Maternal Genetics at The Willows
Alongside our terminal flock, we also run a maternal stud flock which was established in 2004. Even though fertility is only 5% heritable, the traditional system of joining a Border Leicester over a Merino had to be challenged if we wanted to make any gain on the current 1st X ewe fertility range.
We realized we had to take control of selecting for fertility and design a ewe that can wean 140% lambs not 120%. In reality, hybrid vigor was assisting the relatively low fertility of the merino, which is 50% of the 1st X ewe's genetic makeup.
The demand for quality rams for use in self replacing enterprises is growing at a fast rate and we are increasing our maternal flock yearly to meet this demand. Our maternal sheep are a composite, comprising mainly White Suffolk and composite genetics, aiming to produce an animal with superior maternal performance. Our focus within the maternal flock is on mothering ability, high WR (Weaning Rate - fertility), higher PFAT ASBV (genetic fat), fast early growth, moderate adult weight and correct conformation. These all combine to create an animal that is fertile from a young age, resilient and feed efficient, with excellent mothering ability and milking ability. These traits combine to result in more kg of lamb weaned per ewe joined as well as per hectare, and greater feed efficiency within the ewe base which enables higher stocking rates. This all translates to more profit per hectare for the producer.
The recording and measuring of these traits begins at birth and continues on throughout the life of the ewe. We weigh lambs at birth and then weaning time, and then weigh, muscle and fat scan them all at post weaning. We also continue to weigh them at joining to feed their adult weight data back into the Lambplan data base. This data is sent off to Sheep Genetics and used to calculate the growth, muscle and fat ASBV's. In the maternal flock, we are aiming for high early growth which tapers off to a moderate adult weight - This means the ewes will be smaller and more feed efficient but still have good genetic growth potential to pass on to their lambs, and also means the ewes reach a mature weight earlier which allows them to get in lamb at a younger age. For a maternal sheep we are also looking for a genetically fatter animal - Studies show genetic fat is a reliable indicator of resilience in the ewe and results in a higher survival rate and weaning percentage of her lambs. Higher genetic fat has also been strongly linked to IMF (Intramuscular Fat) and higher eating quality. All of our stud ewe lambs are joined at 7-8 months of age and then pregnancy scanned and this fertility data is also sent to Sheep Genetics. At lambing time, we catch every lamb at birth and weigh/tag them. This is also a valuable opportunity to collect data on the ewes mothering ability - We record a flight score on the ewe and the fate of her lambs. This means we can cull any ewes that leave their lambs, lose their lambs, any with milking or udder issues, or those that are excessively flighty or non-maternal.
We use our own maternal rams within our self replacing commercial flock to replenish ewe numbers as we cull our older ewes. We consistently mark 140% lambs to ewes joined - which is an important point - in regards to performance you should always compare lambs marked to ewes joined, not to ewes scanned in lamb or ewes present at lamb marking. It is the only way to get a complete and accurate picture of your flocks performance. This is without checking the mob at lambing - We are busy enough with the stud mobs so we put the commercial ewes out in hill paddocks and leave them to their own devices. We generally do not need to check our ewes except after a wet weather event when ewes getting cast can be a problem. We have little to no Dystocia. We retain the ewe lambs and they are joined at 7-8 months and then join the commercial mixed age mobs as second lambing hoggets the following year.
We purchase an elite maternal ram from Cashmore-Oaklea Maternal or other leading studs every few years to introduce new blood and keep driving the genetic gain within the maternal flock. We are currently expanding our maternal flock to meet the rising demand, and in 2022 we will be starting an AI program within the maternal flock for the first time.
