8 Feb., 1907.] 



Diseases of Farm Auimals. 



67 



In line-firing the instrument used is wedge-shaped, with a curved and 

 moderately sharp edge 3 or 4 inches long. (See Fig. 6a.) Fhe iron 

 should have substance enough to maintain its heat for about five minutes. 

 For pyro-puncture work the firing iron is pear-shaped, sufficiently pointed 

 to puncture the skin and tissues, and having substance enough tO' hold 

 heat. (See Fig. 6b.) 



The part to be fired should be closely clipped, so that the hair will 

 not flame. It is not usually necessary to throw the horse; more often by 

 the application of a twitch tO' the nose, and holding up the opposite fore 

 leg, or applying a side line tO' the opposite hind leg, the horse can be 

 kept under 'sufficient control, and a much better job can usually be made 

 when the horse is standing in natural position. The lines should be 

 made regularly parallel to each other, not less than half an inch apart, 

 and of even depth. The skin should never be cut by the iron, and cross- 

 ing of the lines should be avoided, otherwise sloughing of pieces of skin 

 is likely tO' occur. 



In England it is customary to apply a blister after firing, but in 

 Australia it is found that the practice often results in sloughing of large 

 patches of skin, and consequent permanent blemish, so that it should never 

 be followed. A little vaseline or hog's lard mav be applied after the 



ti. — Instruments for (a) line firing, and [b) p\ro-punclure. 



lapse of a day or soi, and the same precautions as are recommended to be 

 adopted after blistering should be taken to prevent injury to the part 

 operated on. 



Artificial Impregnation. 



This method of o\ercoming certain forms of barrenness in both mares 

 and cows, and also of conserving the fecundating energy of male stud 

 animals, has come into considerable vogue during recent years. ^lany 

 instances of success in this method of breeding have occurred in Australia, 

 and there is no reason why the practice should not' be extended by capable 

 veterinary experts in certain suitable cases. The operation itself is com- 

 paratively simple, but it is in the choice of ^suitable subjects foT its appli- 

 cation that expert knowledge is required. 



To perform the operation, semen in secured, either by producing arti- 

 ficial ejaculation of the male, or b\- extracting it by means of a long 

 flexible syringe from the vagina of a female immediately after copulation. 

 The syringe should be warmed, and its contents kept at about blood heat 

 before use. The same svringe is used for the injection of the female to 

 be impregnated. It is inserted into the neck of the womb and emptied 

 by pressing the bulb. The technique of both operations will be made clear 

 by reference to Fig. 7, a, b, and c. Of course, it is necessary that the 



c 2 



