فصلنامه تحقیقات تولیدات دامی
سال پنجم شماره 3 (پاییز 1395)

This experiment was conducted using 240 one-day-old broiler chicks (Ross 308 strain) in a completely randomized design with 6 dietary treatments, each replicated 4 times with 10 birds/replicate. The dietary treatments were: 1, 2- diets without thyme extract (TE) with and without fat for the entire period of the experiment, 3, 4- diets with 0.5% TE with and without fat for the entire period of the experiment, and 5, 6- diets with 0.5% TE in last two weeks with and without fat. Weight gain (WG), feed intake (FI) and feed conversion ratio (FCR)) of chicks were measured as weekly basis. At day 42, two chicks were selected from each pen and slaughtered for microfloracount and thigh meat cholesterol measurement. Chicks fed diets supplemented with fat had higher body WG and FI, and lower FCR compared to diets without fat (P 0.05). As an overall conclusion, adding TE to the diets during the entire rearing period of the experimentled to significant reduction in thigh meat cholesterol in boiler chickens.

In order to evaluate the effects of feed particle size in pellet and mash diets, 480 Hy-line (W-36) hens at 27 wk of age were assigned to treatments in a 3×2 factorial arrangement with the main factors being mash and pellet feed form, and fine, medium and coarse particle size. Productive traits were recorded during 9 weeks of experimental period and egg quality was measured at the last week of the experiment. In hens fed pelleted diets compared with those on mash diets, feed intake (97.9 and 93.5g, respectively), feed conversion ratio (1.94 and 1.88, respectively), egg weight (58.3 and 57.7g, respectively), body weight gain (73.2 and 38.4g, respectively), Haugh unit (81.5 and 77.5, respectively) and yolk percentage (25.9 and 25.2, respectively) were increased and egg albumen percentage (63.9 and 64.6, respectively) was reduced (P0.05). The main effect and the interaction between feed form and feed particle size for nitrogen retention and excretion was not significant. Result of this experiment showed that FCR was inferior for hens fed pellet compared to mash feeds and increasing corn particle size tended to improve performance parameters.

The aim of this research was to compare the digestibility of two concentrates with chromium oxide (Cr2O3) and lignin as markers in the Turkmen horses. In a completely randomised experiment 16 Turkmen horses, weighting 433 ±50 kg and aged 8 ±3 years were used. The treatments were a control diet (Tc) contained 25 percent of imported concentrate and three diets contained 20, 25 and 30 percent of local concentrate, T1, T2 and T3 respectively. The trial was carried out for a period of 28 days, started with 21 days of adaptation period and 7 days sampling and data collection. When Cr2O3 marker was used, the digestibility of OM (547 vs. 506), CP (545 vs. 527) and NDF (427 vs. 309) were higher (P

In this study, the mathematical models were used for evaluation of ruminal fermentation kinetic of alfalfa hay. These models included exponential (EXP), Michaelis-Menten (MIC), Mitscherling (MIT), Weibull (WEB), Korkmaz-Uckardes (KOR) and France (FRC). The in vitro gas production was carried out in 4 separate periods. Three syringes containing feed samples (3 replicates) were considered for each period and the volume of gas produced in each period at different incubation times (144 hours) was fitted for these models. Mean Square Error (MSE), coefficient determination (R2) and Mean Percentage Error (MPE) were used for models goodness of fit. Durbin-Watson and Shapiro-Wilk tests, Bayesian Information Criterion (BIC), Akaike’s Information Criterion (AIC) and Accuracy Factor (AF) were used for selection of the best model. The results showed that MSE in FRC (0.852) and MIC (0.917) models was lower than that of EXP (7.437) model (P

This research was conducted to evaluate the effects of electron beam (EB) irradiation on chemical composition, apparent digestibility of organic matter and crude protein (CP) and ruminal degradation of dry matter (DM), CP and neutral detergent fiber (NDF) of olive cake (OC). After preparation of OC, samples were irradiated with EB at doses of 200, 250 and 300 kGy using a Rhodotron accelerator system. Four Gezel sheep (41±2 kg) were used for determination of OM and CP digestibilities of OC. The sheep were fed a total mixed ration containing 70% of DM forage and 30% of DM concentrate during two pre-experimental and experimental periods. Apparent digestibility were evaluated using acid insoluble ash method. Ruminal degradation of DM, CP and NDF was determined according to in situ procedure. Untreated and EB irradiated feed samples were incubated in the rumen of four ruminally fistulated Gezel rams at periods of 0, 4, 8, 16, 24, 48, 72 and 96 h and resulting data were fitted to non-linear degradation model to calculate degradation parameters of DM, CP and NDF.EB decreased (P

Chemical composition and in situ (dry matter and NDF) degradability were measured to assess the nutritive value of rice, canola, cotton seed, soybean and corn straw treated with Trametes versicolor and Pleurotus ostreatus fungi. Various straw samples were inoculated with fungi mycelium that collected from Forest (Shastkola) in Gorgan-Iran and were kept in plastic bags with three replicates for 21 days. Then chemical composition and rumen degradability of dry matter were measured. Degradability of dry matter and NDF were obtained from three fistulasted Dalagh rams at 0, 4,8,16,24,48 and 72 hours using in situ technique. The results showed that the CP content in treated corn and cotton seed straws were significantly increased. The NDF content of straws expect corn straw were increased after proceesing with fungi. Data showed that the degradability (72 hours), effective degradability at different k (0.02, 0.05 and 0.08/h) and water soluble fraction(a) of dry matter and NDF content of corn straw treated with Trametes versicolor and Pleurotus ostreatus fungi was higher than other straws. According to findings, it was concluded that Trametes versicolor and Pleurotus ostreatus had different effects on degradability of NDF, CP and dry matter in varieties of straw.

This study was conducted to investigate the effect of adding spearmint and dill essence on performance, growth and blood metabolites of Kordi fattening lambs. In this experiment, 30 male lambs were used in a completely randomized design over a 9-weak trial with three treatments and 10 replicants. Treatments were included: 1) control without essence, 2) containing 0.025% Mentha spicata (spearmint) essence and 3) containing 0.025% Anethum graveolens (Dill) essence. Blood samples at 1, 3, 5, 7 and 9 and rumen fluid at 3, 5 and 7 weak of study were collected from five lamb of each treatment and skeletal growth indices including wither height, rump height, chest girth, body lenght and hip to hip lenght were measured also. The result showed that among skeletal growth indices only wither height between dill and spaermint treatment ( 60.80 and 62.4 cm, respectively) and chest girth among control, dill and spaermint treatments (76, 72.8 and 74.2 cm, respectively) had significant difference. Blood cholestrol singnificantly decreased in dill and spaermint treatment compared to control (51, 51.66 and 58 mg/dl, respectively). Treatments had no significant effect on other blood metabolites and performance growth. Generally, results of this study showed that adding of spearmint and dill essence did not have considerable effect on porformance and growth of fattening lambs.

The aim of this experiment was to evaluate the effect of feeding Scrophularia striata on fermentation characteristics, gas production and fiber and protein digestibility of Lori- Bakhtiari sheep. In this experiment, 12 lambs with average weight 30±1.5 kg divided to 3 groups (treatments) and 4 subgroups (replicate) and were fed with diets containing 6, 3 and 0.0 (control) g Scrophularia striata /kg DM for one month. In the end of experiment, rumen fluid collected from 3 replicates and parameters of fermentation and gas production (after 96 h) and in vitro digestibility of wheat straw and soybean meal were measured (4 replicates per each). The results showed gas production potential of soybean meal (61.19 mL) and straw (50.48 mL) in controltreatment was more than Scrophularia striata treatments (P0.05). Most of PF and efficiency of microbial biomass of wheat straw was for 3 g/kg DM Scrophularia striata (15.03 mg/ml and 86 %, respectively) and most of organic matter digestibility was for 6 g Scrophularia striata (253.85 mg). Dry matter digestibility of soybean meal (83.57 %) was the greatest in treatment containing 3 g/kg DM (P0.05). According to the result, the using of3 g/kg DM Scrophularia striata in Lori-Bakhtiarisheep diet had positive impact on microbial fermentation and digestibility.

The objective of present study was to estimate effect of age at sexual maturity (ASM) on the variance components and respective parameters for cumulative egg numbers in a commercial broiler line. The period of data collection was from 24 to 55 weeks of age. From the weekly records, cumulative egg productions for different weeks were created. Estimates of variance components and heritability were carried out using Restricted Maximum Likelihood (REML) procedure and WOMBAT software. To investigate the effect of ASM on variance components and genetic parameters, the data were reanalyzed, by fitting this effect as a covariate in the model. Also, we analyzed ASM as a trait in multi-traits analysis. Without considering ASM as a covariate, heritabilities for cumulative egg records varied from 0.17 (weeks 1 to 32) to 0.43 (weeks 1 to 4). With implementing ASM in the model, these estimates ranged from 0.12 (weeks 1 to 20) to 0.19 (weeks 1 to 4). When ASM was considered as a trait in two-traits analysis with cumulative egg records, heritability estimates varied from 0.16 to 0.44. These results indicated that considering ASM as a trait in the multiple models could not correct its effect on initial cumulative egg records and it is necessary to implement it as a covariate in the model. Also, the exclusion of age at sexual maturity from the analysis of cumulative egg records, especially for the initial week’s records resulted to overestimation of variance components and their corresponding parameters.