Egg components, total fat, and fatty acid content of specialty eggs were compared. One dozen eggs were collected and analyzed from each of five different brands from hens fed a diet free of animal fat (SP1), certified organic free-range brown eggs (SP2), uncaged unmedicated brown eggs (SP3), cage-free vegetarian diet brown eggs (SP4), or naturally nested uncaged (SP5). Regular white-shelled eggs were the control. A significant (P < 0.05) difference was observed in the egg components and fatty acid content in different brands. The percentage of yolk was lower (P < 0.05) in SP2 and SP4 with a concomitant increase (P < 0.05) in the percentage of white. The percentage of shell was lower (P < 0.05) in SP4 and SP5. The total edible portion was greater in SP4 and SP5. The yolk:white ratio was greater (P < 0.05) in SP3. The total lipid content was lower in SP4 eggs. The content of palmitic (C16:0), stearic (C18:0), and total saturated fatty acids were lower (P < 0.05) in SP1. No difference was observed in the content of palmitoleic (C16:1), oleic (C18:1), or total monounsaturated fatty acids. The content of n-3 fatty acids in SP2, SP4, and SP5 were similar to control eggs. The ratio of total n-6:n-3 polyunsaturated fatty acids ranged from 39.2 for SP5 to 11.5 for SP1 (P < 0.05). No difference was observed in the total polyunsaturated fatty acid content of eggs (P > 0.05).

The effects of incorporating conjugated linoleic acid (CLA) and fish oil in laying hen diets on egg CLA, n-3 fatty acid, tocopherol, and TBA reactive substances (TBARS) during 60 d of storage were investigated. Hens were fed corn-soybean meal-based diets containing 3% yellow grease (YG), 2.75% yellow grease + 0.25% CLA (YG-CLA), 2.5% yellow grease + 0.25% CLA + 0.25% fish oil (YG-CLA-FO), or 2.75% yellow grease + 0.25% fish oil (YG-FO). Eggs were collected and stored at 4 degrees C up to 60 d. On storage d 0, 20, 40, and 60, eggs (n = 8) from each treatment were selected randomly, and tocopherol and TBARS contents were measured. Egg total lipid and fatty acids were determined on d 0 and 60 of storage. Feeding YG-CLA-FO led to a 5.4 and 7.7% reduction in egg total lipids on d 0 and 60 (P < 0.05) when compared with YG eggs. The YG-CLA and YG-CLA-FO diets led to a 12% increase in egg saturated fatty acids compared with YG eggs. The content of monounsaturated fatty acids were lower ( > 19%) in YG-CLA and YG-CLA-FO compared with YG. Egg n-3 was highest in YG-FO eggs and lowest in YG eggs (P < 0.0001). Storage over 60 d led to a 20 and 67% depletion of CLA in the YG-CLA and YG-CLA-FO eggs (P < 0.0001). A 29% reduction was observed in the total n-3 fatty acid content of YG-CLA-FO eggs at d 60 of storage when compared with d 0 of storage (P < 0.0001). Diet and storage increased TBARS (P < 0.0001), which was highest in YG-CLA eggs at 60 d of storage. The YG-CLA and YG-CLA-FO diets reduced alpha and gamma-tocopherol contents at all days of storage compared with YG eggs (P < 0.05). Regardless of diet, egg storage for 40 d or longer depleted egg tocopherol contents (P < 0.05). These data demonstrate that healthy eggs with increased n-3 fatty acids and CLA can be generated by minor diet modifications, but added tocopherol supplementation may be needed to reduce lipid peroxidation when n-3 or CLA is included in the hen diet.

The effect of dietary CLA along with n-3 PUFA on yolk FA profile and hepatic lipid accumulation was investigated. Laying hens (n = 40) were randomly assigned to four experimental diets containing 0, 0.5, 1.0, or 2.0% CLA. Menhaden oil was used as the source of n-3 PUFA. Dietary CLA did not affect the total lipid content of egg yolk (P > 0.05). The amounts of CLA isomers (cis-9 trans-11, trans-10 cis-12) in the egg yolk were proportional to the levels of CLA in the diet (P < 0.05). The total CLA content in the egg yolk was 0, 0.97, 2.4, and 5.3 wt%, respectively (P < 0.05). Addition of CLA resulted in an increase in saturated FA (P < 0.05) with a concomitant reduction in monounsaturated FA (P < 0.05) in the yolk, liver, abdominal fat, breast, and thigh muscle. No difference in saturated and monounsaturated FA content in heart and spleen tissue was noted. Dietary CLA at all concentrations resulted in an increase (P < 0.05) in the total number of fat vacuoles and lipid infiltration in hepatocytes. The number of cells with 75% or higher lipid vacuolation in the cytoplasm was also increased (P < 0.05) by 2.0% CLA. Dietary CLA at 0.5% levels resulted in an increase (P < 0.05) in the total lipid content of hepatic tissue. The total lipid content in leg muscle was lower (P < 0.05) in CLA-fed birds. However, no effect of CLA on lipid content of breast muscle, heart, spleen and adipose tissue was observed (P > 0.05). The current study used CLA in a FFA form. The effects of using CLA in other form such as TG on avian hepatic tissue need to be investigated.

Two experiments were conducted to evaluate the production parameters, muscle fatty acid composition, and lipid stability of birds fed four different cultivars of sorghum. Experiment 1 used ruby red and valpo red, and Experiment 2 used kinsman and mason cultivars of sorghum. The basal diet was a corn, soy, and flax meal, and sorghum cultivars were substituted at 10 or 5% in Experiments 1 and 2. No significant difference was observed for BW, feed consumption or feed efficiency (P > 0.05). The total lipids were reduced (P < 0.05) in the leg muscle of broilers fed the mason cultivar. The TBA-reactive substances (TBARS) were lower (P < 0.05) in the leg muscle of birds fed the mason cultivar when compared to kinsman or control diet. The content of n-3 polyunsaturated fatty acids were higher (P < 0.05) in the breast and leg muscles of birds fed ruby red, kinsman, and mason cultivars of sorghum.

We investigated the effect of dietary conjugated linoleic acid (CLA) along with n-3 polyunsaturated fatty acid (n-3 PUFA) on yolk fatty acid composition and volatile compounds in eggs that were raw (RA), hard-boiled (HB), or hard-boiled, irradiated (HBI, 2.5 kGy). Single Comb White Leghorn laying hens (n = 40) were randomly assigned to one of the four experimental diets containing 0, 0.5, 1.0, or 2.0% CLA. Menhaden oil was used as the source of n-3 PUFA. Eggs collected after 6 wk of feeding were analyzed for fatty acids and volatile compounds. The content of docosahexaenoic acid (C22:6 n-3) was reduced (P < 0.05) in eggs from hens fed the 2.0% CLA diet. Eggs from hens fed 0.5% CLA incorporated the highest concentration of docosahexaenoic acid (P < 0.05) with a concomitant reduction in arachidonic acid (P < 0.05). The yolk contents of cis-9 trans-11 CLA and trans-10 cis-12 CLA increased linearly (P < 0.05) as the dietary CLA supply increased. Total monounsaturates were reduced (P < 0.05) with an increase in saturates in yolk. No difference was observed in the total PUFA content of eggs. Total volatiles were reduced in RA eggs from 1.0 and 2.0% CLA diets. 2-Propanone, hexane, and methyl cyclopentane were the major volatiles in RA eggs and were reduced by dietary CLA at 1.0 and 2.0%. Acetaldehyde, pentane, propanol, acetic acid methyl ester, acetic acid ethyl ester, propionic acid methyl ester, 2-methylmethyl propionic acid, 2-propanone, and octane were the major volatiles in HB eggs and were reduced by 2.0% CLA (P < 0.05). No difference was observed in the acetaldehyde, pentane, propanol, acetic acid ethyl ester, octane, or total volatile content of HBI eggs.