Starling proofing could be well worth the investment on some farms, following new research which equated the negative effect of the birds on ration composition to about £40,000 per winter.
The Nottingham University dissertation, carried out by Kerensa Hawkey, under the guidance of dairy scientist Professor Phil Garnsworthy, monitored the effects of the birds on 10 farms in Cornwall and north Devon. The farms were all Mole Valley Farmers customers, with all silage testing carried out through the farmer-owned business.
Results showed the starlings were not only eating a high proportion of the diet, but also significantly altering the ration make-up, which reduced dry matter concentration and energy and protein levels (see panel).
Mole Valley Farmers nutritionist Dr Robin Hawkey says the trial results have huge implications on ration formulation.
“Usually we say there are four rations; what is formulated, what is mixed, what is fed out and what the cows eat, but maybe we need to reassess and think of the five rations. We could say there is two sets of sorting; the cows and the starlings,” he says.
The removal of the ‘goodies’ in the ration and reduction in energy density not only has ramifications in terms of yields, but also to fresh cow health, potentially leading to higher levels of ketosis if left unaddressed.
The £40,000 feed cost figure calculated as part of the research was based on results from John Osborne’s farm, which was one of the worst affected of the trial farms. However, the fact last year was a mild winter and starling numbers were lower than in some years suggests the figure could be a conservative estimate. As a result, since the trial Mr Osborne has placed starling proofing at the top of his list of priorities.
“We knew they were eating a lot, but we were horrified at how much. That has a huge financial impact on us. I daren’t think how much that has cost me over the years,” says Mr Osborne, who runs the 300-cow herd in a family partnership at Tobarn, near Bude.
Cows yield 9,000 litres and are fed a full winter total mixed ration of grass silage, wholecrop and a blend and fed to yield through out of parlour feeders. Over the last eight to 10 years the herd has experienced various bird-borne diseases, including salmonella. Bouts of winter dysentary have also impacted fertility and knocked production by about five litres/cow/day during the height of the problem.
Prior to the trial, Mr Osborne and the farm team had attempted to mitigate the effects of starlings by moving to a fine blend and changing feed timings so cows were fed more of it in the evening when starlings are less active. However, the trial results clearly highlighted starlings were still having a significant impact. As a result he is convinced starling proofing is the only way forward.
Mark Button, of Polshea Farm, St Tudy, was the only farmer in the trial to have starling-proofed his buildings. By doing so, the number of starlings present on the 940-cow farm was reduced, but not eliminated, leading to a saving of 0.15kg/cow/day in lost feed value.
Miss Hawkey says: “This 0.15kg/cow/day is equal to 25,380kg for 940 cows over a 180-day starling season. In terms of milk yield, that is 55,836 litres or about £11,000. So by improving buildings, farmers could save about £11,000 a year, or even more if starling incidence is higher.”
Mr Button spent about £5,000 on materials and £10,000 on labour to starling-proof milking and dry cow sheds in the winter of 2008/09. After trying numerous ‘bangers, squealers and screechers’ and feed additives, with short-lived success, Mr Button felt this was the only option to put an end to spells of salmonella and winter dysentery caused by starlings.
“In the last winter before I did it, there were that many starlings in the troughs they were almost keeping the cows off the feed,” says Mr Button.
Cows receive a partial TMR of grass, maize, rolled wheat, soya, sugar beet and wheat distillers in indoor troughs.
Rubber flaps were put under all 24 of the shed doors to enable the scrapers to work, but stop starlings from gaining entry. Rubber was also put over the 100mm (4in) square holes around the door latches. A 25mm mesh had also previously been put over the vented ridge, after discovering 38mm mesh was too big. An electric garage door was also put on the shed housing the straight bins.
“We also cut foam material to shape and fitted it under the roof sheets – that was the most time consuming,” says Mr Button, who recalls starlings getting up behind the guttering.
He adds: “I think it has been worth the investment. We do not get winter dysentery now and not as much salmonella. We still get the odd one or two starlings in the shed, but it seems to be 99.5 per cent starling-proofed. Getting the shed blocked up is the only real option if you are in an area with starlings, feeding TMR and/or maize.”
Dr Hawkey suggests all farmers experiencing issues with starlings should assess their TMR and evaluate how much of an issue they have got.
“Take a sample of the TMR at feed-out and in the afternoon and send it for analysis and put it through a Penn State separator to assess the change in particle size,” he explains.
An informed decision can then be made as to whether investing in starling proofing is worthwhile.