JOURNAL OF ANIMAL SCIENCE
Year:2010 | Volume:3 | Issue:3|Papers Count:11

In this study, individual and maternal heterosis of milk yield, fat yield, fat percent and milk days traits were estimated for Brown Swiss and indigenous crossbred dairy cattle using data from Centre Breeding country collected between 1991 to 2002. Average for mentioned traits are 2489.19, 117.5 kg, 3.83 percent and 252 days respectively. Share of the foreign breed gene, individual and maternal heterosis were calculated using the least squares: 10.38, 3.16 and -2.19 kg for milk and 0.12, 0.0342 and 0.029 kg for fat yield and 0.00457, 0.00131 and -0.00132 percent for fat percent, -0.54, -0.174 and 0.277 days for the milk days trait than the mean, respectively.Generally, the results of this study showed that crossbred animal with 50 to 70 percent share of the foreign breed of traits have had a better status.

The main objective of the dairy farmers is the improvement of production. Selection for production traits can result in deterioration of fitness traits (like udder disorders). Therefore, the traits such as reproduction and conformation should be considered in breeding programs. The data of first lactation production, reproduction and conformation traits of two Agro-Industrial Holstein dairy farms in Tehran province were used to investigate the genetic and phenotypic parameters.The Animal Model consisted of herd-year-season of calving (fixed), animal and residual effects (random).The age at first calving was used as a covariate. The average of 305d-2x milk and fat yield were 7019 (16) and 212.4 (0.6) kg, respectively. The average of fat percentage was 3.1 (0.01) percent. The average of calving interval was 407 (1) days. The average of age at first calving was 25.8 (0.02) months. The average of all conformation traits were within the range of values of Iranian Holstein cows. The heritability of milk and fat yield, fat percentage calving interval and age at first calving were 0.27 (0.3), 0.17 (0.3), 0.32 (0.04), 0.02 (0.01) and 0.03 ( 0.01), respectively. The range of heritability estimates for conformation traits were 0.15 (chest width and rear leg side view) to 0.41 (stature). The genetic correlation between first lactation milk yield and fat yield, fat percentage, calving interval and age at first calving were 0.72, -0.70, 0.17 and -0.03, respectively. There was a positive genetic trend for all production and reproduction traits (except fat percentage). The genetic trend for milk yield was 59.6 kg per year and for fat percentage was -0.01 percent per year.

The objective of this study was to investigate the effects of different levels and particle size of Perlite in broiler chick diets on the growth variables such as feed consumption, weight gain and feed conversion rate. For this reason 280 day-old Ross 308 broiler chicks allocated to seven treatments and four replications in a factorial design experiments based on a randomized complete block design. The effect of perlite was considered in two sizes (1.5 and 3 millimeters), and three different levels (1, 3, and 5 percent of the diet). The control diet included no perlite.According to the results, feed consumption of the broiler chicks in the starter phase, affected by the interaction of levels and particle size of perlite (P<0.05), although in the growth, finisher, and whole period, feed consumption was not affected by experimental treatments. In the finisher phase, a linear relation between the amounts of perlite used in the diets and broilers weight gain was observed (P<0.05); while the weight gain of the broiler chicks in the starter, grower, and whole period were not significantly different. Levels and particle size of perlite did not significantly affect the feed conversion ratio, in all experimental periods (P<0.05). According to the results, despite the effects of perlite-containing diets on some of variables, it seems that the perlite did not play any major role in chick's performance improvement.

In order to study of the effect of inbreeding on economic traits, 22494 records were collected from 10 commercial silkworm lines of Iran Silkworm Research Center including Chinese lines of 32, 104, 152, 110, 154 and Japanese lines of 31, 103, 107, 151, 153 during 4 generations from 2005 to 2007. In the linear statistical model, inbreeding was considered as covariable along with the fixed effects of line, sex and generation. All the effects included in the model were highly significant on cocoon weight, cocoon shell weight and cocoon shell percentage (P>0.0001) except inbreeding covariable for cocoon shell weight. Lsmean method was used for mean comparisons. Mean differences among levels of fixed effects and covariables were significant in all the traits (P>0.0001) so that Chinese lines of 32, 152, 104 and Japanese lines of 153, 103, 31 showed good performance. The highest heritability for all the traits was observed in 31 line and the lowest in 153 line. For cocoon shell percentage, the lowest values belonged to 152, 104 and 32 lines. The average inbreeding coefficient was 0 in the first and second generations and 0.03644 and 0.07327 in third and fourth ones. This demonstrated that inbreeding coefficient becomes twice in the fourth generation due to not controlling relative matings.

For Estimation of genetic parameters and correlation coefficients, 1400 records of milk yield, fat yield and fat percentage obtained from two herds of holstein cows in Sari (north of Iran) were used. These records were collected by organization of Jahad Keshavarzi of Mazandaran province at 2001 year. The effect of calving mouth and season, herd, lactation and blood fat percentage on the milk yield, fat yield and fat percentage traits were investigated using General Linear Model of Minitab computer program. Also, genetic parameters (heritability, genetic and phenotypic correlation) were estimated using animal model and Restricted Maximum Likelihood method and by DFREML software. The mean and standard deviation of milk yield, fat yield and fat percentage in total lactation were: 6719.26 101.8, 180.91 2.7 and 2.72 0.34 respectively.Heritability and standard error of milk yield, fat yield and fat percentage were: 0.30 0.09, 0.24 0.08 and 0.14 0.076 respectively using univariate models. Also genetic and phenotypic correlation between milk yield-fat percentage, of milk yield-fat yield, fat yield-fat percentage were: -0.34 and -0.46, 0.69 and 0.64, 0.19 and 0.30 respectively. Considering the results of this study, genotypes performance for production traits in this climate area were determined. Therefore it is suggested that the selection in each area should be taken place according to the suitable selection index of traits for that area.

This experiment was conducted to determine chemical composition and degradability of dry matter (DM) of whole Safflower seed using nylon bags in Ghezel rams. Values of DM, CP, OM, EE, CF, ADF and NDF of whole Safflower seed, were 96.25, 17.63, 94.12, 30.32, 26.13, 40.8 and 63.8 percent, respectively. Water soluble fraction (a), slowly degradability fraction (b), potential degradability (a+b) and rate constant (c), respectively were 8.3, 39.6, 47.83 percent and 0.216 for the DM. Effective degradability (r) 0.02 for DM was calculated. According to these results, whole Safflower seed can be used as a good source of dietary nutrition in ruminants.

This experiment was conducted to evaluate the effects of different mixtures of Malva silvestris, Alhaji maurorum, and Mentha spicata medical plants on performance, carcasses quality and blood biochemical and immunity parameters of broilers. Experiment was conducted in a completely randomized design with 384 of broiler in 4 treatment and 4 replicate (with 24 bird in each replicate) for 42 days and included: control group without using any medical plants, group 2 using 2% of medical plants (50% of Malva silvestris, 25% Alhaji maurorum and 25% of Medicago sativa), group 3(25% of Malva silvestris, 50% Alhaji and 25% of Medicago sativa) and group 4(25% of Malva silvestris, 25% Alhaji maurorum and 50% of Medicago sativa). There were significantly difference between treatments for carcass percent and blood biochemical parameters (P<0.05). The Highest percent of carcass (70.19) was observed in 3 experimental group but the lowest percent of it (66.77) observed in control group. Experimental groups had significantly difference in blood glucose level (P<0.05). The Lowest level of glucose (147.83 mg/dl) was observed in 2 experimental group and the highest level of it (183.5 mg/dl) was observed in control group. The overall results of the present study indicated that in broilers with using 2 percent of mixture of medical plants like medical plants of 3 experimental group (25% of Malva silvestris, 50% Alhaji and 25% of Medicago sativa) the improvement of carcass quality is possible.

Identification of Gilkworm genetic stocks of each country and their potential have large imprtace.Due to lack of sufficient information about the three commercial silkworm pure lines of 31, 103 and 107 under Iranian condition, this research was conducted to assess the effects of gender, generation and line on cocoon economical traits. Phenotypic data for these three lines was collected from Iran Silkworm Research Center (ISRC) in three generations since 2001-2003.The used data included eight families ´ 3 × generations ´ 3 pure lines ´ 3 traits ´ 2 gender ´ 25 individuals (equals to 10, 800 records). Mean comparisons were conducted for each line, generation and gender in total and each pure line separately. Fixed effects of pure line, generation and gender were significant in level 0.01 for cocoon weight, cocoon shell weight and cocoon shell percentage (P<0.01). Trait average of three pure lines were statistically significant difference (P<0.05); so that the average of cocoon weight and shell cocoon weight for pure line of 31 (1.60±0.28 gram and 0.35±0.05 gram) and pure line of 103 (1.62±0.28 gram and 0.36±0.05 gram) were more than pure line of 107 (1.39±0.21gram and 0.28±0.03 grams), but shell cocoon percentage mean in pure line of 103 (22.76±2.75 gram) was more compared to the other pure lines. This trait for pure line of 107 was less then other pure lines (20.90±2.31 gram). In total pure lines of 31 and 103 had most quantitative traits pure line of 107 had less quantitative traits. Generation effect on differences between the cocoon weight, cocoon shell weight and cocoon shell percentage was significant (P<0.05). Second generation in comparison to other generations had more cocoon weight (1.648 gram) and cocoon shell weight (0.353 gram), but the average of cocoon shell parcentage (%21.651) was minimum compared previous and next generations (P<0.05). Also cocoon weight, cocoon shell weight and cocoon shell percentage were significantly different in two gender of female and male. Cocoon weight and cocoon shell weight of female individuals were higher than male individuals (P<0.05).

An experiment was conducted to investigation on some blood biochemistry parameters changes and Performance in broiler fed corn soybean meal - based diets supplementation NSP hydrolyses. Experiment had 5 treatments and 4 replications and 15 broilers in each replication. Groups were randomly assigned to following treatment groups. The diets of all groups were arrangement in an isonitrogeous and isoenergetic diet based corn and soybean meal. In a completely randomized design (CRD), 300 Ross one-day old broiler chicks were used in this experiment. Data on feed consumption, weight gain, feed conversion ratio and triglyceride, cholesterol, LDL and HDL collected. Data were analyzed by General Linear Model using SAS version (9.1). Results showed significant differences (P<0.01) among different experimental diets for weight gain, feed intake and feed conversion ratio. The lowest feed consumption and weight gain were observed in control group while the highest were obtained in groups that fed with multi enzyme supplementation. The data calculated of feed conversion ratio (FCR) shown that highest FCR was observed in control group and best FCR (lowest) were in group that use multi enzymes. enzymes supplementation increased the concentration of blood HDL and decreased triglyceride, cholesterol and LDL at 21, 42 and 49 d of age, (p<0.01).

This experiment was conducted to determine the effects of increasing energy level (higher than NRC, 1994 recommendation) using different fat levels and relative decreasing of protein and nutrient contents in the diet on blood biochemical parameters. With addition of three types of fats including tallow fat, soybean oil and poultry oil in two levels (4 and 8%) to basal diet that were already balanced on National Research Council (NRC, 1994) recommendations, seven different non-isonitrogenic and non-isocaloric diets were provided and given ad libitum. At 35 and 49 days of ages, blood samples were collected from wing vein and then by using Autoanalyser (ALCYON 300) sera were analyzed. Serum lipids concentrations including total cholesterol, triglycerides, HDL, LDL, VLDL and atherosclerosis indicators including LDL/HDL and T-CHOL/HDL showed no significant difference between dietary treatment groups. Serum LDL concentration and LDL/HDL indicator showed significant elevation from 35 to 49 d (p<0.01), whereas serum Cholesterol concentration showed decline at the same times (p<0.05). With increasing in dietary fat level from 4 to 8%, serum Cholesterol level showed significant elevation (p<0.05). Broiler chickens, probably because of bearing some physiological resistance systems, like over compensation (down regulation of lipoprotein lipase) are more resistant to high dietary fat intake.