JOURNAL OF RUMINANT RESEARCH
Year:2020 | Volume:8 | Issue:3|Papers Count:8

Background and objectives: Diarrhea is one of the most common diseases in young dairy calves. This disease results in economic loss on dairy farms. Addition of high fiber by-products to calf starter diet may have beneficial effect on preventing calf diarrhea. Furthermore, milk plane of nutrition has direct effect on calf health and growth during the pre-weaning period and in the future heifers were replaced in the herd. The purpose of this research was to examine the effect of substituting steam-flaked corn grain (SFC) with shredded sugar beet pulp (SBP) in starter feed diet and milk replacer (MR) plane of nutrition on health status in neonatal Holstein calves during the pre-weaning period. Materials and methods: A total of 48 Holstein calves (3 d of age; 40. 1 ± 0. 84 kg of BW; mean ± SE) were assigned randomly to 1 of the 4 treatments: 1) calves fed low MR allowance (LOW; 4 L/d from d 1 to d 58, and 2 L/d from d 59 to d 60 of the study) and SFC containing starter feed without SBP (LOW-SFC), 2) calves fed low MR allowance and partial replacing SFC with SBP (25% of DM) in starter feed (LOW-SBP), 3) calves fed high MR allowance (HIGH; 4 L/d from d 1 to d 2, 6 L/d from d 3 to d 4, 8 L/d from d 5 to d 55, 6 L/d at d 56, 4 L/d from d 57 to d 58, and 2 L/d from d 59 to d 60 of the study) and SFC containing starter feed without BP (HIGH-SFC), and 4) calves fed high MR allowance and partial replacing SFC with BP (25% of DM) in starter feed (HIGH-SBP). The health criteria of the calves were monitored daily by a veterinarian, blinded to the treatments, during the preweaning period (d 1 to 60). Rectal temperature was recorded daily using a digital thermometer placed in the rectum for 1 min. The fecal and general appearance scores were determined daily based on a 1 to 5 system while calves were in individual pens. Results: Results showed that calves fed diets containing SBP vs. SFC had lower and higher chance to develop pneumonia and diarrhea, respectively. Plane of MR nutrition had no effect on developing diarrhea, but calves fed higher plane of MR nutrition had higher chance to develop pneumonia. General appearance (score ≥ 2), frequency and duration of diarrhea or pneumonia were not different among experimental groups; however, calves fed LOW-SBP experienced fewer days of higher rectal temperature compared with other experimental groups. Conclusion: Plane of MR nutrition had no effect on susceptibility to diarrhea but calves fed higher plane of MR experienced more days with pneumonia and medication. Feeding SBP increased and decreased chance of having diarrhea and pneumonia, respectively, which was coincided with more or few days with those diseases.

Background and objectives: In recent years, many countries and regulatory agencies, including the European Union, have banned the use of antibiotics and growth stimulants in animal nutrition, so it is necessary to find suitable alternatives to these compounds in animal feed, especially animal animals. Synbiotic supplements (a mixture of probiotics and prebiotics) reduce the population of pathogenic microbes in the gastrointestinal tract and improve the performance of the host animal by increasing their interaction. Probiotic, prebiotic, and, synbiotic supplement can be controversial options for replacement with antibiotics and growth stimulants. Considering the effective effects of these beneficial additives on the growth performance of fattening animals, this study was performed to investigate the effect of different levels of Biomin® IMBO synbiotic supplements in diet on growth performance, apparent digestibility nutrients, and some blood parameters of fattening Zel lambs. Materials and methods: To perform this study, 24 mixed fattening Zel lambs were examined with a means age of 5 ± 0. 55 months and a means initial weight of 26 ± 2 kg in a completely randomized design for 90 days. Experimental treatments included control treatment (without the addition of synbiotic supplement) and treatments containing 2. 0, 4. 0, and 6. 0 g of synbiotic supplement per lamb per day. The synbiotic supplements used was Biomin® IMBO, which included the bacterium Enterococcus fascium and fructooligosaccharide and seaweed extract. The daily diet was given as total mixed ration to animals twice and then feed intake was recorded. Live weight measurement was performed every 14 days with 12 hours of feed and water deprivation. Measurement of the apparent digestibility of nutrients in the last days of the experiment as well as the study of carcass traits and blood parameters were performed on day 90 of the experiment. Results: The results of growth performance showed that there was a statistically significant difference between experimental treatments in daily weight gain and feed conversion ratio (P < 0. 05). Daily weight gain and feed conversion ratio improved significantly in the treatment containing 6. 0 g of synbiotic supplement. The results of apparent digestibility nutrients in experimental diets showed that there was a statistically significant difference between dry matter, NDF and ADF between experimental treatments (P < 0. 05). Treatments containing 4. 0 g of synbiotic supplement had the highest apparent digestibility of dry matter and treatment containing 6. 0 g of synbiotic supplement had the highest apparent digestibility of NDF and ADF. The results of experimental carcass traits at the end of the experiment showed that there was no statistically significant difference between the experimental treatments. The results of some blood parameters at the end of the experiment showed that there was a statistically significant difference in blood glucose and BUN levels between experimental treatments (P < 0. 05). Treatments containing 4. 0 g of synbiotic supplement had the highest blood glucose levels and control treatments had the highest levels of BUN. Conclusion: The overall results of the study showed that adding Biomin® IMBO synbiotic supplement at the level of 6. 0 g in the diet improved daily weight gain and feed conversion ratio. There was also an improvement in the apparent digestibility nutrients in dry matter, NDF and ADF by consuming levels of 4. 0 and 6. 0 g of Biomin® IMBO synbiotic supplement.

Background and objectives: The use of agricultural by-products and waste because of its high value of nutrients is possible in the preparation of animal feed. About 950 tons of Mentha pulegium pulp is produced annually in Iran. If this pulp dries well, it can be used in animal feed due to its nutritional value. Due to the fact that moisture is a limiting factor for animal feed storage, ensiling can eliminate this limitation. This study was to evaluate the chemical composition of Mentha pulegium pulp silage with wasted date and its feeding effects on dry matter intake, microbial protein yield and blood parameters in sheep. Materials and methods: Four hundred kg of Mentha pulegium pulp were mixed thoroughly with 30 kg of wasted date at levels of 0 (control), 5, 10 and 15% (DM basis) and ensiled for 45 days. After determining the chemical composition and sensory assessment of the silages, level of 20% (DM basis) was used in experimental diets. For determine the effects of Mentha pulegium pulp silage on sheep, four mature ram (with 40 ± 2 live weight) were used in a change-over design with four periods of 21 days. In the 5 days at the end of each period at 0, 3, 6 and 9 h after morning feeding, rumen fluid was sampled from sheep by esophagous tube and were filtered through three layers of cheesecloth. Blood samples were collected at the end of each period and 4 h after morning feeding in 10 mL. To determine the amount of allantoin and microbial protein synthesis, the daily urine produced during 24 h was collected. Results: According to the sensory assessment, silages containing of wasted date get score of very good of 20. Adding wasted date to Mentha pulegium pulp increased the DM and ether extract of silages. DM intake and digestibility of DM, crude protein and NDF of experimental diets were not affected by silages of Mentha pulegium pulp with different levels of wasted date. Nitrogen intake, nitrogen excretion and the percentage of nitrogen retention were not affected by experimental diets. Total purine derivatives and microbial protein synthesis did not change. The level of blood cholesterol and albumin were significantly changed by feeding diets containing Mentha pulegiumsilage with wasted date (P < 0. 05). Conclusion: In conclusion, Mentha pulegium pulp silage could be used up to 20% without additives or with wasted date in sheep diet.

Background and objective: Some previous researches have shown that dietary supplementation with some vitamins and trace elements can increase the ability of animals semen preservation during liquid storage or freezing. Therefore, the aim of this study was to investigate the effect of dietary supplementation of organic selenium and chromium on ram semen quality during liquid storage at 4° C. Material and methods: Numbers of 16 Mehraban rams, with ages ranging from 2-4 years and 69. 75 ± 10. 44 kg average body weight, were divided into four groups of four and were fed by a basal diet consist of 70% forage and 30% concentrate. The experimental design was 2 × 2 × 4 factorial experiment based on randomized complete block design. The experiment lasted for 60 days. In this experiment, three factors were including selenium at two levels (0 and 600 μ g/day/ram selenium as yeast-selenium), chromium at 2 levels (0 and 1000 μ g/day/ram chromium as chromium-methionin) and time at 4 levels (0, 24, 48 and 72 hours after storage). Chromium was fed to rams using edible capsule shells and also selenium by drencher after dissolving in distilled water. In the last three weeks of the experiment, semen samples were collected three times. Semen samples after collection was diluted with tirs-egg yolk base extender and stored at 4° C for 72 h. Sperm cells viability, membrane integrity, abnormal morphology, total motility and progressive motility and some motion parameters is detected by computer-assisted sperm analysis at 0, 24, 48, and 72 hours after storage. Results: The effects of chromium, time and their interaction and also selenium × chromium interaction, selenium × chromium × time interaction were significant for sperm viability and membrane integrity (P<0. 05). The effect of selenium and selenium × chromium interaction was not significant for viability (P>0. 05) but, the effect of chromium, selenium and time and also their interaction for membrane integrity was significant (P<0. 05). The viability reduced over time significantly (P<0. 05) and sperm viability in rams receiving the diet contained 1000 μ g chromium, was higher than diet without chromium after storage at 4° C for 48 and 72 hours (P<0. 05). In addition, sperm viability in rams receiving the diet contained 600 μ g selenium was higher than diet without selenium after storage at 4° C for 48 hours (P<0. 05). Adding 1000 μ g chromium to diet containing 600 μ g selenium, increased significantly sperm viability after storage at 4° C for 48 and 72 hours (P<0. 05). The membrane integrity reduced over time significantly (P<0. 05) and sperm membrane integrity in rams receiving the diet contained 1000 μ g chromium was higher than other groups after storage at 4° C for 24 and 48 hours (P<0. 05). The effect of selenium and chromium and also their interaction was not significant for computer detected parameters (P<0. 05). Interaction of selenium and chromium for abnormal morphology was significant (P<0. 05) but the effects of chromium, selenium, time and their interaction was not significant (P>0. 05). Total motility, velocity in curvilinear line, velocity in straight line, velocity in average path decreased over time during semen storage at 4° C (P<0. 05) and diet supplementation of selenium and chromium did not change these parameters (P>0. 05). Progressive motility, abnormal morphology and straightness did not affected by time, selenium and chromium. Conclusion: Generally, dietary supplementation of organic selenium and chromium in rams leads to increased sperm viability and membrane integrity during chilled liquid storage. Dietary supplementation of selenium and chromium did not change computer detected parameters during semen storage at 4° C. In general, the use of organic selenium and chromium in the diet of rams may increase the ability of sperm storage for artificial insemination.

Background and objectives: Treatment of bacterial diseases with antibiotics has problems such as antibiotic resistance and side effects. Essential oils of medicinal plants have antibacterial effects and are suitable alternatives. Lavandula stoechas and Origanum majorana are two members of lamiaceae family that have shown antibacterial effect against some bacteria. Escherichia coli, Staphylococcus aureus, and Streptococcus agalactiae are major bovine mastitis-causing bacteria. Therefore, this study examined the antimicrobial activity of Lavandula stoechas (lavender) and Origanum majorana (marjoram) essential oil against these bacteria in comparison with gentamycin and amoxicillin/clavulanate antibiotics. Materials and methods: Chemical compositions of essential oils were determined by GC/MS. Broth dilution testing using macrodilution was performed to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of essential oils and licospectinomycin as positive control and the inhibition zones of oils, gentamycin and amoxicillin/clavulanate antibiotics were assayed by disk diffusion method. The effect of sub-MIC concentrations of essential oils on tested bacterial count was obtained at 0, 6, 10 and 24 hours and growth curve were plotted as log cfu/ml. Results: Main components of the Lavandula stoechas and Origanum majorana oils were 17-pentatriacontene (42. 15%), linalyl acetate (26. 82%), eucalyptol (18. 87%), linalool (5. 7%), and 3-cyclohexene-1-ol, 4-methyl-1-(1-methylethyl)-, (R)-(44. 84%), α-terpineol (6. 83%), P-cymene (6. 75%), respectively. MIC and MBC values ranged from 0. 15-0. 62% for lavender and 0. 62-1. 25% for marjoram. MIC and MBC of licospectinomycin antibiotic were 0. 07-0. 31% and 0. 15-0. 64%, respectively. The lavender and marjoram essential oils had the most effective against S. aureus and MIC and MBC values were 0. 15% and 0. 31%, respectively. Also, the most effective of Lincospectinomycin antibiotic was against S. aureus and MIC and MBC values were 0. 07% and 0. 15%, respectively. The Lavandula stoechas and Origanum majorana oils at sub-MIC concentrations significantly reduced the bacterial population at 24 h. The inhibition zone of lavender and marjoram essential oils had no significant difference against S. aureus with gentamycin and amoxicillin/clavulanate antibiotics and against E. coli with gentamycin but against S. agalactiae were significantly lower than gentamycin and amoxicillin/clavulanate. Conclusion: Essential oils of Lavandula stoechas and Origanum majorana had antibacterial activity against Staphylococcus aureus, Streptococcus agalactiae, and Escherichia coli bacteria in vitro. This effect had no significant difference against S. aureus with gentamycin and amoxicillin/clavulanate and against E. coli with gentamycin that show satisfactory effects of oils. Clinical studies on therapeutic effects of Lavandula stoechas and Origanum majorana oils on different diseases such as bovine mastitis are recommended.

Background and objectives: One of the safe ways to increase income and profit is to pay attention to the longevity of dairy cows as well as to increase the efficiency in each livestock units. Since livestock production enterprises are often in a competitive position by input-output market, increase of efficiency is considered as one of the most reliable ways to increase revenue and profitability in each livestock unit. This study aims to determine the efficiency and factors affecting the optimal herd life using data envelopment analysis (DEA) model and dynamic programming in Ardabil city, Iran. Materials and methods: The data of this study was collected from Ardabil dairy farms from March 2018 to March 2019. The economic system of dairy cow herd was divided into income and cost components using system analysis method each which was decomposed to some other subsections. Then, a bio-economic model was simulated using mathematical models and optimization was performed using the Compecon toolbox of Matlab software. Dairy cattle were described through state variables including lactation period, the capacity of milk production, and different states at conception time. To design the data envelopment analysis model, several inputs and outputs were studied in the production process. The main variables used in the current study included herd size (number of cows), food and concentrate (Kg), manpower (individuals per day), health issues (number of excretion per day), production of milk and fertilizer (Kg), and total different incomes. For analyzing the calculations of efficiency, Deap 2. 1 software was used which is based on minimization of input per unit of production. Results: The optimal herd life (from the first parturition to the removal time) under the specified optimal conditions was 4. 55 years. The results showed that the technical efficiency was 0. 719 and 0. 899 with constant and variable return to scale, respectively while the scale efficiency was calculated as 0. 788. In general, the values of technical, allocative and economic efficiencies were 0. 99, 0. 583 and 0. 579, respectively. The results of data envelopment analysis showed that in the variable return to scale conditions, increase in herd size and health costs as well as decrease in the amount of food, concentrate and manpower costs improves the efficiency of inefficient herds by 14. 18%, 0. 83%, 2. 8%, and 5%, respectively while the production level is kept at the same level. Conclusion: The effect of changes in heifer price, milk and discount rate on optimal herd life showed that the percentage of livestock removal from the herd is decreased and the optimal herd life of cattle is increased with the increase in heifer price and discount rate as well as decrease in milk price. To increase the efficiency of an inefficient dairy breeding unit, changes can be applied in the inputs and outputs of the unit and a suitable strategy can be designed to increase the efficiency of herd through determining the differences appeared between efficient and inefficient units.

Background and objectives: The reproductive performance of dairy cows is directly linked to uterine involution and resumption of ovarian cyclicity in the postpartum period. Many factors, such as negative energy balance, metabolic diseases, and hormonal agents can affect reproductive performance in the postpartum period. Hypocalcemia through reduced feed intake reduced nutrient supply to the ovary and delayed return to normal uterus function has a potential role to reduce the reproductive performance of cows after parturition. The aim of this study was to examine the association between the peripartum concentrations of calcium with reproductive performance and also determine the critical threshold of calcium for predicting the possibility of pregnancy in the first insemination after calving. Materials and methods: the study was conducted on 97 Holstein dairy cows. Serum concentrations of calcium were measured in all cows on day 10 prepartum, parturition, 1-2 days after parturition, and on the week 1, 2, 4, and 6 postpartum. Based on Pregnancy success after the first insemination, the interval from calving to first insemination, the interval from calving to first pregnancy and number of services per conception, cows were divided to two, two, three and two groups, respectively and differences of calcium concentration were evaluated among these groups. Receiver Operator Characteristics (ROC) analysis was applied to determine the critical calcium threshold at different times for predicting pregnancy success after the first insemination. Results: Results showed that calcium concentration in pregnant cows with the first insemination was significantly higher than non-pregnant cow in the fourth week. Also, the cows that were became pregnant before 80 days after parturition had the significantly higher calcium concentration than the other cows at 1-2 days and the fourth week after parturition. Based on results of ROC analysis, the calcium concentration at the fourth week after parturition (P = 0. 04) was appropriate to predict the pregnancy success after the first insemination. The optimum critical threshold that had the highest combined sensitivity (57. 1%) and specificity (62. 3%), for calcium in the fourth week was 9. 05 mg/dl. In the cows with success pregnancy before 80 days after parturition the calcium concentration was significantly higher than other cows (P = 0. 03). Conclusion: the results of this study showed that there was a significant relationship between change in calcium concentration and reproductive performance indexes in the postpartum period. It seems that the monitoring of blood calcium concentration in the fourth week after parturition is a complementary index along with other reproductive performance indexes to evaluate the possibility of successful pregnancy after parturition.

Background and objectives: Heat stress (HS) is one of the environmental stressors which has significant effects on the dairy cattle industry. The biological mechanisms by which the thermal stress effects on the livestock production performance can be somewhat explained by reduced feed intake, but it is more relevant to hormonal changes, reduced rumination and absorption of nutrients, as well as increased maintenance requirements, which reduces the amount of nutrients / energy for production purpose. The objective of this study was to identify the direct and indirect effects of acute HS during the last gestation on nutrient digestibility and rumination behavior of dairy cows. Materials and methods: Holstein dairy cows (n= 10/treatment) with similar parity and body weight (BW), were randomly assigned to one of the three following treatments during 45 d before calving: 1) Cooling and ad libitum feed intake (TN), 2) Cooling and pair-feeding (CLPF), and 3) HS and ad libitum feed intake (HS). Cows in all groups received individually the same diet. During the experiment, daily temperature and the relative humidity were recorded. During the 26-21 d and 10 to 5 d before calving, the feed intake behavior was record for 24 hours. Nutrients digestibility was measured on 26-21 d and 10-5 before calving. Results: Heat stressed and feed restricted cows had lower feed intake. Heat stressed and food restricted cows had lower eating time significantly compare to the control group. Heat stressed cows had the lowest rumination activity. Also, the heat stressed cows had significantly lower resting time than the control group. Also, heat stress significantly reduced the DM and NDF digestibility. Conclusion: Late gestation heat stress caused decreased feed intake. Also, nutrient digestibility of the diet negatively affected by heat stress. However, feed restriction in late gestation did not have significant effect on nutrient digestibility than the control group. In addition, heat stress reduced the rumination activity and resting time of the cows.