Tolerability of graded levels of tall oil fatty acids as a nutritional additive for broiler chickens: a 45-day target animal safety study.

1. The following study was conducted to evaluate the tolerability of tall oil fatty acid (TOFA) to broiler chickens, at three graded levels as a nutritional additive in complete feed.2. 256 one-day-old female and male Cobb 500 broiler chickens were assigned to four dietary treatment groups with TOFA at 0 (control), 1.0, 3.0, or 5.0 g/kg within a complete feed for 45 d.3. Birds were weighed individually on days 0, 16, 31 and 45, and the feed intake, bird weight gain, and feed conversion ratio were calculated for the respective starter, grower and finisher phases and over the whole study. On day 45, blood samples were drawn from each bird for haematology and blood chemistry measurements. Two birds per pen were subjected to gross pathological examination and sampling of several tissues for histopathology, including weighing the liver.4. The dietary treatments did not affect zootechnical performance variables or mortality over the whole study period. Bird performance was typical for the breed.5. Haematology, clinical chemistry and histopathology did not reveal any changes associated with dietary TOFA dosing. However, the 5.0 g/kg dose level increased the relative weight of the liver, as a percentage of final body weight, compared to the control group, but there was lack of corresponding histopathology findings.6. In conclusion, the study indicated that oral administration of TOFA for 45 d in feed was well tolerated by the birds at dietary levels of up to 5.0 g/kg.

Establishing the tolerability to broiler chickens and laying hens of nonanoic acid at practical levels of use as a feed flavouring.

1. The following experiments were conducted to evaluate the effects of nonanoic acid (NA) in broilers and laying hens, at practical levels as a flavouring in complete feed.2. In the first experiment, 1100, one-day-old Ross 308 chicks, half male and female, were randomly assigned to 50 floor pens containing 22 chicks each. Chicks were fed one of five treatment diets containing either 0 (control), 100, 300, 500 or 1,000 mg NA/kg complete feed for 42 days.3. The NA treatment had no effect on ADFI, but there was a linear relationship with ADG and FCR. No differences were observed in blood parameters or tissue pathology among treatment groups.4. In a second study, 150 Hyline hens aged 24 weeks old were randomly assigned to 50 pens containing three birds each. Laying hens were fed one of five treatment diets containing 0 (control), 100, 300, 500 or 1,000 mg NA/kg complete feed for 56 days.5. Treatment with NA has no effect on live weight, ADFI or egg production in laying hens, and there were no observed changes in tissue pathology.6. The results supported the toleration of NA in broilers or layers at dietary levels of up to 1,000 mg/kg.

The effect of feeding essential oils on broiler performance and gut microbiota.

1. In this study the effect of a blend of essential oils (EO) comprising 15 g/tonne thymol and 5 g/tonne cinnamaldehyde on the performance and intestinal microbiota of broilers was investigated. 2. A total of 720 male Ross broilers were divided into two dietary treatments with 12 replicate pens per treatment. Broilers were given a control soybean-wheat-based diet with or without added EO in two diet phases (0-21 d and 22-42 d). 3. The blend of EO increased body weight gain of broilers from 0 to 42 d by 45%. 4. Caecal microbiota were affected by the EO blend; in particular increases in the proportions of Lactobacillus and Escherichia coli at 41 d was observed. 5. The EO blend had major effects on caecal metabolites. The proportion of caecal butyrate at 20 and 41 d of age increased, whereas the proportion of caecal acetic acid at 20 d, and propionic acid and isovaleric acid at 41 d, decreased with the EO blend. In addition, the caecal proportion of spermine increased and tyramine decreased at 41 d of age with the EO treatment. 6. The present study shows that EO supplementation exerts a positive effect on intestinal microbiota with a concomitant enhancement in growth performance. The study suggests that modulation of broiler gut microbiota composition and activity through the administration of EO offers an effective means for improving broiler performance.

Dose response of a new phytase on dry matter, calcium, and phosphorus digestibility in weaned piglets.

The present study evaluated the dose response of Buttiauxella phytase on apparent total tract digestibility (ATTD) of DM, Ca, and P in weaned pigs at 2 locations. Experimental diets fed to weaned pigs were a positive control (PC), a negative control (NC), and NC supplemented with increasing levels of Buttiauxella phytase. In Trial A, ATTD of P was 57.2% for PC, 32.5% for NC, and 59.4, 62.0, 63.8, 66.0, and 67.3% for 250, 500, 750, 1000, and 2000 phytase units (FTU) added to NC, respectively. In Trial B, ATTD of P was 45.2% for PC, 28.4% for NC, and 58.7, 64.1, 67.9, and 70.9% for 250, 500, 1000, and 2000 FTU added to NC, respectively. In both studies, the reduction in P in the NC diets reduced (P < 0.01) ATTD of P when compared with the PC diets. Phytase supplementation linearly and quadratically increased (P < 0.01) ATTD of P at all inclusion levels to the NC diet. In conclusion, the average digestible P increase from Buttiauxella phytase (vs. the NC diet) was 1.3, 1.5, 1.6, and 1.7 g digestible P/kg feed for 250, 500, 1000, and 2000 FTU/kg, respectively.