thought for food . by . Anthony Lisle . tests were recently carried out at the national institute for research in dairying , Shinfield , to find the optimum level of restricted feeding for the economic production of baconers . for the particular strains in the Shinfield pig unit and the type of ration in use , it was found that a maximum of 6 1/2 lb a head daily gave the best results . but in an identical trial on another farm , using exactly the same diet on pigs of different breeding , it was not possible to feed much above 5 lb a day without lowering the grading of the carcasses . this illustrates the great difficulty commercial bacon producers are up against in feeding for economic growth and top grading . it also shows why scientists can do little to help in this particular field . what is sound practice on one farm can be economically disastrous on the next . producers will have to carry out their own trials to discover the best way to feed their pigs in their particular environment . it is not easy to carry out accurate trial work and keep detailed records on a busy , practical farm where labour is already being used at full stretch . but it is vitally important to know the most economic way to feed baconers . adopting an arbitrary level of feeding restriction based on other people &apos;s experience will not help . if the pigs are fed less than they are capable of taking before reaching a point of downgrading , they will take an unnecessarily long time to reach bacon weight and throughput will be slowed down . if the daily ration is too large , the pigs will grow rapidly enough , but their grading will be unsatisfactory . the margin between underfeeding and overfeeding is very narrow , and it can only be discovered on a basis of trial and error from farm to farm . closely related to this is the problem of deciding the best stage of growth at which restricted feeding should be introduced . here again , most producers tend to adopt a set age or weight without first endeavouring to establish if it is the best time to make a change . changing from ad lib to restricted feeding when the pigs are 100 lb liveweight may be , and probably is , too soon . if they are allowed to feed to appetite until 140 lb they will reach bacon weight 10 to 12 days earlier . the advice of Dr R Braude , who runs the Shinfield pig unit , is to feed young pigs ad lib until they reach the level of daily intake at which it is intended to restrict them , and then to ration them at that level . his experience has been that it is important not to let the pigs reach a daily feed intake above the restriction level and then drop them down again . this leads to a growth setback . for some time it has been a universal practice among bacon producers to use a two-ration feeding pattern . sow-and-weaner meal is used until a certain stage , when a cheaper , low-protein diet is introduced . once again the question arises : when should the change be made ? Dr Braude feels that the decisions should be based on the appearance of the pigs and their known grading ability . if they tend to put on fat it will pay to keep them on the richer diet up to 120 to 140 lb . but if they are lean and from a good grading strain , the cheaper ration can be introduced between 100 and 120 lb . he emphasises , however , that these figures are only guides : every producer must find out for himself which is the best stage to make the change for his pigs , type of ration , and environment . there is a growing school of thought today which wonders if there is any advantage in making a feeding change at all . it is felt that the continued feeding of sow-and-weaner meal through to slaughter may improve grading , speed throughput and lower feed conversion to an extent that will more than offset the extra cost of the ration . even if this is not so , there are other advantages . the use of only one ration in the piggery speeds the work of feeding and simplifies milling and mixing . it also ensures against any possible growth check which might occur if the change over to a finishing diet is made too early . whether it is economic or not will be determined only on the farm , but it is of interest to note the results of a comparative experiment carried out by the Norfolk School of agriculture : these figures show a distinct grading improvement which , in view of the fact that there was no increase of premium payments for length , must be attributable to the feeding . in addition , baconers on the single ration reached their slaughter weight five days earlier in summer and 10 days earlier in winter than pigs on two-stage feeding . in terms of hard cash , this is calculated to bring in &amp;pound;20 to &amp;pound;25 more profit from every hundred baconers sold , without taking into consideration the streamlining of labour and the simplification of mixing and storage . this illustrates how wrong it is to attach too much importance to the price of a ration . it is the feeding value which counts . a food costing &amp;pound;30 a ton may be dearer to buy than one at &amp;pound;28 a ton but it can be cheaper to feed . if the diet is &amp;pound;2 a ton more expensive because it has a higher nutrient value and its use improves the feed conversion rate of a baconer from 3.5 to 3.2 , the cost of feeding that baconer is reduced by 3 s 1 d . for this reason , trials carried out on the farm to determine the best method for feeding bacon pigs should not be evaluated in terms of feed conversion ratios , as they are in official progeny tests . the best measure of efficiency is the food cost per pound of liveweight gain related , of course , to the grading results obtained . 1,050 galls a cow from a hungry soil . by Philip Bolam . simplicity is the hallmark of David Stevens &apos; farming at Lechlade , Gloucester . the whole business is geared to low-cost milk production from over 100 Friesian cows , with maximum use of grass , on 260 acres of Thames gravel . such a soil would have tempted many farmers to escape from the cow &apos;s tail and the seven-day week - perhaps to adopt some intensive arable cropping along with fat lamb production . but Mr Stevens feels there are advantages in being a specialist . getting the most out of well-manured grassland , keeping up to date with new techniques and managing a large dairy herd profitably is a skilled occupation , especially with the profusion of new ideas from the research stations and the farming press . the herd is milked in a six-stall six-unit Hosier bail , which in summer is drawn round the grass fields and in winter stands on concrete near the loose housing and the self-feed silage clamps . when the bail is in the field an electric fence forms a collecting pen and a simple electric dog speeds milking when concentrate feeding is low . many dairy farmers in this situation are content with moderate yields , relying on low costs to provide a good margin of profit . but Mr Stevens &apos; had a true average of 1,050 gallons per cow consuming 1.9 lb cereal and concentrates for each gallon of milk produced . gross sales per man now stand at &amp;pound;5,000 a year . the labour force consists of two cowmen on contract who also tend all the replacement stock , and a tractor driver who acts as relief milker . critics of the system suggest that the herd should be halved and milked in two separate six-stall three-unit bails with one cowman responsible for each . while partly agreeing with this , Mr Stevens argues that managerial decisions would increase with twice the milking machinery and two sets of grazing to arrange , without much financial advantage . he believes that if concentrates are cubed , the cows learn to eat quickly - after all , they masticate food at leisure . rolled barley is used to balance grass or silage . space was short in the bail , so in-churn milking was discarded in favour of an overhead pipeline which carries the milk to churns at one end . a quick and simple method of washing up is based on the immersion cleaning technique developed by the NIRD , using a 3 per cent caustic soda solution . no daily dismantling is necessary . the caustic soda , stored in a twenty-gallon container in the bail loft , flows by gravity into the milking system . the teat-cups are inverted in racks and each set is filled in turn from the overhead milkline . odd pipes and utensils are soaked in a special container . the solution is sucked back into the storage tank before the next milking , followed by a rinse with cold water . the cost of converting to this system is low , and the only running expense is 10 s worth of caustic soda and water softener each month . the grazing and silage-making programme revolves round Italian ryegrass , kale for autumn grazing and timothy-meadow fescue-white clover leys , together with an acreage of permanent grass . no grass is conserved as hay . leys are ploughed for Italian ryegrass , which in its second summer is heavily coated with farmyard manure and ploughed for kale . the leys are reseeded direct the following spring . this is a hungry soil and fertilisers cost &amp;pound;8 an acre . only two types are used - nitrogen and a concentrated compound . recording the treatment and output of each grass field was started last year , so the present programme might well be modified when sufficient information has been accumulated . there are few hedges or walls . most fields are about 10 acres , separated by one or two strands of barbed wire . these are now being replaced by sprung fencing or the electrified lines of high tensile wire with posts every 50 yards . strip grazing with back fences is preferred to paddock grazing . cows are given two fresh feeds of grass a day , usually in two different fields . the more grass they can be persuaded to eat , the more milk they give . any grass left uneaten is allowed to grow on and cut for silage . herd health is good with culling at 15 per cent . milk fever and hypo-magnesaemia are not common but foul-in-the-foot and arthritis can be troublesome . a phosphorous deficiency was noticed recently and now a high phosphorous supplement is added to the food . the covered yards built eight years ago and open self-feed silage clamps cost about &amp;pound;50 a cow . the two clamps , just outside the covered yard , each hold 375 tons and provide a total feeding face of 64 ft . walls of railway sleepers assist filling , but when the silage has settled the top sleepers are removed and the clamps covered with thin polythene sheeting . the area of concrete between the loose housing and the silos has been kept to the minimum , but slurry disposal was a problem , as buildings and the surrounding land are on the same level . the muck from the silo face and concrete yard is collected by an adapted buckrake and pushed over a concrete ramp by reversing the tractor . it lies untouched till midsummer , by which time it is sufficiently solid to be handled with a muck loader . lying in a low rainfall area , spring reseeding and summer kale sowings were always a risk . in 1959 irrigation was introduced and now it is possible to cover 3 1/2 acres a day with 1 in of rain - although moving the pipes makes heavy demands on the labour force . like many others , Mr Stevens feels his farming must be geared to meet sterner times . he may have some answers when he returns from his visit to New Zealand . fine crops from small farms . the three most powerful impressions I received on my recent tour of the French countryside - in particular some of the recent agricultural trouble spots - were 1 . the absence of any farm labourers , or farmers , for that matter , under 35 or so years of age ; 2 . the comparatively high standard of crop husbandry ; and 3 . the comparatively small size of most farming units , herds and flocks . 