As daylight hours reduce and tupping season approaches, producers are being reminded how important nutrition is to help maximise overall performance and productivity of rams, ewes and, subsequently, lambs. Farmers Guardian reports.
Nutrition throughout the production cycle needs to be managed and pieced together like a puzzle, says Bethany May, ruminant nutritionist at Trident Feeds.
Miss May says: “Planning and implementing nutrition throughout the production cycle can seem like a daunting task because there is so much to consider. For this reason, my advice to all producers is to break the process down into ‘puzzle-like’ pieces to make it more manageable.
“For example, consider ram and ewe nutrition separately. Then break it down into pre-tupping, tupping and pregnancy. It is then a case of putting it all together throughout the season and monitoring progress to make necessary adjustments.”
When preparing for the tupping season, the first piece of the puzzle is getting rams in the best condition possible, because this will influence their performance and condition of the next crop of lambs.
Miss May says: “It is all too easy to focus on ewes and neglect rams. However, producers need to remember ewes are only half the picture, and if rams are unfit for the job, scanning percentages will be negatively affected.
“For this reason, it is important to MOT rams and body condition score [BSC] a good few weeks before tupping starts. They need to be in good condition to produce enough viable semen and semen production begins up to six weeks prior to tupping.”
Producers should be aiming for a BCS of about 3.5 at mating and have enough fat to keep them going through tupping, but not too much, as over-fat rams will be lazy and not work at the required rate.
“For this reason, I would advise feeding any rams lower than BCS 3.5, 0.25-0.5kg of supplementary feed per day, six weeks prior to tupping, to get them to the right condition.
“When fed as part of a blend, sugar beet feed is one of the most palatable feeds available and can be used to tempt rams into consuming the required feed intake.”
The table below gives suggested blends for conditioning rams.
It is important to maintain the focus on ram nutrition during tupping, as a ram may lose 15 per cent or more of its body weight.
Miss May says: “During tupping, access to a supplementary concentrate diet may be necessary to avoid too much BCS loss, particularly if grass quality and quantity is lacking, to maintain service rates.
“However, if feeding cereals, it is important to balance out the rapidly available starch to minimise risk of rumen upset at this critical time.
“Feeds high in digestible fibre, such as sugar beet feed, are recommended, because they ferment to provide energy at a much slower rate, buffering against acidosis, making them the ideal partner to high-starch feeds.”
Nutritional management of ewes before and during tupping is crucial to get them in-lamb successfully and encourage higher ovulation rates.
Miss May says: “Flushing ewes, allowing them access to a high quality ration for a period of time before mating, is common practise, because it encourages stronger heat expression, an increased number of eggs to be ovulated and higher conception rates.
“Responsiveness of the ewe to flushing is greatly affected by BCS. Those with a BCS of more than 3.5 will show little benefit, while lower BCS ewes on a rising plane of nutrition will show the greatest response. However, it is important to consider the lower the BCS, the greater the amount of time needed for a successful effect.
“For example, ewes with a BCS of less than 2 will need flushing for six to eight weeks with 0.5kg/head/day of sugar beet feed [two 25kg bags per day for every 100 ewes], compared to a ewe with a BCS of 3-3.5, which will need flushing for two to four weeks with 0.25-0.5kg/head/day of sugar beet feed.”
After tupping, and when a ewe’s eggs are successfully fertilised, they will start to implant at about day 14 and become fully attached to the uterus wall by about day 25.
Miss May says: “It is particularly important the ewe is not stressed at this stage because this can lead to embryo loss. Stress can be caused by a number of factors, including changes to diet, and therefore the feeding regime used during the flushing period should be maintained.”
Moving into mid-pregnancy, Miss May explains during the period of placental development, ewes tupped in good condition can benefit from slight under-nourishment.
She says: “This has been shown to stimulate placental growth and encourage strong lamb development during late pregnancy. For this reason, allowing a drop in BCS of 0.5 a unit, of ewes tupped in good condition, is acceptable during this period. Therefore, nutrient demand can usually be met by good forage alone.
“However, this is different for ewe lambs, because during pregnancy, they may only be about 75 per cent of their mature weight and therefore need to continue to grow.
“If forage is in short supply, of poor quality, or if weather is not ideal for maximum grazing, it may be necessary to provide a supplementary feed as blend to help maintain growth rates of the ewe and foetus.”
Suitable blends for different forage qualities are detailed in the table. Typical feeding levels of such blends range between 0.1-0.5kg per ewe lamb per day.
Lamb survival and mothering ability of the ewe is greatly affected by nutrition during the last third of pregnancy, as about 70 per cent of foetal growth will take place during the final 50 days.
“It is key to remember as lambs continue to grow in the uterus, they take up a greater proportion of body space, reducing the capacity of the ewe’s rumen. As a result, their appetite can decrease by up to 30 per cent.”
Therefore, she notes the importance of increasing the nutrient density of the ration, as the gestation period progresses to keep nutrient supply at equal pace with foetal growth.
“Producers should aim for an energy content of at least 12.5MJ ME/kg DM in supplementary concentrates, plus at least 16-18 per cent crude protein if feeding hay or silage, or 20 per cent for straw-based rations.
“It is important to be aware a diet high in starch can quickly upset the rumen, causing acidosis. This can lead to lower birth weights and poor milk quality, ultimately affecting early lamb growth rates.
“For this reason, if producers are tempted to feed cereals to bolster the energy content of rations, they should ensure they are fed as part of a mixed ration and balanced adequately.
“This can be managed by including a good amount of digestible fibre, which is available from feed sources such as sugar beet feed.”
Miss May adds nutrition during the production cycle does not have to be daunting.
“Just break it down into manageable chunks and decide what works for you. Then put it all back together and remember to keep monitoring BCS.”