Effects of free-fatty-acid content and saturation degree of the dietary oil sources on lipid-class content and fatty-acid digestibility along the gastrointestinal tract in broilers from 22 to 37 days of age

The aim of the present study is to assess the effect of the free-fatty-acid (FFA) content and saturation degree of dietary fat (added at 6%) on the fatty-acid (FA) digestibility and lipid-class content along the gastrointestinal tract and excreta in broilers from 22 to 37 d of age. This is essential to determine the potential use of acid oils (refining by-products rich in FFA) in broiler diets as an alternative to crude oils. The study consisted of a 2 × 4 factorial arrangement, which included 2 fat sources (soybean oils – unsaturated, or palm oils – saturated) and 4 levels of FFA (5, 15, 35, and 50%). Samples of digestive content of the gizzard, duodenum, jejunum, ileum and of the excreta were obtained at 37 d of age. Irrespective of the dietary fat source, more than 80% of total FA (TFA) was absorbed in the jejunum. Broilers fed with unsaturated diets had a higher absorption efficiency of FA than did those fed with saturated diets. This conclusion is supported by the lower FFA content and the higher TFA and polyunsaturated FA (PUFA) digestibility coefficients in the ileum (P < 0.001) observed in the former group. The dietary FFA level did not affect the FA absorption process as much as the dietary fat source did. This was supported by the lack of statistical differences among the diets with a similar saturation degree but rather different levels of FFA, for TFA, saturated FA, and PUFA digestibility coefficients both in the jejunum and ileum. However, the interactions reported in the ileum for triacylglycerol and diacylglycerol contents (P < 0.001), as well as for monounsaturated FA digestibility coefficients (P < 0.05) show that the dietary FFA content affects the FA absorption process. The present results show that the inclusion of acid oils in grower-finisher broiler diets with FFA levels up to 35% does not have a negative impact on the FA absorption process.

Soybean lecithin as an alternative energy source for grower and finisher broiler chickens: impact on performance, fatty acid digestibility, gut health, and abdominal fat saturation degree

An experiment was performed to assess the inclusion of soybean lecithin (SL) in the replacement of soybean oil (SO), for grower and finisher broiler chicken diets (up to 15 d of life), and its effects on performance, fatty acid (FA) absorption, gut health, and saturation degree of the abdominal fat pad (AFP). A total of 1,440 female Ross-308 chickens were distributed in 60 pens and were fed 5 experimental diets. The control diet (T1) was supplemented with SO (grower and finisher diets at 2.00%), and 4 levels of SL were included in replacement: T2 (0.25% in grower and 0.50% in finisher diets), T3 (0.50% in grower and 1.00% in finisher diets), T4 (0.75% in grower and 1.50% in finisher diets), and T5 (1.00% in grower and 2.00% in finisher diets). At day 39, titanium dioxide was added to finisher diets at 5 g/kg to perform a digestibility balance. At day 46, AFP, tissue, and gut digesta samples were collected to characterize FA digestibility, adipose saturation degree, microbial groups, and histomorphometry. No effects were associated with SO replacement by SL on performance (P > 0.05), ileal digestibility of total, saturated and monounsaturated FA (P > 0.05), nor jejunal morphology (P > 0.05). Total replacement of SO by SL reduced ileal absorption of polyunsaturated FA (P < 0.02) and increased jejunal Lactobacillus spp. counts (P = 0.049). Higher levels of SL inclusion (T4 and T5) lowered polyunsaturated FA concentration of the AFP (P = 0.002) and, thus, slightly reduced its unsaturated-to-saturated FA ratio (P = 0.005). Soybean lecithin inclusion did not modify performance parameters, total FA absorption, nor jejunal morphology, however caused changes on polyunsaturated FA absorption, jejunal microbiota, and saturation degree of the AFP. The study demonstrates that soybean lecithin can be included, in combination with or in replacement of soybean oil, as an alternative energy source for grower (up to a 1%) and finisher broiler diets (up to 2%).

Effects of dietary free fatty-acid content and saturation degree on lipid-class composition and fatty-acid digestibility along the gastrointestinal tract in broiler starter chickens

The aim of the present study is to assess the effect of the dietary free fatty acid (FFA) content and dietary fat saturation degree on the fatty-acid (FA) digestibility and lipid-class content along the gastrointestinal tract and excreta in broiler chickens. The 8 experimental diets resulted from replacing crude soybean oil with soybean acid oil from chemical refining, or crude palm oil with palm FA distillate from physical refining. Thus, there were 4 soybean and 4 palm diets with 6% added fat varying in their FFA% (5, 15, 35, and 50%). Samples of digestive content (gizzard, duodenum, jejunum, and ileum) and excreta were collected at 14 D for the determination of the FA digestibility and lipid-class content. The total FA digestibility coefficients reported for the chickens fed S diets in the jejunum, ileum, and excreta were higher than for those fed P diets (P ≤ 0.02). The general greater digestibility of the unsaturated diets was mainly explained by a higher contribution of the ileum to the absorption of saturated FA. The dietary FFA content mainly affected the FA absorption process. The diets with 50% FFA presented lower saturated FA digestibility coefficients in the jejunum and ileum (P ≤ 0.03), and higher content of FFA in the ileum and excreta (P ≤ 0.014), in comparison to the diets with 5% FFA. The 15% FFA diets were not different from the 5% FFA diets, regarding the saturated FA digestibility in the jejunum and excreta, and the FFA content in the ileum and excreta. It was concluded that unsaturated diets with moderate content of dietary FFA (up to 15%) could be used in broiler-chicken starter diets, as they led to similar FA absorption and performance results to the diets with the lowest dietary FFA content. From the present study, it has also been concluded that dietary saturated FA content has a greater impact on FA absorption than the dietary FFA content has.

Crude soybean lecithin as alternative energy source for broiler chicken diets

Two experiments were conducted to evaluate the use of crude soybean lecithin (L) as an alternative energy source in broiler feeding and to study its influence on performance, fatty acid (FA) digestibility between 9 to 11 D and 36 to 37 D, feed AME content, and the FA profile of the abdominal fat pad (AFP). A basal diet was supplemented at 3% with soybean oil (S; experiment 1) or a monounsaturated vegetable acid oil (A; experiment 2) and increasing amounts of L (1, 2, and 3%) were included in replacement. The inclusion of L did not modify performance results (P > 0.05). In starter diets, the replacement of S by L reduced feed AME content (P < 0.001) and lowered PUFA digestibility (P = 0.028), whereas in the grower-finisher phase, a blend of 2% of S and 1% of L did not modify feed AME content or FA digestibility. When L was included instead of A, no effects on feed AME value and total FA digestibility (P > 0.05) were shown in the starter phase, whereas in grower-finisher diets, a blending of 2% of A and 1% of L enhanced feed AME content (P < 0.001) and total FA digestibility (P = 0.001). The FA profile of the AFP reflected the FA composition of the diets. Crude soybean lecithin represents an alternative energy source for broiler chickens, and it can be used in growing-finishing diets in replacement of 1% S. The best option to include both alternative fats (L and A) was 2% of L with 1% of A in starter diets and 1% of L with 2% of A in grower-finisher diets because they showed positive synergic effects. The results suggest that dietary FA profile have a bigger impact on the AFP saturation degree than the different dietary lipid molecular structures.

Soybean Lecithin High in Free Fatty Acids for Broiler Chicken Diets: Impact on Performance, Fatty Acid Digestibility and Saturation Degree of Adipose Tissue

Simple Summary

The search of alternatives for soybean oil, as a dietary energy source, has generated a lot of interest in broiler feeding due to economic and supply reasons. Soybean lecithin, as a co-product derived from the soybean oil degumming process, and its blending with other by-products derived from the vegetable oil refining process such as acid oils, may represent an alternative energy source for broiler chicken diets formulation. The current study has demonstrated that soybean lecithin high in free fatty acids can be included in grower–finisher diets, as a partial replacer of soybean oil or in combination with an acid oil, without impairing performance or fatty acid digestibility and causing minor changes in the fatty acid composition of the abdominal fat pad.

Abstract

Two experiments were conducted to evaluate the inclusion of soybean lecithin with a high free fatty acid content (L) in starter and grower–finisher broiler diets, as well as its influence on performance, energy and fatty acid (FA) utilization and the FA profile of the abdominal fat pad (AFP). A basal diet was supplemented with soybean oil (S; Experiment 1) or acid oil (AO; Experiment 2) at 3%, and increasing amounts of L (1%, 2% and 3%) were included in replacement. The inclusion of L did not modify performance parameters (p > 0.05). The S replacement by L reduced energy and total FA utilization (p ≤ 0.05) in starter diets; however, in grower–finisher diets, a replacement up to 2% did not modify energy and FA utilization (p > 0.05). The AO substitution by L produced no modifications on energy and FA utilization (p > 0.05) during the starter phase, while the blend of 1% of AO and 2% of L resulted in the best combination in terms of the FA digestibility. The FA profile of the AFP reflected the FA composition of diets. The addition of L could replace, up to 2% or be blended with AO in broiler grower–finisher diets as an energy source.

Effect of feeding of prefermented bioproduct containing gamma-linolenic acid and beta-carotene on selected parameters of broiler chicken meat quality

The aim of the work was to evaluate the effect of addition of prefermented bioproduct with a increased content of polyunsaturated fatty acids (especially gamma-linolenic acid) and beta-carotene into commercial feed on the selected qualitative parameters. The chemical composition, the color, the loss of water, the pH and the concentration of lactic acid of the meat of broiler chickens (COBB 500) were monitored. Bioproduct was prepared from corn scrap, which was fermented using the lower filamentous fungus Umbelopsis isabellina CCF2412. The prepared material was mixed into the commercial compound feed intended for broiler chickens at a ratio of 10%, and was fed from the 11th day of age of the chickens until the time of slaughter. The obtained results were compared with the results of control group, which was represented by broiler chickens fed only with a commercial compound feed. Feeding of bioproduct, in terms of chemical composition, affected mainly the fat content in breast and thigh meat, which was lower in the experimental group. Meat color (measured by colorimetric assay) was not affected and differences were significant only at a value a*, which was higher in the experimental group. Statistically significant differences in the water losses of meat were not recorded, but the feeding of bioproduct affected the pH of the meat, and also the concentration of lactic acid and both parameters were higher in the meat of control group.