Behzad Khorrami; Seyed Alireza Vakili; mohsen danesh mesgaran
Abstract
Introduction: Today, the use of antimicrobial agents such as antibiotics in livestock diets is facing reduced social acceptance because of the appearance of residues in milk and meat, and therefore, ruminant nutritionists are seeking for appropriate alternatives for these feed additives. The study of ...
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Introduction: Today, the use of antimicrobial agents such as antibiotics in livestock diets is facing reduced social acceptance because of the appearance of residues in milk and meat, and therefore, ruminant nutritionists are seeking for appropriate alternatives for these feed additives. The study of essential oils (EOs) as natural feed additives capable of improving rumen microbial fermentation has taken into consideration by nutritionists. Among the EOs, thyme (THY) and cinnamon (CIN) oil have attracted significant attention due to their antimicrobial activity against ruminal microorganisms. Therefore, more research is required to understand their impacts on rumen microbial fermentation in ruminants. Moreover, to the best of our knowledge, few studies has synchronously compared the influences of THY and CIN on rumen fermentation and microorganisms. This study was conducted to evaluate the effect of THY and CIN on performance, and rumen microbial fermentation under in vitro and in vivo conditions.
Materials and methods: In the in vitro experiment, different concentrations (0, 125, 250, 500, and 1000 mg/l) of THY and CIN were incubated for 24-h in batch culture. In the in vivo study 18 growing Holstein calves were used in a completely randomized design to examine effects of supplementing a basal diet (CON) with thyme oil (THY, 5 g/d/calf) or cinnamon oil (CIN, 5 g/d/calf) on performance and rumen microbial fermentation. Calves were fed ad libitum diets consisting of 15% forage and 85% concentrate for 80 d.
Results and discussion: The high concentration of THY and CIN (1000 mg/l) inhibited rumen microbial fermentation thereby decreasing total gas production and DM disappearance at 24 of incubation, and total VFA concentration. Cinnamon oil at 1000 mg/l increased final pH of batch culture (P<0.05). The lower concentration of THY and CIN (125 and 250 mg/l) decreased the acetate to propionate ratio (P<0.05), without reducing VFA concentration. Supplementation of THY or CIN did not affect DMI and ADG. There were also no effects of EOs on ruminal pH, rumen concentrations of ammonia nitrogen and total VFA; whereas molar proportion of acetate and ratio of acetate to propionate decreased (P<0.05), and the molar proportion of propionate increased (P<0.05). Rumen molar proportion of butyrate was significantly increased (P<0.05) by adding CIN. The population of protozoa and methanogens bacteria decreased in the rumen of calves receiving EOs (P<0.05). Ruminal population of Fibrobacter succinogenes was not affected by treatments, but populations of Ruminococcus albus and flavefaciens decreased by THY and CIN (P<0.05).
Conclusion: Based on the results of the present study, although dietary addition of THY and CIN did not have a significant effect on the performance of feedlot calves, but it improved the rumen fermentation properties, which may be considered as potential alternatives for antibiotics in beef production systems.
Masoud Norozi-ِDeeyarjan; ali assadi-alamouti; Ahmad Afzalzadeh; mohsen danesh mesgaran
Abstract
This study examined the effects of partial replacement of soybean meal (SBM) with heat-treated soybean meal (HSBM) in heat-stressed cows. 32 multiparous Holstein cows (DIM = 110 ± 20; milk yield = 40 ± 4.1 kg) were used in a complete block randomized design with a 2×2 factorial arrangment ...
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This study examined the effects of partial replacement of soybean meal (SBM) with heat-treated soybean meal (HSBM) in heat-stressed cows. 32 multiparous Holstein cows (DIM = 110 ± 20; milk yield = 40 ± 4.1 kg) were used in a complete block randomized design with a 2×2 factorial arrangment of treatments. Treatments included two dietary crude protein levels (i.e. 17 and 15.5%) each combined with HSBM partially replaced for SBM. The experiment was conducted in two periods of 28 days with the last seven days for sampling and collection of data of tempreature, nutrient intake and digestibility and blood variables. Average THI showed that cows were in mild heat stress (70.60 and 71.50 for periods 1 and 2, respectively)(p > 0.05). Diets with 15.5% CP and based on HSBM increased intakes of dry and organic matter (p < 0.05); however, this was not observed in diets with 17% CP. Milk yiled and composition, apparent nutrient digestibility and blood variables were unaffected (p > 0.05). Butyric and isovaleric acid were increased in cows received HSBM (p < 0.05); however, level of CP had no effect. Results showed that feeding HSBM in diets with 15.5% CP could be regarded as a nutritional sterategy for improving DM intake of mild heat-stressed cows.
Abstract
The aim of this study was to compare the effect of glycogenic and/or lipogenic diets fed in Baluchi ewes treated with an estrus synchronization method to reduce delivery distance and improving reproductive parameters. Ninety heads of Baluchi ewes selected and randomly placed into three parallel groups. ...
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The aim of this study was to compare the effect of glycogenic and/or lipogenic diets fed in Baluchi ewes treated with an estrus synchronization method to reduce delivery distance and improving reproductive parameters. Ninety heads of Baluchi ewes selected and randomly placed into three parallel groups. Each ewe of group was fed in with three different diets based on the fat and starch sources. In order to do the estrus synchronization, all ewes were put CIDR in 30 day of the trial. After 14 days, they were removed, then four hundred IU eCG hormone were injected. As soon as estrus signals was observed, ewes were inseminated. Ultrasonography was done to observe the number of dominant follicle, CL and pregnancy diagnosis. After parturition, reproductive parameters like lambing and twining rate were analyzed. The most of examined ewes showed clearly estrus signals. The consequence of ovary sonography did not indicate significant effect in average of dominant follicles numbers among the experimental diets. The number of dominant follicles was increased significantly from time of estrus to artificial insemination. Ovulation, pregnancy and twining rate were considerably (P< 0.05) higher in glycogenic and glycogenic+lipogenic rations compared with lipogenic ration. Generally, the feeding of starch source alone and or along with low proportion of fat sources might improve the effect of estrus synchronization on reproductive performance of Baluchi ewes.
Ahmad Afzalzadeh; Hadi Ghorbani Farmad; mohsen danesh mesgaran; Ali Akbar Khadem
Volume 12, Issue 2 , October 2010, , Pages 37-50
Abstract
The effect of feeding of soaked barley straw on milk production and composition and rumen characteristics was studied. The degradability of soaked barley straw (for 24, 48 and 72 hours) and unsoaked barley straws were studied in the first experiment. The unsoaked barley straw had more readily degraded ...
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The effect of feeding of soaked barley straw on milk production and composition and rumen characteristics was studied. The degradability of soaked barley straw (for 24, 48 and 72 hours) and unsoaked barley straws were studied in the first experiment. The unsoaked barley straw had more readily degraded fraction (a) than soaked straw treatments (p> 0.05). There was no significant difference between slowly degradable fractions (b) and degradation rates (c, %h) in various treatments of barley straw. The degradability parameters of different rations also studied. The differences between readily (a) and slowly (b) degradable fractions were not significant. In the second experiment the effect of partial replacement of alfalfa hay with unsoaked barley straw and 24h soaked barley straw on performance of 9 multiparous lactating dairy cows in midlactation (580.9 ± 39.3 BW) with 27.8 ± 4.5 kg daily milk yield was studied in a crossover design. The effects of different treatments on milk yield (p< 0.05), milk fat (g/kg yield) (p< 0.05), N-NH3 rumen liquor (p< 0.0001), rumination and chewing activity (min/d) were significant. The rumination and chewing activity (min/d) were increased in diets that contained barley straw. In conclusion utilization of soaked barley straw in ration of midlactation cows is recommended.