Nitrogen is the most important factor limiting the growth and performance of crops, especially cereals. Therefore, with the aim of investigating the nitrogen use efficiency and its components in different cereals under the conditions of control (no use nitrogen) and optimal conditions of nitrogen, a factorial field experiment was conducted base on randomized complete block design with three replications at Gonbad Kavus University in 2017-2018. The experimental treatments included cereals at 7 levels, including bread wheat Koohdasht cultivar, durum wheat Seimareh cultivar, two rowed barley Khoram cultivar, six rowed barley Sahra cultivar, hull less barley Line 17, triticale Javanilo cultivar and oat Canadian cultivar) and the nitrogen factor were evaluated at two control (zero) and optimum levels. The result showed that cereal × nitrogen interaction was not significant on nitrogen utilization efficiency, nitrogen uptake efficiency and nitrogen use efficiency, nitrogen harvest index, nitrogen content and grain protein. But the main effect of nitrogen and cereals on nitrogen uptake efficiency, nitrogen utilization efficiency and grain protein percentage was significant at 1% level. While the nitrogen harvest index was only affected by cereals, Also, nitrogen remobilization was affected by cereals, nitrogen and cereals × nitrogen interaction. Finally, the results of this experiment showed that nitrogen use efficiency increased in all studied cereals under optimal nitrogen conditions. Nitrogen use efficiency consists of two components, nitrogen uptake efficiency and nitrogen utilization efficiency, as a result, the increase in nitrogen use efficiency is mostly due to the improvement in nitrogen uptake efficiency. Also, in all cereals under optimal nitrogen conditions, protein percentage and grain yield increased, in order to the increase in protein percentage was due to increased nitrogen remobilization. On the other hand, hull less barley had a higher nitrogen use efficiency than other cereals.

Predatory mite Amblyseius swirskii Athias-Henriot is one of the most important species of Phytoseiidae. In the current study, the effects of feeding on different preys including two-spotted spider mite Tetranychus urticae Koch, cereal mite Tyrophagus putrescentiae (Schrank), silverleaf whitefly Bemisia tabaci (Gennadius); together with integrated treatments of these preys including spider mite+cereal mite, spider mite+whitefly, cereal mite+whitefly and spider mite+cereal mite+whitefly on the biological charactristics of adult females of this predator (predation, fecundity and survivorship) were investigated after seven days storage at 10 °C. Larva and adult female with 72.34 and 11.76 % mortality had the highest and lowest susceptibility of this predator to temperature of 10 °C, respectively. The highest feeding of predatory mite after cold storage was observed on the larva and protonymph of T. urticae (91.63 prey). The lowest feeding was recorded on eggs of cereal mite (10.18 prey). Total fecundity of the predatory mite was significantly affected by different prey; the highest (5.13 egg) and lowest (1.55 egg) values of this parameter were recorded when the predatory mite fed on “spider mite+cereal mite+whitefly” and “cereal mite”, respectively. In the view point of mortality, the highest percentage was recorded in the predatory mites that reared on the cereal mite. According to the results obtained, integrated treatment of “spider mite+cereal mite+whitefly” was the most suitable treatment for the storage of A. swirskii at cold conditions than other treatments tested.

The objective of this study was to investigate the effect of two processing methods of barley and corn grains (steam-flaking or cracking) and the addition of a probiotic containing Enterococcus faecium (10 g/d to provide 2.5 × 1011 colony-forming unit) to diet on nutrients digestibility, fecal pH, blood glucose, and pathologic problems of horses. In this experiment, 12 adult Kurdish horses with an average weight of 416± 43 kg were used in a replicated 4×4 Latin Square experiment with a 2×2 factorial design during four periods of 28 days, including 21 days for dietary adaptation and seven days for sampling. Experimental diets (60:40 forage to concentrate ratio) were: 1) Cracked grains based diet without probiotic, 2) Cracked grains based diet with 10 g/d probiotics, 3) Steam-flaked grains based diet without probiotic, 4) Steam-flaked grains based diet with 10 g/d probiotics. Results showed that mean fecal pH was 6.57 in different treatments and was not affected by the type of grain processing, probiotic supplementation, and their interaction (P>0.05). Also, digestibility of dry matter, organic matter, NDF, and ADF, as well as blood glucose, lameness, and colitis incidence were not affected by two types of cereal processing including cracking or steam-flaking, the addition of probiotic, and their interaction. Overall, our results showed that replacing steam-flaked corn for cracked corn and supplementing 10 g per day enterococcus faecium probiotic did not affect digestibility, fecal pH, and blood glucose. However, further research is recommended to investigate the effects of higher enterococcus faecium probiotic doses in high grain diets.