A SERIES of nutritional-management workshops across Queensland's south-west recently have given dozens of Merino producers some new tools to help boost future production, despite the current challenging seasonal conditions.
Run by Leading Sheep in conjunction with Making More from Sheep, the workshops at Longreach, Cunnamulla, Bollon and St George were attended by about 85 sheep producers.
The workshops featured detailed presentations from former Queenslander and now WA-based scientist and nutrition consultant, Dr John Milton.
An associate professor at the Institute of Agriculture at the University of WA, Dr Milton said his presentation was tailored to give Merino producers another option to help them "match the feed with the need".
"Given the seasonal conditions facing producers across western Queensland this year, matching the feed to the need has never been more important," he said.
"The most important thing for producers to remember is that ewe condition score is critical. Ewes need to be in condition score three for optimum reproduction and, using the Ram Effect, we can introduce some targeted feeding strategies to boost fertility, fecundity and colostrum production."
The ram effect
Many Queensland sheep producers have traditionally joined Merino ewes for a spring lambing. But given spring is often one of the driest periods of the year, Dr Milton suggests a March to May lambing may help improve survival and growth of lambs.
"We want producers to appreciate there is another joining option that may help boost future production by avoiding lambing in spring," he said.
A March to May lambing would mean joining from October to December, but Dr Milton said ewe fertility and fecundity (FF) are lower during this period, as it is outside the natural Merino breeding season from February to June.
However, Dr Milton said a short-term feeding strategy in concert with the Ram Effect could improve FF during this period.
"A great thing about the Merino ewe is that she can mate outside the breeding season using the Ram Effect to synchronise oestrus," he said.
"This programs Merino ewes from mating to lambing so feeding can be targeted to when the ewe requires it most for optimum reproduction.
"That means producers are in control and can plan better if the season turns bad."
The Ram Effect involves introducing 'teasers' (usually wethers treated with testosterone) on day 0 of the joining program.
Dr Milton said the teasers induce the ewes to ovulate so that after the rams go in on day 15, they will mate with the ewes that ovulate again from days 18 to 26.
Dr Milton suggests the rams be joined at 3pc and removed with the teasers on day 44 after a 30-day joining that has covered two cycles. Feeding lupins or pulses (without acidosis) from days 11 to 22 provides a surge in nutrition during the critical period to lift FF.
Feeding strategies
Using the Ram Effect not only enables producers to target feeding to boost FF, but also enhances colostrum production, according to Dr Milton.
"To rear more lambs, we need to reduce the loss of twins around birth," he said.
"Colostrum plays a critical role in this. Ewes must have runny colostrum so lambs can suck within the first hour after birth. Some twin-bearing and maiden ewes have no colostrum or only pasty colostrum for up to six hours after lambing.
"But the good news is that a large increase in nutrient intake in the last week of pregnancy reduces the level of progesterone in the blood and this facilitates the onset of colostrum production.
"If extra glucose is available for colostrum synthesis just before lambing, the ewe will accumulate a lot of runny colostrum in the udder at lambing.
"A special feed in the week before lambing so that ewes have a lot of starch or protein passing out of the rumen helps achieve this."
Dr Milton said their research had shown that corn or barley fed as extra feed in the last week of pregnancy or grazing a pasture legume that has tannins increases the amount of runny colostrum available at birth, lamb birth weight and survival.
"The ewe-lamb bond is strengthened by the ewe suckling her lambs soon after birth, which should ultimately mean more twins are reared."
Peri-partum relaxed immunity (PPRI)
Dr Milton said hormonal changes and the ewe's big demand for energy around lambing resulted in ewes with low immunity to worms. However, he said it is possible to implement a feeding strategy to help avoid PPRI.
"Ewes with twins and maiden ewes grazing short, green pick are the most susceptible," he said.
"So, we lift the intake of metabolisable protein and ME to ensure their immune system is not compromised, and this also coincides with the need to feed extra to lift colostrum production of twin-bearing and maiden ewes. Lick feeders, when used appropriately, are a valuable tool to supplement ewes to lift colostrum output and immunity to worms."
Maiden ewes
Dr Milton suggests maiden Merino ewes joined as hoggets be 70pc of mature weight, score 3 at joining and, as for all ewes, not lose weight during joining.
"Lambs from maidens should have the best genetics so it's important to maximise the number of lambs they rear," he said.
"Some strategies to improve their lambing rate include joining and lambing them separate from mature ewes as some maidens won't seek out rams and mature ewes often hog the rams. Maidens that are scanned pregnant need adequate feed for foetal and their own body growth but, to avoid problems at lambing, they should not be overfed."
Pregnancy scanning
Dr Milton considers pregnancy scanning an essential tool for optimum ewe management, especially when feed resources are limited during dry years. He said producers should scan ewes for zero, one and two foetuses and manage them separately so that the feed offered is adequate to meet their requirements.
"It is important that ewes scanned with twins have a good udder and two functional teats," he said.
