Effect of Feeding Olive Pomace Acid Oil on Dark Chicken Meat Lipid Composition, Oxidative Stability, Color, and Sensory Acceptance.

This study evaluated the effect of using olive pomace acid oil (OPAO) instead of crude palm oil (PO) or refined olive pomace oil (ROPO) on lipid composition, lipid oxidation, and quality of chicken meat. Broiler chickens were fed diets with 6% of PO, ROPO, or OPAO, and deboned legs with skin were sampled. Fresh and refrigerated (commercial conditions; 7 days) chicken meat samples were assessed for fatty acid (FA) composition, tocopherol (T) and tocotrienol (T3) content, lipid oxidative stability, 2-thiobarbituric acid (TBA) values, volatile compounds, color, and sensory acceptance. Using ROPO and OPAO led to meat richer in monounsaturated FAs and OPAO to lower α-T levels compared to PO. Oxidative stability, TBA values, volatile compounds, and overall acceptance of meat were not affected by diet. Refrigeration increased TBA values and some volatile compounds' concentrations, but it did not decrease redness or consumers' overall acceptance. Therefore, the OPAO used was an adequate fat source for chicken diets at 6%, as it produced dark meat lower in saturated FAs than PO without affecting lipid oxidation or overall acceptance. According to this, upcycling OPAO as an energy source in chicken diets would be possible, which can contribute to the sustainability of the food chain.

Replacement of Palm Oil with Soybean Acid Oil in Broiler Chicken Diet: Fat Digestibility and Lipid Class Content along the Intestinal Tract.

This study aimed to evaluate the replacement of palm oil (P) with increasing levels of soybean acid oil (SA), a by-product of soybean oil (S) refining, on lipid class content and fatty acid (FA) digestibility in the intestine and excreta of chickens at 11 and 35 days (d). Five experimental diets were obtained by supplementing a basal diet with 6% of P (P6), 6% of SA (SA6), 4% of P + 2% SA (P4-SA2), 2% of P + 4% of SA (P2-SA4) and 6% of S (S6). A total of 480 one-d-old female broiler chickens (Ross 308) were housed in metabolic cages (6 cages/treatment, with 16 birds/cage). Replacing P with SA improved fat absorption at 11 and 35 d (p < 0.05), but not feed AME values and saturated FA (SFA) digestibility at 11 d. As age increased, the absorption of SFA and free fatty acids (FFA) improved, and the contribution of the upper ileum to FA absorption increased (p < 0.05). At 35 d, SA6 (56% FFA) and P2-SA4 (40% FFA, 2.6 unsaturated-to-saturated FA ratio) could replace S6 without impairing fat utilization. The replacement of P with SA represents a suitable strategy to use this by-product.

Methods to determine the quality of acid oils and fatty acid distillates used in animal feeding.

Acid oils and fatty acid distillates are by-products from the refining of edible oils and fats. They are used as feed ingredients, but their highly variable composition sometimes affects the productive parameters of the animals. Thus, their quality control and standardization are necessary. The official methods recommended for crude and refined fats and oils must be modified to give reliable results when applied to acid oils and fatty acid distillates. This article summarizes the drawbacks that were encountered during the setup of the analytical methods and how were they overcome by adapting the methods to these type of fat samples. Some methods such as the determinations of fatty acid composition, tocopherol and tocotrienol content, unsaponifiable matter, acidity and peroxide value had to be minimally adapted. However, others such as the determinations of moisture and volatile matter, insoluble impurities, lipid classes and p-anisidine value showed important drawbacks that required a more significant adaptation.•All the analytical methods have been successfully applied to acid oils and fatty acid distillates.•A detailed description of the sample preparation for analysis and applied analytical methods is provided as a compendium of methods in the supplementary material.•These methods will be extremely useful to improve the quality control of these heterogeneous feed ingredients.

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

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.

Composition and Nutritional Value of Acid Oils and Fatty Acid Distillates Used in Animal Feeding.

Acid oils (AO) and fatty acid distillates (FAD) are oil refining by-products rich in free fatty acids. The objective of this study is their characterization and the identification of their sources of variability so that they can be standardized to improve their use as feed ingredients. Samples (n=92) were collected from the Spanish market and the MIU value (sum of moisture, insoluble impurities, and unsaponifiable matter), lipid classes, fatty acid composition, and tocol content were analyzed. Their composition was highly variable even between batches from the same producer. As FAD originated from a distillation step, they showed higher free fatty acid amounts (82.5 vs 57.0 g/100 g, median values), whereas AO maintained higher proportions of moisture, polymers, tri-, di-, and monoacylglycerols. Overall, the MIU value was higher in AO (2.60-18.50 g/100 g in AO vs 0.63-10.44 g/100 g in FAD), with most of the contents of insoluble impurities being higher than those in the guidelines. Tocol and fatty acid composition were influenced by the crude oil's botanical origin. The calculated dietary energy values were, in general, higher for AO and decreased when a MIU correction factor was applied. The analytical control and standardization of these by-products is of the outmost importance to revalorize them as feed ingredients.

Antimicrobial Effects of Black Soldier Fly and Yellow Mealworm Fats and Their Impact on Gut Microbiota of Growing Rabbits.

This study aimed to evaluate the in vitro antimicrobial activities of two types of insect fats extracted from black soldier fly larvae (HI, Hermetia illucens L.) and yellow mealworm larvae (TM, Tenebrio molitor L.) and their effects as dietary replacement of soybean oil (S) on cecal fermentation pattern, and fecal and cecal microbiota in rabbits. A total of 120 weaned rabbits were randomly allotted to three dietary treatments (40 rabbits/group) -a control diet (C diet) containing 1.5% of S and two experimental diets (HI diet (HID) and TM diet (TMD)), where S was totally substituted by HI or TM fats during the whole trial that lasted 41 days. Regarding the in vitro antimicrobial activities, HI and TM fats did not show any effects on Salmonella growth. Yersinia enterocolitica showed significantly lower growth when challenged with HI fats than the controls. The insect fat supplementation in rabbit diets increased the contents of the cecal volatile fatty acids when compared to the control group. A metataxonomic approach was adopted to investigate the shift in the microbial composition as a function of the dietary insect fat supplementation. The microbiota did not show a clear separation as a function of the inclusion, even if a specific microbial signature was observed. Indeed, HI and TM fat supplementation enriched the presence of Akkermansia that was found to be correlated with NH3-N concentration. An increase in Ruminococcus, which can improve the immune response of the host, was also observed. This study confirms the potential of HI and TM fats as antibacterial feed ingredients with a positive influence on the rabbit cecal microbiota, thus supporting the possibility of including HI and TM fats in rabbit diets.

Evaluation of dietary supplementation of a novel microbial muramidase on gastrointestinal functionality and growth performance in broiler chickens.

This study was conducted to assess the effect of dietary supplementation of Muramidase 007 to broiler chickens on gastrointestinal functionality, evaluating growth performance, apparent ileal digestibility, intestinal histomorphology, vitamin A in plasma and cecal microbiota. A total of 480 one-day male chicks (Ross 308) were distributed in 16 pens allocated in 2 experimental diets: the control diet (CTR) without feed enzymes, coccidiostat or growth promoters, and the experimental diet (MUR): CTR supplemented with 35,000 units (LSU(F))/kg of the Muramidase 007. Digesta and tissue samples were obtained on days 9 and 36 of the study. A lower feed conversion ratio was observed in the MUR treatment. Apparent ileal digestibility of DM, organic matter and energy were improved by Muramidase 007. It was also observed that MUR improved digestibility of total fatty acids, mono-unsaturated fatty acids and poly-unsaturated fatty acids, and content of vitamin A in plasma at day 9 (P < 0.05). Histomorphological analysis of jejunum samples revealed no differences in the villus height or crypt depth; but a higher number of goblet cells and intraepithelial lymphocytes at day 36 with MUR. No differences were observed in plate counts of enterobacteria or Lactobacillus along the gastrointestinal tract, neither on the cecal short-chain fatty acids. An statistical trend was observed for reduction of cecal clostridia at day 9 for MUR. Analysis of cecal microbiota structure by 16S rRNA gene sequencing revealed relevant changes correlated to age. At day 9, broilers receiving MUR showed decreased alpha diversity compared to CTR that was not detected at day 36. Changes in specific taxonomic groups with an increase in Lactobacillus genus were identified. In conclusion, evaluation of the variables in this study indicates that dietary Muramidase 007 contributes to improve feed conversation ratio and gastrointestinal function in broiler chickens. Effects could have been mediated by slight shifts observed in the intestinal microbiota. More studies are guaranteed to fully understand the mechanisms involved.

Consumption of dietary n-3 fatty acids decreases fat deposition and adipocyte size, but increases oxidative susceptibility in broiler chickens.

The aim of this study was to determine the effects of an omega-3 (n-3) polyunsaturated fatty acid (PUFA)-enriched diet on animal fat depots and lipid oxidation in the blood and meat of broiler chickens. Abdominal fat pad (AFP), sartorius muscle and liver histology were used to assess the effect of the dietary fat on animal lipid depots. A total of 60 female broilers (14 days old) was randomly divided into two groups which received a diet containing 10 % of tallow (S diet), rich in saturated fatty acids or 10 % of a blend of fish oil and linseed oil (N3 diet), rich in n-3 PUFA from 14 to 50 days of life. Both absolute and relative weights of AFP in N3 animals were lower than in the S group (P < 0.05). These results paralleled with a lower adipocyte mean area (P < 0.001) obtained in N3-fed animals, leading to a higher number of fat cells per unit of surface measured (383.4 adipocytes/mm(2) vs. 273.7 adipocytes/mm(2)). Similarly, fat content and the intramuscular fat-occupied area of muscle were lower in N3 (P < 0.0001) than in the S-fed birds. Neither macroscopic nor microscopic differences were observed in the liver. The inclusion of dietary n-3 PUFA increased meat and erythrocyte oxidation susceptibility; however, the erythrocytes from the S group were less resistant to osmotic changes. Results indicate that feeding an n-3 PUFA diet influences fat distribution and the oxidative status of broiler chickens.

Chemical composition and energy content of chickens in response to different levels of dietary polyunsaturated fatty acids.

Two experiments were performed to study the effect of dietary polyunsaturated fatty acids (PUFA) on abdominal fat pad weight and chemical composition of broilers. In Experiment 1, different fat sources were blended in different ratios keeping added fat level constant (9%). In Experiment 2, PUFA gradient was obtained by increasing the level of inclusion (2, 4, 6 and 8%) of PUFA-rich oil. The treatments had 15, 34, 45 and 61 and 28, 38, 48 and 59 g PUFA/kg diet, respectively. Apparent metabolizable energy intake was similar in both experiments, except for the more saturated diet in Experiment 1 (15 g PUFA/kg), where it was lower. In Experiment 1, abdominal fat pad weight, total body fat and body energy were lower in the animals on the high PUFA diets (p < 0.05) compared to the animals on the saturated-rich ones, meanwhile in Experiment 2 there were no differences on chemical and energy composition by increasing added PUFA-rich oil inclusion level. In conclusion, PUFA-rich chicken diets, compared to saturated-rich ones, cause a lower body fat deposition, but not compared to low-PUFA low-fat diets.