The study was designed as a 2 x 5 factorial arrangement with main effects of feeding blood meal as a replacement of 0, 25, 50, 75 or 100% of dietary fish meal and the duration of this substitution at 1-42 or 21-42 days of age. One thousand 1 day old male Cobb 500 broiler chicks assigned randomly to each of 40 floor pens (25 birds/pen) and were fed five isonitrogenous and isocaloric feeds formulated to contain 20.38 and 17% crude protein and 2900 and 3000 kcal kg(-1) metabolizable for starter and grower periods, respectively. Duration of dietary manipulation didn't affect the measured parameters. More than 25% blood meal/fish meal substitution ratios significantly increased chickens daily weight gain and decreased the cost of producing a unit of meat. Other traits didn't affect by dietary fish meal/blood meal replacement ratio. Spleen and proventriculus percents and small intestine length affected by level of replacement but didn't follow a distinct pattern. These results indicate that this locally produced blood meal is a suitable substitute for dietary fish meal and a full replacement didn't cause any adverse effect on performance, carcass important traits and dietary nitrogen retention of broiler chickens.

No abstract

Citrus Limon Oil (CLO) is known as antioxidant resource and contains limonoids, flavonoids and phenolic compounds. This study was conducted to investigate the effects of different levels of CLO on blood parameters and antioxidant status in Afshari ewes. Six adults Afshari ewes (3-4 years old and 51±5 kg) were randomly allocated to 3×3 Latin square design with three diets in 21 days period. Dietary treatments included:1) control diet, 2) control diet with 200 mg/day CLO, and 3) control diet with 400 mg/day CLO. To evaluate the antioxidant effect of the CLO, sustainable elimination of free radicals by DPPH and ABTS methods were used. The antioxidant activity of essential oils in DPPH method at doses of 32.5, 45, 130, 260 and 520 mg/ml were 9, 16, 31, 49 and 89%, respectively. Also, antioxidant activity of essential oils in ABTS method at doses of 32.5, 45, 130, 260 and 520 mg/ml were 49, 73, 81, 89 and 95%, respectively. CLO treatments did not affect glucose, blood urea nitrogen, albumin, total protein, low density lipoprotein, while improved the concentration of high-density lipoprotein (P>0.01). Results showed that supplementation with CLO significantly decreased (P<0.01) cholesterol, triglycerides and very low density lipoprotein concentrations compared with control. There was no significant difference in analyzed blood bio-chemicals and serum enzymes level between different antioxidant activity methods and groups, suggesting general well-being of ewes. These results suggest that, CLO supplementation had a positive impact on blood traits and antioxidant status of the Afshari ewes.

Rumen fluid from slaughtered animals is one of the wastes of slaughterhouses released to the environment that, due to its high nitrogen and phosphorus contents, can lead to soil and groundwater pollution. Meanwhile, it contains ruminal microbes and some bioactive compounds such as enzymes, minerals, vitamins and organic acids. This study was designed to examine the potential of rumen fluid as a feed additive. Therefore, the effects of spray-dried rumen fluid (SDR) with 1% maltodextrin on the performance, blood metabolites and some cytokines of sucking dairy calves during the pre-weaning phase were investigated. Forty male Holstein calves, with a mean weight of 39.4 ± 3.7 kg and 7 ± 1 days old, were randomly assigned to four groups (n = 10 calves per group) in a completely randomized design. Experimental treatments were: control diet with no additive (CON); control diet with 0.5 g/day of SDR (SDR0.5); control diet with 1 g/day of SDR (SDR1); and control diet with 1.5 g/day of SDR (SDR1.5). Daily feed intake and average daily gain of calves were not affected by feeding SDR as a feed additive. Cholesterol concentration was significantly affected by the 20th and 40th days of the experiment and decreased linearly by increasing SDR feeding level. Levels of liver enzymes, including aspartate aminotransferase and alanine aminotransferase, in the blood decreased by feeding SDR at day 40 of the experiment. Serum concentration of interleukin-6 at day 20 was not affected by dried rumen fluid feeding, whereas at day 40, a significant effect was observed among experimental treatments. The lowest value was recorded for SDR1.5 v. control calves. At day 20, the serum concentration of interferon-γ was influenced by supplementing SDR, and the highest value was recorded for SDR1.5 calves. The inclusion of SDR with 1% maltodextrin in suckling dairy calves had beneficial effects on the stimulation of calves’ immune system.

The main objective of the livestock industry, as an economic production system, is to increase production efficiency through changes in performance and to increase economic productivity. Therefore, in designing genetic improvement programs for domestic animals, it is necessary to pay attention to recognizing the system of production and the factors affecting its performance and the profitability of systems, that is, revenues and costs. For estimation of market liquidity flow and economic returns, using a bio economic model, data on the revenues and costs was used of traditional and industrial cattle in Ardebil province during the years 2012-2016. The nourishment method based on the type of management was divided into two methods: traditional nourishment (in pasture) and industrial nourishment. The results of this study showed that the highest share of revenue and costs of nourishment units was related to milk sales and nutritional costs in both systems respectively. The investment risk level for industrial systems with different levels of milk production (high production, average production and low production) and the traditional system were estimated to be 0.032, 0.078, 0.030 and 0.013, respectively using standard deviation that these numbers represent the degree of deviation of the real result from the average result with medium returns which shows the high risk of investment in industrial dairy cattle compared to traditional dairy cattle. In both systems, the highest estimated relative significance was related to production traits, followed by survival and growth traits, respectively and the least value was related to reproductive traits.