237. There are undoubted welfare implications of inappropriate nutrition (and associated problems, such as metabolic disorders, mastitis, lameness and subfertility). These may arise either with low input systems, where supply is insufficient to meet the demands of the cow, or with higher input systems, where feeding mismanagement can lead to digestive upsets. Feeding knowledge on-farm may fall short of the exacting demands of the cow and lead to a variety of problems. A further complication may be producers purposely trying to lower milk output as a consequence of EU milk quota regime i.e. when in danger of going over quota. The genetic drive of the cow can be such that, in spite of reduced nutrient input, milk output continues with consequential liveweight loss due to mobilisation of body reserves, causing varying types and degree of metabolic disorders. Manipulation of the diet to meet certain market needs, e.g. low fat milk, requires alterations to the diet which may lead to digestive disorders and energy deficits if not properly managed.
238. Additionally, there are the problems of feeding cows selected for high yield. It has been suggested that these cows may be at more risk of metabolic problems. In practice, the opposite appears to be the case as these cows tend to be managed with better standards of stockmanship. Nonetheless, there is a potential problem where cows of high genetic potential are introduced into herds where management is not experienced at providing for the needs of these animals.
239. Information on feeding of average yielding cows to minimise or prevent nutritional upsets is readily available. There is a vast range of feeding strategies and feeds available. These have been studied in detail by others and are outside the scope of this review.
240. Lactating cattle should be fed according to milk output, stage of lactation and body condition. Feeding should be accurately and frequently monitored by checking weights and composition of feed offered. Any changes in the diet should be planned and the ration phased in slowly.
241. The use of feed of animal origin should be avoided unless very careful studies have demonstrated its safety for cattle and fool-proof feed treatment procedures are used.
242. Individual daily milk yields should be recorded at least monthly and monitored against lactation curves appropriate to the yield level of the herd by month of calving. This will allow evaluation of the effectiveness of the feeding regimen and identify potential welfare problems at an early stage.
243. Sufficient trough space should be available, commensurate with the size of cow, to allow all animals to feed at once. Consideration should be given to the shy cows and heifers. In most circumstances, self-feed silage faces should be augmented with silage in ring feeders or troughs.
244. When only concentrated dry feeds are fed, amounts should be limited to a maximum of 4 kg in any one feed (for example, per milking) to reduce the risk of rumen acidosis and other metabolic disorders.
245. Alternative feeds should be made available ad libitum when concentrates and/or the energy density of the feed is reduced, such as in mid-to-late lactation or to reduce milk production.
246. Water troughs of sufficient capacity and suitable design, or other sources of water, should be readily available within any grazing area where there is not an adequate natural supply of potable water.
247. The supply of drinking water should be matched to the number of cattle and peak demand and sufficient water be available to allow at least 10% of housed cattle to drink at any one time.
248. Cows should be offered at least 5% more than their expected daily intake of complete trough-fed feeds. Surplus feed should be removed daily to maintain freshness as old and stale feed can taint and contaminate fresh feed and lead to reduced intake.
249. If cows of high genetic potential are being introduced into a herd, appropriate advice on nutrition should be sought.
250. Dry cows should be dried off abruptly and put on a palatable forage diet, low in protein and energy, to maintain body condition. A suitable ration should be offered from 2-3 weeks before calving.
251. Where animals are isolated for treatment, feed and water must be available. The feed should not be appreciably different from that normally on offer to the animals.
252. Farmers should use condition scoring as a routine management tool to check that dairy cows are in optimum condition. They should familiarise themselves with the MAFF booklet, Condition scoring of dairy cattle', once this is available. We understand this is currently in preparation.