Agri Kultuur January / January 2018 - Page 32

of inseminators. When comparing herd performance, the number of natural services should also be considered as that would reduce (or improve) the average SPC figure. To determine heat detection efficiency, two indicators can be used, i.e. the number of days from CFS and the average number of days between heats (breeding interval). The proportion of CFS intervals within 80 days after calving also gives an indication of heat detection. Breeding interval (BI) is estimated by subtracting the CFS interval from the interval between calving date and conception date (DO) and dividing that by the number of SPC minus one, i.e. (DO-CFS)/(SPC-1). Dividing 21 by BI gives the heat detection efficiency, i.e. for a BI of 42 days, heat detection is 50% which means that only every second heat was observed. The most accurate way is to estimate the average number of days between heats by using service dates for each cow. To evaluate the performance of heat spotters and inseminators, records of all cows in the herd should be used. Results should be presented on an ongoing basis in graphs showing the trend for each worker over time. In closing Establishing the standard of reproduction management of dairy farmers is a first step towards improving fertility in dairy cows. Poor reproduction management may induce infertility in otherwise fertile cows. Ways to improve fertility in dairy herds depends on (i) a short term plan such as providing a clean, dry and sunny calving down area, monitoring cows post calving for early detection of uterine infections, checking heat cycling performance of cows within the first 80 days after calving; (ii) a medium term plan such as having an action plan for cows more than 150 days in milk not confirmed pregnant, having a heat detection programme in place, ongoing checking of AI techniques (or performance) of inseminators, checking semen quality and (iii) a long term plan by using sires for AI with breeding information such as daughter pregnancy rates and productive life estimated breeding values. Onoortreflike gehalte en professionele diens - in Suid-Afrika geteel vir Suid-Afrikaanse vlieë Hoe werk hierdie program? Vliegparasiete ( Muscidifurax raptor) word in ‘n insektarium geteel en is beskikbaar in pakkies van 5 000. Hierdie parasitiese wespes word gereeld by vliegbroeiplekke op die plaas losgelaat. Die volwasse wesp steek die papie van die vlieg, dood dit in die proses en lê eiers in die papie. Die eiers teer op die dooie vliegpapie en ontwikkel in ‘n wespe. Die wespe broei binne 19-21 dae uit en begin dan die soektoeg na vliegpapies as voedsel en waarin hulle kan eiers lê. www.bioinsectsa.com AgriKultuur |AgriCulture BISA bied u: Vliegbeheer op die natuurlike manier. Langtermyn ekonomiese voordele. Minder chemiese besoedeling. ‘n Bemarkingsvoordeel deur omgewings- vriendelike landbouproduksie. SLIM BEHEER VAN VLIEË BISA het agente landswyd. Vir meer inligting, nader: Besturende direkteur Arno Moore (PhD) Sel 083 270 4866 | Epos arno@bioinsectsa.com Kantoor Helouise Rumbles Sel 083 5664784 | E-pos bisa@bioinsectsa.com 32