Operation changes boost flock's fertility

Operation changes boost flock's fertility


Sheep
GENETIC GAINS: Gary Drew, Northwood, Brocklesby, NSW, has introduced electronic identification tag technology to help monitor ewe reproductive performance in a busy program of joining, shearing and lambing every eight months.

GENETIC GAINS: Gary Drew, Northwood, Brocklesby, NSW, has introduced electronic identification tag technology to help monitor ewe reproductive performance in a busy program of joining, shearing and lambing every eight months.

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Joining, lambing and shearing every eight months is giving Gary and Heather Drew's Merino enterprise in southern NSW a significant boost in flock fertility and productivity.

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Joining, lambing and shearing every eight months is giving Gary and Heather Drew's Merino enterprise in southern NSW a significant boost in flock fertility and productivity.

Mr Drew introduced the intensive management program about six years ago, which includes joining ewe lambs at 11 months of age to lift lambing rates and fast-track his flock's genetic gain.

The family have always run Merino sheep, including a small stud started by Mr Drew's grandfather on their 1500-hectare property, Northwood, at Brocklesby, NSW.

The stud was retired in 2010 and the family now runs a commercial self-replacing flock of 1500 Merino ewes and sow about 1100ha of wheat, canola and pulses each year.

"I did a Bred Well Fed Well workshop and it challenged me, I realised that in our area the seasons can be variable and at different times of the year, my sheep were carrying a lot of condition around and not doing anything with it," Mr Drew said.

"It sounds complicated, but I have basically compressed 12 months of sheep operations into an eight month cycle.

"So I have one joining, one lambing, one shearing and one weaning every eight months and all ewes, including ewe lambs, have to line up in that particular time period.

"My operation gives the ewe the opportunity to express her genetic potential much quicker and if she can do good things for my flock it will be done twice as fast.

"The reproductive potential of a Merino ewe is really exciting, some of them are amazing, to be joined so young and conceive twin lambs every eight months, the challenge is to keep those lambs alive."

The ewes are joined for five weeks to lamb in April, December and the following August, over a two-year period.

All the ewes are shorn and lambs weaned eight weeks after the start of lambing which then gives the ewes two to three weeks recovery before being joined again.

Pregnancy scanning is carried out after each joining and ewes will be separated into single and twin-bearing mobs so the ewes carrying twins can be looked after more carefully.

Depending on the time of year, twin-bearing ewes may be supplementary fed and they will lamb in the most sheltered paddocks and in mob sizes of about 150 ewes.

"We have not seen a decline in conception rates since changing to joining and lambing every eight months," he said.

"In the adult Merino ewes we are averaging 135-140 per cent conception rates and marking more than 100pc of lambs per ewe joined.

"But the reality is my overall lambing percentage per ewe joined is between 80-90pc as I am joining ewe lambs and their conception rates can be more variable."

Mr Drew aims to select rams with above average Australian Sheep Breeding Values for traits strongly correlated with lamb survival, including eye muscle depth, yearling fat depth and weaning weight.

The Drews are long-term clients of the Coddington family's Roseville Park stud, and have also sourced rams from Kerin Poll.

"I have set some targets for ram selection, based on Bred Well Fed Well guidelines, which includes +0.6 for eye muscle depth, +0.3 for yearling fat and +7 for post weaning weight," he said.

"Maintaining fleece quality is also important so the rams need to be +13 for clean fleece weight and structurally sound.

"When we had a Merino stud the focus was on the wool, but my breeding objectives have changed. I would much rather have more live lambs on the ground."

Mr Drew said weaning could be a challenging time as some of the lambs were only five to six weeks old, but this year he introduced a yard weaning program with great success.

"We started them off with controlled feeding in the troughs and within the week the larger lambs were on a full ration of grain, they also had access to hay or straw for roughage and good quality, clean water," he said.

"We were forced into it this year as we had no paddock feed, and although it was a bit labour intensive, the results were amazing with very few losses."

Once the lambs have adjusted to their diet, they are moved onto pasture paddocks with ad-lib self-feeders available.

"It really depends on what stage of the year and what pasture feed is available as to how long we leave them on the feeders when we are weaning," he said.

At six months of age, the lambs are crutched and divided into ewe and wether mobs to be grown out and shorn at 10 months of age.

A staple length of 80 millimetres and a wool cut of more than four kilograms per head is targeted, which Mr Drew said the lambs achieved comfortably.

The adult sheep cut 5kg/head and the overall flock averaged 18 micron.

Ewe lambs were classed with a focus on wool quality, frame size, structure and weight.

Mr Drew targets more than 40kg liveweight at joining.

"I have been weaning the lambs this young for a long time and I think if it was detrimental to their growth, I wouldn't be able to join the ewe lambs at 11 months of age," he said.

Depending on the seasonal conditions and prices, the wether lambs would be sold either over the hooks or through the saleyards in Corowa, NSW, at a carcase weight of about 24kg.

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