompetent (high activity of G6PDH). Higher proportion (P<0.01) of BCB positive oocytes was found in >6mm follicles (81.1%) than in 1-3mm (73.1%) and >3-6 mm (76.5%) follicles. BCB positive oocytes from 1-3 mm follicles had higher (P<0.05) blastocyst rate (18.94%) than BCB negative oocytes (9.7%), however no significant difference was found in their cleavage rates (P > 0.05). No difference in cleavage and blastocyst rates was found between BCB positive and negative oocytes from follicles with >3-6 mm in diameter. The cleavage and blastocysts rates with BCB positive oocytes increased as follicle diameter increased. In conclusion, in Boran cows as follicle size increases the activity of G6PDH decreases in the whereas COC developmental competence increases and follicles as small as 1-3 mm in diameter are able of producing developmentaly competent oocytes.