نشریه پژوهش های علوم دامی
سال بیست و دوم شماره 4 (زمستان 1391)

The purpose of this study was protein fractionation and determination of degradability and fermentative characteristics using nylon bag and gas production methods. In this experiment, 2 ruminaly fistulated Gizel mature wether were used. Data were analyzed using SAS software as compeletly randomized design. After 48 h of incubation, barley grain and alfalfa hay had greatest and lowest gas production volume among test feeds (335.84 and 244.82 ml/g DM, respectively). The gas production potential amounts of alfalfa hay, corn and barley grains were obtained 254.16, 298.81 and 374.27 ml/g DM (P<0.05), respectively. Barley grain had greatest estimated metabolizable energy concentration among the feedstuffs. Alfalfa hay had the biggest true protein and buffer soluble protein fractions among feedstuffs. Alfalfa hay and corn had biggest and smallest ADIN among feedstuffs, respectively. In situ DM disappearance of corn grain at 24 and 48 h of incubation was higher than the other feedstuffs. Alfalfa hay had the lowest in situ dry matter disappearance value within the feedstuffs at the most incubation times. Barley grain and alfalfa hay had the highest and lowest CP a value (slowly degradable fraction) within the feedstuffs (16.77% and 14.16%, respectively). Potentially degradable CP fraction (b) and its disappearance rate for barely were more than the other feedstuffs. Alfalfa hay and corn grain had biggest and smallest metabolizable protein among feedstuffs, respectively. Among the test feeds barley grain and alfalfa hay had the biggest metabolizable energy and metabolizable protein, respectively.

In order to determine the effect of different levels of soybean oil in diets of Holstein dairy cows in early lactation on milk yield and it's composition, this study was carried out. The experimental cows used according to change over design with 4 experimental diet. Treatments in diet of 1 to 4 content 0, 3, 5 and 7 of soybean oil (%DM). All diets were isonitrogenous and isoenergetic and fed as ad libitum. Cows were fed individually twice daily and milked three times. Milk samples were collected at last 2 days. FCM yields, milk composition and plasma metabolites were determined. Milk yield in 5 and 7 % of soybean oil decreased (P<0.05). Milk fat percentage, milk yield, dry matter intake, weight gain showed significantly differences (P<0.05), whereas milk protein percentage, milk lactose percentage, SNF percentage indicated no significant differences. The concentrations of triglyceride, cholesterol, BUN and phosphorous were significant differences (P<0.05), but the other plasma metabolites were not significant differences. It was concluded the diet containing of 3 % soybean oil improved milk yield and plasma metabolites of Holstein dairy cows

Marker assisted selection is one of the common methods which can improve the accuracy and response to selection. Diacylglycerol acyltransferase1 enzyme (DGAT1) is a Microsomal enzyme that plays an important role in lipid metabolism. DGTA1 encodes the catalyst enzyme of the reaction between diacylglycerol and acyl-CoA. This reaction is a final step in the synthesis of triglyceride¬. Lori-Bakhtiari sheep is an important breed for meat production but it has the highest fat-tail weight than other breeds. The aim of this research was to determine the genetic diversity of DGAT1 gene and its effect on carcass quality in this breed. In this study, the records on 152 Lori-Bakhtiari sheep which slaughtered in the abattoir industry in Qom province in 2009 were used. DNA was extracted using salting-out method, and 309 bp fragment of exon 17 was amplified with polymerase chain reaction then restricted using AluI. The results revealed three genotypes TT, TC and CC, with frequencies of respectively 0.558, 0.378 and 0.064. The results of this experiment showed that there is a significant correlation between some of genotypes with fat-tail weight and backfat thickness, so that the CC genotype significantly (P<0.05) heavier fat-tail and higher backfat thickness than TT genotypes. Thus some polymorphisms at this gene forms may be a useful tool in marker assisted selection programs.

This experiment was conducted to evaluate the effects of using different levels of nettle (Urtica dioica) medicinal herb on performance, egg traits, biochemical and immunity responses of laying hens. This experiment was conducted in a completely randomized design with 180 of hy- line (W36) laying hens in 5 treatments and 3 replicates (with 12 hen in each replicate) from 60 to 72 weeks of age and included: 1) control group without using nettle. In treatments of 2 until 5 the amount of nettle was 0.5, 1, 1.5 and 2 percent. The results showed that the using of different levels of nettle medicinal herb in laying hens diets significantly affected egg traits and blood biochemical parameters (P<0.05). The highest amount of egg yolk color index (4.84) and the lowest level of blood glucose (183 mg/dl) were observed by 1.5 percent of nettle. The lowest amount of egg albumin weight (33.59g) and the lowest levels of blood cholesterol and triglyceride (67.83 mg/dl and 798.3 mg/dl) were resulted by 1 percent of nettle and the lowest percent of heterophiles, the highest percent of lymphocytes and the lowest ratio of heterophiles/lymphocytes were observed by 0.5 percent of nettle. The results indicated that 1 percent of nettle in laying hens diets has positive effects on their egg traits and blood biochemical parameters.

The environmental factors affecting fleece weight measured at one to six years of age were analysed using records on 12083 Raeini cashmere goats originated from 289 sires and 2426 dams born between 1994 to 2008. The environmental factors including sex, flock, birth month, birth year, age of dam and shearing age were found to be important in the current study. Fleece weight increased significantly up to 3 years of age, and then decreased at the later ages. Males significantly produced more fleece than the females in the all ages. Age of dam had significant influence on fleece weight in the first shearing. Type of birth had not significant effect on the fleece weights. The results of this study can be used for the flocks’ management. In addition the important fixed effects; investigated; should be fitted in the genetic analysis models for the fleece weight traits in Raieni cashmere goats.

To compare genetic evaluation methods for milk yield of Mashhad’s Holstein cows, two fixed and random regression test day models were used. The data set consisted of 95,510 test day milk records collected from 11,054 first parity Holstein cows calved between 1994 and 2007 Mashhad’s dairy farms. The number of sires, dams and total animals in pedigree file were 807, 8,835 and 11,054, respectively. Average daily milk was 26.92±6.91 Kg. Fixed and random regression test day models had fixed effects of herd – year – season of recording - milking times - sperm origin, as well as covariables of Holstein gene percentage, stage of pregnancy, age of cow at recording, and daily temperature. To take into account the shape of the lactation curve at phenotypic, genetic and environmental levels, orthogonal Legendre polynomials (order 4) was implemented in the random regression test day model. The models were fitted to the data by DXMRR software. There was a high positive and significant (P<0.001) rank correlation coefficient (0.939) between predicted breeding values (PBV) obtained by two models. Averages PBV were found to be 0.1695 and 0.1524 Kg for fixed and random regression test day models, respectively which were significantly (P<0.0001) different from each other. Genetic trends for daily milk were 0.044 and 0.077 Kg annually for fixed and random regression test day models, respectively.

A total of 336 one-day old Japanese quail chicks were divided in 7 groups for investigating the effect of probiotic administration methods on carcass quality of Japanese quail (Coturnix coturnix japonica). Protexin (Protexin, Somerset, UK) was used as a probiotic. Experimental groups were including: 1. Control group (no probiotics treatment), 2. Continuous in-drinking water probiotic supplemented, 3. Intermittent in-drinking water probiotic supplementation in every 2 d out of 4 d pattern, 4. Intermittent in-drinking water probiotic supplementation in every 1 d out of 5 d pattern, 5. Continuous in-feed probiotic supplemented, 6. Intermittent in-feed probiotic supplementation in every 2 d out of 4 d pattern, 7. Intermittent in-feed probiotic supplementation in every 1 d out of 5 d pattern. The in-feed probiotic supplemented groups received 150 g/ton and 100 g/ton probiotic product in the starter (1-14) and the finisher (15-35), respectively. As the drinking water is approximately two folds of feed intake, the drinking water groups received half amount of probiotic, which was supplemented in feed to balance for different in water and feed consumptions. Carcass weight and percentages of ether extract, protein and ash in dry matter did not show significant differences between administration methods and control group (P>0.05). Dry matter percentage significantly increased by using probiotic (P<0.05). Tiobarbituric acid reactive substances (TBARS) were determined as an index of lipid oxidation development. Data analyseis showed significant differences in TBARS content measured in fresh samples (P<0.01). Carcasses of continuous in-feed probiotic supplemented birds had the lowest lipid oxidation (P<0.01). The other methods only showed insignificant reduction of TBARS. Carbonyl content of fresh samples was determined as an index of protein oxidation development. All administration methods except intermittent in-feed (1 d out of 5 d) resulted in significant reduction of protein oxidation (P<0.05).

This experiment was conducted to evaluate the performance and carcass characteristics of broiler chickens which were fed with wheat and barley based diets with different levels of vitamin premix in battery cage system from 29-42 days. A total of 112 male broilers (Ross 308) were allocated to 7 treatment groups, with 4 replicates per treatment group and 4 birds per replicate pen. The treatments were composed of 0, 33.33, 66.66 and 100 percent of vitamin premix (according to the recommendation of vitamin premix Producer Company) which used from 29 to 42 days; moreover, three treatments were composed of 0, 33.33, 66.66 and 100 percent of vitamin premix, which were eliminate from the diets at age 36-42 day. At the 35 and 42 days of age live weight and feed intake of each replicate were measured and the average of feed intake, body weight gain and feed conversion ratio were calculated. In two periods of 35 and 42 days after the slaughter, carcass yield, percentage of thigh and breast meat, abdominal fat and liver were measured. The results showed that birds fed with different levels of vitamins had no significant differences (P>0.05) on productive performance and carcass characteristic in the period of 29-35 days of age in finisher period, but birds which were fed on diets without vitamin premix (zero level) in the period of 36-42 days of age had significant difference with other levels (P>0.05). Therefore, it seems according to the lower level of vitamin premix (33.33%) there is the possibility of reduction of its level during finisher rearing of broiler chickens in battery cage system.

The effects of various levels of whole cottonseed(WCS) on performance, carcass characteristics, blood parameters, an experiment in completely randomized design (CRD) with four diets containing 0, 4, 8 and 16 percent WCS on 20 Chaal male lambs with initial average weight 30.4±1.8 kg and 5-6 months old for 90 days was performed. In comparison of control diet with diets contain WCS in aspect of daily weight gain, feed intake, the percent of tail weight and also abdominal fat was significant difference(p<0.01). The effect of diet on concentration of blood parameters was significant (p<0.01). Glucose concentration with increasing of WCS in diet was decreased, whereas concentration of cholesterol and triglyceride in blood were increased linearly (r2 = 0.98). This experiment showed that, the WCS could be included up to 16 percent of the fattening male lamb’s diet.

This experiment was conducted to investigate the effects of chromium picolinate and oil extract of propolis on growth performance, heterophil:lymphocyte ratio and serum glucose and insulin levels in broiler chicks reared under heat stress conditions (34 ±2°C, 5 hours/day). Treatments were included different levels of chromium picolinate (500, 1000, and 1500 µg/kg), propolis (1500 mg/ kg) and a control group. Two hundred day-old male Ross broiler chicks were randomly allocated to five dietary treatments with four replicate pens per treatment (10 birds/ pen). From 1-6 weeks, birds fed 1500 mg/kg propolis had significantly higher feed intake (P<0.01). Different levels of chromium picolinate and propolis significantly increased (P<0.05) body weight gain (P<0.01) and decreased feed conversion ratio (P<0.05) in comparison to control group. There was no effect of treatments on serum glucose and insulin levels, heterophil and lymphocyte counts and heterophil/lymphocyte ratio. Birds fed chromium (at 1000 and 1500 µg/kg levels) and propolis had the highest relative weight of burs fabricius (P<0.01). These results showed that dietary chromium picolinate and propolis supplementation could improve growth performance of broiler chicks in heat stress condition.

In present study investigated the effects of different levels of corn silage and alfalfa hay on rumen metabolites and milk production of Holstein cows. Fifteen Holstein cows (37 ±10 days in milk) were used in a completely randomize design. Treatments included three levels of hay and corn silage included: 1) 10% alfalfa hay -30% silage corn (CS), 2) 20% alfalfa hay -20% silage corn (AH- CS) and 3) 30% alfalfa hay -10% silage corn (AH); And the ratio of forage: concentrate was 60:40. Cows were fed the total mixed rations (TMR) twice daily. Cows were milked 3 times daily at 0200, 1000, and 1800 h. Milk production recorded at each milking time. Milk composition was measured every week and individual dry matter intake (DMI) was measured daily. DMI was higher when cows were fed diets AH-CS (23.20 kg per day) compared with diet CS (22.95 kg per day) and diet AH (18.64 kg per day). Treatments affect on milk production (P= 0.009). Replacing corn silage with alfalfa hay increased milk fat percent, but didn’t affect on milk protein percent (P>0.05). Average concentration of volatile fatty acids (VFA) in rumen were 75.90, 65.58 and 71.40 mM/l, for cows receiving diet 1, 2 and 3 respectively, that did not show significant differences (P>0.05). The results of this experiment indicated that feeding alfalfa hay more than corn silage reduced DMI, therefore decrease milk production, although had a trend to increase milk fat percentage.

In order to evaluate the effects of wheat processing with different fat sources on performanceruminal and blood metabolites of fattening calves, Holstein bull (n=28) averaging 296±56kg were randomly allotted in four treatment (7 bulls each). An experiment was conducted in a 2 × 2 factorial arrangement (two methods of wheat processing: steam flake and treatment with formaldehyde and lipid source: roasted soybean and rumifat) with completely randomized design. The study lasted 98 d (14d adaption).At Last days of experiment, from each bull samples of blood were collected from the coccygeal vein and samples of ruminal fluid were collected by stomach tube. Dry mater intake (DMI), average daily gain (ADG) and feed efficiency were not affected by dietary treatments. No significantly differences were detected for apparent total tract digestibility of none the nutrient composition of diets. There were no significantly differences among diets for ruminal pH, total volatile fatty acids (VFA) and ammonia nitrogen (NH3-N) concentrations. Concentration of propionate was greater, in steers fed steam flake wheat (P < 0.01).Other VFA concentrationswere not affected significantly by treatments. Plasma cholesterol and triglyceride concentrations were significantly lower and higher respectively in bulls fed roasted soybean (P < 0.01 and P < 0.01)rather than bulls fed Rumifat. Plasma glucose concentration was higher (p < 0.01) in bulls fed wheat treatment with formaldehyde. Bulls fed roasted soybean had lower (p < 0.01) blood urea nitrogen (BUN). Plasma NEFA and total protein concentrations were unaffected by dietary treatments. Results of this study showed that wheat treated with formaldehyde might be expected to protect starch from rumen degradation. Also results of blood metabolites showed that roasting of soybean may protect ether extract and protein from rumen degradation.

This experiment was conducted to investigate the effects of spearmint sativum essence added to starter concentrate of Holstein calves. For this purpose, thirty calves (15 male and 15 female) with the mean of 41.3± 0.73 kg birth weight were used in a completely randomized design. The experiment was done from 3 days age to 3 weeks after weaning. Three levels 0 (control), 0.025 and 0.05% of the essence were added to the calves starter concentrate as dry matter (DM) basis. Plasma samples and ruminal fluid were collected at different times. Weight records, feed consumption, fecal score and weaning age were determined. Results showed that the treatments had no significant effect on DM intake and average daily gain during the different weeks of experiment. However, the 0.05% essence increased (P<0.05) alfalfa intake in entire trial. Also, the high level of essence reduced (P<0.05) claves weaning age. During the preweaning period 0.05% essence increased (P<0.05) fecal score, however this effect was not significant in postweaning and entire periods. Plasma parameters and ruminal metabolites were not affected by the essence. It was concluded that 0.05% spearmint essence added to starter concentrate decreased calves weaning age and increased their forage consumption.

The objective of this study was to investigate electrolyte alterations in urine and blood of cows diagnosed with Left displacement of the abomasum (LDA) and to identify the occurrence of paradoxical aciduria in these cows from July 2007 to April 2009. Fifty two cows were diagnosed as LDA by Shahrekord University Veterinary Service clinicians. Blood samples were collected from jugular vein and urine samples were obtained from all cows by spontaneous micturition. Also, fecal score was determined (1, 2, 3 and 4). Out of 52 cows, twelve developed paradoxical aciduria (23.07 %) with mean urine pH 5.86±0.56 and forty did not develop paradoxical aciduria (76.93%) with mean urine pH 8±0.1. Cows that developed displacement of the abomasum and paradoxical aciduria had lower serum calcium, Magnesium, phosphorous and potassium than without paradoxical aciduria. The serum sodium was higher in animals with paradoxical aciduria than those had not paradoxical aciduria. The urine calcium, Magnesium and phosphorous in the group that developed paradoxical aciduria was higher than the group that did not develop paradoxical aciduria. In cows with paradoxical aciduria the urine sodium and potassium was lower than those without paradoxical aciduria. Fecal score 4, 3, and 2 was observed in 55.55, 33.33 and 11.12 % of cows with paradoxical aciduria and fecal score 1, 2 and 3 observed in 50, 40 and 10 % of those without paradoxical aciduria respectively. Paradoxical aciduria was not occurred in the all of cases of LDA except in those that developed diarrhea and dehydration. Therefore in the cases of LDA that occurred paradoxical aciduria the veterinarians must attention to correct the abnormality in blood electrolytes than those without paradoxical aciduria.

The main aim of present research was estimation of genetic parameters of some economic traits in Mazandaran native fowl. For reach this goal 4 different animal model with considering and ignoring maternal effects was used. For data analysis the Bayesian statistic methods via Gibbs sampling technique was used. In this study for estimation of variance components 73432 records of 19 generations of chickens that were collected between (1991 to 2010) in Mazandaran breeding center were used. The studied traits were body weight at 8 weeks of age, age at sexual maturity, egg weight at 30 weeks age, average egg weight in(28, 30 and 32weeks of age), laying intensity and egg number. Estimated heritability’s for average egg weight, egg weight in 30 weeks of age, age at sexual maturity, body weight at 8 weeks of age, egg number and intensity of egg production based on best model were 0.54, 0.39, 0.30, 0.23,0.15 and 0.15 respectively. Positive and high genetic correlation between body weight at 8 weeks of age and average egg weight was estimated (0.45) that the estimated genetic correlation between age at sexual maturity and egg number was negative and equal to -0.35.According to the value of estimated heritability’s for studied traitsthere are multiple breeding programs possible in this center.

The aim of this experiment was to determine metabolizable energy of five wheat varieties (Alvand, Zarrin, Sabalan, Sardari and Azar2) with or without enzyme supplementation (multi enzyme carbohydrase Kemin). Chemical composition and nitrogen corrected apparent metabolizable energy of wheat varieties was determined by standard and complete diet (wheat-soybean meal) method respectively. Ten diets containing 62% of experimental wheat varieties and enzyme (0 or 0.2 gr/Kg of diet) were used. Sixty 21-day old male broiler chicks, with average initial body weight 751±3.32 g were used in a completely randomized design in a factorial arrangement. The AMEn values of wheat experimental varieties did not have significant difference. The AMEn content of wheat varieties ranged from 3120.25 to 3191.29 Kcal/kg, and the highest and lowest AMEn content were related to Zarrin and Sabalan varieties, respectively. The average AMEn content of wheat varieties was 3150.07± 22.37 Kcal/kg. Enzyme supplementation increased the AMEn content of wheat grain up to 11.45% (P<0.01). No interaction was found between wheat varieties and enzyme addition on AMEn content. The equation of AMEn = 4827.03-986.52 Ash+144.15 EE (R2= 0.99) showed the best fit as the predictor of AMEn content of wheat from chemical composition. This experiment demonstrated that kemin a non – starch polysacide degrading enzyme can improve the metabolizable energy content of wheat grain.

The purpose of this study was to evaluate concentrations of some metabolites and hormones and their effects on the incidence of ovarian cyst at postpartum in dairy cows. Blood samples were obtained from 93 dairy cows. The concentration of glucose, urea, total protein, phosphorus, zinc and beta-hydroxy butyric acid as well as estrogen and insulin hormones in blood serum were measured. The results revealed that the Zinc concentration in cystic primiparous cows was significantly lower than the control and cystic multiparous cows (P<0.05). Serum glucose concentration showed significant differences between cold and warm seasons (P<0.05). Phosphorus concentration in the warm season was higher than that of the cold season (P<0.05). Serum urea concentrations in control and cystic primiparous cows showed significant differences compared with serum urea concentrations of all multiparous cows (P<0.01). Beta-hydroxy butyrate concentrations of serum of cows with healthy low milk production were lower in comparison to cystic cows (P<0.05). Serum insulin concentrations had significant difference among the higher milk producing cystic cows compared to the higher milk producing normal cows (P<0.05). No significant differences were observed among the cows considering their serum concentrations of total protein and estrogen hormone. The results showed that the Zinc concentration, level of milk production and calving season affected the incidence of ovarian cyst significantly.