Soybean Oil Replacement by Palm Fatty Acid Distillate in Broiler Chicken Diets: Fat Digestibility and Lipid-Class Content along the Intestinal Tract

Abstract

Palm fatty acid distillate (PFAD) is a by-product of palm oil (P) refining. Its use in chicken diets is a way to reduce the cost of feed and the environmental impact. Its low unsaturated:saturated fatty acid ratio (UFA:SFA) and its high free fatty acid (FFA) level could be partially counteracted by its blending with soybean oil (S). The objective was to assess the effect of replacing S with different levels of PFAD on lipid-class content and fatty acid (FA) digestibility along the intestinal tract and in the excreta of 11 and 35-day-old broiler chickens. Five experimental diets were prepared by supplementing a basal diet with S (S6), PFAD (PA6), two blends of them (S4-PA2 and S2-PA4), or P (P6) at 6%. Replacing S with PFAD did not affect performance parameters (p > 0.05) but negatively affected feed AME, FA digestibility, and FFA intestinal content (p < 0.05), especially in starter chicks. Including PFAD delayed total FA (TFA) absorption (p < 0.05) at 11 days, but at 35 days it did not affect the TFA absorption rate. The use of PFAD blended with S, when FFA ≤ 30% and UFA:SFA ≥ 2.6, led to adequate energy utilization in broiler grower-finisher diets.

Keywords: alternative energy source; broiler chickens; fat by-product; fat digestibility; fatty acid distillate; free fatty acid; intestinal tract; lipid classes; poultry.

Figure 1

FFA content ¹ in the feed, upper jejunum, lower jejunum, upper ileum, lower ileum, and excreta for the five different diets; with 6% of soybean oil (S6), blend with 4% soybean oil and 2% palm fatty acid distillate (S4-2PA), blend with 2% soybean oil and 4% palm fatty acid distillate (S2-2PA), with 6% of palm fatty acid distillate (PA6) and with 6% palm oil (P6) in (a) 11-d-old broiler chickens and (b) 35-d-old broiler chickens. ¹ FFA concentration (mg/g)/Ti concentration (mg/g) in each intestinal segment and excreta. Values are pooled means of 6 replicates per each diet with 12 chickens/replicate at 11 d, and 2 chickens/replicate at 35 d. a–d: columns not sharing a common letter within each intestinal segment are significantly different (p ≤ 0.01).

Figure 2

Contribution of each intestinal segment to the apparent fatty acid digestibility, calculated as a proportion of total digestibility reached at the lower ileum, along the intestinal tract for the five different diets; with 6% of soybean oil (S6), blend with 4% soybean oil and 2% palm fatty acid distillate (S4-2PA), blend with 2% soybean oil and 4% palm fatty acid distillate (S2-2PA), with 6% of palm fatty acid distillate (PA6) and with 6% palm oil (P6) in (a) 11-d-old broiler chickens and (b) 35-d-old broiler chickens. TFA (Total Fatty Acids), Palmitic (C16:0), stearic (C18:0), oleic (C18:1n-9) and linoleic (C18:2n-6) acids. Values are means of 6 replicates per each diet with 12 chickens/replicate at 11 d, and 2 chickens/replicate at 35 d. a–d: columns with the same intestinal segment not sharing a common letter are significantly different (p < 0.01).