JOURNAL OF RUMINANT RESEARCH
Year:2014 | Volume:1 | Issue:4|Papers Count:12

The effect of different fatty acids in close–up period on population and size of follicles and blood parameters related to the energy state of the body after calving of lactating dairy cows was measured. In this study 12 Holstein cows were selected by expected date of parturition (around 30 days before calving) and assigned them randomly within one of the three experimental treatments including: 1) control (with carbohydrate source), 2) Rumen-protected fat (RF) and 3) Roasted Soybean (RS). The diets were formulated to be isonitrogenous and not iso-caloric. Blood samples were collected at 7 day intervals in -21, -14, -7, 1, 7, 14, 21 periods of calving. Also dry matter intake and body condition score cows were recorded. Ovarian activity was monitored by daily transrectal ultrasound scanning from 30 to 40 and 60 to 70 DIM. In blood parameters section only glucose concentrate, significantly was different among treatment groups and the value of glucose in RS group was higher than RF group. Reproductive activity in cows that were fed RS group was higher than RF group. Differences in dry matter intake and body condition score were not significant.

In this study, effects of probiotic and synbiotic addition to colostrum and milk on passive transfer of immunoglobulins, and growth and health parameters in calves were investigated. Sixteen newborn male Holstein calves were assigned to four treatment groups and received the treatments for 48 days in a completely randomized design. Treatments were included as 1) colostrum and milk without any additive (control), 2) colostrum and milk with 2.5 g probiotic/day (the recommended level), 3) colostrum and milk with 5 g probiotic/day, and 4) colostrum and milk with synbiotic (2.5 g probiotic + 25 g prebiotic/day). Feeding the colostrum was performed immediately after the birth and then three times a day. Blood samples were collected on days 0, 1, 8, 16 and 48. Results showed that serum Immunoglobulin G concentrations were significantly greater in groups received probiotic than control and synbiotic groups (P<0.05), where the greatest was observed in 2.5g probiotic group. There were no significant differences among groups in serum total protein concentrations. The starter intake in control group was significantly greater than other groups (P<0.05). Liveweight of calves at the end of the study was significantly increased in probiotic group than synbiotic group (P<0.05). Feed conversion ratio was improved by adding of probiotic to colostrum and milk when compared to control and synbiotic groups (P<0.05). The use of probiotic or synbiotic significantly improved the fecal score (P<0.05), but no significant differences were observed in the health score among groups. In conclusion, probiotic addition is an effective tool to increase immunoglobulin’s uptake from colostrum into calf and also improve growth performance, so the recommended level of 2.5% is confirmed to achieve the beneficial effects.

Fifteen multiparous cows with mean weight 630+50 and 50+ 40 DIM were selected for comparison of different levels of soybean and allocated randomly to three treatments. The rations were fed to cows as total mixed ration and ad libitum. The cows were and milked three times a day and daily milk yield was recorded while milk samples taken once per week for determination of milk composition and samples of rumen liquor and blood were taken at the last week of experiment. Dry matter intake increased with increasing of soybean levels. The average of milk yield with respect to the rations 1-3 were 29.9, 28.9 and 28.7 and fat corrected milk yield for 4% fat were 27.4, 29.2 and 28.7 kg per day respectively. That it wasn’t significantly different. Milk composition including fat, protein, solid non fat and total solid percent were not affected. Treatments had no significant effect on feces PH and rumen pH. The average of weight change to body weight was 0.2, 1.8 and 4.2 that was not significantly different. Chewing activity (minute per day) was numerically decreased in second diet, but chewing activity to dry matter intake was significantly decreased in second diet. Concentration of calcium, cholesterol, albumin, total protein, urea nitrogen, T3 and T4 in blood of cows receiving different diets were not different, while concentration of glucose and phosphorus in blood were different.

In order to investigate effects of partial replacement of starch with neutral detergent soluble fiber (NDSF), 16 lambs were used in completely randomized design. The length of the experiment was 90 days. Dietary treatments were 1- Control (without beet pulp), 2-18% beet pulp, 3-36% beet pulp and 4-54% beet pulp (high soluble fiber). Dry matter and Organic matter digestibility was highest in treatment 1 and lowest in treatment 4. NDF and ADF digestibility significantly increased with increasing amount of beet pulp in the diet. Rumen ammonia nitrogen decreased significantly with increasing level of beet pulp in the diet. Highest and lowest hot carcass weight observed in treatment 1 and 4 respectively. Treatment 3 and 1 showed highest full and empty rumen weight respectively. Total carcass fat decreased with increasing level of beet pulp in the diet. Potential gas production was the same between treatments but the rate of gas production between straw and sugar cane pith were different. The results of this study indicate that partial replacement of starch with neutral detergent soluble fiber from beet pulp to 36% of ration dry matter could improve fiber digestibility and reduce rumen ammonia nitrogen concentration but inclusion of 54% beet pulp in the diet could not support growth like the high starch diet.

This experiment was conducted to determine the chemical compositions of the garlic and clove essential oils and compare their antimicrobial activity with nanosilver and current antibiotics used in veterinary medicine. The garlic and clove plants were processed for oil extraction. Chemical composition of essential oils was determined using gas chromatography. Diallyl disulfide and eugenol had the greatest contribution in the essential oil of garlic and clove, respectively (25.50 and 63.37%). Garlic and clove essential oils and nanosilver in 5 levels (0.5, 1, 2, 4 and 8 microliter) and commom antibiotics in veterinary medicine were infused into sterile 6 milimeter filter paper discs. The discs were put on muller hinton agar that cultured with rumen fluid. After 24 hours, inhibition zone diameter were measured with caliper. Differences between inhibition zone diameter of treatments were significant (P<0.05). Neomycin and tetracycline combination and oxy tetracycline had the highest antibacterial activity with inhibition zone diameter of 38.033 and 25.020 millimeter respectively. Inhibition zone diameter of nanosilver and clove essential oil was significantly higher than neomycin (P<0.05). Antibacterial effect of nanosilver versus clove essential oil was only higher in level of 0.5 and 8 (P<0.05).

The aim of this research was to compare the nutritive value of straw from two varieties (Shiraz and Pishtaz) and two lines (C-79-15 and M-79-7) of wheat in order to select the superior variety and line. The heads were removed from the bushes of wheat and samples of straw were analyzed for botanical fractions (leaf, stem and node) and chemical composition. Fermentability of the samples was determined with gas test method. The results showed that variety of Shiraz contained less stem and more leaf and nodes compared to Pishtaz. No difference was observed between the two lines in percentage of leaf and stem but percentage of node in line of M-79-7 was higher than that of C-99-15 (9.02 vs. 7.62). Shiraz variety contained less Neutral Detergent Fiber and Crude Fiber as compared to Pishtaz (78.00 and 44.33 vs. 75.60 and 41.60 percent respectively). Results of gas production showed that the two varieties and their botanical fractions were not different in total gas production. Similar results were observed for the two lines except for 48, 72 and 96 hours of incubation. Results showed that chemical composition and fermentability of straw from the two varieties and two lines were similar and therefore no difference was observed in nutritive value between the two varieties and lines. Since ratio of straw to total plant in variety of Shiraz and line of M-79-7 was higher compared to another variety and line, they were chosen as superior.

Rumen acidosis can be caused by overeating of readily fermentable carbohydrate, and as a result an imbalance may be seen in rumen microbial population. In order to characterization of lactate producing bacteria 30 isolates were collected from ruminal fluid of three male Mehraban sheep (receiving a diet containing 60% concentrate and 40% alfalfa hay) using specific cultural media. The isolates were evaluated based on gram staining, catalase activity, indole production test and their ability to ferment some sugars. Identification of isolates was undertaken using 16s rRNA gene sequences. A RFLP procedure was used to test the genetic homogeneity of isolates. Four isolates were selected and their 16s rRNA were sequenced. Based on information obtaind from Gene Bank, the isolates were closely (>99%) related to Streptococcus macedonicus, Streptococcus luteciae, Enterococcus faecalis and Escherichia fergusonii.

In this study, records of 64220 first lactation dairy cows were used. Data were collected from 749 herds during 1996 to 2009 by the Animal Breeding Center of Iran. Data included of production (305 d milk yield, 305 d fat percentage, 305 d protein percentage and lactation length) and reproduction (dry days, age at first calving, calving interval and days open) traits. Data analysis was performed by restricted maximum likelihood procedure using DFREML software. The estimated heritabilities of milk yield, fat percentage and protein percentage and lactation length were 0.197, 0.282, 0.333 and 0.031, respectively. The estimated heritabilites of dry days, age at first calving, calving interval and days open were 0.015, 0.079, 0.035 and 0.036, respectively. Genetic correlations between production traits were from 0.52 for milk yield and fat percentage to 0.74 for fat percentage and protein percentage. Genetic correlations between reproduction traits were from 0.07 (age at first calving and calving interval) to 0.95 (dry days and calving interval). Estimated genetic correlation between production and reproduction traits were from -0.63 (milk yield and dry days) to 0.96 (lactation length calving interval). Considering negative genetic correlation between production and reproduction traits, planning of selection programs in dairy cows based on a combination of production and reproduction traits is recommendable.

The aim of this study was comparison of restricted maximum likelihood and Bayesian statistical methods to estimate of (co)variance components of production traits of Iranian Holstein cows by multi-trait random regression animal model. Data included 181,226 test-day records collected on 21,469 fist lactation cows. The model included herd-year-season of calving, year-month of test day, somatic cell score, age of calving and milking time as fixed effects, and random regression coefficients for additive genetic, and permanent environmental effects. For restricted maximum likelihood method, heritability's of test-day milk yield were higher in the middle (0.30) than at the beginning (0.08) or the end (0.23) of lactation, but for Bayesian method the highest value was observed for end of lactation (0.31). Genetic correlations among 305-d yield traits ranged from -0.502 (milk yield-protein percentage) to 0.712 (fat-protein percentage) for restricted maximum likelihood method and from -0.525 (milk yield-protein percentage) to 0.703 (fat-protein percentage) for Bayesian method. Residual variances of production traits for first method were 0.005 (%2) to 0.64 (kg2) higher than these values for second method.

In this research, in order to predict genetic parameters and genetic and environmental trends of birth weight and weaning weight of Najdi calves, 1249 records collected during the period of 1989 - 2004 in Najdi cattle Research Station of Khuzestan were used. Variance components, genetic parameters and predicted breeding values were estimated for traits, using animal model with direct and maternal additive genetic effects as the best model and restricted maximum likelihood method based on a derivative-free algorithm. Phenotypic, genetic and environmental trends were calculated as the regression of average phenotypic values, predicted breeding values and environmental values on year of calf birth, respectively. Direct and maternal heritability for birth weight and weaning weight were estimated 0.37±0.11, 0.08±0.04, 0.13±0.06 and 0.1±0.06, respectively. Phenotypic trends of traits were 0.07±0.05 kg/year and 0.21±0.3 kg/year for birth weight and weaning weight, direct additive genetic trends for these traits were 0.06±0.01 kg/year and 0.13±0.04 kg/year, and maternal additive genetic trends for these traits were 0.03±0.005 kg/year and 0.13±0.01 kg/year, respectively. Environmental trends were estimated as 0.02±0.06 kg/ year and 0.04±0.3 kg/year, respectively.

To assess the economics of rural sheep production systems and estimation of economic values of important traits in Zandi breed, bio-economic approach was used. In order to estimate economical parameters for using in bio-economical equations and to calculate the EVs of traits, two farms with the flock sizes of 500 and 450 head of Zandi sheep breed in Varamin were studied since the beginning of September 2010 to September 2011. EVs (economic values) of six important traits including pregnancy rate (FE), litter size (LS), lamb weights at birth (BW0), 3 (weaning; BW3), 6 (BW6) months old and survival rate until the age of 6 months (SRL6) were estimated. To estimate the EV of each trait, the level of the trait was increased by both 1% of its mean value and 1 unit while all other traits were constant in their mean values and the amount of change in the profit of system was considered as the EV of the trait. The sensitivity of the EVs was investigated by changing prices of feed and live weight of animals by ±20%. The economic analysis results indicated that the average of feeding cost ratio to the overall costs; and also the average of management cost ratio to the overall costs of rural sheep production system were 64.5 and 33.2 percent respectively and the average annual profit of each breeding ewe in rural sheep production system was 1109594 Rials. The most important trait in this system was FE, followed by LS, BW6, SRL6, BW3 and BW0, respectively when used by 1% increase.

In this study, according to the role of the milk production and dairy cattle breeding industry in GDP and food security and also the role of Isfahan province in Iran's animal husbandry sector, some economical indexes of milk are investigated in Isfahan County. Therefore, dairy farms efficiency was evaluated by using Data Envelopment Analysis and the Total Factor Productivity (TFP) of farms measured by using Tornqvists-Theil indicator. Gathering the data for this study was done by using documents, observation and interview methods. The results of efficiency calculation with assumption of constant return to scale and basis on minimization of inputs show that 75 of farms were technically efficient. But average of allocative and economic efficiency showed inefficiency in milk production. The results of scale return showed that 19 farms had increasing growth in production with increasing capacity, five farms has been growth in production and 36 farms had constant growth with increasing capacity. The average of TFP in farms was equal to 0.94 that showed dairy farms in Isfahan County had negative growth in TFP means that production growth in them has been less than inputs growth.