Hematology and Some Biochemical Parameters of Wild Rodents in Pistachio Gardens of Kerman Province, Southeast Iran

Wild rodents were collected using live snap traps in pistachio gardens of Kerman Province, Southeast Iran from 2007 to 2009, then some physiological parameters of them were measured. The samples were identified as follow: Nesokia indica, Meriones persicus, Meriones lybicus and Tatera indica. Blood samples were obtained from the heart, then the blood parameters (glucose, cholesterol, triglyceride, total protein, HDL, red and white blood cell number) in wild species of rodents and laboratory rat were compared. The results showed that there were no significant differences in serum glucose, triglyceride, HDL and total protein levels among different experimental groups. The concentration of cholesterol in T. indica was more than that in N. indica (P < 0.01). The total numbers of red blood cells also showed significant difference between wild garden rodent species and laboratory rat (P < 0.01), while the numbers of white blood cells showed no significant difference.     

Effects of bacterial inoculum and moisture adjustment on composting of pig manure

Spent litter (a mixture of partially composted pig manure and sawdust) was taken from pig pens employing the pig-on-litter system with and without the addition of a commercial bacterial product (Odor control (OC)-organic fertilizers (OF)). A duplicate series of windrows was set up with spent litter which contained the bacterial product and a further duplicate series was set up with spent litter which did not contain the bacterial product. All four sets had their initial moisture content adjusted to 60% but one of each duplicate pair had its moisture content adjusted to 60% during the entire period of further composting in windrows. The rate of further (windrow) composting was significantly different in the litter which contained no bacterial product and which only had its moisture content adjusted at the beginning of the experiment. Decomposition was incomplete in this set even after day 91. In the three other sets, the rate of decomposition was faster and the spent litter became stabilised by day 56. This result suggests that if the bacterial product has been added during the initial pig-on-litter composting process, moisture adjustment during further (windrow) composting is not important. Conversely, if moisture was adjusted during further composting, the addition of bacterial product during initial pig-on-litter composting would be of no value. Such a finding is of remarkable significance in the further composting of spent litter since this indicates that the process could be run on a much more economical basis.     

Effects of composting on phytotoxicity of spent pig-manure sawdust litter

The phytotoxicity of spent pig-manure sawdust litter (spent litter) was evaluated during further composting. Aqueous extracts of the spent litter were prepared by shaking the sample with water (1:10 w/v), and the toxicity of these extracts was determined on relative seed germination, relative root elongation and germination index (GI, a factor of relative seed germination and relative root elongation). The sensitivity of six plant species, namely Brassica parachinensis (Chinese cabbage), Brassica albogalera (Chinese kale), Allium sativum (onion), Cucumis sativus (cucumber), Amaranthus espinosus (Chinese spinach), and Lycopersicon esculentum (tomato) were compared. The effect of different moisture levels during composting on the phytotoxicity of the spent litter was also examined. Phytotoxicity of the spent litter was only evident during the earlier stage of composting (first 14 days) and, that seed germination and root elongation reached 100% (same as the control) towards the end of the composting. The concentrations of the major inhibitors, water-extractable Cu and Zn, and NH4(+)-N of the spent litter, declined during composting, indicating that these inhibitors were gradually eliminated as composting proceeded. Multiple regression analysis showed that the NH4(+)-N content of the spent litter was the most important chemical factor affecting phytotoxicity of the plant species selected for this study. Relative root elongation and GI were more sensitive indicators of phytotoxicity than seed germination. In the present study, the GI's of all plant species were >80% at day 60, indicating that the spent litter had reached its maturation by day 60. The responses of different plant species to the water-extracts of the spent litter were different. Among the six species, Chinese cabbage and Chinese spinach were the most sensitive species, and tomato and cucumber were the least sensitive species to indicate phytotoxicity of the spent litter. Moisture adjustment during the composting process did not affect the results of the phytotoxicity test.     

Fate of nitrogen during composting of chicken litter

Chicken litter (a mixture of chicken manure, wood shavings, waste feed, and feathers) was composted in forced-aeration piles to understand the changes and losses of nitrogen (N) during composting. During the composting process, the chemical [different N fractions, organic matter (OM), organic carbon (C), and C:N ratio], physical, and microbial properties of the chicken litter were examined. Cumulative losses and mass balances of N and organic matter were also quantified to determine actual losses during composting. The changes in total N concentration of the chicken litter piles were essentially equal to those of the organic N. The inorganic N concentrations were low, and that organic N was the major nitrogenous constituent. The ammonium (NH(4)(+))-N concentration decreased dramatically during first 35 days of composting. However, the rapid decrease in NH(4)(+)-N during composting did not coincide with a rapid increase in (NO(3)(-)+NO(2)(-))-N concentration. The concentration of (NO(3)(-)+NO(2)(-))-N was very low (<0.5 g kg(-1)) at day 0, and this level remained unchanged during the first 35 days of composting suggesting that N was lost during composting. Losses of N in this composting process were governed mainly by volatilization of ammonia (NH(3)) as the pile temperatures were high and the pH values were above 7. The narrow C:N ratio (<20:1) have also contributed to losses of N in the chicken litter. The OM and total organic C mass decreased with composting time. About 42 kg of the organic C was converted to CO(2). On the other hand, 18 kg was lost during composting. This loss was more than half (59%) of the initial N mass of the piles. Such a finding demonstrates that composting reduced the value of the chicken litter as N fertilizer. However, the composted chicken contained a more humified (stabilized) OM compared with the uncomposted chicken litter, which would enhance its value as a soil conditioner.     

Composting of spent pig litter in turned and forced-aerated piles

A study was carried out to compare the compositing efficiency of spent litter (a mixture of partially decomposed pig manure and sawdust) in turned and forced-aerated piles. Duplicate piles were built with manual turning (every 4 days) during composting, and duplicate piles were set up with forced aeration using an air pump. The present study demonstrated that the efficiency of composting in the turned and forced-aerated piles was similar. Spent litter in these piles reached maturity at the same time (60 days). The forced-aerated piles went through similar physical, chemical, and microbial changes with the turned piles during composting. The forced-aerated composting system was also as effective as the turned system in eliminating Salmonella sp. in the spent litter. These results suggest that a forced-aerated composting system could be used as an alternative method in composting spent litter. The similarities in temporal changes in temperature, chemical, and microbiological properties of the forced-aerated piles, compared with the turned piles, indicate that addition of a bulking agent under forced aerated composting of spent litter is not necessary. The partially decomposed sawdust in the spent litter provided enough free air space, allowing the delivery of oxygen for the microorganisms in the spent litter piles.     

Composting of spent pig litter at different seasonal temperatures in subtropical climate

To investigate the effects of seasonal temperatures on the composting of spent pig-manure sawdust litter (spent litter), two sets of experiments were carried out: one during winter, the other during summer. Physicochemical and microbial parameters including temperature, pH, inorganic N, humification indicators (HA and FA), heavy metals (Cu and Zn), total aerobic heterotrophs, ATP content and dehydrogenase activity were measured to understand changes in the spent litter during composting. Results demonstrated that the composting was faster during summer than winter. The spent litter during the summer trial reached maturity at day 56 whereas that of the winter trial was still immature at the end of composting (days 91). Microbial activities during the thermophilic stage of composting were much lower in the winter trial. Values began to increase during the latter part of composting, indicating that the spent litter in this winter trial was biologically unstable and must be further composted to reach full maturity. The changes in the microbial activities of the spent litter during summer or winter reflected the changes in their temperatures and chemical properties. The maturation of the spent litter during summer was accompanied by stabilization of the microbial and chemical properties and a drop in temperature to ambient level. Results of correlation analysis showed that temperature correlated not only with the microbial parameters but also with most of the chemical parameters. These parameters also correlated with each other. Among all the parameters measured, the trend of temperature changes is the simplest and most rapid parameter that can be used to evaluate the maturity of spent litter.