Dietary Supplementation with Fumaric Acid Improves Growth Performance in Nile Tilapia Juveniles

Organic acids have recently been identified as promising replacements for antibiotics in aquafeeds that promote fish growth and feed efficiency. This study evaluated the inclusion of fumaric acid (FA; 0, 5, 10, 15, 20, and 30 g/kg) in diets (350 g/kg CP; 3.4 kcal digestible energy/g) of Nile tilapia juveniles. Fish (average weight 1.7 ± 0.1 g) were distributed in three 40 L aquaria per treatment (13 fish/aquaria) in a completely randomized design. Over 35 days, the fish received the experimental diets three times daily to apparent satiety. The maximum weight gain, feed efficiency ratio, and protein efficiency ratio were recorded in fish supplemented with 14–15 g/kg FA. After 28 days, Enterobacteriaceae was registered only in the gut of tilapia without FA augmentation. Gram-negative bacteria in the fish gut decreased (p < 0.05) in fish receiving 17 g/kg of dietary FA, increased after this level. The intestinal villi height and width were affected (p < 0.05) by FA levels and feeding time. Thus, inclusion of 15 g/kg of FA was effective in promoting growth, improving intestinal morphometry, and decreasing negative gut bacteria of Nile tilapia juveniles after 35 days.

Administration of Dietary Microalgae Ameliorates Intestinal Parameters, Improves Body Weight, and Reduces Thawing Loss of Fillets in Broiler Chickens: A Pilot Study

This pilot investigation aimed at studying the feasibility of using a low dose (0.2%) of dietary microalgae as a means of improving intestinal morphometry, body weight, and selected meat quality parameters in broilers. A total of 72 one-day-old ROSS 308 male chicks were randomly separated into four groups; three experimental pens in which the birds were fed with biomass from Tysochrysis lutea, Tetraselmis chuii, and Porphyridium cruentum over 30 days and a control group. T. chuii and P. cruentum had a positive effect with regard to body weight. In treated animals, duodenal and ileal sections showed characteristic tall and thin villi, with serrated surfaces and goblet cell differentiation. In both sections, values of the villus-height-to-crypt-depth ratio were increased by microalgae ingestion. The thawing weight loss of fillets was reduced in T. chuii-fed animals. The positive effects exerted by T. chuii and P. cruentum on intestinal architecture were associated with the improved body weight. Arguably, these outcomes exhibit the potential of using these species to enhance growth performance in broiler chickens by promoting gut homeostasis and thus nutrient absorption.

Supplementation with Agave fourcroydes powder on growth performance, carcass traits, organ weights, gut morphometry, and blood biochemistry in broiler rabbits

The aim of this study was to evaluate the effect of dietary supplementation with Agave fourcroydes powder on growth performance, carcass traits, organ weights, gut morphometry, and blood biochemistry in broiler rabbits. A total of 40 male rabbits (New Zealand × Californian) weaned at 35 d were randomly selected for a control diet (CD) and CD + 1.5% of A. fourcroydes powder, with 10 replicates and two rabbits per replicate. After 60 d, A. fourcroydes powder increased body weight, feed intake, and weight gain (P<0.05), without affecting feed conversion ratio and viability (P>0.05). Furthermore, this natural product did not affect the edible portions and the indicators determined in the Longissimus dorsi, nor the organ relative weights and the intestinal morphometry (P>0.05); however, a decrease in cecal pH was observed and consequently an increase in cecal beneficial bacteria (P<0.05) were found. Also, A. fourcroydes powder reduced (P<0.05) the serum concentration of glucose, harmful lipids, HDL and atherogenic index although without change for the ureic nitrogen, creatinine and VLDL (P>0.05). Agave fourcroydes powder as a zootechnical additive promoted better growth, in addition, it showed lipid-lowering and hypoglycemic effects, without modifying the edible portions and organs digestive.

Effects of autolyzed yeast on performance, blood parameters, intestinal morphometry, immunohistochemistry and microbiological parameters of weaned piglets in a tropical humid climate

This study aimed to evaluate the effects of dietary supplementation of autolyzed yeast (AY) from fermentation of sugarcane on performance, blood parameters, intestinal morphometry, immunohistochemistry and microbiological parameters of weaned piglets of different weight categories. A total of 480 piglets were distributed in a 3 x 2 factorial design study, with three inclusion levels of AY (0, 4 and 8 g/kg) and two weight categories (light and heavy, 5.71 ± 0.21 kg and 6.99 ± 0.25 kg, respectively), i.e., 6 treatments with 8 replicates pen each. There was no significant interaction between weight category and linear or quadratic effect of AY levels on performance, blood parameters, intestinal morphometry, immunohistochemistry and microbiological parameters (P > 0.05). The dietary supply of AY for nursery piglets linearly decreased the monocytes concentration of the piglets at 63 days of age (P < 0.05). AY levels linearly increased the villus height, mucosal thickness, absorptive area and number of mitotic cells of the duodenum, as well as the villus height:crypt depth ratio, mucosal thickness and number of mitotic cells of the jejunum (P < 0.05). Heavy piglets had higher ADFI in all evaluated periods, as well as higher values of villus height in the duodenum, and mucosal thickness in the duodenum and jejunum than light animals (P < 0.05). Dietary supplementation of autolyzed yeast positively influences health status, intestinal morphometry and immunohistochemistry of nursery piglets. Heavy weaned piglets have higher feed intake and greater intestinal morfometry than light animals.

Fishmeal Replacement with Hermetia illucens Meal in Aquafeeds: Effects on Zebrafish Growth Performances, Intestinal Morphometry, and Enzymology

Fishmeal (FM) is still the most important protein source in aquafeeds. However, due to the reduction of wild fish stocks used for FM production, its manufacturing it is now unsustainable. Insect meal represents a valid alternative to FM, due to the low carbon footprint of its production and its high nutritional value. The aim of this study was to investigate the potentials of replacing FM with black soldier fly (Hermetia illucens) meal (HIM) in aquafeeds, using zebrafish as the animal model. Four diets were formulated with increasing HIM/FM replacement rate (the control diet contained 20% FM). Mortality rates, growth performances, and feed consumptions were measured, and fish intestine samples were collected for histological and enzymatic analysis. After 49 days, all groups almost tripled their initial body weight (cumulative body weight gain ranged between 143.9 and 155.2 mg), and no statistically significant differences among treatments were observed in relation to growth performances and histological traits. Contrarily, trypsin, alkaline phosphatases, and alpha amylase–glucoamylase activities were significantly reduced when the FM replacement rate was increased. In conclusion, HIM may represent an alternative to FM, since no adverse effects were observed when it was included up to 20% in the zebrafish diet, even when replacing 100% of the FM.

Comparative Effect of Potentiated Zinc Oxide and Antibiotic Growth Promoters on Intestinal Morphometry and Nutrient Digestibility in Broiler Chickens

This study aims to determine the comparative effects of potentiated zinc oxide (pZnO) and antibiotic growth promoters (AGP) supplementation on intestinal morphometry and nutrient digestibility in broiler chickens. Four hundred straight-run day-old broiler chicks were randomly allotted to one of four dietary treatments replicated 10 times with 10 birds per replicate. Dietary treatments were: T1: Basal diets without AGP (negative control; NC), T2: Basal diets with 500 g/ton Maduramicin 10g and 500 g/ton Zinc bacitracin 150 (positive control; PC), T3: NC added with 150g/ton pZnO, and T4: PC added with 150g/ton pZnO in a 2x2 factorial design in RCBD. At days and 35, 10 birds were randomly selected per treatment 18 for morphometry of the duodenum, jejunum and ileum. At day 38, eight birds per treatment were used for the nutrient digestibility study. Results showed significant interaction effects (P<0.05) of AGP and pZnO supplementation on day 35 intestinal morphometry of duodenum’s villi height and villi height: crypt depth, and ileum’s crypt depth; apparent CODGE, AME, CP, DM and EE. Significant differences (P<0.05) with pZnO supplementation were only observed on feed intake and FCR of birds fed with pZnO at days 8-14 and fecal quality at days 0-7. Results of the study suggest that pZnO has the potential to replace AGPs without negatively affecting the intestinal morphometry, digestibility and growth performance of broiler chickens.