Influence of free fatty acid content and degree of fat saturation in laying hen diets on egg quality, yolk fatty acid profile, and cholesterol content.

The aim of the present study was to evaluate the effect of dietary free fatty acid (FFA) content and the degree of saturation on egg quality, yolk fatty acid (FA) profile, and yolk cholesterol content. For a 15-wk period, a total of 144 laying hens (19-wk-old) were randomly assigned to 8 treatments arranged in a 2 × 4 factorial design, with 2 sources of crude oil (soybean oil and palm oil) and 4 levels of FFA (10, 20, 30, and 45%). The dietary treatments were achieved by progressively substituting the original oils with equivalent amounts of their corresponding acid oils (soybean acid oil and palm fatty acid distillate, respectively). No differences in ADFI or egg mass were found. However, dietary FFA reduced egg production (linear, P < 0.05) and increased the feed conversion ratio (linear, P < 0.05). Higher levels of FFA in soybean diets resulted in higher egg weight with higher albumen and yolk weights (linear, P < 0.01). Palm diets presented higher yolk:albumen ratio than soybean diets (P < 0.001), but the effect of FFA did not follow a linear trend. Hens fed soybean diets laid eggs with higher Haugh units (HU) than palm diets (P < 0.001), although increasing the dietary FFA% reduced the HU values in both (linear, P < 0.001). Palm diets enhanced shell quality with greater resistance to breakage, and higher dry matter and ash content than soybean diets (P < 0.05). No differences in egg chemical composition and yolk cholesterol content were found (P > 0.05). The saturation degree had a significant effect on all the analyzed yolk FA (P < 0.001) except for arachidonic acid (C20:4 n-6), whereas increasing the FFA content did not affect to a great extent. These results show that varying dietary FFA level did not affect egg quality and yolk composition as much as the dietary fat source did, supporting the use of acid oils and fatty acid distillates as fat ingredients for feed.

Olive pomace oil and acid oil as alternative fat sources in growing-finishing broiler chicken diets.

The aim of the present study was to investigate the effect of dietary supplementation of olive pomace oil and olive pomace acid oil, which are rich in monounsaturated fatty acids (FA) but differ in free FA content, on growth performance, digestibility and FA profile of abdominal fat and breast meat. A total of 3,048 one-day-old mixed-sex broiler chickens (Ross 308) were randomly distributed into 24 pens and 3 dietary treatments (8 replicates per treatment). Experimental diets were administered for growing (from 22 to 29 d) and finishing (from 30 to 39 d) periods, consisting of a basal diet supplemented with 6% (as-fed basis) palm oil (PO), olive pomace oil (O), or olive pomace acid oil (OA). Animals fed O achieved the lowest feed conversion ratio (P < 0.01), together with the highest AME value (P = 0.003), but no differences were observed between OA and PO. Regarding FA digestibility, O and OA showed higher values than PO for all FA in both apparent ileal digestibility (AID) and apparent total tract digestibility. Comparing the AID between O and OA, no differences were observed for total FA, monounsaturated FA, or polyunsaturated FA, but animals fed OA showed lower AID values for saturated FA than those fed O (P < 0.001). The FA profile of abdominal fat and breast meat reflected that of the diet, with higher monounsaturated FA and lower saturated FA in animals fed O and OA compared to those fed PO. In sum, the inclusion of both olive pomace oil and acid oil in growing-finishing broiler chicken diets led to great performance parameters and high FA digestibility values, together with an enrichment with monounsaturated FA in abdominal fat and breast meat compared to the use of palm oil. However, a better AID of saturated FA and feed conversion ratio is achieved with O compared to OA.

Crude and acid oils from olive pomace as alternative fat sources in growing-finishing pigs.

The inclusion of crude and acid oils from olive pomace can lead to more unsaturated meat products and, especially in the case of olive pomace acid oil, achieve a more economically and environmentally sustainable swine production. The objective of this trial was to study the effect of dietary supplementation with crude and acid oils from olive pomace, which are rich in monounsaturated fatty acids (FAs) and have differing free FA content, on growth performance, digestibility, carcass parameters and FA profile of Longissimus muscle (LM) and backfat in growing-finishing pigs compared to the conventional crude palm oil. A total of 224 male and female pigs [(Landrace × Large White) × Duroc] were randomly distributed into 48 pens according to initial BW (58.7 ± 9.71 kg, mean ± SD) and sex. Four experimental treatments were randomly assigned (n = 12 pens/treatment; 4-5 pigs/pen) for the growing (0-42 days) and finishing (40-62 days) phases. Treatments consisted of a basal diet supplemented with 5% (as-fed basis) palm oil (PO), olive pomace oil (O), olive pomace acid oil (OA) or a mixture (M) of PO and OA at 50/50. No differences were found in the growth performance results between PO, O or M, but animals fed OA showed a lower gain to feed ratio than M (P = 0.008). No differences were found in apparent ileal digestibility among treatments, however, animals fed O and OA showed the highest values of total FA apparent total tract digestibility, while those fed PO had the lowest values, and M had intermediate values (P < 0.001). No differences were observed in carcass composition among treatments. In relation to backfat and the LM FA profile, O and OA treatments led to a higher unsaturated FA to saturated FA ratio and a lower content in saturated FA than PO. Moreover, O showed a higher intramuscular fat (IMF) content in LM than PO (P = 0.037). It is concluded that olive pomace oil is an interesting alternative fat source that can be included at 5% in growing-finishing pig diets, leading to meat products with more IMF, rich in monounsaturated FA, reaching high FA digestibility values and good pig performance parameters. Alternatively, olive pomace acid oil blended with conventional palm oil did not negatively impact fat utilisation nor performance. Including these fat by-products reduced feeding costs and led to a more efficient and environmentally sustainable production.

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%).

Effect of fibrous diet and vitamin C inclusion on uniformity, carcass traits, skeletal strength, and behavior of broiler breeder pullets.

This experiment studied the effect of broiler breeder nutritional strategies on uniformity, carcass traits, tibia parameters, and behavior during rearing and prebreeder periods (up to 22 wk of age). One-day-old pullets (n = 384) were randomly assigned to 4 treatments arranged as a 2 × 2 factorial, with 2 fiber levels (control vs. fibrous diet, 15% diluted in AMEn and nutrient content) and 2 vitamin C feed inclusions (0 vs. 200 mg/kg). At 6, 15, and 22 wk, blood sampling was carried out (4 birds/replicate) to determine serum alkaline phosphatase (ALP) levels, and behavior was observed by visual scan sampling. At 22 wk, carcass traits, tibia parameters, and intestinal morphology were assessed (2 birds/replicate), and tail- and wing-feather integrity of all birds were scored. Fibrous diet did not modify BW uniformity, mortality, or tibia growth when compared with control diet. Pullets fed the fibrous diet had lower tibia breaking strength, elastic modulus, and ash content values (P < 0.05). They also had lower ALP serum level at 6 and 22 wk (P < 0.05), their breast muscle was less developed (18.5 vs. 19.8%, P < 0.05), and their abdominal fat deposition was higher (1.14 vs. 0.87%, P < 0.05). At 15 and 22 wk, they performed, on average, 97% less grasping feather pecking and 45% less non-food object pecking behaviors, and their wing-feather score was lower (P < 0.05) at 22 wk. Tail- and wing-feather scores of the control treatments were reduced by vitamin C inclusion (tail: 0.30 vs. 1.15, P < 0.05; wing: 0.98 vs. 1.26, P < 0.05) at 22 wk. In conclusion, fibrous diet improves carcass traits (reduces breast muscle and increases abdominal fat deposition), deteriorates bone mineral deposition and thus skeletal strength, and reduces stereotypic behaviors, improving wing-feather integrity. Vitamin C inclusion improves tail- and wing-feather integrity of lower in feed allowance.

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.

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.

Evolution of lipid classes and fatty acid digestibility along the gastrointestinal tract of broiler chickens fed different fat sources at different ages.

The aim of the present study is to evaluate the effect of the dietary fat saturation degree and age on the lipid class (TAG, DAG, MAG, and FFA) composition and fatty acid digestibility along the gastrointestinal tract (GIT) and excreta in broiler chickens. A total of 120 one-day-old female broiler chickens were randomly distributed in 2 dietary treatments (6 cages/treatment), which resulted from the supplementation of a basal diet with 6% of soybean oil or palm oil. Two digestibility balances were carried out at 14 and 35 d and fatty acid digestibility and lipid class composition were determined in the gizzard, duodenum, jejunum, ileum, and excreta. Along de GIT, both fatty acid digestibility and lipid class composition were influenced by the dietary fat source and the age of the chickens. The absorption of the unsaturated fat was more efficient and faster than it was for the saturated fat. The ability of adult chickens to absorb fat was higher than for young chickens. The results show that the duodenum is the main place of fat digestion (hydrolysis), and the jejunum the main place of fat absorption. The role of the ileum on fat absorption is very important, as it is the last segment of the GIT where the absorption of fatty acids has been described. Thus, it was the contribution of the ileum that was responsible for the higher fat utilization observed for animals fed the unsaturated diet than for those fed the saturated diet at 14 d, and it was also responsible for the improvement on the utilization of the saturated diet between 14 and 35 d. All the results suggest that the absorption of fatty acids is more limiting than is hydrolysis, because the main differences were observed in the jejunum and ileum, where the absorption of fatty acids takes place.

The different molecular structure and glycerol-to-fatty acid ratio of palm oils affect their nutritive value in broiler chicken diets.

The aim of this study is to assess how the fat molecular structure and its glycerol-to-fatty acid ratio (G : FA) affect the fatty acid (FA) apparent absorption of palm oils in broiler chickens. The experimental diets were the result of a basal diet supplemented with 6% of different palm oils. Native palm oil (N), rich in triacylglycerols, was the positive control (T1), and acid palm oil (A), rich in free FA, was the negative control (T2). In order to improve the nutritive value of A, two different nutritional strategies were performed. The first strategy was achieved by adding increasing amounts of free glycerol (G) (4% (T3), 8% (T4) and 16% (T5)) to A, and the second one by adding increasing amounts of mono- (MAG) and diacylglycerols (DAG), coming from re-esterified palm oil (E) (40% (T6), 70% (T7), and 100% (T8)) to A. As a result, eight dietary treatments were formulated with a G : FA ratio ranging from 0.04 to 0.67. These treatments were randomly assigned to 192 one-day-old female broiler chickens (Ross 308), distributed in 48 cages. The results showed how, by keeping the G : FA ratio constant (0.33 mol/mol), the diet with a high MAG and DAG content (T7) achieved higher saturated FA apparent absorption values than did the diet with a high triacylglycerol content (T1) and this, in turn, more than did the diet with a high free FA content (T4). The behavior of oils with high or low G : FA ratio was dependent on whether G was in a free state or esterified as part of acylglycerol molecules. Thus, increasing amounts of G to A did not enhance the total FA apparent absorption, but rather quite the opposite, even impairing the absorption of mono- and polyunsaturated FA. However, increasing amounts of E (rich in MAG and DAG) to A (rich in FFA) did enhance total FA apparent absorption, primarily due to the increased absorption of saturated FA. In conclusion, the greater the G : FA ratio of a palm oil, the greater the absorption of total FA, as long as G is esterified as part of acylglycerol molecules. Thus, the re-esterification process for obtaining E makes sense in order to give added value to A, achieving even greater digestibility values than does its corresponding N.

Use of re-esterified palm oils, differing in their acylglycerol structure, in fattening pig diets.

Re-esterified oils are new fat sources obtained from the chemical esterification of acid oils with glycerol (both economically interesting by-products from oil refining and biodiesel industries, respectively). The different fatty acid (FA) positional distribution and acylglycerol composition of re-esterified oils may enhance the apparent absorption of saturated fatty acids (SFA) and, therefore, their overall nutritive value, which might lead to an increased deposition of SFA. The aim of the present study was to investigate the potential use of re-esterified palm oils, in comparison with their corresponding acid and native oils in fattening pig diets, studying their effects on fatty acid apparent absorption, acylglycerol and free fatty acid (FFA) composition of feces, growth performance, carcass-fat depots and fatty acid composition of backfat. Seventy-two crossbred boars and gilts (average weight of 24.7 ± 2.55 kg) were blocked by initial BW (nine blocks of BW for each gender), housed in adjacent individual boxes, and fed one of the four dietary treatments, which were the result of a basal diet supplemented with 4% (as-fed basis) of native palm oil (PN), acid palm oil (PA), re-esterified palm oil low in mono- and diacylglycerols (PEL), or re-esterified palm oil high in mono- and diacylglycerols (PEH). Regarding results from the digestibility balance, PA and PN showed similar apparent absorption coefficients (P>0.05), despite the high, FFA content of the former. However, re-esterified palm oils (both PEL and PEH) showed a higher apparent absorption of total FA than did their corresponding native and acid oils (P0.05). We conclude that re-esterified oils are interesting fat sources to be considered in fattening pigs.

Effect of different levels of calcium and phosphorus and their interaction on the performance of young broilers.

A study was conducted to evaluate the interaction among 3 levels of Ca and 4 levels of nonphytate phosphorus (NPP) on broiler performance, bone ash, and whole-body fractional retention of Ca and P. Ross male broiler-chicks (n=420) were sorted by BW at d 1 posthatch and assigned to 5 cages/diet with 7 birds/cage. Twelve diets were arranged in a 3×4 factorial of 3 levels Ca (at 0.5, 0.7, or 0.9%) and 4 levels NPP (at 0.25, 0.31, 0.38, or 0.45%) with a high dose of phytase (1,150 U/kg) in all diets. On d 14, chickens were euthanized and the right tibia was collected from 3 birds/replicate; the rest of the animals were used to measure whole-body Ca and P retention. An interaction was observed between the level of Ca and NPP on feed intake (FI), tibia weight, and bone-ash content (P<0.05). Increasing the level of NPP from 0.25 to 0.38% increased FI (P<0.05) on chickens fed the high-Ca diet (0.9%), but not with Ca at 0.5 or 0.7%. Broilers achieved their greatest weight gain (WG) and bone formation with 0.7% Ca and 0.38% NPP. Increasing the dietary Ca decreased its fractional retention from 74% with dietary Ca at 0.5 to 46% with Ca at 0.9%. The increase in the levels of dietary P steadily increased the fractional retention of Ca from 53 to 61%, and increased the whole-body Ca content (g/kg BW). It can be concluded that a dietary level of 0.38% NPP/kg in diets containing a high dose of phytase (1,150 U/kg) and 0.7% Ca are adequate to ensure broiler performance and bone ash of broilers from d 0 to d 14 posthatch.

Use of combinations of re-esterified oils, differing in their degree of saturation, in broiler chicken diets.

Re-esterified oils contain higher proportions of mono- and diacylglycerols, and also higher proportions of saturated fatty acids (SFA) at the sn-2 position of acylglycerol molecules than does a native oil with the same degree of saturation, which enhances the apparent absorption of SFA. Moreover, as happens with native oils, their nutritive value could be further improved by blending re-esterified oils of extreme degrees of saturation. Therefore, the aim of the current study was to assess the effect of increasing the dietary unsaturated-to-saturated fatty acid ratio (UFA:SFA) by adding re-esterified soybean oil in replacement of re-esterified palm oil, on fatty acid (FA) apparent absorption and its consequences on growth performance, carcass fat depots, and FA composition of abdominal adipose tissue. For this purpose, one hundred twenty 1-day-old female broiler chickens were randomly distributed in 30 cages. The 2 pure re-esterified oils, together with 3 re-esterified oil blends, were included in the basal diet at 6%. The increasing dietary UFA:SFA ratio resulted in an improved total FA apparent absorption (linear effect for the starter period, P = 0.001; quadratic effect for the grower-finisher period, P = 0.006) and, therefore, an improved feed conversion ratio (FCR) for the overall period (linear effect, P = 0.003). In the starter period, the improved fat absorption was due to the growing presence of linoleic acid and the enhanced absorption of SFA, mono- and polyunsaturated FA (associative effects among FA; P < 0.05). In the growing-finishing period, however, the absorption of mono- and polyunsaturated FA was not affected (P > 0.05). The UFA:SFA ratio of the abdominal adipose tissue varied in the same direction, but to a lesser extent than that of the diet. Whilst the deposited-to-absorbed ratio of polyunsaturated FA remained relatively constant as the dietary UFA:SFA ratio increased, the deposited-to-absorbed ratio of SFA increased, and that of monounsaturated FA decreased. Taken together, the addition of re-esterified soybean oil in replacement of re-esterified palm oil improved fat absorption, but no synergism was observed between re-esterified oils.

Evaluation of the use of esterified fatty acid oils enriched in medium-chain fatty acids in weight loss diets for dogs.

Esterified fatty acid oils (EAOs) are obtained from esterification of vegetable acid oils with glycerol. These fat sources have the same fatty acid (FA) composition as their respective native oils but new chemical properties. Several studies have confirmed the potential of medium-chain fatty acids (MCFA) to reduce fat mass (FM) in humans and rodents. This study investigates the use of EAOs with different MCFA proportions on food preferences, digestibility and weight loss management in dogs. A basal diet was supplemented with 8% of three different fat sources: C0: soya bean-canola EAO, C20: soya bean-canola (80%) coconut (20%) EAO and C40: soya bean-canola (60%) coconut (40%) EAO. Food preference of these EAOs was tested using a two-pan preference test. Dogs presented a higher daily food intake of C20 and C40 compared to C0 (C20: 155 ± 18.6 g vs. C0: 17 ± 7.0 g, p < 0.001; C40: 117 ± 13.9 g vs. C0: 28 ± 10.5 g, p < 0.05 respectively). Also, the digestibility of the three experimental diets was tested. C20 and C40 showed higher ether extract, total FA and saturated FA digestibilities (p < 0.05) than C0 diet. Lastly, the three diets were investigated in a 14-week weight loss study, following 16 weeks of ad libitum feeding to induce overweight condition. Body weight (BW) reduction was lower (C0: 20.1 ± 2.32%, C20: 14.6 ± 1.43% and C40: 15.7 ± 1.23%, p < 0.05) and FM was higher (FM, 18.7 ± 3.42%, 27.9 ± 3.90% and 28.2 ± 2.88% for C0, C20 and C40, respectively, p < 0.05) for diets C20 and C40 than for C0. Feeding diets with MCFA at these inclusion levels to experimentally overweight dogs during 14 weeks do not result in faster weight loss compared to unsaturated long-chain FA.

Use of re-esterified palm oils, differing in their acylglycerol structure, in weaning-piglet diets.

Re-esterified oils are new fat sources obtained from chemical esterification of acid oils with glycerol (both economically interesting by-products from oil refining and biodiesel industries, respectively). The different fatty acid (FA) positional distribution and acylglycerol composition of re-esterified oils may enhance the apparent absorption of saturated fatty acids (SFA) and, thus, their overall nutritive value. The aim of the present study was to investigate the potential use of re-esterified palm oils, in comparison with their corresponding acid and native oils, and also with an unsaturated fat source in weaning-piglet diets. The parameters assessed were: FA apparent absorption, acylglycerol and free fatty acid (FFA) composition of feces, and growth performance. One-hundred and twenty weaning piglets (average weight of 8.50±1.778 kg) were blocked by initial BW (six blocks) and randomly assigned to five dietary treatments, resulting in four piglets per pen and six replicates per treatment. Dietary treatments were a basal diet supplemented with 10% (as-fed basis) of native soybean oil (SN), native palm oil (PN), acid palm oil (PA), re-esterified palm oil low in mono- (MAG) and diacylglycerols (DAG) (PEL), or re-esterified palm oil high in MAG and DAG (PEH). Results from the digestibility balance showed that SN reached the greatest total FA apparent absorption, and statistically different from PN, PA and PEL (P0.05), but PEH achieved the greatest total FA apparent absorption. Animals fed PEL, despite the fact that PEL oil contained more sn-2 SFA, did not show an improved absorption of SFA (P>0.05). Animals fed PA and PN showed similar apparent absorption coefficients (P>0.05), despite the high FFA content of PA oil. The acylglycerol and FFA composition of feces was mainly composed of FFA. There were no significant differences in growth performance (P>0.05). Results of the present study suggest that, despite the different acylglycerol structure of re-esterified oils, there were no significant differences in digestibility or performance with respect to their corresponding PN and PA oils in weaning-piglet diets.

Use of re-esterified oils, differing in their degree of saturation and molecular structure, in broiler chicken diets.

The aim of the present study was to investigate the potential use of re-esterified oils, differing in their degree of saturation and molecular structure, in comparison with their corresponding acid and native oils in broiler chicken diets. For this purpose, 144 one-d-old female broiler chickens were randomly distributed in 48 cages. Birds were fed a basal diet supplemented with 6% of native palm oil ( PN: ), acid palm oil ( PA: ), re-esterified palm oil low in mono- ( MAG: ) and diacylglycerols ( DAG: ) ( PEL: ), re-esterified palm oil high in MAG and DAG ( PEH: ), native soybean oil ( SN: ), acid soybean oil ( SA: ), re-esterified soybean oil low in MAG and DAG ( SEL: ), or re-esterified soybean oil high in MAG and DAG ( SEH: ), which resulted in a 2 × 4 factorial arrangement. Digestibility balances showed that the degree of saturation of fat generally exerted a greater impact than did the fat molecular structure. The dietary utilization of S sources was higher than that of P sources. However, the increased sn-2 saturated fatty acid ( SFA: ) content of EL oils in the starter period and the increased MAG and DAG content of EH oils in the grower-finisher period yielded favorable effects on the SFA apparent absorption, especially in those birds fed re-esterified palm oils. The excreta acylglycerol and free fatty acid composition was mainly composed of free fatty acids, and their amount almost paralleled the results observed for SFA apparent absorption. For growth performance, birds fed S exhibited better feed conversion ratios and lower abdominal fat-pad weights than did those fed P. The fatty acid composition of abdominal adipose tissue was also mainly affected by the degree of saturation of dietary fat sources. We concluded that re-esterified oils, mainly from P sources, can be used in broiler chicken diets as alternative fat sources since they show similar or even higher total fatty acid apparent absorption than do their corresponding native and acid oils, with small changes in abdominal adipose tissue fatty acid composition.

Re-esterified palm oils, compared to native palm oil, do not alter fat absorption, postprandial lipemia or growth performance in broiler chicks.

Re-esterified palm oils are obtained from the chemical esterification of palm acid oils (rich in free fatty acids) with glycerol, both economically interesting by-products from oil refining and biodiesel industries, respectively. Thus, re-esterified palm oils could be an economically interesting alternative to native palm oil in broiler chick diets. However, because they may have different physicochemical properties than have their corresponding native oil, we assessed the effect of fatty acid (FA) positional distribution within acylglycerol molecules and the effect of acylglycerol composition on FA apparent absorption, and their possible consequences on the evolution of postprandial lipemia and growth performance in broiler chicks. Seventy-two 1-day-old female broiler chicks were randomly distributed into 18 cages. The three treatments used were the result of a basal diet supplemented with 6 wt% of native palm oil (N-TAG), re-esterified palm oil (E-TAG), or re-esterified palm oil high in mono- and diacylglycerols (E-MDAG). Chemical esterification raised the fraction of palmitic acid at the sn-2 position from 9.63 mol% in N-TAG oil to 17.9 mol% in E-TAG oil. Furthermore, E-MDAG oil presented a high proportion of mono- (23.1 wt%) and diacylglycerols (51.2 wt%), with FA mainly located at the sn-1,3 positions, which resulted in a lower gross-energy content and an increased solid-fat index at the chicken's body temperature. However, re-esterified palm oils did not alter fat absorption, postprandial lipemia, or growth performance, compared to native palm oil, so they can be used as alternative fat sources in broiler chick diets.

Comparison of postprandial lipaemia between native and palm random esterified acid oils in two different monogastric species (dogs and broiler chickens).

It has been reported that applying a chemical reesterification process to a native fat results in a new fat source with different physicochemical properties due to their different fatty acid (FA) positional distribution within the glycerol moiety and their different proportions of mono (MAG)-, di (DAG)- and triacylglycerides (TAG). Thus, this reesterification could affect fat digestion, absorption and metabolism; and this effect could vary among species given their differences in fat metabolism. The aim of this study was to compare the effect of feeding two different random esterified acid oils (REAO), presenting different MAG, DAG and TAG proportions, with their corresponding native oil on postprandial lipaemia in broiler chickens and dogs. For this purpose, 18 dogs and 54 broiler chickens were fed a basal diet supplemented with palm native oil, palm REAO low MAG or palm REAO high MAG. The inclusion level of the oils was 10% of the diet in dogs and 6% in broiler chickens. Serum postprandial TAG concentration (mg/dl) after feeding a single meal was measured at different time points during 12 h in dogs and 3 h in chickens. Although fasting serum TAG concentration values were similar for both species (47 ± 2.4 mg/dl for dogs and 44 ± 3.0 mg/dl for broilers; p = 0.522), postprandial TAG concentrations tended to be higher in broilers than in dogs (p = 0.058). Treatment had no effect on TAG concentration at any time point in any species (p = 0.768 for dogs, p = 0.947 for broilers). However, the postprandial TAG curves were very different between species; in broiler chickens, TAG concentration returned to the fasting values 3 h after feeding while in dogs, the TAG concentration still had not returned to basal levels 12 h after feeding.

High levels of dietary unsaturated fat decrease alpha-tocopherol content of whole body, liver, and plasma of chickens without variations in intestinal apparent absorption.

An experiment was designed to assess the effect of dietary unsaturated fat inclusion level on alpha-tocopherol apparent absorption and deposition in broiler chickens at 2 ages (20 and 39 d). The dietary fat was a mixture of linseed and fish oil, rich in polyunsaturated fatty acids (PUFA). The experimental treatments were the result of 4 levels of supplementation with alpha-tocopheryl acetate (0, 100, 200, and 400 mg/kg; E0, E100, E200, and E400 treatments, respectively) and 4 dietary oil inclusion levels (2, 4, 6, and 8%; O2, O4, O6, and O8 treatments respectively). Almond husk was used as an energy dilutor in the high-fat diets. Apparent absorption of total fatty acids was high in all treatments averaging 88% and was higher with high fat dietary inclusion level. alpha-Tocopheryl acetate hydrolysis and apparent absorption of alpha-tocopherol were similar in both ages and were not affected by fat inclusion level, except for a reduction of the absorption in the low-fat diet (O2) in the E100 treatment at 20 d of age. Despite this lack of differences in hydrolysis and absorption, higher-fat PUFA diets induced lower concentrations of free alpha-tocopherol in the excreta, at high alpha-tocopherol doses, suggesting an increase in the destruction of alpha-tocopherol by lipid oxidation in the gastrointestinal tract. Similarly, total and hepatic alpha-tocopherol deposition was lower in the birds fed high-PUFA diets in the E200- and E400-supplemented birds, possibly due to a destruction of vitamin E when protecting these PUFA from lipid peroxidation. alpha-Tocopherol concentration in liver and, to a lesser extent, in plasma was a useful indicator of the degree of response of this vitamin to different factors that can affect its bioavailability; however, in the present experiment, CV were too high to use liver and plasma concentrations as estimators of total body vitamin E.