JOURNAL OF RUMINANT RESEARCH
Year:2015 | Volume:3 | Issue:3|Papers Count:10

Background and objectives: Based on studies, there is a need to determination of blood parameters of dairy cows especially during the transitional period to assess the physiological status of cows and following that to assess nutritional status of them and in case of diet imbalance and possible deficiency in the farm, diet is balanced and reducing the quality and quantity of milk production can be prevented, also it may cause increase of reproductive efficiency. Therefore, the aim of this study was to evaluate the nutritional status of fresh cows through blood metabolites and providing suitable strategy to improve the nutrition of this group of dairy cattle.Materials and methods: seven dairy farms which are members Union of Agricultural Cooperatives livestock industry in Isfahan random from each of the 7 postpartum cows were selected and sampled. Sampling was conducted in July 2013. Samples for measurement of cholesterol, albumin, urea nitrogen, total protein, glucose, BHBA, NEFA, calcium and sodium blood were sent to the laboratory. Data was then analyzed based on randomized completely design. Duncan’s analysis used for comparison means of dairy farms, as well as, each of the metabolites through t test were compared with the normal range.Results: The results showed that the blood sugar level of dairy cows in some of dairy farms was lower than normal value (50 mg dL-1) in summer (P<0.05), so that 65.3 percent of samples had lower than normal level of blood sugar. Also, the majority of dairy cows blood sodium levels were lower than normal level. Blood albumin content of 39 percent of samples was lower than normal level. Open day was high in the most of farms (even more than 6 month). The farms had different significantly in content of blood NEFA, glucose, calcium and sodium (P<0.05). There was no significant difference between the farms in the other factors.Conclusion: generally, it can be concluded that there was sodium deficiency during early lactation in the most of farms. The lower level of albumin, glucose, sodium and calcium in some of case than the normal levels can be key factors in increasing of open days in the most of dairy farms.

Background and objectives: Based on studies, safflower seeds contain highest levels of linoleic acid among other oilseeds and are produced in certain regions of Iran. Importance of processing of oilseeds and beneficial effects of microwave irradiation processing and its influence on rumen ecosystem is known, therefore this study carried out to determine the effects of adding raw and microwaved safflower seed on rumen ecosystem.Materials and methods: Three rumenaly fistulated sheep were used for determination of the effect of adding raw and microwaved safflower seed on rumen ecosystem such as rumen pH, ammonia-N, total volatile fatty acid, protozoa population and rumen microbial protein yielding. This experiment carried out in three period and each period lasted 24 days, 21 days for adaptation and 3 days for data collection. Total volatile fatty acid, ammonia-N, protozoa population and rumen microbial protein yielding were determined by Markham steel, spectrophotometer, neobar lam and purine derivative excretion, respectively.Results: Adding raw and treated safflower seed hadn’t any significant effect on rumen pH, ammonia-N and total volatile fatty acid but adding raw and treated safflower seed decreased ruminal protozoa population (P<0.05). Feeding microwaved safflower decreased rumen entodinium population (P<0.05) but adding raw and microwaved safflower seed had no effect on rumen diplodinium population. The results showed that microbial nitrogen supplied to the duodenum, purine derivatives and purine absorption decreased by adding microwaved safflower seed (P<0.05).Conclusion: Results show that inclusion of safflower seed up to 4% of diet dry matter had no effect on rumen ecosystem such as pH, total volatile fatty acid and ammonia-N, so we can use safflower seed in sheep and ruminant diets as valuable oil seed.

Background and objectives: The effect of essential oils on in vitro gas production and rumen fermentation has been studied but there are few experiments about the interaction between essential oils and diet type. This experiment was conducted to study the effect of Zataria multiflora essential oil (ZMEO) in diets containing different sources of starch (different degradation rate) and different sources of fat on in vitro gas production kinetics, ruminal digestion and fermentation parameters.Materials and methods: Experimental diets in first experiment consist of: 1- corn based diet, 2- wheat and barley based diet.3- first diet with monensin, 4- second diet with monensin, 5- first diet with ZMEO, 6- second diet with ZMEO and in second experiment experimental diets consist of: 1- diet containing calcium salts of fatty acids, 2- diet containing soybean oil, 3- first diet with monensin, 4- second diet with monensin, 5- first diet with ZMEO and 6- second diet with ZMEO. Gas production (GP), pH, ammonia-N concentration, apparent in vitro dry matter digestibility (AIVDMD) and true in vitro organic matter digestibility (TIVOMD) were measured. Gas production parameters, fermentation parameters and metabolisable energy (ME) were estimated.Results: In both experiments ZMEO and monensin significantly decreased the gas production after 24 h of incubation (GP24), gas production potential, VFA concentration, ammonia-N concentration and ME (P<0.05). The results of first experiment showed that both of ZMEO and monensin significantly decreased the rate of gas production (RmaxS), microbial biomass production (MBP), apparent in vitro dry matter digestibility (AIVDMD) and true in vitro organic matter digestibility (TIVOMD) (P<0.05). In comparison with monensin, ZMEO significantly decreased GP24, potential gas production and the time at which the maximum of substrate degradation is reached (TRmaxS), MBP, AIVDMD, TIVOMD and VFA (P<0.05) and increased half life of gas production and pH (P<0.05). ZMEO significantly increased potential of gas production, maximum gas production per hour, AIVDMD, TIVOMD and MBP and reduced efficiency of MBP and pH in diet containing corn starch in comparison to diets containing wheat and barley starch.Results of the second experiment showed that both of ZMEO and monensin significantly decreased maximum gas production per hour and half life of gas production (P<0.05). Both of ZMEO and monensin significantly increased the time at which maximum rate of gas production is reached (TRmaxG) and rate of gas production (P<0.05). In comparison with monensin, ZMEO significantly increased GP24, AIVDMD, VFA, rate of gas production, maximum gas production per hour and time at which maximum rate of gas production is reached (TRmaxG). None of the in vitro gas production parameters and fermentation were influenced by addition of ZMEO on the different fat sources in the diets (P>0.05).Conclusion: It is concluded that ZMEO changed the ruminal fermentation and digestion and its effect depending on substrate type.

Background and objectives: Due to limited rainfall, fertile land and poor distribution of water resources in the country, providing the feed for animal only through the cultivation of fodder or other feedstuffs is not enough. Understanding the nutritional value of native resistant species of each region for livestock, is a way to provide the animal feed requirements and consequent human food. Therefore, the aim of present study was compared the nutritional value of the leaves, pods, seeds and whole branches of Leucana (Leucaena leucocephala) in both winter and summer.Materials and methods: The chemical composition in different components of Leucana was measured. The Gas production and two steps digestion methods were used for determination of digestion and fermentation of the samples.Results: The crude protein, ash, ADF and NDF content of leaves, pods and seeds of the plant were higher in summer compared to the winter. The tannin concentration of all components of Leucana in summer was higher than winter. The protein content of alfalfa was less than all components of Leucana, except the winter pod (P<0.05). The gas production (GP) of alfalfa was higher than all components of Leucana in the both seasons (P<0.05). Partitioning factor (PF) and microbial biomass efficiency (MBE) of Leucana in summer was more than winter. All mentioned fermentation parameters, in the components of Leucana, were higher than alfalfa (P<0.05). The SCFA, ME, OMD of leaves, pods, seeds and whole branches of Leucana in winter samples were higher than summer samples (P<0.05). The ME of seed, pod and whole branches of Leucana in winter, and OMD of all components of Leucana were higher than alfalfa in the both seasons (P<0.05). The digestibility of Leucana components in winter samples was higher than summer samples; and for all components of Leucana, except the the seed, the digestibility was less than alfalfa (P<0.05).Conclusions: Overall, summer Leucana had less digestability compared to the winter Leucana. Totally, all components of the Leucana especially the grain had the high nutritional value that was consistent with the alfalfa or even higher, so it may be used as an alternative for alfalfa in susceptible areas.

Background and Objectives: Forage particle sizes has two opposite effects on animal performance, on the one hand fed with long particle increases ruminant activity and rumen buffer and reduce the risk of subacute acidosis, on the other hand decreases the flow rate of digestion and subsequently feed intake and milk production. Therefore this experiment was done to determine the functional response of lactating cows when fed diets containing alfalfa hay forage whit 3.09 and 4.65 mm geometric mean.Materials and methods: In this study was used of 8 Holstein cows similarly, with regard to the production stage, weight, age, breed and health, in rotate design 2×2 and the two period 21-day (2 weeks to adaptation with the diet and 7 days for samples) with four replicates for each treatment. During the 7 days of sampling, was measured feed intake, indicators blood and milk.Results: The cows DMI increased with reduced forage particle size (25 versus 22.5 kg per day). Non-fiber carbohydrates, organic matter, neutral detergent fiber, ash, and acid detergent fiber intake was reduced by increasing the particle size alfalfa hay. Physically effective fiber greater than 8 mm intanke in the experiment was statistically significant between the two treatments, that diet smaller particle size had lower levels compared to the larger particle size diet (0.41 to 0.52 kg). With increase geometric mean particle size alfalfa hay of diet from 3.09 to 4.65 mm did not change the amount of milk production, while the fat content of the milk production increase from 3.26 to 3.65 percent. In this experiment protein content, lactose, urea, solid nonfat, total solids, somatic cell counts of milk were not significantly different between the two treatments. By increasing the particle size of alfalfa hay increased blood glucose and triglyceride levels. Blood insulin levels was more in cows fed diets greater geometric mean alfalfa hay (16.29 and 12.86 mg per deciliter). Cholesterol levels, antioxidants, urea and beta-hydroxy butyric acid were not significantly different between two treatments of alfalfa hay particle size in diet. According to the results of this experiment, the particle size reduction of alfalfa hay and diet was decreased in the rumen fluid pH. The rumen fluid pH for diets containing alfalfa hay with geometric mean 3.09 and 4.65 was 6.09 and 6.39 respectively.Conclusion: With increasing the forage particle size increased pH of the rumen fluid, dry matter intake and milk fat.

Background and objectives: The use of roasted soybeans in the diet of dairy cows is common, but the roasting temperature and its effect on cow performance and protein fraction of diets have not been fully understood. To eliminate the anti-nutritional substances and increasing bypass protein, soybean seeds are processed, and heat is the most common way used to processing soybeans. The main objectives of this research were the estimate of the effect of soybean roasting temperature on protein fractions of diets, dairy cow performance, and economical comparison between roasted soybean and lignosulfonate-treated soybean.Materials and methods: To evaluate the effect of soybeans roasted at different temperatures on feed intake, milk yield and composition, 8 mid-lactation Holstein cows, averaging 92 ±14 days in milk and 42.9 ±3 kg of milk/day were assigned to a replicated 4 × 4 Latin square design. Control treatment contained lignosulfonate-treated soybean meal and calcium salts of fatty acids, and treatments 2, 3, and 4 contained soybean grains roasted at 115, 130, or 145°C, respectively. The total mixed rations included 40% forage on a dry matter basis and 60% concentrates.Results: Dry matter intake (DMI) tended to be greater for control treatment compared with the roasted soybean treatments (P=0.08). Actual milk and 3.5% fat-corrected milk yield was greater for control diet than for roasted diet (P<0.01). No differences were observed between the control and the roasted soybeans, or between different roasting temperatures on feed efficiency (3.5% fat-corrected milk/dry matter intake). Milk fat was higher for soybeans roasted at 130°C than for those roasted at either 115 or 145°C. Economically, control diet was more expensive than roasted soybean diets and income to feed cost ratio significantly was greater in roasted soybean diets rather than control diet. The diet contained roasted soybean at 130°C rather than other diets had lower digestible protein in intestine. Soybean roasted at 130 and 145°C in comparison with soybean roasted at 115°C and control treatment had lower moderately degraded true protein (B2) and higher slowly degraded true protein (B3). Rumen degradable protein than rumen degradable protein has greater correlation with milk yield and DMI. Between different fractions of protein, moderately degraded true protein fraction has high correlation with DMI, milk yield and composition.Conclusion: The results of this research showed that cows fed control diet had higher DMI and milk yield than cows fed roasted soybean diets. Among different roasting temperatures (115, 130, and 145°C), soybeans roasted at 115°C led to higher milk production and lower DMI. The moderately degraded true protein had the most important fraction between different fractions of protein and highest correlation with DMI and milk yield and composition.

Background and objectives: Four treatments were conducted to determine the effects of Varying Proportions of Corn Silage and Alfalfa hay (as forage source) and crude protein (CP) levels in mid lactating Holstein cows on milk production and content and nitrogen efficiency. Diets with low crude protein but with rumen degradable protein (RUP) suitable can be effective both for economic and environmental factors. In addition to the protein intake type of feed ingested may be important. Two forage corn silage and alfalfa hay in the diet of dairy cows are very common. Corn silage is a source of fermentable carbohydrate and alfalfa is also rich in RDP. The proportion of these sources of forage in the diet can have an impact on the use of nitrogen.Materials and methods: Sixteen primiparous (n=8) and multiparous (2-5) (n=8) cows were allocated to one of four diets in balanced randomized complete design in two periods (28 day). The diets were as follows: 1) 19% CP, 2) 17% CP and, 3) 15% CP and 4) 17% CP and Diets consisted of 50% forage and 50% concentrate (dry matter basis) and alfalfa hay- to-corn-silage ratios for the forage part of the diet: 80: 20, 80: 20, 20: 80, and 20: 80.Results: DMI in cows feed experimental diet have significant different (P<0.01). Milk yield was not significant. Both milk urea nitrogen and blood urea nitrogen concentrations increased the protein content of the diet was increased. When dietary protein was increased from the lowest to the highest concentrations, mean fecal N concentration increased from 2.8 to 3.0%, and urinary N from 5.8 to 7.3 g/L.Conclusion: Overall, based on N utilization as well as milk production, 17% protein in diets utilizing various proportions of alfalfa hay and corn silage as the forage source appeared sufficient for cows producing 27.56 kg/d of milk in this study. Reducing protein to this amount (17%) can reduce N excretion, especially environmentally labile urinary N, without affecting milk production. Use of four treatments with different levels of protein and varying proportions of corn silage and alfalfa hay can’t affect on milk yield, but with increasing concentration of protein, nitrogen excretion increased.

Background and objectives: The Markhoz goat is one of the most important breeds In Iran. These animals had an important cultural role in Kurdistan because the mohair obtained from these animals is used for making national clothes. The mating of related individuals produces an inbred offspring and leads to an increased homozygosity in the progeny, genetic variance decrease within families and increase between families. The ratio of homozygosity for individuals was calculated by inbreeding coefficient. The trend of inbreeding is an indicator for determination of inbreeding level in the herd. Result of researches showed increasing of inbreeding resulted to decrease of phenotypic value in some of production and reproduction traits. So the aims of this study were estimation of inbreeding coefficients and its effects on birth weight (BW), weaning weight (WW), average daily gain to weaning (ADG), 6 month weight (6MW), 9 month weight (9MW) and yearling weight (YW) of Markhoz goats.Materials and methods: In this study, pedigree data of 4186 Markhoz goats which were collected from 1992-2012 by Markhoz Goat breeding center located in Sanandaj, were used. Inbreeding coefficient was estimated by the CFC software program. Inbreeding depressions in growth traits were estimated by restricted maximum likelihood (REML) method under 12 animal models that animal and dam’s inbreeding coefficients added to models as a covariate. The most appropriate model for each trait was determined by Akaike’s information criterion (AIC).Results: The 58.07% of animal were inbred. The mean inbreeding coefficient for the herd and inbred population was 3.03 and 5.21% respectively. Maximum inbreeding coefficient was 31.25%. The 47.04% of animal was inbreeding coefficient between 0 to 10 percent.553 head of dams were inbred and inbreeding coefficient for the whole and inbred dams was 2.05 and 4.91% respectively. Inbreeding coefficient was increased 0.24±0.04 percent in each year (P<0.01). Inbreeding depression per 1 percent increase in individual inbreeding for BW, WW, ADG, 6MW, 9MW and YW were -0.5±1.57, -20.20±7.21, -0.11±0.13, -30.49±12.38, +9.49±17.87 and -58.67±24.40 gr, respectively. Inbreeding depression per 1 percent increase in dam inbreeding for these traits were -0.05±2.08, -6.62±9.74, -0.03±0.16, -13.90±9.76, -39.27±13.59 and -49.37±25.12 gr, respectively.Conclusion: Estimated inbreeding coefficients for this breed showed high degree of close mating in this flock and due to significant effect of inbreeding on some growth traits it is suggested that this breeding station should use a breeding plan to avoid mating of close relative animals.

Background and objectives: Improving female reproductive performance is an important objective for increasing the profitability of sheep. Random regression model is a method to estimate variance components. This model provides behavior over time continuous observation and be able to combine heterogeneous (co) variance over time by reducing the number of parameters. The objective of this study was to estimate the variance components and heritability for the number of lambs at weaned per lambing trait, with B-spline random regression models in Lori-Bakhtiari sheep.Materials and methods: A number of 6146 lambing records of Lori-Bakhtiari sheep, collected during years 1990 to 2013 were utilized from a research flock at the Lori-Bakhtiari sheep breeding station. The flock was managed under a semi-migratory or village system. The lambs were weaned at 90 ± 5 days of age. The fixed factors affecting the studied trait were identified using general linear model analysis. Variance components were estimated as based on linear, quadratic and linear-quadratic B-spline random regression models with 4 to 6 knots, using WOMBAT software.Results: The mean and standard deviation for number of lambs at weaned per lambing trait was 1.17 ± 0.42. The effects of lambing year and age of ewe at lambing had highly significant effects on studied trait. The models were compared using AIC and BIC indices, out of which model LLL4 (linear for fixed regression, additive genetic and permanent environmental effects with 4 knots) was found out as more suitable than the others. According to this model, estimates of additive genetic, permanent environmental and phenotypic variances this trait was in the ranges of 0.003 to 0.090, 0.002 to 0.066 and 0.081 to 0.267, respectively. The range of heritability and the ratio of permanent environmental variance to phenotypic variance estimate for the number of lambs at weaned per lambing trait were 0.02 to 0.34 and 0.01 to 0.25, respectively.Conclusion: The heritability estimates for the number of lambs at weaned per lambing at 14 to 25 months of age were higher than those for the other ages. Therefore, based on the heritability and standard error, accuracy of breeding values for the number of lambs at weaned per lambing trait is higher in the 14 to 32 months of dam age.

Object and Background: The purpose of this study was to evaluate the polymorphism of two candidate genes including Leptin (exon 2 and intron 2) and growth hormone receptor (promoter) genes and their effects on semen quality of Holstein bulls.Materials and Methods: For this purpose information from two breeding stations including the Animal Breeding Center of Northwest (41bulls) and the National Animal Breeding Center and Promotion of Animal Products (28 bulls) were used. Information of 69 bulls, which were sampled between 2003-2013 years was used. Four qualitative sperm traits including volume of ejaculation (mL), sperm population (million/mL), and percentages of live sperm before and after freezing (%) were measured. Polymorphism of leptin gene was evaluated by PCR-RFLP and the variation in the growth hormone receptor gene was evaluated by PCR-SSR.Results: The results of this study showed that all investigated loci were polymorphic and the frequency of TT, AT, AA genotypes in exon 2 were 0.28, 0.20 and 0.52, and frequency of T and A alleles, were 0.62±0.041 and 0.38±0.041, respectively. Additionally, genotype frequencies for AA, AB, and BB genotypes in the intron 2 were estimated 0.68, 0.32 and 0.16 and estimated A and B allele frequency were 0.84±0.031 and 0.16±0.031 respectively. For promoter of growth hormone receptor, results indicated that three genotypes of TG17/TG17, TG17/TG21 and TG21/TG21 had frequencies of 0.27, 0.48 and 0.25 and two alleles of TG21 and TG17 had frequencies of 0.49±0.042 and 0.51±0.042, respectively. There was Hardy-Weinberg equilibrium for the promoter of growth hormone receptor (P<0.67) and intron 2 of leptin (P<0.12), while there was no Hardy-Weinberg equilibrium for the variation of exon 2 of leptin (P<0.01).Conclusion: Generally, there was a significant association (P<0.01) between polymorphisms in all loci and semen quality traits. Specially, in exon 2 of leptin, the AA genotype was the favorable genotype for semen volume and percentage of live sperm before freezing and the TT genotype was the favorable genotype for sperm population and percentage of live sperm after freezing. For intron 2 of Leptin, the AA genotype was the best genotype for all traits. In promoter of growth hormone receptor, the genotype of TG17/TG17 was the favorable for all traits except for semen volume and TG21/TG21 was the best genotype for semen volume. Also the result of this study can be used in marker-assisted selection to improve expressed traits.