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.

Tall oil fatty acid inclusion in the diet improves performance and increases ileal density of lactobacilli in broiler chickens.

1. Studies were conducted with tall oil fatty acids (TOFA) to determine their effect on broiler chicken performance and ileal microbiota. TOFA, a product originating from coniferous trees and recovered by fractional distillation of side-streams from pulp production, mainly comprises free long-chain fatty acids (~90%) and resin acids (~8%). Conjugated linolenic acids and pinolenic acid are characteristic fatty acid components of TOFA. 2. TOFA products at 750 mg/kg feed were tested in two 35-day broiler chicken trials, each using a wheat soya-based diet and with 12 replicate pens per treatment. In both trials, TOFA improved body weight gain at all time points (P < 0.001) and feed conversion efficiency during the first 21 days (P < 0.01). Two different dry TOFA formulations (silica carrier and palm oil coating) were tested and showed performance effects similar to liquid TOFA. 3. Ileal digesta of the broiler chickens was analysed for total eubacteria, Lactobacillus spp., Enterococcus spp., Escherichia coli and Clostridium perfringens on days 14 and 35. TOFA significantly increased total eubacteria and lactobacilli density on day 14 (P < 0.05). There was a significant positive correlation between these bacterial groups and broiler body weight on day 14 (P < 0.01). 4. A numerical reduction in C. perfringens was observed. In vitro growth inhibition studies showed that C. perfringens was strongly inhibited by 10 mg/l TOFA (P < 0.001), while common lactobacilli were resistant to >250 mg/l. The in vitro results were thus in line with in vivo observations. 5. The mechanisms behind the bacterial shifts and their role in performance improvement are unknown. Further purification of TOFA components is needed to identify the effective agents.

Trends of phosphorus, nitrogen and chlorophyll a concentrations in Finnish rivers and lakes in 1975-2000.

During recent decades the amounts of nutrients discharged to Finnish surface waters have markedly decreased. This has been achieved by considerable investments in water protection, which were made mainly to improve municipal and industrial wastewater purification. We investigated whether these water protection measures have decreased phosphorus and nitrogen concentrations in Finnish rivers and lakes. In addition, possible trends in chlorophyll a concentrations in lakes were studied. The data consisted of a total of over 68000 monitoring results of 22 rivers and 173 lakes (or sub-basins of lakes) with different types of catchment areas. The study period covered the years 1975-2000 and the non-parametric Kendall Tau b and Seasonal Kendall tests were applied for detecting trends. Decreasing nutrient concentration trends were typical in many lakes and rivers earlier polluted by municipal and industrial wastewaters. Increasing nutrient concentration trends were common in smaller rivers and lakes receiving diffuse loading from agriculture. The results show that the investments directed towards wastewater purification have effectively improved the quality of Finnish inland waters. However, no clear effects of decreasing non-point loading were found. Thus, more effective measures should be directed towards decreasing non-point source loading.

Losses of nitrogen and phosphorus from agricultural and forest areas in Finland during the 1980s and 1990s.

The temporal changes and spatial variability of phosphorus and nitrogen losses and concentrations in Finland during the period 1981-1997 were studied in 15 small agricultural and forested catchments. In addition, four coastal river basins with high agricultural land use located in southern Finland were included in the study in order to assess the representativeness of agricultural loss estimates from small agricultural catchments. The mean annual loss specific for agricultural land was estimated to be on average 110 kg km(-2) a(-1) for total phosphorus and 1500 kg km(-2) a(-1) for total nitrogen. The results from small agricultural catchments were in agreement with the corresponding loss estimates from rivers, with an average of 137 kg km(-2) a(-1) for total phosphorus and 1800 kg km(-2) a(-1) for total nitrogen. The results from the studied agricultural catchments and rivers during the period 1981-1997 suggest that weather-driven fluctuation in discharge was usually the main reason for changes in nutrient losses, and little or no impact of changes in agricultural production or management practises can be observed. In forested areas the total phosphorus loss (average 9 kg km(-2) a(-1)) and total nitrogen loss (average 250 kg km(-2) a(-1)) were lower than in agricultural areas. In forested catchments the impact of forestry operations, such as clear-cutting and fertilization, and the impact of atmospheric nitrogen deposition can be seen in changes in nutrient losses.