400 Growth and Development of Breeds and Crosses of Plcjs 



and " Live " Classes at 1 1 months old as compared with 154 lbs. and 156 lbs. 

 for Berkshire and Large Whites respectively. At ') months old tlic Live 

 Classes are only 16 per cent, heavier than the Carcase Clas.ses, yet at 

 11 months old this difference is increased to 62 per cent., the young 

 animal being much more diflicult to overfatten than the old one. 



The carcase percentage for the different breeds is shown in Table VII ; 

 the variations at different ages are discussed below (see Age) as also are 

 the relative orders of the breeds at the younger ages (see Early Maturity). 



The Middle White has the highest carcase percentage and is followed 

 by the Berkshire, Large White, Tamworth and Large Black in the order 

 named. The proportion of pluck is in inverse proportion to the carcase 

 percentage and so the order of breeds as regards this part is reversed. 



The carcase percentages are on the whole less than those of pigs 

 exhibited at the International Live Stock Show at Chicago (3i) which 

 vary from 83 to 88 per cent, but there a different type of pig — the lard 

 pig — is required. 



Table VII. Proporlioii.s of or(jans in different bree(U of pigs — 

 as percentage of the live weight. 



3 months 5 month.s 7 months !t rnoiUhs 11 months 



t3 T3 Ts -a -0 



^ ^ <^ CJ 9 



S .5 c S 3 ^ c 



9 



a 



Breed Q S 5^ O S &£ O S t)>2 O S D£ O S D^ 



Aliddle White ... 74-3 6-0 19-7 76-8 5-2 180 82-4 4-5 131 840 40 12-0 85-2 30 10-9 



Berkshire ... 770 5-5 175 78-7 S-S lo-S 811 4-7 14-2 82-5 4-5 130 83-1 4-4 12-5 



Large White ... 730 5-9 211 76-9 5-4 17-7 80-9 4-7 14-4 81-3 4-5 14-2 83-5 40 12-5 



Tamworth ...— — — 70-1 6-1 23-H 76-3 5-2 18-5 80-4 4-7 14-9 84-8 4-0 11-2 



Large Bhiek ... 72-9 5-8 21-3 73-9 GO 201 79-7 4-8 ir,-5 80-3 4-8 14-9 SO-7 51 14-2 



Lincohishire Curly SO-9 4-3 14-8 — — — ^ __ ____ ___ 



Coated 



Average (4 breeds) 74-3 5-8 199 70(i 5 5 17-9 810 4-7 14-3 820 4-4 13(> 831 4-3 12i; 



Age. The effect of age on the rate of growth iu live weiglit in the 

 different breeds, calculated as increase in lbs. per day since birth, is seen 

 in Table II and V. The rates of growth of two breeds (Berkshire and 

 Middle White) of which sufficient numbers have been available at all 

 ages, have been averaged and are shown in Fig. 1 . 



The rate of growth in these two breeds falls from 3 to 5 months and 

 then rises till it reaches a maximum at 9 months old when it falls again. 

 The reason for the first drop between 3 and 5 months is to a very small 

 extent caused by neglecting the birth weight which would naturally play 



