Review/Oorsig Volume 22, Issue 01 - Page 15

Volume 22 • Issue 01 • 2018 pregnancy at 1 year than ewe lambs which grew at 230g/day. Weaning is also the time when new oocysts are selected by the ewes for the next breeding cycle in a once a year breeding system. Thus it is important to ensure that they are in a good body condition(need flock average of > 2.7) at this time. If they are not, nutrition must be adapted to increase their body condition to adequate levels before the next breeding season. At three weeks pre-breeding, ewes must be evaluated again. If they are in a body condition score of 3.5 or more no special nutrition is needed. Giving more food at this level will have no influence on breeding rates. At an average score of 3 a short 7 day period just before breeding (when teasers are in) of a high protein supplement at 120g/ ewe/day can be used to increase ovulation rates. If the average score is below 3, then 2 to 3 weeks of high energy and protein supplements at raising levels up to 200g/ewe/day can be used to increase ovulation rates. During breeding and until about 20 days after breeding NO changes must take place as any increase or decrease in nutrition will lead to higher levels of liver enzymes which will lead to lower levels of progesterone and thus less viable foetuses. Foetal programming starts as early as 15-20 days of foetal age thus correct nutrition is very important. During early pregnancy under/over nutrition can also impair placental development which will have a serious impact on foetal development During mid-pregnancy adequate nutritio is needed as ewes must not lose weight but overnutrition can lead to many problems in late pregnancies as well as negative foetal programming. Body condition must not be over 3.5. Late pregnancy is an extremely important time because of foetal programming, the large increase in foetus growth, udder development and the SPACE availability. A single foetus, placenta and foetal membranes account for about 8kg. Multiples can be as much 15-18kg. This limits rumen space available as well as rumen function. Thus, high quality feed and supplements as well as adequate time to consume it is necessary. Lush pastures or high moisture feed will lead to undernutrition. However too much feed can lead to overnutrition which can lead to many other problems e.g. pregnancy toxaemia and mastitis. This is especially important whe