HE herbaceous legume Indigofera spicata Forsk. (pre-T viously Izdigofera eizdecaphylla Jacq.) (5) , also called creeping or trailing indigo, has features which, were it not for its toxic nature,would make it one of the foremost tropical forage legumes. Breeding work with the objective of obtaining a nontoxic strain of creeping indigo has been hampered by the difficulty and expense of experimenting directly on cattle with toxic materials. Since the original finding that creeping indigo was toxic to cattle (9; I O) , all attempts to identify the toxic substance have been with small test animals. Rosenberg and Zoebisch (11) showed that chicks would exhibit characteristic symptoms when fed creeping indigo. Evidence that the toxic chemical is 3-nitropropanoic acid has been brought forward by workers in Puerto Rico and Hawaii (2, 4, 8) u s i n g chicks as test 'Published with the approval of the Director of the Hawaii Agricultural Experiment Station as Technical Paper No. 626.

Two experiments involving 124 Single Comb White Leghorn (Hy-Line) laying pullets and hens were conducted to determine the effect of zinc toxicity on bird performance. Twenty milligrams of zinc per gram of diet fed for 5 days significantly lowered fertility and hatchability of pullet eggs collected 14 to 28 days after the 5-day zinc feeding period. Zinc significantly depressed body weight on the day 5 of zinc feeding and significantly lowered egg poroduction from 0 to 4 weeks of test. Egg production from 4 to 12 weeks, feed conversion from 0 to 12 weeks, final body weight, and livability were not significantly affected. Hens fed the supplemental zinc for five days had depressed egg production from 0 to 4 weeks. Egg production from 4 to 12 weeks, feed conversion, final body weight, and livability were not significantly affected. Compared to their respective controls, 2% supplemental zinc fed for 5 days significantly improved hen but not pullet egg weight. Hen eggs collected 28 days after hens received the zinc diet contained significantly less potassium, copper, and zinc than the controls.

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Creeping indigo ( I n d i g o f e r a endecaphyllaJacq.) is a spreading or suberect perennial legume that has been studied for its agronomic desirability in Africa, Ceylon, Cuba, Hawaii, India, Java, Puerto Rico, and the Philippine Islands. Bogdan (1949) reported that this species was fed to steers and sheep for a few hours each day during a 16-day feeding trial and that it was palatable to them. Mundy (1932) andFajardo (1934) reported, respectively, that mules and horses also ate this crop. Emmel and Ritchy (1941), however, have reported that New Zealand rabbits, when permitted t o graze in a plot of I n d i g o f e r a endecaphylla, died within a period of 6 to 15 days. The rear quarters of afflicted animals were paralyzed and respiration became feeble. No reference has been found regarding the effect of this legume on chickens.Recent investigations by the Departments of Animal Husbandry and Agronomy of the University of Hawaii have indicated that this member of the legume family may have induced premature births of stillborn calves. With regard to poultry, there had been an unconfirmed field report that dehydrated creeping indigo, when substituted for 50 percent of a standard grower mash during a period of acute feed shortage, caused death of 12-to 13-week-old cockerels after 3 days on the feed. This study was undertaken to procure information on the effects of creeping indigo on growth and livability of chicks. MATERIALS AND METHODSFor trials 1 and 2, terminal vine cuttings of creeping indigo were run through an ensilage cutter and dried in an electric oven at 100°C. Excess cuttings were stored on a wire screen so that the last of this sample was placed in the oven on the third day. The dried whole forage was then ground in a hammer mill and the coarser stems were separated by passing the milled material through a seed cleaner. In trial 3, leaves were hand stripped 12 to 18 inches from the terminal portions of the vines and dried at 100°C. The entire sample * Published with the approval of the Director of the Hawaii Agricultural Experiment Station as Technical Paper No. 206.

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