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.

The present study aimed to determine the effects of zinc oxide nanoparticles (ZnO-NPs), thyme oil (THO), or their combination on the nutrient digestibility coefficients, reproductive parameters, and some blood metabolites of male Californian rabbits. One hundred rabbits, 29-weeks of age (initial body weight 3.48 ± 0.08 kg) were randomly distributed into four groups, 25 rabbits each. Treatment groups were fed a control diet, a control diet supplemented with ZnO-NPs (100 mg/kg), THO (500 mg/kg), or combination of ZnO-NPs (100 mg/kg) and THO (500 mg/kg). The feeding trial lasted for 35 days. Results showed improvements in dry matter, crude protein, ether extract, and crude fiber in ZnO-NPs, THO, and their combination treated groups compared to those of control. Furthermore, semen volume, sperm motility, vitality, and morphology were significantly improved (p < 0.01) in ZnO-NPs and THO groups rather than the control. Both ZnO-NPs and THO, as either individual or combined treatments significantly improved the serum alanine amino-transferase (ALT), aspartate amino-transferase (AST), urea, and creatinine compared to the control. Moreover, serum concentrations of testosterone were significantly increased in rabbits supplemented with ZnO-NPs, THO, or their combination compared to those of control (p < 0.05). In conclusion, ZnO-NPs, THO, or their combination improved the digestibility of nutrients, liver/ kidney functions, semen characteristics, and testosterone concentration in male rabbits.

Essential oils had been received much attention due to their antimicrobial properties against a wide range of microorganisms that manipulate rumen fermentation towards a better utilization of energy and protein. Six fistulated non-lactating Friesian dairy cows were used to investigate the effect of adding Crina® Ruminants (blend of essential oil) with 1g per cow per day to total mixed ration (grass silage, maize silage, soybean meal, rapeseed meal and wheat) of 7kg per day on the in-situ rumen dry matter degradability (ISDMD) and total tract digestibility using TiO 2 as marker. Fistulated cows were used as 3x2 Latin Square with factorial arrangement of treatment (with or without Crina® addition) in two periods. Each period extended for 45days (30days pre-experimental phase and 15days experimental phase). Ruminal fluid samples were collected to investigate the rumen fermentation parameters (ruminal pH value, volatile fatty acid (VFAs), and ammonia nitrogen (NH 3 N) as well as acetate propionate ratio). The results indicated that adding of Crina® to ruminant diet had significantly decreased ISDMD of grass silage and total mixed ration especially at long incubation time (12 and 48hours). The ISDMD and in-situ rumen crude protein degradability of soybean and rapeseed meal significantly increased due to Crina® addition. Crina® had no effect on total tract digestibility of dry matter(DM), organic matter(OM), crude protein(CP), starch, ether extract(EE), crude fiber(CF) and fiber fractions. Rumen fermentation parameters did not affected due to addition of Crina®. Results concluded that Crina® could limit the degradability of grass silage, increased degradability of soybean and rapeseed meal and had no effect on rumen fermentation characteristics.