Effects of dietary medium-chain fatty acids on performance, carcass characteristics, and some serum parameters of broiler chickens

Comparative impact of bacitracin and select feed additives in the feeding program of Lohmann LSL-Lite pullets at the onset of lay through to 31 weeks of age

There are limited investigations on the role of feed additives in easing transition of pullets to egg production phase. We investigated the effects of supplementation of bacitracin methylene disalicylate (BMD) and select feed additives (myristic acid [MA], benzoic acid [BA], and Aspergillus niger probiotic [PRO]) in feeding program for pullets from the onset of lay through to 31 weeks of age (woa). Parameters measured included hen-day egg production (HDEP), feed intake (FI), feed conversion ratio (FCR), egg quality characteristics, ceca microbial activity, apparent retention of components, and plasma metabolites. A total of 1,200 Lohmann LSL Lite pullets were procured at 18 woa and placed in enriched cages (30 birds/cage) based on body weight (BW) and allocated to five diets. The diets were a basal diet formulated to meet specifications or basal mixed with either BMD, MA, BA, or PRO. Birds had free access to feed and water throughout the experiment. Between 18 and 20 woa, birds fed BMD ate a similar (P > 0.05) amount of feed to BA birds, but more (P = 0.0003) than birds fed basal, MA, or PRO diets. Basal birds had lower HDEP (P = 0.001) and lighter eggs (P < 0.0001) than birds fed any of the feed additives between 21 and 31 woa. The basal hens had a higher (P = 0.009) abundance of Escherichia coli than birds fed BMD, BA, and PRO diets. Consequently, BMD, BA, and PRO birds had a higher (P = 0.011) Lactobacilli: E. coli ratio (LER) than hens fed the basal diet. Specifically, relative to basal-fed hens, the LER of the BMD, MA, BA, and PRO hens was higher by 37%, 21%, 26%, and 45%, respectively. Moreover, birds fed PRO tended to have a higher concentration of ceca digesta acetic acid (P = 0.072) and a lower concentration of isobutyric acid (P = 0.096). In conclusion, supplementing pullet diets with broad-spectrum antibiotics or feed additives (MA, BA, and PRO) had a positive impact on FI, and egg production linked to modulation of indices of gut health. The results suggested supplementing feed additives in feeding programs for pullets at the onset of lay can bolster productivity outcomes.

Comparative effects of medium-chain fatty acids or phytobiotics-based feed additives on performance, caecum microbiota, volatile fatty acid production and intestinal morphology of broilers

Antibiotic growth promoters have been utilized in broiler nutrition to alleviate the negative effects of the pathogenic microbes to promote performance. However, after the prohibition of antibiotics because of the increasing disclosure related to public health issues, various products have been developed as alternatives. This study was carried out to determine the effects of medium-chain fatty acids (MCFAs) or phytobiotics (essential oils [EOs] and alkaloids [ALKs]), blended feed additives on the growth performance, jejunum histomorphology, and cecal microbiota of broiler chickens. A total of 765 male Ross 308 chicks were randomly distributed into 5 experimental groups, each having 9 replicates with 17 chicks. The experimental procedures were as follows: a control group without supplementation (T1); control group+ MCFAs and EOs blend (T2); control group+ different EOs blend (T3); control group+ ALK sanguinarine (T4); and control group+ EOs and ALK piperine mixture (T5). The results showed that, broilers fed with MCFAs blended with EOs had significantly greater body weight gain during overall period in comparision to the control and T3 groups. Further, only MCFAs blended with EOs group significantly improved jejnum morphology in comparison with the control group (p ≤ 0.05). Besides, the MCFAs blended with EOs group significantly elevated propionate, acetate and butyrate concentration, and decreased the concentration of branch chain fatty acids in caecum (p ≤ 0.05). The results indicated that, the combination of MCFAs and EOs seems to have improvement effects and could be preferred as an efficient feed additive in broiler production.

Effect supplementation of black soldier fly larvae oil (Hermetia illucens L.) calcium salt on performance, blood biochemical profile, carcass characteristic, meat quality, and gene expression in fat metabolism broilers

This study evaluated the effect supplementation of black soldier fly larvae oil calcium salt (BSFLO-SCa) on performance, blood biochemical profile, carcass characteristic, meat quality, and gene expression in fat metabolism broiler chickens. A total of 280 male New Lohmann strain MB 202 broiler chicks (1-day-old) were randomly placed into 4 treatments, including a control group (T0) were fed basal diet and a basal diet supplemented with 1% (T1), 2% (T2), and 3% (T3) BSFLO-SCa. Each treatment consisted of 7 pens with 10 chickens each. Results showed that 1% BSFLO-SCa supplementation significantly reduced (P < 0.05) abdominal and meat fat, while gene expression on fat synthesis (FAS, ACC) was downregulated. Meat fatty acid profiles such as medium-chain fatty acid being dominant in lauric and myristic and monosaturated fatty acid significantly increased (P < 0.05). On the other hand, polyunsaturated fatty acid significantly decreased (P < 0.05). In addition, the other parameters did not affect by supplementation of 1% BSFLO-SCa. The addition starting from 2% significantly reduced (P < 0.05) performance and carcass characteristics. Blood biochemical profiles (HDL, protein, albumin) and meat qualities (protein, cholesterol, water-holding capacity, cooking losses, a* (redness), and b* (yellowness) values) were significantly increased (P < 0.05), while gene expression on fat oxidation (CPT-1) was upregulated. In conclusion, broiler chicken that received of 1% BSFL-SCa does not negatively affect growth performance and carcass characteristics but reduced fattening in broiler meat.

Evaluation of dynamic effects of dietary medium-chain monoglycerides on performance, intestinal development and gut microbiota of broilers in large-scale production

Medium-chain monoglycerides (MG) have been reported to affect the productive performance, gut microbiota and health of broiler chickens reared in ideal experimental conditions at home and abroad. However, the effects of MG on performance, intestinal development and gut microbiota of chickens in large-scale farms during different feed stages remain unknown. The present study was conducted on a modern farm with a total of 12,000 yellow feathered broiler chicks that were randomly allotted to 2 groups (1000 chicks/replicate, 6 replicates/group) for a 70-day trial. The control group (CON group) received a basal diet, and the treated group (MG group) was fed a basal diet containing 300 mg/kg mixed MG. The results revealed that dietary MG significantly (P < 0.05) increased the body weight and average feed intake, but notably reduced the feed conversion and mortality of chickens in large-scale production during the starter phase. The villus height of the duodenum in the MG group at 1, 2 and 7 wk of age increased notably, and the villus height to crypt depth ratio at 1, 2, 5 and 10 wk of age was improved. Dietary MG decreased the serum insulin content of chickens at 5, 7 and 10 wk of age, and decreased the serum lipopolysaccharide at 3 and 7 wk of age. The triglyceride level of chickens at 3, 5 and 10 wk of age and the low-density lipoprotein cholesterol level of chickens at 7 and 10 wk of age in the MG group decreased notably, while the high-density lipoprotein cholesterol increased significantly. Moreover, MG supplementation selectively increased the relative abundance of genus Bacteroides (family Bacteroidaceae) and Lachnospiraceae_NK4A136_group, but decreased the content of genus Rikenellaceae_RC9_gut_group, Collinsella and family Barnesiellaceae in the cecum of chickens at 3, 7 and 10 wk of age. Conclusively, these findings showed that dietary MG notably enhanced chicken performance, health and feed nutrient utilization at early ages by regulating gut microbiota, intestinal development and serum biochemical indices.

Effects of Glyceryl Monolaurate on Production Performance, Egg Quality, Oviduct Cytokines and Intestinal Microflora of 66 Weeks Old Laying Hens

The principal purpose of this research was to study the effects of glycerol monolaurate (GML) on the production performance; egg quality; health state of the oviduct, ovary and ileum; and gut microbiota of laying hens in the later stage. The laying hens were randomly assigned to two groups: a control group and an experiment group, for which 1000 mg/kg of GML was added to a control diet. The results showed that GML increased the laying rate, average egg weight, albumen height, yolk color and Haugh unit and decreased the feed conversion ratio and defective eggs (p < 0.05). GML increased the intestinal villi height and the ratio of villus height to crypt depth (p < 0.05). Moreover, GML improved the contents of cytokines in the oviduct, ovary and ileum mucosa; ameliorated the expression of TLR2, TLR4, MyD88, IL-4, IL-1β and TNF-α; and increased the expression of Occludin and Muc-2 in the ileal mucosa. The supplementation of GML increased the volatile fatty acids in the cecal contents, such as acetic acid and propionic acid, and up-regulated Bacteroides (p < 0.01) and Alistipes (p < 0.05) richness in the cecal contents. In summary, GML improved production performance, egg quality and immunity; ameliorated the health status of the oviduct, ovary and ileum; enhanced the intestinal barrier function; improved the content of intestinal volatile fatty acids; and regulated the abundance of cecal flora.

Impact of Dietary Supplementation with Sodium Butyrate Protected by Medium-Chain Fatty Acid Salts on Gut Health of Broiler Chickens

Nutritional strategies to improve gut health of broilers are under research. This study investigated the effect of dietary supplementation with sodium butyrate protected by sodium salts of medium-chain fatty acids as a feed additive on broiler gut health. The first experiment was conducted to evaluate the effect of supplementing at 0.5, 1, and 2 kg/t in broilers housed under optimal conditions. Supplementation at 0.5 and 1 kg/t maintained goblet cell counts at 10 days of age (p ≤ 0.05), and supplementation at 1 kg/t decreased intraepithelial lymphocyte counts compared to 2 kg/t at 39 days (p ≤ 0.10). Abdominal fat pad levels of lauric and myristic acids were gradually increased by supplement dose (p ≤ 0.05). In the second experiment, the feed additive at 1 kg/t was evaluated in coccidiosis-challenged broilers. Experimental treatments were as follows: non-challenged, control-challenged, and supplemented-challenged treatments. Coccidiosis negatively impact performance and modify histomorphometry and microbiota (p ≤ 0.05). The feed additive increased crypt depth at 7 days post-inoculation and goblet cell count at 14 days post-inoculation (p ≤ 0.05). Further, supplementation interacted with the microbiota modification led by the coccidiosis (p ≤ 0.05). These results suggest that this feed additive could be a useful strategy to reinforce the gut barrier, especially for birds under coccidiosis-challenge treatments.

The effect of different medium chain fatty acids, calcium butyrate, and salinomycin on performance, nutrient utilization and gastrointestinal tract of chicken of Polish Green Legged Partridge hen

The present study aimed to determine the effect of diets supplemented by feed additives, on the growth performance and digestive tract functioning in chicken of green-legged partridge hen (GLPH). Two types of diets were used. The both “low-digestible” (LD) diet characterized by high level of crude fibre and lard, and “high-digestible” (HD) diet characterized by low content of crude fibre and soybean oil were supplemented by different additives such as 0,34% DM (dry matter) salinomycin, 0,30 % DM medium-chain triglycerides (MCT), 1,00 % DM calcium butyrate (CB), or 0,85 % DM medium-chain fatty acids (MCFA). The experiment was conducted on 960 one-day-old male chickens of GLPH, randomly divided into 10 treatment groups. One group consisted of 12 replications (each with 8 birds). Chickens fed HD diet presented significantly higher body weight gain (BWG) in 15-56 days and also 0-56 days of experiment and lower feed conversion ratio (FCR) during whole time (0-56 days) of experiment (P < 0.05). Addition of CB and MCFA did not affect the differences in BWG (15-56; 0-56 days) and FCR (15-56 days) in comparison with the control diet. Significant interaction between the type of diet and additives (P < 0.05) was observed for feed intake (FI) throughout the experiment. The highest FI was found on LD diet with CB. On LD diet, all additives resulted in significantly worse nitrogen retention, however, on HD diet, it was observed only for salinomycin. The additives had no impact on fat digestibility when chickens were fed HD diet. There was significant (P < 0.05) lower-fat digestibility when LD diet with MCT, CB, and MCFA was used. The greatest value of nitrogen-corrected apparent metabolizable energy (AMEN) was found on HD diet (P < 0.05). The addition of MCT, CB, and MCFA increased the percentage share of ileum, and MCT also significantly increased the percentage share of the liver. The lactic acid bacteria and C. perfringens counts were lower on HD diet (P<0,05). The addition of MCT and CB increased the count of lactic acid bacteria in ceaca (P<0,05). Many interactions between experimental factors in this experiment showed that the efficacy of using different feed additives depends on the type of diet. The results suggest that MCFA may be the most beneficial feed additive for GLPH chicken as an alternative for antibiotic growth promoters (AGP).

Overview of the Use of Probiotics in Poultry Production

Simple Summary

Probiotics are feed additives that have gained popularity in poultry production following the ban of antibiotic growth promoters (AGP). They are one of the more universal feed additives and can be easily combine with other additives. Probiotics, above all, have many advantages, including stimulation of the host microflora or immunomodulation. The statement “immunity comes from the intestines” has become more important in the poultry industry because probiotics have proven helpful in the fight against diseases of bacterial origin and against zoonoses. Positive effects on the organism have already been studied at the cellular level, where probiotics were responsible for changes in gene expression, leading to alleviation of heat stress. In addition to the health benefits, the utility value of the animals increases. The numerous advantages are overshadowed by a few drawbacks, which include the possibility of lowering semen quality in roosters and the diversity of production processes affecting the persistence of the probiotic. In addition to bird health, probiotics have improved the taste and quality of poultry products. Future prospects are promising as scientists are working to maximize the positive effects of probiotics by increasing the integrity of probiotics within the bird organism, taking into account, among others, bacterial metabolites.

Abstract

In recent years, probiotics have become more popular in the world of dietary supplements and feed additives within the poultry industry, acting as antibiotic substitutes. Above all, probiotics are universal feed additives that can be used in conjunction with other additives to promote improved performance and health. Their positive effects can be observed directly in the gastrointestinal tract and indirectly in immunomodulation of the poultry immune system. Nutritional effects seen in flocks given probiotics include increased laying and egg quality, increased daily increments, and improved feed conversion ratio (FCR). There has also been an improvement in the quality of meat. This suggests producers can improve production results through the use of probiotics. In addition to these production effects, bird immunity is improved by allowing the organism to better protect itself against pathogens and stress. The lack of accuracy in the formulation of non-European preparations needs to be further developed due to unknown interactions between probiotic bacteria strains as well as their metabolites. The versatility of probiotics and the fact that the bacteria used in their production are an integral part of animal digestive tracts make them a safe feed additives. Despite restrictions from the European Union, probiotics have potential to improve production and health within the poultry industry and beyond. The following article will review the use of probiotics in poultry production.

Effects of Medium Chain Fatty Acids on Intestinal Health of Monogastric Animals

Medium-chain fatty acids (MCFAs) are the main form of Medium Chain Triglycerides (MCTs) utilized by monogastric animals. MCFAs can be directly absorbed and supply rapid energy to promote the renewal and repair of intestinal epithelial cells, maintain the integrity of intestinal mucosal barrier function, and reduce inflammation and stress. In our review, we pay more attention to the role of MCFAs on intestinal microbiota and mucosa immunity to explore MCFA's positive effect. It was found that MCFAs and their esterified forms can decrease pathogens while increasing probiotics. In addition, being recognized via specific receptors, MCFAs are capable of alleviating inflammation to a certain extent by regulating inflammation and immune-related pathways. MCFAs may also have a certain value to relieve intestinal allergy and inflammatory bowel disease (IBD). Unknown mechanism of various MCFA characteristics still causes dilemmas in the application, thus MCFAs are used generally in limited dosages and combined with short-chain organic acids (SOAs) to attain ideal results. We hope that further studies will provide guidance for the practical use of MCFAs in animal feed.

Dietary medium-chain α-monoglycerides increase BW, feed intake, and carcass yield in broilers with muscle composition alteration

Glycerol monolaurate (GML), a member of medium-chain α-monoglycerides (MG), is proved to be beneficial for productive performance, feed efficiency, and health of broilers based on recent research. The present study aims to evaluate the effect of MG mixture rich in GML and glycerol monodecanoate on performance, intestinal development, serum parameters, carcass yield, and muscle composition in broilers. A total of 528 chicks were weighed and randomly assigned into 4 groups (22 chicks/replicate, 6 replicates/group) for a 56-d experiment. The control group received a basal diet containing 0 mg/kg MG (CON), and the treated groups fed basal diets containing 300 (MG300), 450 and 600 mg/kg MG. The results revealed that the BW (P < 0.05), ADG, and ADFI were notably increased in MG-containing groups during the finisher phase compared with the CON group. Remarkable intestinal improvements were observed in the duodenum and jejunum of MG-treated groups, but no statistical differences were obtained. Dietary MG significantly (P < 0.05) increased the serum high-density lipoprotein cholesterol, total protein, and superoxide dismutase content in broilers. Inclusion of 300 mg/kg MG in diet increased the eviscerated yield (P = 0.066), leg muscle (P < 0.01) and breast muscle yield (P = 0.083), and improved the fresh meat quality with reduced drip loss (P < 0.01) and pH decline (P < 0.01) compared with the CON group. Moreover, the saturated fatty acid (P = 0.073), flavor amino acid (P < 0.05), and total amino acid (P < 0.05) content was notably higher in the muscle of the MG300 group than that in the CON group. In summary, these findings revealed that mixed MG can be used as an effective and novel feed supplement to improve productive performance and quality of broilers.

Effect of Dietary Medium-Chain α-Monoglycerides on the Growth Performance, Intestinal Histomorphology, Amino Acid Digestibility, and Broiler Chickens' Blood Biochemical Parameters

Simple Summary

The addition of biologically active materials to animal feed is a very recent topic regarding antibiotic alternatives. This study inspected the influence of graded levels of medium-chain α-monoglycerides, glycerol monolaurate (GML) on the growth performance, apparent ileal digestibility coefficient (AID%) of amino acids, and intestinal histomorphology of broiler chickens. Broiler chickens (76.82 g ± 0.40, n = 200) were fed on four experimental diets that were complemented with 0; 1; 3; or 5 g kg⁻¹ glycerol monolaurate (GML0; GML1; GML3; and GML5). The findings suggested that glycerol monolaurate supplementation can improve the immune status and intestinal histomorphology of broiler chickens with no improving effect on the growth performance.

Abstract

This trial was conducted to assess the impact of medium-chain α-monoglycerides, glycerol monolaurate (GML) supplementation on the growth performance, apparent ileal digestibility coefficient (AID%) of amino acids, intestinal histomorphology, and blood biochemical parameters of broiler chickens. Three-day-old chicks (76.82 g ± 0.40, n = 200) were haphazardly allocated to four experimental groups with five replicates for each (10 chicks/replicate). The treatments consisted of basal diets supplemented with four glycerol monolaurate levels; 0, 1, 3, or 5 g kg⁻¹ (GML0, GML1, GML3, and GML5, respectively). Growth performance was determined at three periods (starter, grower, and finisher). Dietary GML had no significant effect on the growth performance parameters (body weight, weight gain, and feed conversion ratio) through all the experimental periods. GML1 diet increased the AID% of leucine and decreased the AID% of arginine. GML1 diet increased the duodenal and jejunal villous height and the jejunal muscle thickness. GML3 and GML5 diets increased the goblet cell count in the duodenum. GML supplementation increased the serum level of high density lipoprotein (HDL)-cholesterol. GML5 diet increased the serum levels of IgM and interleukin 10 compared to the control group. We could conclude that dietary supplementation of glycerol monolaurate can supplement broiler chicken diets up to 5 g kg⁻¹ to enhance the immune status and intestinal histomorphology of birds with no improving effect on growth performance.

Glycerol monolaurate improves performance, intestinal development, and muscle amino acids in yellow-feathered broilers via manipulating gut microbiota

Recent studies reveal that glycerol monolaurate (GML) is regarded as an effective feed supplement in the production of broilers; however, the underlying mechanism remains unknown. The current study aimed to investigate how GML affected production performance and meat quality in yellow-feathered broilers. A total of 528 chicks were randomly assigned into four groups for a 56-day feeding trial. The control group received a basal diet, and the treated groups fed basal diet containing 300 (GML300), 450 (GML450), and 600 (GML600) mg/kg GML. Results revealed that dietary GML notably increased the average daily feed intake (p < 0.05) and body weight in broilers during 28-56 days of age and improved the duodenum and jejunum morphology. Dietary GML increased the total cholesterol in broilers (p < 0.05), but the hepatic, abdominal, and muscular fat deposition, as well as muscle fatty acids, were not affected. The flavor amino acids and total amino acids in muscle of GML300 and GML 450 groups were notably (p < 0.05) increased. GML supplementation selectively increased the colonization of an unclassified genus of Lachnospiraceae family and Bifidobacteriaceae, which were significantly (p < 0.05) correlated with the increase of muscle amino acids. Meanwhile, dietary GML notably increased short chain fatty acids content and the microbial DNA abundance of carbohydrate, amino acids and lipid metabolism pathway in cecum. These findings demonstrated that dietary GML improved performance, intestinal morphology, and muscle amino acids in broilers mainly by manipulating community, function and metabolites of gut microbiota. KEY POINTS: • GML improves performance, muscle composition, and feed efficiency in broilers. • GML alters gut microbiota community, function, and microbial metabolites in broilers. • Improvements of broilers by GML closely associated with gut microbiota alteration. Graphical abstract.

Medium-chain α-monoglycerides improves productive performance and egg quality in aged hens associated with gut microbiota modulation

The present study aimed to evaluate the effects of medium-chain α-monoglycerides (MG) on productive performance, egg quality, serum biochemical indices, and gut microbiota in laying hens. A total of 252 40-wk-old Hy-Line Brown laying hens were randomly allotted into two groups (21 hens per replicate, 6 replicates per group) and fed with a basal diet (CON group) or a basal diet containing 300 mg/kg of MG (MG300 group). The eggs laid were recorded daily on a replicate basis, and egg quality was measured at 48, 56, and 64 wk of age. At the end of this trial, three randomly selected hens from each replicate were slaughtered, and the serum and cecal digesta were collected for analysis of serum biochemical indices and sex hormones and gut microbiota composition determination. The results revealed that the laying rate was significantly (P < 0.05) increased in the MG300 group, and the feed conversion ratio was decreased (P < 0.01) during 40–64 wk of age. The eggshell strength at 56 wk of age and eggshell thickness at 56 and 64 wk of age were significantly (P < 0.05) increased in the MG300 group. In addition, dietary MG significantly (P < 0.05) increased levels of serum follicle-stimulating hormone, luteinizing hormone, estradiol, glucose, Ca, serum total cholesterol, triglycerides, and high-density lipoprotein cholesterol, but decreased the lipopolysaccharide level. Notably, MG supplementation increased (P < 0.05) the relative abundance of genera Lachnospiraceae_NK4A136_group, Romboutsia, Syntrophomonas, Victivallis, Ruminiclostridium_6, and Family_XIII_UCG_001 (P < 0.01) and simultaneously decreased the abundances of Proteobacteria, Faecalibacterium, Alistipes, Cerasicoccus, Schlegelella, and Treponema_2. Spearman's correlation analysis indicated that the differentiated genera were significantly associated with the serum biochemical indices and sex hormone. In summary, the present study revealed that dietary supplementation with MG can improve productive performance and egg quality by modulating gut microbiota, suggested that MG may act as an efficient feed supplement in aged hens.

Black soldier fly larvae oil as an alternative fat source in broiler nutrition

The present study was conducted to investigate growth performance, carcass characteristics, short-chain fatty acids, fatty acid composition in abdominal fat, and serum parameters in broiler chickens fed diets containing corn oil, coconut oil, or black soldier fly larvae (BSFL) oil at the level of 50 g per kg of diet during the 30-day-feeding period. A total 450 one-day-old male broiler chicks (Ross 308) were randomly allocated to one of 3 dietary groups. Each treatment had 10 replicates with 15 chicks per replicate. Feed conversion ratio was decreased in the coconut and BSFL oil group compared with the corn oil group. Dietary BSFL oil increased ileal weight-to-length ratio at day 30 after hatch. Dietary BSFL oil increased significantly ileal branched-chain fatty acid (P < 0.05) and moderately total short-chain fatty acid in 15-day-old broilers (P = 0.074). At day 30, ileal propionate was highest in the coconut oil group but cecal propionate was highest (P < 0.05) in the BSFL oil group. Fatty acid composition of abdominal fat was affected by dietary fat sources. Especially, chickens fed diets containing coconut oil or BSFL oil had higher contents (P < 0.05) of saturated fatty acid being dominant in lauric and myristic acids compared with those fed on corn oil. On the other hand, the reverse trend was noted (P < 0.05) as to polyunsaturated fatty acids being dominant in corn oil compared with coconut oil and BSFL oil. Coconut oil vs. corn oil significantly increased total and high-density lipoprotein cholesterol. Finally, BSFL oil vs. corn oil significantly increased total antioxidant capacity in chickens. It is concluded that dietary BSFL oil improves feed conversion ratio and increases the incorporation of medium-chain fatty acids into abdominal fat pad and serum antioxidant capacity in broiler chickens.

Effects of dietary glycerol monolaurate on productive performance, egg quality, serum biochemical indices, and intestinal morphology of laying hens

Glycerol monolaurate (GML) has been widely used as an effective antibacterial emulsifier in the food industry. A total of 360 44-week-old Hy-Line brown laying hens were randomly distributed into four groups each with six replicates of 15 birds, and fed with corn-soybean-meal-based diets supplemented with 0, 0.15, 0.30, and 0.45 g/kg GML, respectively. Our results showed that 0.15, 0.30, and 0.45 g/kg GML treatments significantly decreased feed conversion ratios (FCRs) by 2.65%, 7.08%, and 3.54%, respectively, and significantly increased the laying rates and average egg weights. For egg quality, GML drastically increased albumen height and Haugh units, and enhanced yolk color. Notably, GML increased the concentrations of polyunsaturated and monounsaturated fatty acids and reduced the concentration of total saturated fatty acids in the yolk. The albumen composition was also significantly modified, with an increase of 1.02% in total protein content, and increased contents of His (4.55%) and Glu (2.02%) under the 0.30 g/kg GML treatment. Additionally, GML treatments had positive effects on the lipid metabolism of laying hens, including lowering the serum triglyceride and total cholesterol levels and reducing fat deposition in abdominal adipose tissue. Intestinal morphology was also improved by GML treatment, with increased villus length and villus height to crypt depth ratio. Our data demonstrated that GML supplementation of laying hens could have beneficial effects on both their productivity and physiological properties, which indicates the potential application of GML as a functional feed additive and gives us a new insight into this traditional food additive.

Effects of medium-chain fatty acids on performance, carcass characteristics, blood biochemical parameters and immune response in Japanese quail

This study had the aim of evaluating the effects of medium-chain fatty acids (MCFA) on performance, carcass characteristics, some blood parameters and antibody titre against sheep red blood cells (SRBC) in quail. A total of 240 quail chicks were allotted to 4 treatments consisting of respectively 0, 1, 2 and 4 g/kg dietary MCFA. There were no significant differences in body weight, feed intake and feed conversion ratio among treatments at different stages of the experiment. MCFAs had no significant effect on breast, thigh, liver, spleen and bursa of Fabricius weight ratios. However, the relative weight of abdominal fat significantly decreased in quail receiving 0.2 and 0.4 MCFA as compared to other treatments. Concentrations of low-density lipoprotein-cholesterol (LDL), triglycerides and total cholesterol were decreased and high-density lipoprotein (HDL)-cholesterol was increased in quail chicks receiving MCFA compared with control quail chicks. The concentrations of SRBC antibody were not statistically different among treatments. It is concluded that MCFA significantly decreased LDL, triglycerides, cholesterol and abdominal fat and increased HDL in quail chicks.

Effects of dietary fats rich in lauric and myristic acid on performance, intestinal morphology, gut microbes, and meat quality in broilers

This study investigated the hypothesis that dietary fats rich in lauric (C12) and myristic acid (C14) increase broiler performance and that the underlying mechanism involves antimicrobial effects on gut bacteria and changes in gut morphology. One hundred eighty 1-day-old Cobb-500 broilers were allotted to 3 groups. All groups received a basal diet consisting of maize, wheat, soybean meal, and a fat source (4.5, 7.0, 7.6, and 8.0% of fat product in the diet during d 1 to 9, 10 to 17, 18 to 27, and 28 to 35, respectively) until 35 d of age. The diet of the control group contained a fat with 67% of oleic and linoleic acid and 1.4% of C12 and C14 of total fatty acids, that of the esterified lauric and myristic acid (ELA) group a fat with 33% of esterified C12 and C14 and that of the free lauric and myristic acid (FLA) group a fat with 31% of both esterified and free (1:1) C12 and C14 (6 replicates/treatment, 10 birds/replicate). Gain and feed consumption did not differ between groups, but feed:gain was lower in FLA group as compared to the control group (P < 0.05). Carcass weight, liver weight, triglyceride content of liver and muscle, and muscle cholesterol were similar between groups; however, breast muscle weight was higher in the FLA than in the control group (P < 0.05). The villus height:crypt depth ratio of the duodenal wall did not differ between groups, but in the jejunum, it was lower in the FLA group as compared to the control group (P < 0.05). DNA copy numbers of Lactobacillus, Bifidobacteria, Enterobacteria, Escherichia coli, and Campylobacter jejuni in jejunal digesta were similar among groups. The study shows that dietary fats rich in free C12 and C14 improved feed:gain and breast muscle yield, but the observed effects could not be conclusively explained based on the parameters measured. The decreased jejunal villi:crypt ratio may point to changes in gut protein or cell turnover.