The animals suffered in their turn, the battery horses from want of exercise, the train horses and mules from over-work, and all from the excessive heat and insufficiency of proper forage. There was never enough hay; the deficiency was partly eked out by making fodder of the standing corn, but this resource was quickly exhausted, and after the 3d of July, when Taylor sealed the river by planting his guns below Donaldsonville, all the animals went upon half or quarter rations of grain, with little hay or none. At length, for two or three days, the forage depots fairly gave out; the poor beasts were literally starving when the place fell, nor was it for nearly a week after that event that, by the raising of Taylor's blockade below and the arrival of supplies from Grant above, the stress was wholly relieved. The two colored regiments, the 1st and 3d Louisiana Native Guards, besides strongly picketing their front, were mainly occupied, after the 27th of May, in fatigue duty in the trenches on the right. While the army was in the Teche country, Brigadier-General Daniel Ullmann had arrived at New Orleans from New York, bringing with him authority to raise a brigade of colored troops. With him came a full complement of officers. A few days later, on the 1st of May, Banks issued, at Opelousas, an order, which he had for some time held in contemplation, for organizing a corps of eighteen regiments of colored infantry, to consist, at first, of five hundred men each. These troops were to form a distinct command, to which he gave the name of the Corps d'Afrique, and in it he incorporated Ullmann's brigade. By the end of May Ullmann had enrolled about 1,400 men for five regiments, the 6th, 7th, 8th, 9th, and 10th. These recruits, as yet unarmed and undrilled, were now brought to Port Hudson, organized, and set to work in the trenches and upon the various siege operations. About the same time the formation of a regiment of engineer troops was undertaken, composed of picked men of color, formed in three battalions of four companies each, under white officers carefully chosen from among the veterans. The ranks of this regiment, known as the 1st Louisiana engineers, were soon recruited to above a thousand; the strength for duty was about eight hundred. Under the skilful handling of Colonel Justin Hodge it rendered valuable service throughout the siege. Company K of the 42d Massachusetts, commanded by Lieutenant Henry A. Harding, had for some months been serving as pontoniers, in charge of the bridge train. During the siege it did good and hard work in all branches of field engineering under the immediate direction of the Chief Engineer.