Research On Animal Production
Year:2013 | Volume:3 | Issue:6|Papers Count:7

This study was carried out to evaluate the impact of litter additives on growth performance, immune system response and the incidence of ascites syndrome in broiler chickens. This experiment was investigated in a completely randomized design with four treatments and four replications and 24 day-old chicks in each pen. Experimental treatments were addition of 1) aluminum sulfate+CaCO3, 2) natural zeolite + citric acid, 3) treatments 2 and 3 together, to litters and a group with no litter additive was considered as control. Litter additives were applied on surface of the litters by 1.115 kg/m2, at 24 h before arrival of the birds. Weight gain, feed consumption and feed conversion ratio were not affected by the treatments (P>0.05). On day 42 posthatch, mortality, the incidence of ascites, heart relative weight, right ventricular relative weight, heart ascites index (AHI) hematocrit and dermal and humoral antibody response to phytohemaglotinin and sheep red blood cells inoculation were not affected by the treatments (P>0.05). Birds reared on the litters treated with aluminum sulfate+CaCO3 and natural zeolite + citric acid showed significantly greater means for bursa and spleen relative weights respectively (P<0.05), while there was not significant difference among other treatments. The pH value and moisture percentage were significantly affected by treatments until 5wk (P<0.05). On day 42, pH value, moisture and nitrogen (%) in litter were not affected by treatments (P>0.05). It could be concluded that while litter additives enhanced some of litter characteristics, it did not have effect on broilers performances.

The main aim of this study was to determine the effect of dietary Anethum graveolens essential oil on some blood parameters, egg yolk cholesterol concentration, hatchability and chick quality in broiler breeder hens. A total number of 80 hens and 8 cocks of Ross 308 strain (105 weeks age) were divided into 4 groups with 2 replicates with 10 hens and 1 cock in each replicate. One group was given a control diet and other group diets supplemented with 10, 20, 40 ml essential oil/100kg diets for 4 weeks. Essential oil significantly increased plasma cholesterol concentration (P<0.05), but plasma triglyceride, high density lipoprotein cholesterol (HDL-C) and egg yolk cholesterol concentrations were not influenced by dietary essential oil. Essential oil supplementation to diet did not significantly affect chick quality, while hatchability of total eggs set were positively affected by supplementation of the essential oil in the diet (P<0.05). The results of this study showed that supplementation of diet with 10 mg/100 kg diet Anethum graveolens essential oil improved hatchability of total eggs set of broiler breeders.

This study designed to survey the effects of Saccharomyces cerevisiae probiotic and organic acids on performance and intestinal morphology of broiler chickens. At 1-42 days of age, the experimental birds fed the experimental diets containing probiotic, organic acid mixture (a commercial mixture of formic acid, lactic acid, malic acid, citric acid, tartaric acid and orthophosphate acid) or the both the above supplements. The type of the dietary supplement did not affect broiler chickens performance. The birds received diet containing both the probiotic and organic acid mixture the villi height increased and the epithelium thickness and goblet cell numbers decreased and the crypt depth increased. The results of the present study showed the positive effects of organic acids on villi height and favorite effects of both supplements on reduction of small intestine epithelial thickness, but these observed intestinal morphological differences did not have significant affect on broiler chickens performance.

Data used in this study related to reproductive traits in Shal sheep that were collected during 1998 to 2009 by Agricultural Jahad organization of Qazvin province. Reproductive performances studied in this research were analyzed via main and composite traits. The main traits were conception rate, number of lambs born and number of lambs at weaning. The composite traits were total litter weight at birth, total litter weight at weaning, total litter weight at birth per ewe exposed and total litter weight at weaning per ewe exposed. The data were analysed with restricted maximum likelihood procedure by the use of ASREML software. The effect of environmental factors such as mating year and age of ewe at mating were significant (P<0.05) on all of reproductive traits. Estimates of heritability for animal genetic effects were mainly small and ranged from 0.06 to 0.13. The low level of heritability may be due to the typical high influence of environmental factors on reproductive traits and non-normal distributions of some traits. Estimates of repeatabilities for animal permanent environmental effects were small to medium 0.10 to 0.19. Genetic and phenotypic correlations among conception rate with number of lambs born, number of lambs at weaning, total litter weight at birth, total litter weight at weaning are negative but other genetic and phenotypic correlations among traits are positive estimated. The results suggested that selection based on TLWW could be more effective than the other traits for improvement of reproductive performance in Shal ewes.

In this research, 701212 test day record for milk yield of first lactation of 199903 Holstein cows from 2006 to 2010 that were collected by Karaj breeding center were used. Random regression model with Legendre polynomials fitting order 2 to 5 of additive genetic effects and permanent environmental effects, Wilmink and Ali-Schaeffer functions were compared under homogeneous residual variance assumption throughout lactation. Genetic parameters were estimated using restricted maximum likelihood (REML). For comparison of models, from -2logL, Akaike’s information criterion (AIC), Bayesian information criterion (BIC), Residual Variance (RV) and Likelihood ratio test (LRT) was used. Based on obtained results, random regression model with Legendre polynomial function (2, 5) were chosen as better model. Residual variance decreased as the increase of fitting order for permanent environmental effects in Legendre polynomials. Permanent environmental variance was estimated higher in early lactation than the other lactation stages and additive genetic variance in the early lactation was lower than at the end of lactation. Phenotypic variance of milk yield during lactation was not constant, it was higher at the beginning and the end of lactation. The heritability during lactation did vary among different functions, range from 0.08 to 0.23.

Four 2 years fistulated Zel sheep (BW=28±2 kg) were used in a 4´4 chang over design in four 32 d (adaptation 14 d and sampling period 18 days) in order to evaluate the effects of alfalfa particle size (fine or long) and soybean oil (0 or 4%) on nutrients digestibility, chewing activity, passage rate and ruminal particle size distribution. Sheep were equally fed at maintenance level, twice daily at 8 A.M. and 20 P.M. with 4 TMR that contained forage to concentrate ratio of 40 to 60. Manually ruminal evacuation carried out at 3, 7.5, 12 h post-feeding and total ruminal contents were separated into solid and liquid phases. In each period, using Cr-mordanated NDF, the ruminal passage rate of ruminal digesta particulate was determined. The treatments had no effect on apparent digestibility of DM, OM, nutrients, eating and rumination time and total chewing activity. The treatment containing long alfalfa without oil supplement showed the lowest ruminal passage rates and the highest ruminal mean retention time. However, there were not significant differences between ruminal passage rate and retention time in the other three treatments. Reduction of alfalfa particle size and supplementation of soybean oil in treatment that contained large particle ruminal passage rate and retention time increased and decreased, respectively. At 3h after feeding, the ruminal inescapable DM, as well as the escapable ones, were not significantly affected by treatments. The ruminal inescapable DM increased 11.44% and the ruminal escapable DM decreased 11.63% by reducing roughage particle size and soybean oil supplementation at 7.5 h post-feeding. The ruminal unescapably DM increased, at 12h post-feeding, due to forage particle size reduction and soybean oil supplementation. The particle size reduction was expected to decrease the consistency of mat, chewing activities, but the supplementation of soybean oil had adjusted the effects of particle size that ultimately the similar results have obtained. The reduction of alfalfa hay particle size as well as soy bean oil supplementation in rations helped to achieve appropriate ruminal particle distribution or formation of consistent ruminal mat.

Number of services per conception is a valuable reproductive characteristic due to its effects on different reproductive, genetic and economic parameters of herd. On the other hand, this parameter is affected by the use of reproductive technologies like sexed semen. At the current study, employing a deterministic simulation model, four different scenarios (including continuous use of conventional semen, continuous use of sex sorted semen, the use of sexed semen at the first service followed by conventional semen at remained services and the use of sexed semen at the first and the second services followed by conventional semen for the later services) were compared by their effect on number of services per conceptions in heifers. Results indicated that the average number of services was greater when continuous utilization of sexed semen comparing to the rest of scenarios (4.2±1.33). a quadratic trend was found as a result of change in number of services per conception at different conception rates. Compared to continuous utilization of sexed semen, concurrent use of conventional and sexed semen had a moderating effect on number of services per conception. Due to lower fertility of heifers from second insemination it seems that mixed use of conventional and sexed semen is a preferable scenario. However choosing the suitable scenario needs further economic consideration.