STUDIES ON REDUCTION AND SOLIDIFICATION OF SWINE EXCRETA THROUGH MODIFICATION OF FEEDS

Twelve classes of feeds with 5 varying TDN values of 65-85 and 4 varying crude fiber contents of 2-8% were employed for our series of tests on the effects of the variations of feeds upon the amounts and general and physicochemical properties of excreta, digestibility of the feeds etc. The results were as described below.<br>1. The amount of excreta from the highly nutritive and less fibrous feed with a TDN of 80 and a crude fiber content of 2% was about 40% against, and tended to produce more solidified excreta than, “the conventional feed for meat production performance test” with a TDN of 65, of which excreta was regarded in this case as 100. The amounts of daily excreta from fattening pigs weighing 70kg fed on the quantified feeding system of the same amounts of nutriments to pigs on the constant body weight level assessed in accordance with the standards for “meat production performance test” were about 2kg with less nutritive feeds such as “the conventional feed for meat production performance test”, about 1.5kg with moderately nutritive feeds such as “the new feeds for meat production performance test”, and about 700g with highly nutritive and less fibrous feeds such as the feed No. 4 for performance test of kanagawa pref. and those with addition of fats and oils.<br>2. The amounts of urination under close correlation with the amounts of water drinking indicated appreciable variation with individual animals, but the amounts of urination can be assessed about 4-10 liters, if water is taken ad libitum in summertime by fattening pigs weighing about 70kg.<br>3. Digestibility remained within normal ranges with all the feeds tested, but higher digestibility of crude fibers tended to be noted with groups of lower crude fiber contents and consequently smaller absolute amounts of crude fibers, and groups of higher energy levels and consequently smaller feed intakes, if the crude fiber contents are on the same level. Higher DM excretion rate and more excretion tended to be noted in the groups of animals fed on rations with higher fiber content had therefore lower digestibility of crude fibers.<br>4. The BOD, TS, and SS values of excretion tended to be generally higher in the groups fed on rations with higher energy levels and lower crude fiber contents. No fixed trend was observed with the amounts of urination because of considerable effects of the amounts of excretion mixed into urine.<br>5. The loads of fecal BOD, TS, and SS tended to be lower in the groups fed on rations with higher energy levels and lower crude fiber contents. The share of feces in the total loads of feces and urine in any group of the test exceeded 80%, 85%, and 96% in terms of BOD, TS, and SS, respectively.<br>6. Loads of daily excretion of both feces and urine from fattening pigs weighing 70kg fed on quantified feeding and ad libitum water drinking were assessed to be 200-240g, 170-180g, and 140-150g of BOD, respectively, and 500-550g, 400-420g, and 280-310g of SS, respectively, if fed on rations with lower, moderate, and higher nutritive levels. It was found out that these loads could possibly be reduced to a considerable extent by varying the quality of feeds, if these loads were compared with 200g of BOD and 700g of SS both regarded as generally acceptable standards of loads of fattening pigs.