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TAS Country : February 10th 2011
12 Tasmanian Country Friday, February 11, 2011 Dairying Knowing calving dates makes a difference Figure 1: Days on lead feed v first test day milk Figure 2: Days on lead feed v incidence metabolic disease LEAD feeding springing cows with a sound dietary cation/anion differ- ence (DCAD) for 21 days is so well documented in research work con- ducted by Ian Lean and Peter DeGaris in Australian herds, that it should be standard practice. I believe the greatest cause of failure to achieve this is accurate calving dates to ensure cows are on lead feed for the full 21 days. Herein lies the real problem: the capacity to have accurate calving dates in most Australian herds. Only herds that practise 100 per cent artificial insemination will be able to easily pregnancy test at four to five weeks post-joining. It is possible, using heat detection aids, to monitor and record natural matings and then pregnancy test at four to five weeks if no further observations of heat ac- tivity are made. This would require real commit- ment of the dairyman, but I'm sure the economic returns would well justify the effort. The two graphs verify this from the perspective of both milk production and metabolic disease prevention (both clinical and sub-clinical). Negative energy balance occurs when energy intake is less than energy consumed in producing milk plus allowance for cow maintenance. Mobilisation of body fat must bal- ance the equation. Moderate fat mo- bilisation is normal and sustainable without inducing health issues and metabolic diseases of milk fever, ketosis, uterine infection and dis- placed abomasum. Sub-clinical milk fever and ketosis are far more costly than clinical cases that are visible and treated. Both will bring on immune deficiency symptoms mostly commonly verified in elevated cell count and clinical mastitis. As input costs have been reduced over the past two years I have been confronted with unprecedented incidence of ''mid- lactation'' milk fever. There is little doubt that in reality, it is both milk fever and ketosis as they are rarely separated, one will induce the other. A cow suffering with sub-clinical metabolic disease will not make a profit in that lactation. Heifers are prime candidates for poor performance in production and reproduction in- duced by sub-clinical metabolic dis- ease. The second major cause of negative energy balance post-calving is low dry matter intake. It is mostly precipitated by inadequate lead feeding programs. It can also be due to lack of quality (nutrient dense) feeds available im- mediately post calving. This has been common in recent (dry) years in all but spring calving cows because of the very limited pasture available. We have, over the last few years, attempted to meet the needs of fresh cows through autumn and winter by extending our summer cropping plans to run well into winter with rape-sorghum mixes (dry grown). Hormonal drive for milk production in fresh cows has little tolerance to inadequate energy intake. When not met, excessive fat mobilisation occurs, inducing fatty liver syndrome and ketosis. I am hopeful that a milk test strip for ketosis will be available shortly. This will enable an easy way to check fresh cows for sub-clinical ketosis and treat, at least dealing with a problem that otherwise goes unnoticed. There will be obvious benefits in both production and reproduction. All too frequently we see autumn calving cows achieve peak milk yields in October. This is real ''tell-tale'' of inadequate energy intake in early lactation as peak milk should have occurred at 80 to 100 days in milk. As peak milk at 80-plus days will determine whole of lactation potential, clearly a peak at 150-plus days is telling us we have really missed our pro- duction potential. Feed budgets are an essential tool to plan and realise adequate energy-dense feeds 12 months of the year; and this is achievable. John Lyne is a dairy production specialist with Dairytech Nutrition. dairytechnutrition.com.au Own a bright future Our dealers are sweating. But it s nothing to do with the weather. The fact is there s never been a better time to buy a New Holland, with massive offers across our full tractor range. Your local dealer will work hard to give you a great deal, including finance. But if you can t find him when you pop into the New Holland showroom don t worry. He hasn t run away. He s probably just changing his shirt. Tractoriffic deals unfolding all summer NEWHOLL0171_TC
February 3rd 2011
February 17th 2011