The aim of this study was to assess the effects of 2 different phytogenic products on performance, ileal nutrient digestibility, and composition of the intestinal microbiota. The 2 phytogenic products contained different essential oil mixtures (EOM) characterized by either menthol (Mentha arvensis; EOM-M) or cinnamon aldehyde (Cinnamomum aromaticum; EOM-C) as main constituents. Three treatments consisted of control diet without EOM addition and diets supplemented with EOM-M or EOM-C. Reproducibility of the effects was examined in 4 trials with a total of 300 male castrated and female piglets weaned at 25 d of age. The number of pens per treatment in trials I through III were 7, 9, and 9, respectively, for research station conditions, and 10 in trial IV for simulated farm conditions. In research station conditions, the experimental unit consisted of flat deck pens with 2 piglets per pen, whereas it consisted of floor pens with straw bedding with 5 piglets per pen in farm conditions. The feed additives had no effect on feed intake or BW gain. Improvements (P < 0.05) in G:F were observed for EOM-M supplemented diets in 2 of 4 trials as well as for the combined data of all trials. These improvements were associated with greater (P<0.05) apparent ileal digestibility of CP and of most AA. The effect of EOM-C on these response criteria was intermediate between control and EOM-M. Real-time PCR analysis of the gastrointestinal contents for 7 bacterial groups (Lactobacillus spp., Enterococcus spp., Clostridium coccoides and Clostridium leptum cluster, Escherichia spp., and Escherichia coli toxin estII) indicated no effect of treatments on the gastrointestinal microbiota. It was concluded that EOM-M consistently improved feed efficiency in weaned piglets, and it was associated with improved ileal protein and AA digestibility. In general, however, the effectiveness of EOM as feed additives differs considerably depending on the constituents.

Climatic changes and heat stress have become a great challenge in the livestock industry, negatively affecting, in particular, poultry feed intake and intestinal barrier malfunction. Recently, phytogenic feed additives were applied to reduce heat stress effects on animal farming. Here, we investigated the effects of ginseng extract using various in vitro and in vivo experiments. Quantitative real-time PCR, transepithelial electrical resistance measurements and survival assays under heat stress conditions were carried out in various model systems, including Caco-2 cells, Caenorhabditis elegans and jejunum samples of broilers. Under heat stress conditions, ginseng treatment lowered the expression of HSPA1A (Caco-2) and the heat shock protein genes hsp-1 and hsp-16.2 (both in C. elegans), while all three of the tested genes encoding tight junction proteins, CLDN3, OCLN and CLDN1 (Caco-2), were upregulated. In addition, we observed prolonged survival under heat stress in Caenorhabditis elegans, and a better performance of growing ginseng-fed broilers by the increased gene expression of selected heat shock and tight junction proteins. The presence of ginseng extract resulted in a reduced decrease in transepithelial resistance under heat shock conditions. Finally, LC-MS analysis was performed to quantitate the most prominent ginsenosides in the extract used for this study, being Re, Rg1, Rc, Rb2 and Rd. In conclusion, ginseng extract was found to be a suitable feed additive in animal nutrition to reduce the negative physiological effects caused by heat stress.

N,N-dimethylglycine (DMG) is a tertiary amino acid that naturally occurs as an intermediate metabolite in choline-to-glycine metabolism. The objective of the present trial was to evaluate tolerance, safety and bioaccumulation of dietary DMG in broilers when supplemented at 1 g and 10 g Na-DMG/kg. A feeding trial was conducted using 480 1-d-old broiler chicks that were randomly allocated to twenty-four pens and fed one of three test diets added with 0, 1 or 10 g Na-DMG/kg during a 39 d growth period. Production performance was recorded to assess tolerance and efficacy of the supplement. At the end of the trial, toxicity was evaluated by means of haematology, plasma biochemistry and histopathology of liver, kidney and heart (n 12), whereas bioaccumulation was assessed on breast meat, liver, blood, kidney and adipose tissue (n 8). Carcass traits were similar between the control and 1 g Na-DMG/kg feed groups (P.0·05), but the feed:gain ratio was significantly improved at 1 g Na-DMG/kg feed compared with the control or the 10-fold dose (P¼0·008). Histological examinations showed no pathological effects and results of haematology and plasma biochemistry revealed similar values between the test groups (P. 0·05). Bioaccumulation occurred at the 10-fold dose, but the resulting DMG content in breast meat was comparable with, for instance, wheat bran and much lower than uncooked spinach. In conclusion, DMG at 1 g Na-DMG/kg improved the feed:gain ratio in broilers without DMG being accumulated in consumer parts. Furthermore, dietary supplementation with DMG up to 10 g Na-DMG/kg did not induce toxicity or impaired performance in broilers.Key words: Dimethylglycine: Feed additives: Broilers N,N-dimethylglycine (DMG), a methylated derivative of the amino acid glycine with the chemical formula (CH 3 ) 2 NCH 2 COOH, has been used for various human and animal applications. The molecule was first reported in 1943, and is a naturally occurring intermediate metabolite in plant and animal cells (1,2) . The choline-to-glycine pathway starts with choline being oxidised into betaine. Next, DMG is formed within the mitochondria from betaine (N,N,N-trimethylglycine) by the removal of one methyl group and, after this, it is further demethylated to sarcosine (N-methylglycine) and finally to glycine (3,4) . DMG is claimed to enhance oxygen utilisation and diminish muscle acidification, and for this reason, it is currently used as an enhancer of athletic performance in human athletes as well as in racing dogs and horses. This application is, however, primarily based on anecdotal reports.To date, only a few randomised, controlled studies have been performed and these have failed to demonstrate the aforementioned claims related to athletic performance (5) . A new application of DMG is in its use as a dietary supplement in poultry diets. Dietary supplementation with 167 mg Na-DMG/kg has been demonstrated to improve apparent total tract digestibility corrected for uric acid (ATTD ua ) of crude protein and N-free extract in broiler chicke...

Dimethylglycine (DMG) is a naturally occurring glycine derivative, which is useful as 30 additive to broiler diets as it improves nutrient digestibility and reduces the development of 31 broiler ascites syndrome. This study evaluated the efficacy of dietary DMG to enhance 32 performance of broiler chickens. Three trials were conducted to evaluate the effect of dietary 33 supplementation with 1 g Na DMG/kg on growth performance and carcass characteristics. In 34Trial 1, the effect of sex was also assessed in a 2 x 2 factorial arrangement of treatments. In 35 Trials 1 (Germany), 2 (Austria), and 3 (Italy), each treatment consisted of 6, 12, and 11 36 replicate pens with 20, 15, and 16 one-day-old broiler chickens per pen, respectively. Dietary 37 DMG supplementation resulted in improved feed conversion ratio (FCR) in the starter phase 38 by 8.8 (P = 0.004), 6.4 (P = 0.001), and 4.8% (P = 0.006) compared with the control diet in 39 Trials 1, 2, and 3, respectively. The overall FCR improved in broiler chickens fed the diets 40 supplemented with DMG by 3.8 and 4.1% in Trials 1 (P = 0.007) and 3 (P = 0.006), 41respectively. In addition, final body weight increased by 5.5% (P = 0.001) in Trial 2 and 42 production value improved by 6.8% (P = 0.015) in Trial 1 by dietary DMG supplementation. 43 Mortality in all trials was similar between dietary treatments. In all 3 trials, cold carcass 44 weight and total meat yield were as well similar between broiler chickens fed the control and 45 DMG diets. In Trial 1, dietary DMG had no effect on breast meat yield in male broiler 46 chickens, but it increased breast meat yield in female broiler chickens (diet x sex, P = 0.004). 47Organoleptic quality of roasted breast meat assessed only in Trial 2 was not affected by 48 dietary treatments. In conclusion, dietary supplementation of DMG at 1 g Na DMG/kg can 49 considerably improve s production performance in broiler chickens. 50