مجله تولیدات دامی
سال بیست و دوم شماره 1 (بهار 1399)

In order to determine the interference of dominant effects on the estimation of genetic parameters, two models including additive and additive-dominance were used for estimation of genetic parameters of carcass traits in 631 hybrid beef bulls. Data analysis was conducted using Plink (V. 1.9) and GVCBLUP (V. 3.9) softwares. Results of this study showed that most carcass quality traits have high heritability,but two traits namely hot carcass weight and ultrasound ribeye area had low heritability (0.15 and 0.11). Dominance variances have high contribution to the total variation of hot carcass weight, ultrasound ribeye area, ultrasound backfat thickness and ribeye area (0.13, 0.44, 0.89 and 0.33 respectively). However, dominant effect for other traits (lean meat yield, marbling score, backfat thickness, ultrasound ribeye area and grade of carcass) was not observed or was in very low amount. When dominance variance is low, its effect on GBLUP estimates is negligible. The estimates of heritability did not change significantly by the adding dominance effect into the model. The most important genomic regions that affect the carcass quality traits were belong to LAP3, THBS4 and PCDH9 genes. It is suggested that for the better understanding of the genetic structure of traits and better breeding plan, the dominance effects should be added into the model for geneticparameter estimation.

This study was done in order to estimate genetic parameters of growth and feed efficiency traits in Japanese quail. The data set consisted of 7762 records for feed efficiency traits and 12113 records for body weight gain traits were collected at Research Center of Special Domestic Animals, University of Zabol. The following traits including body weight gain from 20 to 25, 25-30, 30-35, 35-40, 40-45 and from 0 to 45 days of age, feed intake, feed conversion ratio and residual feed intake from 20 to 45 days of age were evaluated. The genetic parameters were estimated through single and bivariate animal models via Gibbs sampling method. Heritability estimates for body weight gain varied from 0.02 to 0.23 and for feed intake, feed conversion ratio, residual feed intake was in ranges of 0.04 to 0.11. Genetic correlations estimates between body weight gain and feed conversion ratio 20-25, body weight gain and feed conversion ratio 25-30, body weight gain and feed conversion ratio 30-35, body weight gain and feed conversion ratio 35-40, body weight gain and feed conversion ratio 40-45 were -0.56, -0.49, -0.57, -0.70 and 0.25 respectively. Considering estimated genetic correlations of this study, we recommend that selection for body weight gain and decrease feed efficiency have potential to improve feed efficiency traits in Japanese quail. It is expected that by selecting for these traits the costs of breeding programs such as feeding and phenotyping would be reduced.

This study was conducted to investigate the effect of dry corn gluten feed (DCGF) on nutritive value of corn silage by in vitro and in vivo methods. The firs stage of the experiment was conducted in a completely randomized design, included three treatments and 5 replicates, in which chopped corn forage was mixed with 0.0, 5 and 10 percent of DCGF and ensiled in 200L polyethylen barrels. After three months of ensiling, the silages were opened and evaluated. Voluntary intake and digestibility of the silages along with basal diet (Alfalfa hay+wheat straw+barley ground) were determined, using mature (two years old) male Shal sheep. Including of DCGF to corn silage increased (p<0.05)dry matter (DM) and crude protein (CP) in the silages respectively, but pH and organic matter values were not affected by the treatments. However, the DM content did not reach to optimum (35%) point. Concentration of neutral detergent fibre (NDF) was increased but acid detergent fibre (ADF) was decreased (p<0.05) as DCGF was increased in the corn silages. Addition of CGF increased dry matter intake of the silages (p<0.05). The digestibility of DM, OM and NDF were higher in silages containing  DCGF (p<0.05). The intake of the digestible DM, OM and NDF were higher in DCGF content silages than those of basal diet and control silage (p<0.05). In general,adding DCGF to corn silage could improve silage quality as well as increasing voluntary intake (g/d) and digestibility when fed to sheep.

The present study aimed to investigate the effect of dietary betaine supplementation on circulating homocysteine, antioxidant enzymes and lipid peroxidation in pregnant Sanjabi ewes. Twenty multiparous pregnant ewes (3-5 years old) were fed either a basal diet (Control: 71.2±3.6 kg BW) or the basal diet supplemented with five g per kg dry matter betaine (Betaine: 71.6±3.8 kg BW) during the last five weeks of gestation in a completely random design. Feed intake, body weight (BW) and body condition score (BCS) were weekly recorded. Blood samples were taken from the jugular vein at 28, 14, seven, and one-day pre-partum. The activity of glutathione peroxidase (GPx), catalase (CAT) and blood concentration of homocysteine, and malondialdehyde (MDA) were determined. Dry matter intake, BCS, and BW of ewes were not affected by betaine consumption. In both groups, the activity of GPx increased (P<0.05), while CAT and MDA decreased (P<0.05) as gestation progressed. The activity of GPx and CAT remained unchanged by betaine. Ewes receiving betaine showed greater (P<0.05) blood homocysteine, but lower (P<0.05) MDA as compared to the control ewes. The birth weight of lambs in Betaine ewes was heavier (P=0.06) than those of control ewes. In conclusion, dietary supplementation of betaine was beneficial for alleviating oxidative stress and improving lambs' birth weight in Sanjabi ewes.

Effect of different processing methods of corn grain were investigated in 36 Holstein suckling female calves (body weight = 38.2 ± 1.20 kg) on performance and blood and ruminal parameters. Treatments were whole corn, ground corn, cracked corn and steam-flaked corn. Starter diets were mixed five percent of the chopped wheat straw and offered to calves from day 4. Milk was fed in a gradual step-up step-down method to all calves. Calves weaned at 71 days and total intake of starter and body weight of calves were measured until 84 days. Starter intake and ADG were significantly higher for cracked corn and steam-flaked corn than for ground corn and whole corn treatments in pre- and post-weaning and overall period (P≤0.01). At weaning and day 84, the average body weight of calves fed cracked corn and steam-flaked corn were significantly higher than those fed whole corn and ground corn treatments (P≤0.01). Treatments also affected serum protein of calves (P<0.05). According results of this study, feeding calves with cracked corn or steam-flaked corn increased feed intake and improved ADG and body weight through pre- and post-weaning periods.

This study was carried out to assess the effects of two types of fatty acids-calcified salts on the performance of dairy cows in the transition period. In total, 32 multiparous Holstein cows with body weight mean of 723=39.9 kg in a 6-week time range (three weeks before until three weeks after parturition) were assigned to treatments in a completely randomized design. There were four diets including control (without fat supplement), diet supplemented with unsaturated fat, diet supplemented with saturated fat and diet supplemented with both unsaturated and saturated fats. Fat supplements as calcium salts were applied at the level of 1.5% and 3% in the pre-partum and post-partum diets,respectively. Based on the results, it turned out that pre-partum DM feed intake, post-partum body weight and body condition score were not affected by the diets, whereas, post-partum DM feed intake appeared to be different (p < 0.05). In addition, the digestibility coefficient appeared to be different among pre- and post-partum trial diets (p < 0.05). However, no significant difference was observed for blood parameters as well as milk yield and its composition. In conclusion, the results revealed that fat sources as calcium salt supplements can improve the digestibility of nutrients in the digestive system, without any adverse-effects on performance in dairy cows.

The effects of different sources of selenium supplementation and rosemary essential oil on growth performance, microflora population and intestinal morphology in broiler chicken with using of 480 male broiler chicks in a factorial arrangement (2x5) with 10 treatments and 4 replicates were investigated. Two experimental factors consisted of different sources of selenium (level of 0.3 mg/kg of diet from selenomethionine, nanoselenomethionine, selenitsodium, nano selenium bonza and without selenium) and rosemary essential oil (0 and 300 mg/kg of diet). Results showed that broilers received diet of without Se and rosemary essential oil had lower weight gain and feed intake.Broilers received diet of nano selenium bonza with rosemary essential oil had lower feed conversion ratio as compared to the other broilers (P<0.05). Broilers fed on diets of nanoselenomethionine with rosemary essential oil and nano selenium bonza with rosemary essential oil were increased villus height in jejunum (P<0.05). The crypt depth of intestinal in birds which received nanoselenium was more than the birds that consumed other sources of selenium in the diet (P<0.05). Crypt diameter nano selenium bonza with rosemary essential oil treatment was higher as compared to other treatments (P<0.01). Selenomethionine and nanoselenomethionine alone and in combination with rosemary essential oil treatments had high lactobacillus population and lactobacillus population to total microbial population ratio of ileum as compared to without Se and rosemary essential oil treatment (P<0.05). Based on the results, inclusion nanoselenium (0.3 mg/kg) supplement with rosemary essential oil (300 mg/kg) into the diet of broiler chicken can improve performance, gut morphology and microflora.

This study was conducted to assess the effects of dietary flaxseed and sesame oils, on the semen parameters, fatty acid composition of sperm as well as the fertility and hatchability eggs from aged roosters. In a completely randomized design, 24 Ross-308 roosters (aged 45 week) assigned to four groups, comprising six replicates and one bird in each. The birds received different diets including basal diet (control), basal diet supplemented with 2% flaxseed oil (FO), basal diet supplemented with 2% sesame oil (SO) and basal diet supplemented with 1% flaxseed oil and 1% sesame oil (MO). The diets were iso-caloric and iso-nitrogenous, containing the same level of vitamin E. The roosters were fed diet for 60 days, during which semen samples were collected on 1st, 20th, 40th and 60th days and the samples were tested for different characteristics. The results indicated that different diets affected semen qualities, except semen volume and the morphology. The concentration, progressive motility, MDA as well as viability of sperms were significantly different during different times of the experiment. The sperm quality parameters including total and progressive motility as well as MDA turned out to improve in the roosters fed FO or MO. Furthermore, the integrity of sperm membrane, DHA and DPA concentration, as well as the fertility were higher in the treatment group containing FO. It seems that supplementation of aged rooster’s diet with flaxseed oil or mixed oils, together with vitamin E improves the semen qualities and it can be applied as an appropriate strategy to preserve the reproductive performance of aged rooters.

In order to evaluate the effect of different levels of corn gluten feed on performance, immune responses, intestinal morphology and some blood serum biochemical parameters of broiler chickens, an experiment was conducted using 500 male Ross 308 broiler chickens in a completely randomized design with four treatments, five replicates and 25 birds per replication. The experimental treatments included levels  of zero (control), 2.5, 5 and 7.5 percent corn gluten feed in the diet which fed to broilers from 15 to 42 days of age. The results showed that dietary inclusion of corn gluten feed up to 7.5 percent had no significant effect on average weight gain, feed intake and feed conversion ratiocompared to control treatment. Also, jejunal morphological indices and blood biochemical parameters including triglyceride, cholesterol, albumin, phosphorus and alkaline phosphatase concentrations, livability, European broiler index and feed cost per kg of weight gain were not affected by dietary treatments. Antibody titer in response to sheep red blood cell (SRBC) injection was higher in treatment containing 2.5 percent corn gluten feed comparing to other treatments (P<0.05). Based on the obtained results, corn gluten feed can be included in grower and finisher diets of broilers (15 to 42 days of age) up to level of 7.5 percent without any adverse effect on performance.

The aim of this study was to investigate the effect of finisher diet nutrient density and slaughter age on energy and protein retention efficiency of broiler chickens. Three hundred 23-day-old Cobb-500 male broiler chickens were assigned in a 5×2 factorial arrangement of completely randomize design with 10 treatments, 6 replicates and 5 birds each. The experimental treatments included five nutrient levels of finisher diets (102.5, 100, 97.5, 95, and 92.5% levels of nutrient composition recommendations stated by the Cobb-500 Commercial Management Guide) and two slaughtered ages (38 and 46 days of age). As increased dietary nutrient density significantly and l inearlyincreased weight gain, feed efficiency, energy and protein retention efficiency and decreased maintenance energy requirements per unit of weight gain (P<0.05). By increasing slaughter age from d38 to d46, above indices significantly deteriorated (P<0.05). The highest residual feed intake belonged to birds fed the finisher diet with 97.5% of strain recommendation nutrients level. Dietary nutrient density level for optimal weight gain, feed efficiency, and energy and protein retention efficiency by linear broken line models were estimated 101.7, 98.7, 97.7 and 99.5% of strain recommendation, respectively. Whereas, these values were 2.3-5.5 percent less than those estimated by the quadratic broken-line model. As a conclusion, residual feed intake methodology can be a viable alternative to measure dietary energy efficiency. Formulation broiler finisher diet with nutrients concentration lowers than 97.5% of strain recommendation is not suitable.

For carry out of this study we used 560 Ross 308 (mixed sex) broiler chickens, in a completely randomized design with seven t reatments, four replicates and 20 chickens per each replicate. Experimental treatments were: control (no additive), diets containing levels of 400 and 500 mg/kg Satureja essential oil, diets containing levels of two and four percent garlic powder and diets containing levels of five and 10 percent clover leaf powder. The results of this study showed that weight gain of birds that fed with diets containing Satureja khuzistanica essential oil, garlic and clover leaf powder was less than the control birds (P<0/05) across the trial period. Experimental treatments had no significant effect on serum concentration of thyroid hormones (T3 and T4), cholesterol, triglyceride, HDL and LDL and percentage of dry matter and crude protein of breast muscle. Also, according to different holding times of breast muscle in the freezer (0, 24 and 48 hours), experimental treatments had no significant effect on the amount of MDA and free N at 24 and 48 hours after freezing. According to the results, using of Satureja essential oil, garlic and clover leaf powder at levels investigated in this study, do not have a significant effect on the performance and the antioxidant potential of breast muscle to modulate lipid per oxidation. Therefore, further studies are needed to evaluate the effectivness and active constituents of these nutrients and ensure their properties.

The aim of this research was to study the effect of adding enzyme preparations and ration formulation on performance, nutrient digestibility and intestinal microflora of broilers. Two hundred and fifty six day-old male and female broiler chicks of Ross 308 strain were used in a 2×2×2 factorial experiment consisting of two methods of diet formulation (total and digestible amino acid), two levels of Natuzyme Plus (0 and 0.035%) and two levels of Multi-behzyme (0 and 0.02%) as additives. The factors were arranged as a completely randomized design with eight treatments and four replications. Diet formulation based on total amino acids improved the average daily gain (ADG) and feed conversion ratio (FCR) during the grower and finisher and total periods, but decreased daily feed intake during the finisher and total periods (P ≤ 0.05). It also increased dry matter digestibility, dressing percentage and intestinal length, but it decreased fat digestibility (P ≤ 0.05). Natuzyme Plus increased dry matter, crude protein and fat digestibility and decreased the number of E .coli in the cecum. (P ≤ 0.05). Multibehzyme improved ADG during the grower period, FCR during the finisher period and total period and it increased dry matter, crude protein and crude fat digestibility (P ≤ 0.05). It was concluded that Multi- behzyme could be replaced with Natuzyme Plus, and its inclusion in the diets formulated by digestible amino acid and low protein content can improve the negative outcome of low level protein diets.

This experiment was conducted to investigate the effect of using hydroalcoholic sage extract after experimental copper poisoning on performance and blood metabolites of Japanese quail, in a completely randomized design with 320 one-day old Japanese quails in 4 treatments with4 replicates and 20 birds per each replicate. Experimental treatments were: 1) control (basal diet), 2) basal diet + 750 mg/kg copper sulfate, 3) basal diet + 10 g/kg sage extract and 4) basal diet with 750 mg/kg copper sulfate and 10 g/kg of sage extract. The feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR) were measured weekly and calculated for starter, grower and whole periods. The results of this experiment showed that in starter period, FI was highest in control group compared to other treatments (P <0.05). In the starter and total periods, the average BWG of birds that received diet contained copper was significantly lower than birds in control and the birds that received diets supplemented with sage extract (P <0.05). In the starter period, the FCR was improved when diets supplemented with sage extract in comparison with the birds that received copper (P <0.05). Higher levels of blood glucose and triglyceride and lower levels of HDL and LDL were observed in birds receiving copper in their diet (P <0.05). The results of this experiment showed that supplementation Japanese quail’s diet with sage extract can improve BWG and FCR in starter period, and it may alleviate harmful effect of copper poisoning.

The current study was conducted to evaluate the efficacy of Thymbra spicata (TS) and Echinacea purpurea (EP) powders on quality of breast muscle in broiler chickens exposed to Campylobacter jejuni. A total of 192 one-d-old straight-run broiler chicks (Ross 308) were randomly allocated to 6 dietary treatments in a completely randomized design with 4 replicates and 8 birds per each. The experimental diets were as follows: 1) basal diet without additive (control group); 2,3) basal diet supplemented with EP powder (0.25 and 0.50%; EP-0.25 and EP-0.50); 4,5) basal diet supplemented with TS powder (0.25 and 0.50%; TS-0.25 and TS-0.50), and 6) basal diet supplemented with Erythromycin (55 ppm). All of the broiler chicks were orally gavaged with Campylobacter jejuni (4×1011 cfu/mL) on d 21. Malondialdehyde concentration in breast muscle was significantly decreased by supplementing diets with EP-0.25, TS-0.25, and erythromycin (P<0.05). All experimental treatments also resulted in a significant decrease in the colonization of psychrophilic bacteria in breast muscle when compared with the control group (P<0.05), however, aerobic bacteria count was significantly decreased only by TS-0.25 and erythromycin (P<0.05). Other traits such as pH, color, chemical composition, water holding capacity, drip loss, cooking loss, and press loss were not significantly affected by treatments. As a conclusion, for the prevention of lipids peroxidation and the decline of psychrophilic bacteria count, it could be advised to use EP and TS with 0.25% diet instead of erythromycin, however, TS is preferable to EP, because of the higher antibacterial activity on reduction of aerobic bacteria count.

The aim of this study was to evaluate the effect of Tribulus terrestris powder on thyroid hormones (T3 &T4) and IGF-I concentrations in blood serum of Arabi male lambs. For this purpose, 18 Arabi male lambs with an average age of 3 months and average weight of 16.14 ± 2 kg were used in a completely randomized design with 3 treatments and 6 replications per treatment for 5 months. Experimental treatments included the zero (control), 15 and 30 gr/kg of Tribulus Terrestris powder in diet. The weights of lambs were measured monthly. At the age of 4-8 months, 5 consecutive samples were collected monthly to measure serum T3, T4 and IGF-I concentrations. The results showed thatTribulus terrestris powder had no significant effect on body weight. The concentrations of T3 and T4 were higher in lambs treated with Tribulus terrestris powder compared to control group (p<0.05). Concentrations of T3 at the age of 7 months and T4 at 8 months of age in lambs fed 30g/kg of Tribulus terrestris were significantly higher than control group (p<0.05). IGF-I concentration in lambs feed with 15g/kg of Tribulus terrestris at the age of 6 months was higher than control group (p<0.05). In general, the results of this study showed that feeding of 15 g/kg of Tribulus terrestris powder in Arabi male lamb diet by modulating thyroid hormones and IGF-1 and improving the reproductive system, prevents the reduction of sexual behavior and failure of reproductive activity.

This research was conducted in order to compare the blood parameters and fattening performance of Zel and Dalagh breeds male lambs (three to four months old), and their crossbred with Romanov in different thermal-humidity conditions. Fattening trial was conducted in Gonbad kavous with four treatments and six replicates for 84 days from mid-August to early November. Based on the temperature-humiity index (THI), the lambs were under very severe and severe of heat stress up to 8th weeks of trial, followed by non-stress conditions (THI index of 25.6 and above that, 23.3 up to less than 25.6 and less than 22.2 respectively). In the very severe heat stress condition, the performance of treatments was the same. In the severe heat stress, the performance of Dallagh lambs and their crossbred with Romanov was better than Zel and Zel-Romanov crossbred (P<0.05). In un-stress conditions, performance traits in Zel Romanov crossbred was lower than other treatments (P<0.05). Glucose and cholesterol concentration were lower when the lambs were in heat stress condition than normal time (P<0.05). Unlike, blood urea concentration in heat stress condition was higher than lack of stress time (P<0.05). Concentrations of nonstratified fatty acids (NEFA) in the middle period of experiment, during severe heat stress, were higher than those of very severe and nonstress periods. In whole of fattening trial period, all of the breeds had lower performance than expected, indicating the effects of heat stress on them. Totally, Dalagh breed lams had better fattening performance than Zel and their crossbred with Romanov, especially under very severe heat stress condition.