Apparent
ileal amino acid digestibilities in diet formation for pigs: 1) Principles
of protein digestion in the small and large intestine of the pig; 2)
Apparent ileal amino acid digestibility and their impact on performance
parameters in growing pigs.
A digestibility experiment was conducted with Ross-broiler chickens
(age 24 days) to determine the coefficient of ileal apparent digestibility
of amino acids in meat and bone meal and several oilseed protein ingredients.
The birds were fed semi-purified diets with the protein ingredient supplying
the protein source. The coefficient of ileal apparent digestibility
was determined using the slaughter technique. A 37-day growth study
was conducted with 2880 Ross-broiler chicks to compare feed formulation
systems based on apparent digestible ileal values or total lysine values.
The barley-based diets were formulated to test the value of using ileal
apparent digestibility values. The results of the digestibility studies
were:
| Coefficient of ileal apparent digestibility (%) | ||||
| Lysine | Methionine | Threonine | Cystine | |
| Meat and bone meal | 0.60 | 0.66 | 0.48 | 0.34 |
| Full-fat soybeans | 0.81 | 0.75 | 0.68 | 0.67 |
| Soybean cake | 0.86 | 0.86 | 0.76 | 0.62 |
| Soybean meal | 0.85 | 0.84 | 0.74 | 0.63 |
| Full-fat rapeseed | 0.59 | 0.59 | 0.43 | 0.53 |
| Rapeseed cake | 0.68 | 0.81 | 0.64 | 0.53 |
| Rapeseed Meal | 0.63 | 0.75 | 0.54 | 0.43 |
The growth study indicated that the final weight and growth rate were the highest when digestible lysine based feed formulation was used compared to using total lysine values (<0.001). The proportion of breast meat to total live-weight and the weight of the breast muscle increased ((P<0.05) in birds fed diets formulated on the basis of digestible lysine compared to total lysine. Growth rates and final weight gains were higher for the birds fed diets containing soybean meal compared to those containing rapeseed meal or meal and bone meal. (These results demonstrate the quality of soy protein and the value of formulating diets on the basis of digestible lysine).
Perttila, S. and co-workers. 2002. Apparent ileal digestibility of amino acids in protein feedstuffs and diet formulation based on total vs. digestible lysine for poultry. Animal Feed Sci. and Tech. 98(3-4): 203-218.
