فهرست مطالب

  • Volume:7 Issue: 2, 2019
  • تاریخ انتشار: 1398/09/10
  • تعداد عناوین: 8
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  • Ali Sharbafan, Mojaver, Ebrahim Ghasemi *, Masoud Alikhani Pages 1-7
    In this study, the effects of partially replacing cereal grains (corn and barley) by forage (straw) or non-forage (beet pulp) source in lamb starter diets were investigated on performance, chewing behavior, nutrient digestibility, and blood energy parameters. Thirty Ghezel lambs (body weight of 5.3 ± 0.5 kg) from 2 to 65 days of age were assigned to 3 starter feeds: 1) with no fiber source [NF, 16.3 % neutral detergent fiber (NDF), 48.7% starch], 2) containing 7 % wheat straw (WS, 20.5 % NDF, 43.7% starch), and 3) containing 15 % beet pulp (BP, 19.7 % NDF, 39.1 % starch). Lambs were free to suckle their dams until d 30 and were then pair-housed and allowed to suckle at night until weaning on d 45 of age. Lambs had free access to starter creep feeds during pre- and postweaning periods. The results showed that offering both fiber sources improved starter intake by 15%. Feeding BP decreased total tract dry matter (DM) digestibility from 77.6 to 70.1%, but NDF digestibility was similar across the treatments. Postweaning body weight (27.5 kg), average daily gain (341 g/d), and postweaning feed efficiency (0.41) were not affected by the treatments. Further, dietary treatments did not affect serum concentrations of cholesterol, total protein, albumin, and globulin, but WS inclusion increased triacylglycerol, glucose, and beta-hydroxybutyrate concentrations. Eating (221 vs. 174 min) and ruminating (383 vs. 278 min) activities were also greater in lambs on WS as compared with lambs on NF or BP. These results indicated that decreasing starch content in the starter with the inclusion of a fiber source, in particular WS, did not negatively affect the growth performance, but appeared to be associated with better chewing activity and rumen metabolic development.
    Keywords: suckling lamb, rumen development, wheat straw, beet pulp
  • Mohsen Kazemi *, Elias Ibrahimi Khorram Abadi, Amir Mokhtarpour Pages 9-15
    There is little information on the nutritive value of ensiled Iranian melon (Cucumis melo cv. Khatooni) wastes (IMW) for sheep feeding; therefore, the nutritional value of IMW was investigated before and after ensiling. Treatments were 1) Fresh IMW as control [FIMW], 2) Ensiled IMW [EIMW], 3) Ensiled IMW with 1% grape vinegar [EIMW+1% GV], and 4) Ensiled IMW with 2% grape vinegar [EIMW+2% GV]. The IMW samples (after harvesting the ripe fruits) were ensiled in the polyethylene tubes for 60 days. Ensiling IMW increased the contents of dry matter (DM) and crude protein (CP). The concentration of CP was also increased (P<0.05) in the silages supplemented with GV. However, neutral and acid detergent fiber (NDF and ADF, respectively) and ash contents were unchanged among treatments. The addition of grape vinegar to the silage increased the concentrations of lactic and acetic acids and decreased NH3-N compared to control silage (P<0.05). However, total volatile fatty acids (TVFA) and pH of silages were not significantly affected by the treatments. The highest values of gas production parameters (gas12, 24, 48, 72 h and bgas), true dry matter (TDMD) and organic matter degradability (TOMD) were observed in FIMW (P<0.05). Ensiling IMW without additive, decreased TDMD and TOMD, whereas treating silages with GV increased its digestibility (P<0.05). The highest partitioning factor (PF) and efficiency of microbial mass yield (EMMY) were detected in EIMW+2% GV (P<0.05). Generally, it can be concluded that IMW can be used as a potential forage source in sheep feeding either as fresh or ensiled by-product. However, because of the high moisture content of IMW, ensiling with 2% GV could improve the nutritional value and fermentation parameters.
    Keywords: nutritional value, Iranian melon wastes, gas production, silage
  • Reza Tahmasbi *, Sakine Ebrahimi, Omid Dayani, Mohammad Mehdi Sharifi Hoseini, Amin Khezri, Poorya Dadvar Pages 17-27
    The aim of this study was to evaluate the effect of feeding alfalfa pulp ensiled with waste date (Phoenix dactylifera L.) on digestibility, microbial protein synthesis and ruminal fermentation characteristics in Kermani sheep. Alfalfa (Medicago sativa L.) pulps were ensiled with waste date (15% in dry matter) in buckets. After 45 days, chemical composition and pH of the silage were evaluated using four Kermani rams in a change-over design with four 21-day periods comprising of 16 days for adaptation and 5 days for sample collection. Treatments containing 4 diets: 1) control diet (without silage); 2) diet containing 10% silage; 3) diet containing 20% silage and 4) diet containing 30% silage. The results of this study showed that adding 15% waste date to alfalfa pulp during ensiling, improved silage quality and DM. The Flieg point and pH of silage were 94.26 and 3.8, respectively, with a total score quality evaluation of 19 that seemed to be a very good score. Nutrient digestibility, nitrogen (N) retention, blood parameters, urinary purine derivatives and microbial protein synthesis were not affected by treatments. The total population of Entodinium and total protozoa species were increased linearly with the increase in the level of alfalfa pulp ensiled with waste date in the diets. In conclusion, ensiling of alfalfa pulp with 15% waste date increased DM and silage quality and its feeding to sheep did not have negative effects on feed intake and nutrient digestibility. Due to the relatively low costs of alfalfa pulp and waste date, their inclusion in sheep diets can reduce the cost of feed and environmental pollution.
    Keywords: silage, Flieg point, digestibility, purine, protozoa
  • Morteza Mokhtari *, Arsalan Barazandeh, Moslem Moghbeli Damaneh, Zahra Roudbari, Najmeh Kargar Borzi Pages 29-35
    Data on early growth traits of 1574 Kermani lambs, the offspring of 874 dams and 122 sires, were recorded between 1992 to 2010 at the Breeding Station of Kermani sheep breed in Shahr-e Babk city, Kerman province, Iran. The traits included the birth weight (BW), weaning weight (WW) and weight at six months of age (6MW). Preliminary investigations demonstrated the decisive effects of direct and maternal genetic influences on the expression of these traits. The data were used to adopt three models of genetic analysis. The first model was the standard multivariate model (SMM), which does not consider the causal relationships among the traits. The second model was the fully recursive multivariate model (FRM), which assumes the existence of causal influences of BW on WW and on 6MW, and the influence of WW on 6MW. The third model was the temporal recursive model (TRM), in which BW causally impacts on WW, and WW on 6MW. The Bayesian approach, via Gibbs sampling, was used for genetic analysis. The adopted models were compared considering the deviance information criterion (DIC) and mean square error of prediction (MSE) as criteria for assessing the predictive ability of the models. The DIC values revealed the superiority of TRM over FRM and SMM. Under the investigated multivariate models, the values of MSE were similar for BW but those obtained for WW and 6MW were the lowest under TRM. The causal effect of BW on WW and that of WW on 6MW were statistically significant estimates of 1.10 kg and 0.70 kg, respectively. Furthermore, accounting for causal relationships,the early growth traits in Kermani sheep may have advantageous impacts on prediction of the breeding values and consequently the accuracy of lamb ranking for selective breeding purposes. Generally, significant causal relationships were detected among the early body weight traits in Kermani sheep, and the superiority of TRM over other models showed the necessity of considering such causal influences in the genetic evaluation of these growth-related characteristics.
    Keywords: body weight, maternal effects, Predictive Ability, recursive model
  • Roghaie Barzegar Mashak, Jamal Seifdavati *, Hossein Abdi, Benemar, Farzad Mirzaei Aghjehgheshlagh, Reza Seyedsharifi, Taher Yalchi Pages 37-45
    The purpose of this study was to investigate the effect of processed alfalfa silage with acetic acid and Ecosyl on feed intake, microbial protein synthesis and blood parameters in four Moghani male sheep (90±2 kg BW) using a changeover design consisting of four 14-day periods. The experimental treatments were 1) alfalfa silage without additive as control, 2) alfalfa silage treated with Ecosyl, 3) alfalfa silage treated with 5% acetic acid, and 4) alfalfa silage treated with acetic acid and Ecosyl. The results showed that feed intake was not affected by treatments. The amounts of excreted purine derivatives were 12.29, 7.02, 12.03 and 8.64 g/d for alfalfa silage (control), alfalfa silage treated with acetic acid or Ecosyl and their combination. Also, the adsorbed purine derivatives values were 13.46, 7.19, 13.14 and 9.12 g/d for control, alfalfa silage treated with acetic acid or Ecosyl and their combination. Untreated alfalfa silage, treated with either acetic acid, Ecosyl or their combination resulted in 9.79, 5.23, 9.56 and 6.63 g/d of microbial protein synthesis, respectively. The excreted purine and adsorbed purine derivatives and microbial protein synthesis were reduced in alfalfa silage treated with acetic acid and Ecosyl and their combination (P<0.05). There were no significant differences in blood metabolites among the treatments, except for cholesterol values. Alfalfa silage treated with acetic acid alone did not change the nutritional values; however, alfalfa silage treated with acetic acid and Ecosyl improved the nutritional parameters in sheep.
    Keywords: alfalfa silage, acetic acid, Ecosyl, purine derivatives
  • Roghayeh Jabbari Ori, Jalil Shoja *, Ali Esmailizadeh, Seyed Abbas Rafat, Karim Hasanpur Pages 47-55
    Ascites syndrome (AS), caused by an imbalance between high oxygen demand and its supply by cardiopulmonary system in broiler chickens, is a major problem in the broiler industry worldwide. An experiment was designed to investigate the differences in biochemical parameters between the ascitic and healthy chickens in a pure broiler sire line under cold conditions. A total of 817 one-day-old mixed-sex chickens from 71 half-sib families were grown and AS was induced on day 21 using a cold temperature model. On the 32nd day of the trial, blood samples from five birds per sire family were collected and blood parameters (hematocrit percentage and serum metabolites including, glucose, total protein, albumin, triglycerides, cholesterol, high-density lipoprotein cholesterol (HDL), calcium, magnesium, phosphorus, alanine aminotransferase, aspartate aminotransferase, malonedialdehyde and total antioxidant status) were measured. The results showed that the male birds were more sensitive to AS than the female birds. Hematocrit percentage of the ascitic chickens was higher than the healthy chickens (P
    Keywords: Cold stress, broiler line, HDL, hematocrit, pulmonary hypertension syndrome
  • Seyyed Hasan Hafezian, Jabar Jamali, Mehsan Gholizadeh *, Alireza Ehsani Pages 57-63
    The aim of this study was to investigate the trend of bias in genomic estimated breeding values (GEBVs) arising from selective genotyping of the candidate population in an ongoing selection scheme. The bias was calculated as the regression of true breeding values (TBVs) on GEBVs. A simulation study was performed under two scenarios with selection intensities (SI) of 0.798 and 1.755 for three traits with heritability (h2) of 0.1, 0.25 and 0.4 in 10 consecutive generations. Regression of TBVs on GEBVs was close to one for the first generation when selective genotyping was random, and it continuously receded from one as selection shifted to choose animals with high EBVs from generations 2 to 10. Biasedness became larger with increased SI and decreased h2. Further, biasedness increased over the generations but the rate of change in biasedness decreased dramatically after the second generation and became almost steady after generation 4 which may be due to Bulmer effect. The findings showed that scaling down the GEBVs, using a scale parameter, might help removing biasedness in generation 4 onwards.
    Keywords: genomic selection, Selective genotyping, bias
  • Anass Benmoula, Abdelmoughit Badi, Kaoutar Elkhalil, Larbi Allai, Moussa Elfadili, Bouchra Elamiri * Pages 65-75
    The aim of the present study was to evaluate the effects of holding semen for 4 h at 15 °C in different extenders prior to cryopreservation on sperm characteristics and subpopulation kinematics in INRA180 sheep. Semen samples were collected using an artificial vagina from two animal groups. Group 1: the rams kept next to the lab (G1) considered as a control and group 2: the rams kept in a farm faraway (170 km) from the lab (G2). The semen was extended in Milk egg yolk, Andromed® and Tryladil® extenders to reach 0.2 x 109 spermatozoa/mL. Before freezing, the samples from G1 were directly cooled to 5 °C during 2 h. While those for G2 were transported within 4 h to the laboratory in a temperature-regulated cooler box at 15 °C then cooled to 5 °C. Differences in sperm motility, viability and abnormality in pre- and post-thaw steps and subpopulation kinetic parameters in post thaw step were detected between the two groups, and between extenders within the groups. Evaluation of the kinetic data obtained with a CASA (Computer-Assisted Sperm Analysis), applying a cluster analysis, yielded in INRA180 rams two post thaw sperm subpopulations (SPs). The SP1 and SP2 included spermatozoa characterized by low and high kinetic parameters, respectively. Disregarding the extender type, the proportional size of SP1 was lower than SP2 in G1, Nevertheless, in G2 the percentage of SP1 was higher than SP2. In conclusion, changing conditions during the equilibration time (from 2 h at 5 °C to 4 h at 15 °C) can extend the total process duration and causes a decrease in post-thawed semen quality in INRA180 rams.
    Keywords: Ram, Spermatozoa, extenders, sperm subpopulation, cryopreservation