The drop in relative weight of males is probably due to the effect of castration and weaning. Wilkens (1929) also found that the difference in weight increased with age in favor of males. In the rest of the paper, there will be no difference between the results of the two crosses.
The average daily gains are in the same order as the final ages of the five grades. Almost the same changes are shown by the average daily gains of the pigs during the feeding trials. The grading of the carcasses in the three groups and the genders in the different weight groups is interesting.
The small difference in the percentage of healed sides in favor of the men is again reflected. There is a marked increase in the average thickness of the back fat with an increase in the rate of gain. The intensity of back fat also increases, but there is no difference between the two.
When only the rate of increase increases, the thickness of the back fat still shows a clear increase. With an increase in length, the depth of the side decreases when the weight remains constant. According to Larsson (1928), the thickness of the back fat is the best indication of the degree of obesity in a pig.
In the depth of the flank is marked v- Clease, when the pig is fattening. The thickness of the back fat increases as the depth of the side increases the correlation coefficient. The proportion of linoleic acid (1) clearly increased with increasing unsaturation in the dietary fatty oil, and (2) also increased from leaf fat to the outer layer of back fat.
Racial differences in firmness of the fat haYe purchased at Purdue University (Kelly, 1932).
SUMMARY
In the first two groups, the average refractive indices are somewhat variable, but remain constant in the last two. These results show that age does not affect the stability of back fat when the thickness of the latter is kept constant. . From the evidence given and discussed, no other conclusion can be reached than that apart from such factors as feed, breed and climate, the thickness of the back fat or the degree of fattening of the pig is the only factor affecting the stability of the fat of the pig. the back. The various factors affecting the firmness of carcasses as given by Day (1922), such as lack of maturity, lack of finishing and no saving, are true in so far as these conditions affect the thickness of the back fat and so indirectly affect the hardness. es of fat.
The fact was mentioned above that the outer layer of the back fat ic; much less affected by feed than the inner layer and if it is true that the composition of the outer layer remains practically constant under the same environmental conditions, then one would not expect it to change to any significant extent as the back fat thickens. The strengthening will then be more due to the change that takes place in the inner layer and the outer layer which makes up less and less of the total fat on the back. The average refractive indices given of the outer and inner layers separately and the two together, show that the average of the back fat (1·4597) is much closer to that of the inner layer (1·4596) than to that of the outer layer. layer (1 · 4601).
These results also indicate along which lines some future investigations on fat hardness can be conducted. Relative gains are given for fast, medium and slow growers of both sexes, females being lower. The average results of the two crosses show no obvious differences; however, there are large differences between the average scores of offspring of different pigs of the same breed.
The best grade, 1 Lean Sizable, is deficient in length compared to the requirements of the UK market. The length decreases and there is a marked increase in the depth of the side (correlation, the flank measurements increase faster than the shoulder. Thielmes of back fat still increases with the depth of the side when the gain is constant, and the smoothness of the back fat increases with depth when the thickness remains constant.
Factors that influence the firmness of the fat. The refractive indices were determined to get a measure of the firmness of the fat. When the thickness of back fat is held constant, live weight and the rate at which back fat increases have no effect on fat firmness and the data also indicate that age has no influence either. These factors only affect the firmness of the fat because they are correlated with the thickness of the back fat.
ACKNOWLEDGMENTS
Influence of Depth of Side.-The shrinkage decreases along the way and the batter percentage increases more markedly with increase in depth than with increase in fat and this is still the case when thickness of back fat is kept constant. The depth of the silk seems to affect the rating, the optimum being 15 to 16-9 inches, and that depth/weight ratio remains about the same.
LITERATURE
Influence of the depth of the side. The shrinkage along the way decreases and the dressing percentage increases more markedly with the increase in depth than with the increase in fatness, and this is still the case when the thickness of the back fat is held constant. The share of the shoulder decreases, so does the relative depth at the shoulder. The influence of the nature of the ration on the composition of the body fat of pigs. The effect of dietary fat on body fat, as shown by the separation of the individual fatty acids from the body fat.
The influence of a low-fat ration on the composition of the body fat of pigs. A statistical study of the relationship between different expressions of fertility and strength in the guinea pig. A comparative study of the costs of breeding and manure carts, sterilized females and gilded pigs for the market.
