Effects of anhydrous ammonia and urea treatments on the feeding value of corn stover and in feed costs of bull production. (Short Communication)

Abstract

EFFECTS OF ANHYDROUS AMMONIA AND UREA TREATMENTS ON THE FEEDING VALUE OF CORN STOVER AND IN FEED COSTS OF BULL PRODUCTION Mao Huaming*, Zhang Xiaoming* and Feng Yanglian* Treatment of corn stover with 34g anhydrous mnia for 40 days and with 5Og uroea/kg stover dry matter (DM) for 50 days at a man arrbient temperature of 23 C, raised its crude protein (CP) content from 6.1 to 11.5 and to 12.5%, and decreased its neutral detergent fiber (N>F) from 76.2 to 70.2 and 68.9% on DM basis, respectively. The potential degradability of DM and N>F, determined by the losses of DM and IWF from stover incubated in nylon bags in the rumen of Hereford x local cattle for various periods, was increased from 66.0 and 63.0 to 80.5 and 76.5% by anhydrous mnia treatment and to 76.8 and 73.7% by urea treatment, respectively. Treatments also increased the rate of DM and N>F degradation in the rumen. CP, N>F content and the potential degradability of DM and N)F of millet straw approximated that of untreated corn stover and wre 5.9, 76.2, 61.7 and 60.3% respectively. Twenty four Holstein x local cattle bulls averaging 400kg liveweight wre randomly assigned by live weight to four diets for 62 days. Results in the table show that treatments of corn stover with anhydrous ammonia and with urea markedly increased daily DM intake (DM11 from 3.55 to 4.40 and 4.35kg WO.01). Daily average live weight gain (W of bulls fed the NI$-C diet and urea-C diet were increased from 5099 for bulls fed UC diet to 710 and 6969 respectively (P<O.OS). DM1 of millet straw was 4.36kg DM and markedly higher than that of untreated corn stover, but LWG of bulls fed the millet straw diet was only 5329 and not significantly different from that of bulls fed UC diet. Anhydrous arrzronia and urea treatment cost of one tonne of corn stover was 55.5 and 51.6 Yuan. The feed cost per lkg WG for bulls fed -C, urea-C, corn stover and millet straw+ased diets were 2.7@ 2.7r 3.1 and '3 Y respectively. 3. *DepartmentofAnir& Science, Beijing Agricultural University, Beijing 100094, China. 21A