Metabolizable Energy Value of Conjugated Linoleic Acid for Broiler Chicks and Laying Hens

Abstract

Two experiments with broiler chicks and one experiment with laying hens were conducted to determine the MEn value of conjugated linoleic acid (CLA). In Experiment 1, for 8 d, 16-d-old chicks were fed diets in which 4, 8, or 12% of CLA Source A or 4, 8, or 12% of soybean oil (SO) was substituted for glucose. Dietary MEn increased linearly (P < or = 0.001) with increments of CLA Source A or SO. Regression analysis relating increases in dietary MEn and increments of the dietary fat sources showed that the MEn values of CLA Source A and SO, when evaluated separately, were 7,419 and 8,429 kcal/kg, respectively. In Experiment 2, feed was withheld from laying hens for 38 h and then the hens were force-fed diets containing 15% glucose, 15% CLA Source A, or 15% SO (two feedings of 30 g each). Excreta samples were collected for 36 h after the last feeding. The MEn values obtained for CLA Source A and SO were 8,517 and 8,437 kcal/kg, respectively. The MEn of CLA Source B (higher in unsaturated fatty acids than CLA Source A) was determined in Experiment 3 by feeding diets containing 4, 8, or 12% CLA Source B to 14-d-old chicks. Increases in dietary MEn with increments of CLA Source B were curvilinear, with resulting MEn of 9,375 to 9,588 kcal/kg of fat when CLA Source B was fed at 4 or 8% of the diet and 7,917 kcal/kg when fed at 12% of the diet. Results of this research show that CLA sources can contribute substantial energy to diets, but the MEn value of CLA sources for young chicks varies with fatty acid composition and dietary concentration.

Effect of dietary protein concentrations, amino acids and conjugated linoleic acid supplementations on productive performance and lipid metabolism of broiler chicks

“…The other nutrients profiles were determined (Association of (National Research Council 1994). The CLA supplemented to the diets replaced soybean oil on weight to weight basis, assuming similar ME n value (Sell et al 2001). The experimental diets were fed from 7 to 28 d of age.…”

Perfil de ácidos grasos de la carne de pollos alimentados con diferentes fuentes de aceites

“…The use of oils with high PUFA content, such as soybean and sunflower, have as a result a decrease in the levels of myristic acid (14:0) and oleic acid (18:1n-9), and an increase in content of linoleic acid (18:3n-6) level present in adipose tissue of chickens. Sell, Jin & Jeffrey (2001) demonstrated in their study, that there is a linear increment of 18:3n-6 level in the meat, according to this research, this happens when chickens have a feed rich in linoleic acids, such as soybean oil.…”

“…Rymer, Hartnell & Givens (2011) evaluated the effect of the addition of soybean oil rich of 18:4n-3 in the feed on the deposition of n-3 fatty acid in chicken meat and, similarly did not find differences in broiler chicken performance. Sell et al (2001) also did not find the difference in the performance of the broiler chickens fed with different concentrations of conjugated linoleic acid, applied to broiler chicken and laying hens in their study. Similar results of final weight, gain weight, food consumption and feed conversion were reported by Crespo & Esteve-Garcia (2000) which studied dietary…”

A Comparison of the Effects of Dietary Conjugated Linoleic Acid Contents, Cholesterol, Lipid Oxidation and Drip Loss in Pork Loin and Chicken Breast

“…The capacity of de novo biosynthesis of lipid in the liver of birds is very high compared with that of mammals. Unlike mammals, fatty acids are the main energy source for birds, and Sell et al. (2001) reported that the metabolizable energy values for CLA seemed no different from linoleic acid in broilers.…”