مجله تحقیقات دام و طیور
سال چهارم شماره 4 (1394)

Accurate prediction of breeding value of animals is influenced by several factors such as selection of the best genetic analysis model. For this purpose, pedigree and phenotypic information of birth weight (BW0), weaning weight (BW3) and six-month weight (BW6) of Lori-Bakhtiari sheep from 1989 to 2011 were used. (Co) variance components were estimated by Restricted Maximum Likelihood (REML) with different univariate and multivariate animal model. The results showed that heritability of traits is constant in different two and three trait models (0.47, 0.27 and 0.12 for BW0, BW3 and BW6, respectively), but absolute difference between the genetic and residual correlations changed up to %11 in different models (0.23, 0.32 and 0.65 in two-trait vs. 0.19, 0.31 and 0.54 in three-trait for BW3-BW6, BW0-BW3 and BW0-BW6 analyses, respectively). The correlation coefficients between animal breeding values were principally upper 0.99 for BW0 in different models, whereas these coefficients for BW3 in total population were 0.43-0.97, in ewe population 0.89-0.98 and in rams population 0.92-0.99, and for BW6 in total population 0.53-0.93, in ewes population 0.52-0.94 and in rams population 0.58-0.93. Rank correlations were also high for BW0 in three studied populations, but BW3 rank correlations between single with two and three-trait models in three populations were 0.42-0.96, 0.90-0.98 and 0.92-0.97, and for BW6 0.52-0.60, 0.54-0.56 and 0.61-0.67, respectively. The results showed that there was no difference between different models to predict breeding values of birth weight, but differences were significant for other two traits.

The present experiment was conducted to evaluate the effects of four medicinal plants mallow (Malva neglecta L.), nettle (Urticaceae dioica L.), summer savory (Satureja hortensis L.) and peppermint (Menta piperita L.) on performance, carcass characteristics and biochemical and hematological parameters of broilers. Two hundred and eighty broiler chicks (Ross 308) in a completely randomized design with five treatments and four replicates and 14 chicks in each replicate were used. Treatments were control (no use of medicinal plants) and groups with 2% of mallow, nettle, summer savory and peppermint. Experimental results showed that the amount of daily feed intake, daily weight gain and feed conversion ratio in treatments receiving 2% of the medicinal plants had no significant difference with control group. Treatments had no affects on carcass composition. Hematocrit, hemoglobin, white blood cells, heterophils, lymphocytes, and the heterophil to lymphocyte ratio were not affected by treatments. However, the highest count of red blood cells was related to summer savory which it had significant difference compared to others (P

In this study, (co)variance components and heritability for performance traits of body weight in 12 weeks, body weight at sexual maturity, age at sexual maturity and egg number of 43,180 birds native Azerbaijan during 14 generations (1988 to 2010) were estimated. Data analysis were undertaken using restricted maximum likelihood method through applying a multivariate animal model. Heritability of the traits was in the range of 0.097 (egg number) to 0.409 (body weight in 12 weeks). High genetic correlations were found between age at sexual maturity and egg number (-0.83) and between body weight at 12 weeks and body weight at sexual maturity (0.744). Genetic trends for body weight at 12 weeks, body weight at sexual maturity, age at sexual maturity and the number of eggs were 14.29 g, -5.5 g, -1.62 day and 0.23 numbers, respectively. The findings of this research revealed that lowering the age of sexual maturity will increase the egg number.

The objective of this research was to study polymorphism of CAST gene and its association with birth weight and cashmere traits in Kerman Raini goat. Blood samples were randomly collected from 108 Kerman Raini goats. DNA was extracted by salting out method and a fragment length of 247 bp of exon 6 of the gene using polymerase chain reaction (PCR) was amplified. SSCP obtained by acrylamide gel and stained with silver nitrate. Three patterns AA, AB and AC were detected for CAST gene with frequencies of 0.426, 0.28 and 0.296, respectively. The population deviated from Hardy–Weinberg equilibrium. Birth weight and year of shearing had no significant effects on cashmere wool but the effect of genotype was significant on birth weight (P

This study was conducted to determine the amount of usable energy in Sistan and Baluchestan range plants for livestock to obtain of regression equations and completing the Iranian feed composition tables. The raw data were collected from the Animal Nutrition Laboratory of Animal Science Research Institute (ASRI) (from 1987 to 2011) and Animal Nutrition Laboratory of Tehran University as well as final report of some research projects. The Tilly & Terry experimental data used. Linear, logarithmic, inverse, quadratic, cubic, power, S, and exponential fitted equations with SPSS software from DOMD data were very significant. Among the fitted equations, the linear for its precision was chosen. For ME estimation of Sistan & Balochestan range plants DOMD as independent predictor and in this regard estimated metabolizable energy was equal: ME (Mcal/ DM) = -6.147E - 15 0.0037 (DOMD g/Kg). ME estimation of metabolizable and net energy for lactation (NEL) of Sistan & Balochestan range plants was 1.78 base on tilly & terry method and NEL was 1.09 Mcal/Kg DM. Net energy for maintenance (NEm) and net energy for growth (NEg) were receptively 0.94 and 0.38 Mcal/Kg DM.

This study was performed to evaluate the effect of different levels of probiotic and heat stress on performance, carcass characteristics and some blood parameters in broilers.192 day-old Ross 308 broiler chicks were divided into two group (2×3 factorial method), two heat levels (normal and heat stress) and three levels of Protexin probiotic (0, 150 and 250 mg/kg). Four replicates were applied for each treatment. However, within the third week, with linear increase in feed intake and addition of various levels of Protexin daily feed, feed conversion ratio (FCR) and daily food consumption was observed to be increased compared to control group. Different levels of probiotic and rearing conditions (normal and heat) did not cause a significant increase in the relative weight of carcass components on day 42 of age. The relative weights of hearts of the birds under heat stress were significantly reduced (P0.05). Broiler diets supplemented with 0.15 probiotics significantly reduced serum cholesterol levels compared to those of the zero level of probiotic. Components of lipid metabolites in birds under heat stress were increased except for HDL. According to the results of this study, the use of probiotics in heat stress conditions have more positive effects on performance in broiler chickens as well as decreased levels of the metabolites of cholesterol compared to those of normal heat conditions.