UNIVERSITY OF CALIFORNIA COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA ELECTRIC PIG BROODERS JAMES R. TAVERNETTI and E. H. HUGHES BULLETIN 618 December, 1937 UNIVERSITY OF CALIFORNIA BERKELEY, CALIFORNIA CONTENTS PAGE Construction of brooders 3 Method of conducting the trials 5 Trials in 1935 5 Trials in 1936 6 Trials in 1937 6 Results 6 Costs 7 Initial cost 7 Operating costs 7 Summary 8 ELECTRIC PIG BROODERS 1 2 JAMES R. TAVERNETTP and E. H. HUGHES^ The electric pig brooder is a device used to reduce the loss of pigs dur- ing the first week or 10 days of their life. It provides a warm protected place for the pigs to lie when not nursing and thus reduces the danger of injury by the sow. Although the heat in the brooder is used mainly to attract the pigs, it is also beneficial during extreme cold weather in preventing the pigs from becoming chilled. In experiments conducted at the North Dakota Experiment Station, 5 69.8 per cent of the pigs far- rowed under usual conditions were raised, and 30.2 per cent lost. Of the number lost, 78 per cent died by accident or otherwise during the first 2 weeks after farrowing. At the North Platte (Nebraska) Branch Experiment Station, records of 159 litters showed that only 60 and 76 per cent of the pigs farrowed were raised by mature and young sows, respectively. In the fall of 1932 and the spring of 1933 several electric pig brooders were constructed and used at the Oregon Agricultural Experiment Sta- tion. 7 Because good results were reported, a manufacturer of rural elec- tric equipment put a ready-made underheat type of pig brooder on the market. To further determine the practicability of electric pig brooders, a series of trials were made during the spring farrowing seasons of 1935, 1936,. and 1937 at the California Agricultural Experiment Station, and the results are reported in this bulletin. CONSTRUCTION OF BROODERS Two types of brooders were used in the trials : one, a radiant type of original design, in which the pigs received heat (fig. 1) from an over- head light; the other, an underheat type (fig. 2), in which pigs received heat by lying on a heated bed. The hovers for both types were the same — 1 Received for publication October 18, 1937. 3 This publication is the fourteenth of a series reporting results of investigations conducted by the California Agricultural Experiment Station in cooperation with the California Committee on the Relation of Electricity to Agriculture. 3 Assistant Agricultural Engineer in the Experiment Station. 4 Professor of Animal Husbandry and Animal Husbandman in the Experiment Station. B Sevenson, Albert. Prolificacy of sows and mortality of pigs. Amer. Soc. Anim. Prod. Proc. 1927:60-62. 1927. 6 Snyder, W. P. Pork production. Nebraska Agr. Exp. Sta. Bui. 147:1-31. 1915. 7 Oliver, R. W., C. J. Hurd, and F. E. Price. The development of an electric brooder for baby pigs. Oregon Committee on the Relation of Electricity to Agri- culture Prog. Rept. 24:1-7. (Mimeo.) June, 1933. [3] 4 University of California — Experiment Station triangular in shape and constructed of wood with enclosed sides and top. The sides were 3 to Sy 2 feet long and 12 inches high. A piece of 2 x 4 inch lumber across the top of the front left an opening about 8 inches high for the entrance. In the radiant brooder a reflector containing an ordinary electric light was placed over a hole in the center of the top of the hover. The reflectors Fig. 1. — Radiant electric pig brooder. The pigs receive heat from an electric light in a reflector over a hole in the top of the hover. varied in size from 12 to 15 inches, and the hole was made % inch smaller in diameter than the base of the reflector. Two types of reflectors were used : one a standard R. L. M. dome with white-enameled interior, and the other a homemade cone of sheet tin. Both 100- and 150-watt lights were used, for comparison. A piece of 1-inch-mesh wire netting was tacked on the underside of the hole to prevent the pigs from contacting the light or reflector. In the underheat brooder a heating unit specially made for the pur- pose was placed on the floor. It consisted of an enclosed galvanized-iron box 2 feet square and 2 inches high mounted on %-inch legs and contain- Bul. 618] Electric Pig Brooders ing open heating coils. The wiring to the heating coils was protected by a piece of conduit fastened to the box and extending up through the top of the hover. The heating element had a connected load of 100 watts. METHOD OF CONDUCTING THE TRIALS The brooders were placed in corners of the regular farrowing pens in the hog barn. They were securely fastened in place, and a barrier about Fig. 2. — Underheat electric pig brooder. The pigs receive heat by lying on the metal pan enclosing the heating elements. 2 feet high was placed over the front to prevent the sows from getting on top of the hover. The sows were placed in the pens a day or so before farrowing, and the heat was turned on in the brooders several hours before parturition. The pigs, after birth, were placed in the brooders by hand until they learned to go in voluntarily. The sows and pigs were left in the pens for 10 days, during which the heat in the brooders was on continuously. Trials in 1935. — For the trials in the spring of 1935, three brooders were used : two of the underheat type and one of the radiant type having a 12-inch R. L. M. dome reflector and a 100-watt light. Checks for these were run in two other pens containing hovers similar to those used for University of California — Experiment Station the brooders, but not heated ; and one of the regular farrowing pens was equipped with guard rails. Except for three litters, farrowed in January and February, all the trials were made during March. Trials in 1936. — For the trials in the spring of 1936, four brooders were used : two of the underheat type and two of the radiant type. Both the radiant brooders were equipped with R. L. M. dome reflectors and TABLE 1 Besults of Trials with Electric Pig Brooders During Spring Farrowing at Davis Type of equipment Year conducted Number of litters Number of pigs farrowed* Number of pigs lostf Per cent lost Radiant brooders • ' 1935 1936 1937 ^ Total 2 5 6 14 35 48 2 4 7 13 14 11 15 13 97 13 1 ' 1935 1936 1937 8 5 6 19 65 35 46 13 4 5 20 11 11 Total 146 22 15 \ 1935 3 10 11 24 71 88 13 13 28 54 Regular farrowing pens 1936 18 1937 Total 32 24 183 54 29 Hovers without 1935 3 23 15 65 * Does not include pigs dead at birth. t Includes pigs killed or dying of natural causes up to 10 days of age. 150-watt lights, but one reflector was a 12-inch and the other a 15-inch. Checks were run in several of the regular farrowing pens equipped with guard rails. All the pigs were farrowed in March. Trials in 1937. — For the trials in the spring of 1937, four brooders were used : two of the underheat type and two of the radiant. Both the ra- diant brooders were equipped with 12-inch reflectors and 150-watt lights, but one reflector was a R. L. M. dome type and the other a homemade cone of tin. Checks were run in the regular farrowing pens equipped with guard rails. All the pigs were farrowed in March. RESULTS The results obtained for the three-year trials are given in table 1. In all three years the percentage of pigs lost was less in the pens with the brooders than in the regular farrowing pens. The loss for the three years with the brooders was approximately half of that in the regular farrow- ing pens. Bul. 618] Electric Pig Brooders 7 Approximately 75 per cent of the pigs lost were killed or died during the first 2 days after birth. This was true both in the pens containing brooders and in the regular farrowing pens. The time required to teach the pigs to go into the brooders varied with different litters. In some cases placing them in the brooder once or twice was sufficient, while in other cases it took a day or more for them to learn to go in. Holding the pigs in the brooders for several hours immediately after birth, by blocking the entrance, helped in getting them to go in voluntarily. The pigs would not go into or stay in the hovers that were without heat, regardless of the number of times they were placed in them. There was practically no difference between the results obtained with the underheat brooders and with the radiant brooders. Some trouble was experienced with the metal brooder's becoming too warm and causing the pigs to move around after lying on it for a short time. The radiant brooder had several other advantages. It was simpler, less expensive, and easier to construct ; the light attracted the pigs and illuminated the pen ; there was less danger from electrical shock ; and the amount of heat could be varied by merely changing the size of the light globes. Both the 100- and the 150-watt lights were satisfactory for the radiant brooders. The 150-watt, however, seemed more desirable, particularly during the first few days after farrowing. Since some sows had a tendency to chew on the hovers, it was neces- sary to fasten the latter securely in place to keep them from being moved. Some trouble was experienced with the large sows lying across the front of the brooders and blocking the entrance. COSTS Initial Cost. — The initial cost of the underheat brooders was approxi- mately $10.00 each, not including the labor for constructing; the ready- made heating unit cost $9.00 and the lumber for the hover about $1.00. The initial cost of the radiant-type brooders was less than $5.00 each, including the hover, the reflector, and the light, but not the labor for constructing. Operating Costs. — The electrical-energy consumption for the under- heat brooders was approximately 2% kilowatts per day or 25 kilowatts for the 10-day brooding period. The energy consumption with radiant brooders was the same as with the underheat when the 100-watt light was used and 50 per cent greater with the 150-watt light. Assuming an aver- age cost of 2 cents per kilowatt-hour for electricit,y, the operating cost for 10 days' continuous operation was 50 cents with the 100-watt con- nected load and 75 cents with the 150-watt. 8 University of California — Experiment Station SUMMARY Electric pig-brooders were successful in reducing the loss of pigs during the first 10 days after birth. In three years' trials the loss was reduced about 50 per cent. Practically no difference in results was obtained with the two types of brooders used — namely, underheat and radiant. The radiant brooder had certain advantages in cost and operation over the underheat. The initial and operating costs of the brooders was low enough to make their use economically feasible. 13m-12, '37(1046)