Review/Oorsig Volume 23, Issue 02 - Page 17

" using intensive management systems like synchronisation, artificial insemination and by applying intensive lambing systems, farmers have unfortunately still not managed to constantly get weaning percentages above 300% in which dairy farmers farm with their cows – mating again 73 days post lambing falls in the middle of the “window of opportunity” in which cows and ewes conceive best. Think of a dairy cow – if you don’t get them pregnant by day 100 post calving, you will have difficulty in getting them pregnant at all! Dairy cows can be kept on zero-grazing systems or be managed on pastures and are fed or supplemented in order to achieve optimal production. Intensifying sheep production means producing more lambs, better lambs, more economically and faster. In 4 words it comes down to – Quality, Quantity, Efficiency and Efficacy. The last one includes speed of production or faster. Think of broiler production here – when I qualified in 1980, broilers were slaughtered at 7 weeks (49 days). This has come down to 31 days nowadays. During the same time period sheep farmers say that they have intensified, using intensive management systems like synchronisation, artificial insemination and by applying intensive lambing systems, but have unfortunately still not managed to constantly get weaning percentages above 300% (let alone 400 and 500% which are possible) and/or managed to decrease the country’s inter-lambing period or the average “days to slaughter”… In and around 1988 I had my first client on the STAR system. In retrospect, we obviously “miss-understood” many of the concepts which Magee and Hogue implemented and after a few unsuccessful attempts at early weaning, Mr Lourens van Eeden from Swellendam started mating his ewes with lambs at foot. In the same way beef producers were doing with their cows. Despite lower conception rates, as well as a lower fecundity Volume 23 • Issue 02 • 2019 rate, he still managed to wean well above what most other farmers were achieving. This made me realize that there was something “different and positive” in the “system”. I initially thought that it was just the “value of time” - speeding up production with shorter inter-lambing periods, but now know that there was more to it than “just that”. In September 1991, I was asked to do a presentation at the Rural Practioners Group- congress (RPG / later on the “Livestock Health and Production Group” and now RuVaSA) at Mount Aux Sources in Natal, on Intensive Sheep Production Systems. On revisiting the proceedings, I found it interesting to note that most of what I said then still holds true today! A few those need to be highlighted again: 1. The Accumulative effect where 3 short mating periods of for example 21 days each, give better results than one long mating season with the same amount of days, namely 63. Three opportunities to conceive in the STAR system at 73, 146 and 219 days after lambing bring us up to one year in total or the equivalent of “once a year mating systems”.. So if a ewe only conceives by 219 days post lambing, she achieves what het counterpart does who was given one chance only. If we have 1000 ewes of which: • • • • • 60% conceive at 73 days (600 ewes), and If the 400 ewes that did not conceive (skips) does so at 60% after 146 days, that gives us another 240 pregnant, rendering 84% pregnancy, conceiving “faster than the accepted normal”. 60% conception on the remaining 160 ewes gives another 96 and a yearly conception of 93.6% after 3 low conceptions of 60% each. This is what I describe as the “Accumulative effect” Three conceptions of 70% each leads to a yearly conception rate of 97.3% in the STAR system We must therefore realize that when analysing multiple systems in the “normal way”, we can make serious “mistakes”. This is much like the difference between simple and compound interest! 2. The second “fact” is that the first documentation of the STAR system was by Brian Magee in 1983. Why, if we know/ knew that they achieved remarkable lambing 17