Pig manure
Pig manure has been included in sheep rations at the level of 40% (in pellets) with good results.
Cattle manure
The dehydration of cattle excreta for use as an ingredient in cattle feed is clearly uneconomical. Steer manure has been fed to finishing beef cattle either mixed fresh with other feeds or as wastelage. When fed fresh, the manure is collected daily from the pen and blended with the ration in the ratio of 2:3. The mixture is kept in a closed container overnight and fed the following day. When fed as wastelage, fresh manure is mixed with ground grass hay in the ratio or 57:43 and stored in a silo, where it ferments and acquires a silage odour. Wastelage from Coastal Bermuda hay averages 13% crude protein and 60% digestible nutrients. The product has been combined with concentrates for feeding to finishing cattle and has also been used as the sole feed for ewes and beef cows. A complete ration recommended for feedlot cattle consists of 40% fresh cow manure mixed with 42% cracked maize and 18% maize silage. The mixture is ensiled for ten days before feeding. When wastelage is fed alone for a long period, it may be necessary to add vitamin A and phosphorus or feeds rich in these growth factors. Feeding manure to dairy cows produces no effect on lactation or milk taste. Dried fresh manure smells like a mixed feed. The dryness of dehydrated manure seems to lessen palatability, but manure fermented as silage is well accepted. Once cattle become accustomed to this feed there is no effect on consumption. Wastelage should not be stored in a rusty structure.
Poultry litter
Fresh poultry manure is about 30% crude protein on a dry basis, about half of which derives from uric acid. For ruminants the digestibility of the crude protein is close to 80% and that of the organic matter about 65%. Poultry manure is also rich in minerals, which makes further mineral supplementation of rations containing dried poultry manure unnecessary. As fresh poultry manure ferments very quickly, it must be dried without delay if it is to be used for feeding. The drying temperature should be no higher than 90 C so as not to damage the protein in the manure and no lower than 70 C so as to sterilize the manure. It should then be ground to facilitate the removal of feathers. Uric acid can be utilized by rumen microbes for protein production. As uric acid is not easily dissolved in the rumen fluid and the ammonia is only slowly released, it is therefore more efficiently utilized than other nonprotein nitrogen (NPN) sources. The rumen flora seems to take about three weeks to adapt before it can fully utilize uric acid. For ruminants dried poultry manure can be used like any other protein concentrate. When dried poultry manure ration is maintained at a normal energy level, the weight gains or milk production are satisfactory. Its low energy value (about the same as hay) may cause low palatability when it is fed at high levels, but various steps can be taken to improve palatability, such as the addition of molasses or fat. The feeding of dried poultry manure does not affect the flavour of meat or milk.
Much of the interest in the feeding of poultry manure has been centred on deep litter, which is a mixture of a suitable litter material and poultry droppings developed over a period of six months or more and maintained in a dry, friable condition. The litter is placed in a layer between 3 cm and 25 cm thick on the floor of the poultry house, mainly to absorb the moisture from poultry excreta, which is about 80% water when voided. This moisture is subsequently disposed of by evaporation and is also used in decomposition. Microorganisms thrive on the manure in the litter and break it down. This microflora produces growth factors, notably vitamin B12, and antibiotic substances which help control the level of pathogenic bacteria. Consequently, the growth rate and health are often superior in poultry raised on deep litter. Various types of litter materials are used, such as sawdust, wood shavings, groundnut hulls and bagasse. The litter material must be sufficiently water-absorbent, reasonably coarse so that packing does not occur, and capable of decomposition. The addition of lime helps keep the litter dry, and the addition of superphosphate reduces the escape of ammonia from the litter, thus maintaining the nitrogen content at a higher level.
When used as feed, the litter should be dried immediately after removal from the poultry house and preferably milled and run over a magnet to remove stray metal scraps. Dried litter can be stored for a long time. Poultry litter has also been ensiled to prevent deterioration. For feeding it should be mixed with energy- rich feedstuffs. The following formula has been recommended: litter 65%, citrus meal 25%, molasses 9% and minerals and vitamins 1%. When mixed in the feed, poultry litter does not keep and must be used quickly. The depth of the litter, as well as the material, affects the nutritive value. Poultry litter is a low-cost material which has given good results in both dairy cows and beef cattle.
Citrus meal is a good litter producer. The subsequent chicken litter is a very good energy-rich feed. It should be noted, however, that citrus seeds must not be included in citrus meal used for litter as they may cause poultry mortalities.
Litter silage has been produced by packing broiler litter into an upright airtight silo, adding water until the total moisture content was 35-38% and leaving the silo sealed and undisturbed for six weeks. This has proved to be an excellent ingredient for cattle feed, and the process partially destroys harmful microorganisms.
Combining broiler litter with other materials (maize, sorghum, potatoes) prior to ensiling has been shown to increase energy and protein digestibility of the resultant silages when fed to cattle (Daniels et al., 1983). It was found to be a satisfactory supplemental protein source for lactating dairy cattle (Sitorus et al., 1980).
Dehydrated broiler litter was fed (0, 15, 30, 40 %) to fattening beef with not negative affects of performance observed, but carcass lean increased and carcass fat declined (Kraszewski, 1983 [?]). Poultry litter waste was found to be a satisfactory source of supplemental protein in growing lambs (Tahir et al., 1987). Composed cage layer waste was fed to ewes and lambs (0, 5.7 %, 11.4 %, 23.8 %, 32.7 %) and was found to be a satisfactory supplemental protein source (Meneses et al., 1992). Broiler litter replaced 50 % of the supplemental protein provided by soybean meal with no depression in performance in goats (Mavimbela, 1988).
Other materials
Activated sewage can be fed to ruminants up to 8%. The crude protein digestibility for ruminants is about 55%.
Droppings from birds or bats contain up to 10% nitrogen and are rich in phosphorus (up to 5% for fish-eating birds). For ruminants it can be used as a nonprotein nitrogen source. It should be used in the same way as urea and usually gives the same response.
