Effect of pelleting and beta-glucanase supplementation on the ileal and fecal digestibility of a barley-based diet in the pig

The influences of pelleting and beta-glucanase supplementation on the digestibility of dietary components in a barley-based diet were investigated in pigs fitted with cannulas in the terminal ileum. The diet contained 49.0% starch, 18.9% crude protein and 14.8% dietary fiber, with arabinoxylans (4.9%), mixed-linked beta-glucans (3.4%) and cellulose (3.3%) as the main fiber components. Pelleting increased mixed-linked beta-glucan solubility from 45 to 62%. Neither treatment influenced the ileal or fecal apparent digestibilities of dry matter (64 and 80%, respectively), energy (62 and 79%), crude protein (53 and 75%), crude fat (26 and 27%) or dietary fiber (58 and 72%). However, pelleting increased (P less than .01) the pre-ileal apparent digestibility of starch from 91.5 to 95.3% and decreased (P less than .03) that of ash from -10 to -23%, while increasing (P less than .005) the fecal apparent digestibility of starch from 98.6 to 99.7%. The solubility of mixed-linked beta-glucans in ileal digesta was lower (P less than .001) in pelleted (26%) than in unpelleted (58%) diets. beta-glucanase supplementation also increased (P less than .05) the ileal apparent digestibility of starch, from 92.6 to 94.3%, and of mixed-linked beta-glucans, from 95.7 to 97.1%. Significant between-pig differences in the apparent digestibility of dietary components were observed. In conclusion, treatments that disrupt the endosperm cell walls in barley can increase the proportion of the diet digested prior to the large intestine.     

The Exploitation of Nematode-Responsive Plant Genes in Novel Nematode Control Methods

The molecular interactions between plants and sedentary nematodes are undergoing intense study, not only for reasons of fundamental research but also for the potential benefits to agriculture. The present technology allows the transformation of an increasing number of crop plants, providing new ways to introduce resistance against plant-parasitic nematodes. The ability of sedentary nematodes to induce specialized feeding sites in plant roots is one of the most fascinating aspects of this host–parasite interaction. Molecular approaches have been initiated to identify and characterize plant genes altered in expression after infection by sedentary nematodes. The results obtained indicate that many genes indeed become up-regulated upon nematode infection. Surprisingly, several so-called constitutive promoters that are normally used to achieve high expression in plant cells are completely ‘silenced’ in the feeding sites within days after nematode infection. Generally, there are two options available for the genetic engineering of nematode resistance: the synthesis of anti-nematode proteins or the localized production of a cytotoxic protein that interferes with the development of feeding cells. Nematode-induced promoters are very useful for the production by plants of sufficiently high levels of anti-nematode proteins at feeding sites. Alternatively, interfering with feeding-cell development is somewhat similar to the hypersensitive response evoked by nematodes in a naturally resistant plant. Here, destruction of specific plant cells can be achieved by the localized expression of a cytotoxin such as barnase, a potent ribonuclease. This approach, however, calls for a highly specific ‘non-leaky’ promoter, which is active only in the feeding cells. Another possibility is to use a two-component system, where the leakiness of the promoter in other tissues is counterbalanced by the constitutive expression of a neutralizing gene.     

Dietary simultaneous replacement of fish meal and fish oil with blends of plant proteins and vegetable oils in yellowfin seabream (Acanthopagrus latus) fry: Growth,digestive enzymes,antioxidant status and skin mucosal immunity

A 56‐day nutritional research was performed to examine the influence of alternative vegetal protein and lipid sources on performance of yellowfin seabream fry (Acanthopagrus latus) (0.5 ± 0.0 g). In this regard, five isoproteic (Ca. 500 g/kg) and isolipidic (Ca. 150 g/kg) diets were formulated in which fish meal (FM) and fish oil (FO) were simultaneously replaced with blends of plant proteins (PP, soybean meal and corn gluten) and vegetal oils (VO, canola and soybean oils) at 20% (SR20), 40% (SR40), 60% (SR40) and 80% (SR80) levels, respectively; meanwhile, a control diet (SR0) was formulated based on FM and FO. Growth and feed utilization were not influenced by experimental diets. The fatty acid profile of fillet drastically altered by dietary treatments. Fish fed with the SR60 and SR80 feeds had higher total protease, trypsin and α‐amylase activities than other treatments. The antioxidant enzyme activities and glutathione content in liver were enhanced in fish fed with the SR40, SR60 and SR80 diets. Skin mucosal immune parameters including total protein content, alkaline phosphatase and alternative complement pathway activities in the control group were relatively lower than the vegetal treatments. According to these results, it is recommended that 410 g/kg of FM and 45 g of FO/kg can be replaced with alternative vegetal sources in diet for A. latus fry.     

Distribution of lipid droplets is an indicator for egg quality in brown trout, Salmo trutta fario

In the eggs of the brown trout, Salmo trutta fario, lipid droplets are clearly visible beneath the oolemma on the surface of the protein yolk. When examining the distribution of lipid vesicles in egg batches of different quality, four categories of lipid vesicle distribution could be distinguished: In the first category, the lipid droplets were evenly distributed throughout the egg. These egg batches had a high quality (percentage of eggs developing to eyed stage embryos: 96.2 ± 5.2). Some lipid droplets had the tendency to coalesce in one pole of the egg in the second category. This coalescing of lipid droplets was accompanied with a reduction in egg quality to about 50% of the first category (% of eyed stage embryos: 40.6 ± 15.2). In the last two categories, the lipid droplets were mostly coalesced in one or two poles of the egg and the egg quality was very low (% of eyed stage embryos: 3.3 ± 2.9 and zero, respectively). In conclusion, examination of lipid droplets distribution, in brown trout, can distinguish between high and low quality eggs in an easy and reliable way.     

In vitro Selection for Tolerance to Fusarium in F1 Microspore Populations of Wheat

Microspore populations of eight Fhybrids of winter wheat (Triticum aestivum L.) whose parents had different levels of resistance to Fusarium were screened in vitro, using phytotoxins of Fusarium as biochemical probe. Two selection methods were compared for the in vitro selection: either embryoids and calli were first initiated from anthers in toxin-free medium and then grown on medium with 0.3—0.9 %Fusarium toxin; or anthers were immediately cultured in modified liquid potato-2 medium in the presence of 1.5, 2.0 and 2.5ml Fusarium toxin per liter culture medium, a concentration which reduced the number of calli and embryoids to about 10 % compared to the toxin-free controls. Microspores from donor hybrids which were produced from very susceptible cultivars were killed by lower toxin concentrations than micro-spores from hybrids of less susceptible parents. From surviving calli and embryoids, originally initiated from 242,000 anthers in both procedures a total of 375 green lines could be regenerated. The results indicate that it is possible to enrich the fraction of regenerating microspores by those which contain the gene complex responsible for reduced susceptibility to Fusarium by the use of a pathotoxin.     

Integrated pest management of Tuta absoluta: practical implementations across different world regions

Journal of Pest Science - The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most Afro-Eurasian countries and is threatening worldwide tomato...     

Pathological and Hormonal Changes in Freshwater Fishes Due to Exposure to Heavy Metals Pollutants

The concentrations of major heavy metals in organs of two cyprinid fish and in water collected from three sections of the Kor River, Iran, were determined using the induction coupled plasma method. The concentrations of heavy metals in tissue of fish from the middle sampling zone were significantly higher (p?<?0.05) than those from the other two sampling zones, whereas no significant differences (p?>?0.05) were detected between the two sexes and species. Estradiol in females and progesterone and testosterone in males from the middle study site were significantly (p?<?0.05) lower than values from the other two sites. Pathological changes in blood cells, liver, and kidneys of fishes were significantly higher in highly polluted areas (middle sampling zone). So heavy metals exposure can effectively decreases estrogenic and androgenic secretion in fish. These results show that industrial activities have polluted the river and that heavy metals exposure can induce pathological changes in fish organs.     

Evaluation of Egyptian sheep production systems: I. Breed crosses and management systems

Our objective was to evaluate life-cycle performance of flocks of two Egyptian breeds, Rahmani (R) and Ossimi (O), and their crosses with Finnish Landrace (F) in two management systems. Management systems were one mating season per year (1M) and three mating seasons per 2 yr (3M). Breeds and crosses studied included purebred R and O, F1 crosses 1/2F-1/2R (FR) and 1/2F-1/2O (FO), and inter se matings of 1/4 F-3/4 R (RFR) and 1/4 F-3/4 O (OFO). A dynamic computer model was used to simulate animal performance and enterprise efficiency and profit. Two measures of lifecycle feed conversion (biological efficiency) were computed: kilograms of TDN input per kilograms of empty body weight output (TDN/EBW) and kilograms of TDN input per kilogram of carcass lean output (TDN/CLN). Profit was measured as gross margin (income minus variable costs per ewe per year, GM/EWE). Input parameters for the model were obtained from published results and analyses of data collected from experimental flocks of the same genetic stocks in Egypt. Profit for FR and RFR was 42 and 6% higher in 1M than in 3M. However, profit for all other genetic types was 4 to 8% greater in 3M than in 1M. Breed rankings changed depending on the measure of evaluation (i.e., biological efficiency or profit). Maximization of system output did not necessarily improve efficiency. Under accelerated lambing systems, greater overhead costs associated with labor and feed offset gains in ewe productivity. Genetic stocks should be matched to resources and management systems.     

Effects of neemgard on phytophagous and predacious mites and on Spiders

The effects of Neemgard, an acaricidal and fungicidal formulation obtained from neem (Azadirachta indica) seed kernels, on the phytophagous miteTetranychus cinnabarinus, the predacious mitePhytoseiulus persimilis, and the predatory spiderChiracanthium mildei, were investigated in laboratory experiments. Neemgard was highly toxic toT. cinnabarinus but had no toxic effect onC. mildei orP. persimilis. Another neem formulation—the insecticidal Neemix 45—caused conspicuous repellency, but no mortality, inT. cinnabarinus.