An investigation into the validity of some of the pasture and veld norms used in budget feed programmes in the Underberg district
Du Plessis, Thomas Marius
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Underberg lies immediately to the east of and below the Drakensberg, which is a mountain range in the province of Natal of the Republic of South Africa. The agriculture extension area is comprised of 200 farms, which on an average are 800 hectares in extent. As a result of an active study group, which for the years 1953 to 1970 kept accurate economic figures, the main cost items on the farm were found to be fertilizer, bought feed, repairs, labour and fuel cost. The extension workers decided to help the farmers by trying to cut the bought feed costs. To this end the idea of budget feeding was introduced and put into practice by the extension workers. Budget feeding was the name given to the plan, which assisted the farmer in calculating the necessary feed required to feed his animals for the 355 days of the year. Knowing the amount of feed required, norms of quantity and quality were applied to the budget feed exercise, leading to the number of hectares of each crop that should be grown. Over a five year period budget feeding was carried out in the Underberg district. The plan was moderately successful. However, there were a number of farmers that were disappointed with the plan, in that they apparently carried out the budget feed plan, but still ran short of feed towards the end of winter. A check was made on the factors that could lead to a budget feed shortcoming. An evaluation on the check points showed that there were some limiting factors, which possibly could hamper the success of an Underberg budget feed plan. 2. It was decided to investigate the limiting factors in more detail, and to this effect the following trials were undertaken. A comparison of the productivity of eight existing farm pastures was undertaken under topland irrigated, topland non-irrigated and lowland non-irrigated conditions. The dry matter yields of the eight types of pasture varied enormously from the dry matter yield norms used in the budget feed exercise. The actual yield of fescue was approximately thirty percent less than the fescue norm used for budget feeding. The trial established that straight clover was a high yielder of crude protein and a low yielder of fibre. A ryegrass and clover mixture, from a feed quantity and quality point of view, performed well. Cocksfoot in general supplied the lowest yield of dry matter per hectare and the fescue was found to be the highest container of fibre and thus the lowest T D N supplier. Kikuyu, although having a shorter growing season for the area, gave the highest overall dry matter yield. The non-irrigated kikuyu out yielded the irrigated kikuyu, a phenomenon which needed investigation. The addition of clover to the grass in the sward was definitely advantageous. Irrigation on average increased the air dry matter yield by 2,81 ton per hectare. Due to irrigation, this extra dry matter yield at 3 cents per kilogram dry matter meant an extra gross amount of R76 per hectare. Non-irrigated lowland pastures, with the exception of straight clover, outyielded their counterparts under non-irrigated topland conditions, the reason apparently being that the lowland conditions have much cooler temperatures over the year. On the average, non-irrigated topland pastures yielded 0,12 ton of air dry matter per hectare more than the non-irrigated lowland pastures. Clover pastures under non-irrigated topland conditions out yielded the clover under non-irrigated lowland conditions by 1 ton of air dry matter (A D M) /ha. 3. A comparison of the dry matter yields of topland irrigated Ariki ryegrass, Danish cocksfoot and Kentucky fescue pastures grown under farm conditions and under plot conditions showed that plot yields on the average yielded 30 percent more than the equivalent pastures on the farm (15,83 air dry matter/ha versus 11,91 A DM/ha). 4. A comparison of Lolium multiflorum cultivars in the Underberg area showed that over the six month winter period, Tetila, Tetrane, Midmar, Local Hipkin and Local Hulleys were significantly superior to the other cultivars under test. Tetila, cultivar, a tetraploid type, gave the highest D M yield of 9,77 ton per hectare. During the critical July and August winter feeding period the cultivar Midmar out yielded all the other cultivars by providing ,2,93 ton of dry matter per hectare. Further, it was found that the diploid cultivars out yielded the tetraploid cultivars during the mid winter period. It is important to note that certain cultivars out yielded others, and hence a specific cultivar should always be stated when applying a norm for budget feeding exercises in the Underberg area. A variation in the quantity and quality of the material on annual ryegrass pastures over the May to mid September period was very apparent. The average quadrat yield dropped from 2,71 kg wet material/m2 in mid May to 0,55 kg wet material/m2 at the end of July. It is thought that heavy frosts dried the foggage out and then heavy berg winds blew much of the conserved foggage away. Over the test period the crude fibre of the ryegrass foggage varied between 17,8% and 33,7%, while crude protein varied between 21,4% and 11,9%. For budget feeding purposes no specific norm of yield and quality of ryegrass foggage can be used over the winter period. It appears to be impractical to apply an accurate ryegrass foggage quantity and quality norm to an Underberg budget feed exercise. An evaluation of a trial on the productivity of Underberg veld with the aim of determining whether the budget feed norm of 0,5 M L U/ha/season carrying capacity was correct was undertaken. All the results showed that 0,5 M L U/ha/season was not too high and thus should the Underberg budget feed farmer be short of feed, the fault would not lie in the fact that an incorrect veld carrying capacity norm had been applied to his budget feed plan. The assessment of the non-utilization of pastures by the grazing animals on seven Underberg farms showed that on average 26,6% of the pasture was not utilized after one grazing. One farmer utilized only 48,6% of the pasture available to him. It appears that the non-utilization of pastures by the farmer was one of the reasons why some Underberg farmers were short of feed after attempting to carry out their budget feed plan. 8. Due to the high non-utilization figure of pasture by grazing animals shown up in Chapter 4.1, a further similar investigation on another twelve farms was undertaken. This trial verified the Chapter 4.1 results by producing an average non-utilization of pasture figure of 39,5%. One farmer in this trial utilized only 40% of the available pasture at one grazing. On nine of the twelve farms there was no apparent advantage to be gained by such poor utilization since the pastures were not subsequently regrazed. By calculation from the protein and fibre figures the highest T D N figure was obtained from the pure clover trial in the pasture productivity study (Chapter 3). The clover fed to an arbitrary 275 kg beef animal would provide the best pasture for obtaining a 1 kg/day gain. Should bloat be a problem the next best pasture, from the point of view of average daily gain, would be kikuyu, which would supply enough nutrients to allow a 275 kg animal to gain 0,85 kg/day. The addition of clover to the grass sward improved the quality of the pasture and appeared to have an economic effect on both pasture and animal production. It is apparent that the correct pasture type should be grown by the Underberg budget feed farmer, as is shown by the difference of 4,4 ton of D M in yield per hectare in favour of kikuyu over cocksfoot when grown under non-irrigated topland conditions. 10. It is important to use an accurate norm in a budget feed plan. The current inaccuracy of as much as 39,1% in the budget feed plan is unsatisfactory. The validity of pasture productivity studies are discussed in paragraph 5.7.1. Certain of the results were verified by trials in an ensuing year. The weaker links in the budget feed scheme formed the main focus of this work. Certain variations in accepted norms and principals in budget feeding are shown up, as summarized below:- pasture productivity studies, up to 39,1% variation from norm used; up to 24,2%; up to 31,8%; up to 26,7%; and up to 39,2%. plot versus farm pasture yield, ryegrass cultivar trial, non-utilization of pasture trial, non-utilization of pasture trial II, The above percentage figures averaged out at 32,3%. A safety factor of 32% extra feed necessary for feeding animals was built into eleven new Underberg budget feed schemes, and the result was that no farmer who carried out his budget feed plan complained of being short of feed.