فصلنامه تحقیقات تولیدات دامی
سال چهارم شماره 3 (پاییز 1394)

This study examined the effect of replacing dietary beet pulp with (BP) with barley in the diet of lactating cows on energy balance, feed intake, digestibility and feeding behavior during the transition period. 24 multi-parity Holstein cows, within 28 d relative to parturition up to day 24 of lactation were tested. Cows were assigned randomly to three dietary treatments containing before and after calving, respectively, were as follows: 1) Control (100% barley), 2) 75% barley +25% BP, and 3) 50% barley + 50% BP. During the pre and postpartum period, daily feed intake and energy intake was highest in 25% BP treatment (P < 0.0001). Dry matter intake as percentage of BW was highest in 50 and 25% beet pulp (P < 0.0001) before and after calving, respectively. Apparent digestibility of nutrients were not significantly different between treatments before and after calving. In postpartum, ruminal pH was lowest in cows fed control diets (P > 0.05). Before calving, cows sorted in favor of large particles (>19.0 mm) (P < 0.05) and against of short particles (>1.18 mm) (P < 0.01) when fed diets without BP (Control). Our results indicate that replacing 25% barley with BP in diets of transition cows improved performance and rumen health.

This study was performed aimed at evaluating the effect of substitution of calcium hydroxidehydrolyzed feather with soybean meal (SBM) in ruminant diet using the in vitro gas production technique. Treatment 1 (control) consisted of 70% concentrate + 30% alfalfa hay. In treatment 2, untreated (raw) feather was substituted with SBM. In treatments 3, 4, and 5, feather hydrolysate obtained following hydrolysis with calcium hydroxide in a reactor at 1400 rpm and 100ºC for 100, 200, or 300 min was replaced with SBM. By increasing the reaction time from 100 to 300 min, the feather solubility increased from 50.8 to 90.7%. Diets containing solubilized feather had greater in vitro digestibility (72.9, 79.0 and 69.3%) compared to the diet containing untreated feather (59.2%), but the increase was not directly correlated with pretreatment duration. No significant difference was recorded in ruminal NH3-N between control treatment (7.82 mg/100 mL) and the treatment containing feather pretreated for 200 min (7.64 mg/100 mL), but significant differences were found between untreated feather (4.17 mg/100 mL) and the control treatment. Microbiological evaluation of the pretreated feather samples showed that hydrolysis conditions were effective in controlling microbial contamination. The results showed that feather pretreated for 200 min could be a promising alternative for replacing a portion of proteins in the ruminant diet; however, the actual value of the hydrolyzed feather for ruminants must be determined in in vivo studies.

This experiment was designed to investigate the effect of feeding different levels of thyme (Zataria moltiflora) leaves powder (TLP) and virginiamycin antibiotic on growth performance, blood metabolites, carcass characteristics and meat quality of Japanese quails. The experiment was conducted in a completely randomized design with 6 treatments and 4 replicates of 20 birds each. The dietary treatments consisted of control diet (without any additives) and the control diet supplemented with virginiamycin (0.02 %) or TLP (0.5, 1, 2 or 2.5%). At the end of the experiment (35 d) one male quail from each replication was randomly selected for bleeding. Then the birds were killed to investigate carcass characteristics. During the entire study, supplementing the control diet with antibiotic and different levels of TLP had no significant effect on weight gain and feed intake. Supplementing the control diet with antibiotic and 2 or 2.5% TLP significantly decreased feed conversion ratio (P<0.05). The relative weight of the carcass was significantly higher in the birds fed antibiotic compared with the birds fed the control diet and the control diet supplemented with 0.5 and 1% TLP (P<0.05). Blood metabolites were not affected significantly by the dietary treatments. TBA value of the thigh muscle was significantly improved in birds fed different levels of TLP (P<0.05). In conclusion, TLP (especially at 2% level) can be used as a good alternative to replace with the antibiotic growth promoters for Japanese quails

In this experiment, 336 one-day-old boiler chicks (Ross strain) were allocated to 7 dietary treatments in a completely randomized design throughout the 42 d experimental period. Each dietary treatment consisted of 4 replicates with 12 chicks in each. The dietary treatments were: 1) basal diet, BD [control group, without Zataria multiflora extract (ZME)], 2 and 3) BD+0.5 and 1% of ZME for 42 days, 4and5) BD+ 0.5 and 1% of ZME in the two last week of rearing period, and 6and7) BD+ 0.5 and 1%of ZME in the last week of rearing period. Feed intake (FI), weight gain and feed conversion ratio (FCR) were recorded at the end of each growth phase. At day 42, two birds per replicate were slaughtered to investigate the effects of dietary treatments on carcass efficiency and carcass parts. On days 21 and 42, digesta samples from ileum of slaughtered chicks were taken for bacterial analyses. Adding ZME to the diets at the levels of 0.5 and 1%significantly (P<0.05) reduced FI (97.78 and 99.67 g) compared to the control group (101.06 g). ZME at the level of 1% for the entire period of experiment improved FCR (1.53 vs. 1.68) compared to the control group (P<0.05). Effect of ZME and its using times on the relative weights of carcass components were not significant (P>0.05). The use of 1% of the extract for 42 days resulted in a significant increase in the relative weight of the thymus (0.7 vs. 0.55%, P<0.05). ZME at the levels of 0.5 and 1% reduced E. coli (5.57 and 5.34 vs. 6.16) and increased Lactobacillus (6.67 and 6.78 vs. 6.22) populations during the first 21 days and the entire period of the experiment (P<0.05). According to the results of this study, dietary inclusion of ZME at 1 % for 42 days significantly improved feed conversion ratio and gut microbial populations in broiler chickens (P<0.05).

In this experiment the effects of different parts of Cichorium intybus L. on performance, egg quality traits and blood parameters of laying hens were evaluated. A total of 199 Hy-line (W36) laying hens (from 52 to 63 weeks of age) were allocated to the experimental units in a completely randomized design in 4 treatments with 4 replicates of 12 hens in each. The experimental groups included: 1) control group, 2) group with 3% aerial parts of Cichorium intybus L, 3) group with 3% root of Cichorium intybus L., 4) group with 3% whole parts of Cichorium intybus L. The results showed that use of Cichorium intybus L, had significant effects on performance, egg quality and blood cells parameters (P<0.05). The highest values of egg production (62.19%), egg mass (38.23%), feed intake (110.68 g), the best feed conversion ratio (2.89), the highest egg yolk color index (4.00), the highest Haugh unit (74.50), the lowest heterophile percentage (9.33%), the highest lymphocyte percentage (90.67%) and the lowest heterophile to laymphocyte ratio (0.104) were observed with using 3% of whole Cichorium intybus L. Using 3% whole Cichorium intybus L caused the eggshell thickness decrease to 0.33 mm. Experimental groups had no effects on blood biochemical parameters. As overall results, in laying hens using 3% whole Cichorium intybus L in contrast to control group and groups contained other parts of Cichorium intybus caused the performance, egg yolk color index, Haugh unit and blood cell immune improve.

This study was conducted to clarify the effects of in-Ovo injection of pyridoxine, methionine, and their combination on broiler breeder eggs hatchability, chick weight, and production attributes. On day 18 of incubation, 400 Ross 308 breeder fertile eggs were weighted and allocated to 5 treatments with 4 replicates of 20 eggs each, in a CRD design. The treatments included: negative control (no injection), positive control (injection of 0.1 ml of Sodium chloride), injection 0.5 ml of pyridoxine (B6), injection of 0.5 ml methionine (Met), injection of 0.5 ml pyridoxine and methionine (B6+Met). The solutions were injected into the amniotic fluid of eggs. Upon hatch, hatchling chicks counted, weighted and then transferred to farm and reared to 42 d of age. Feed intake, weight gain and feed efficiency ratio were recorded.The results of this study indicated that, hatchability, day-old chick weight and hatched chick body weight / Initial egg weightshowed no significant differences (P>0.05). No significant differences was obtained for feed intake, except at 0-3 weeks, while compared to PC, B6+ Met, showed significant differences (P<0.05). Conclusion was that, under the condition of present study, injection of vitamin pyridoxine, methionine and their combination had no significant effects on hatchability and day old chick, despite feed reduction in B6 and Met compared to PC, no significant differences were observed in weight gain and feed conversion ratio, probably due to better efficiency of feed in chicken hatched from treated eggs.

The objective of this experiment was to evaluate the effect of Bentonite as a natural adsorbent to ameliorate the adverse effects of aflatoxin B1 on growth performance and immune systems in broiler chicks. A total of 256 Ross 308 one-day-old broiler chicks were randomly divided into 4 treatments, with 4 replicate pens per treatment and 16 chicks per pen based on a completely randomized design. The following dietary treatments were applied: 1) Basal diet not containing AFB1or Bentonite (control), 2) Basal diet + 5 g/kg Bentonite, 3) Basal diet + 1 mg/kg AFB1, 4) Basal diet + 1 mg/kg AFB1 + 5 g/kg Bentonite. The broiler chicks were fed the experimental treatments from 1 to 35 days of age. Performance parameters were recorded weekly. At d 28, two birds of each replicate were randomly selected and injected with sheep red blood cell antigens. At the end of experiment, four birds in each treatment group were sacrificed for measurement of relative weight of various components of carcasses and lymphatic organ weights in broiler chickens. The results indicated that aflatoxin B1 decreased significantly the BW gain, feed intake and impaired feed conversion ratio in starter and grower periods compared to the control diet (P< 0.05). The addition of Bentonite to diet ameliorated significantly the negative effects of 1 mg/kg of AFB1 on feed intake and weight gain (P< 0.05) but no significant effect on feed conversion rate. Aflatoxin B1 significantly decreased antibody response to the SRBC antigen and bursa of Fabricius relative weight. The addition of bentonite in the contaminated diet not significantly alleviated the inhibitory effect of aflatoxin B1 on immunity parameters. Feeding AFB1 alone caused significant increases in the relative weights of livers and preventiculos compared with the control (P< 0.05). It is concluded that addition of Iranian Bentonite used in the present study could alleviate the adverse effects of aflatoxin B1 in growing broiler diets and this product can be used as a suitable toxic adsorbent in poultry nutrition up to 5 gr/kg.

Economic values for production, reproduction, growth and functional traits in crossbred and Holstein cow production systems in Guilan province were estimated using a total of 16 herds consisting in average 12 and 30 cow, respectively, and a bio-economic model. Economic values were calculated in two production systems for 12 traits, classifying into four categories of production, reproduction, growth and survival. Economic value of each trait was estimated as the amount of change in the annual profit of production system by one unit increase in mean of the considered trait while the means of other traits were hold unchanged. Economic values, relative to the economic value for productive lifetime, for milk yield, fat yield, protein yield, age at first calving, calving interval, pre-weaning daily gain, post-weaning daily gain, birth weight, mature live weight, pre-weaning survival rate and post-weaning survival rate were, respectively 3.7, 0.003, -0.01, -7.26, -32.6, -4.35, -23.4, -46.55, -0.78, 4.26 and 68.68 for crossbred production system, and were 0.92, 0.001, -0.002, -6.72, -20.64, -1.10, -6.10, -11.82, 0.21, 30.49 and 25.29, for Holstein production system. The results showed, although the importance of some traits in two production systems were different, which was a reflection of overall difference in two production systems, the breeding objective of two population should be very close together, considering high similarity of economic values of traits

The objective of this study was to detect genetic structure of Iranian indigenous cattle using dense single nucleotide polymorphism (SNP) markers. In total, 90 cattle individuals comprising Sarabi (n=20), Kurdi (n=10), Mazandarani (n=10), Taleshi (n=10), Sistani (n=10), Kermani (n=10), Najdi (n=10) and Fars (n=10) breeds were sampled. Genotyping was performed using Illumina High-density Bovine BeadChip designed to genotype 777,962 SNPs. After removing sites being in linkage disequilibrium (pairwise sites having r2 greater than 0.2), 64333 SNPs remained for further analyses. STRUCTURE software was used to detect genetic structure of native cattle in this data set. Number of assumed populations per run was selected between two to eight. Results of this study indicated that in the first level of clustering (K=2), Sarabi (97.6%) and Kurdi (94.3%) populations shared the same cluster and Sistani (92%) had another separate cluster while other breeds were admixed from these two clusters. Kurdi population appeared as an independent cluster at K=3. Most suitable number of genetic groups in data set was explained by three clusters (K=3). Genetic differentiation of Iranian indigenous cattle was well detected in this study. Also, similarities of geographical distribution and production characteristics were in good accordance with founded genetic relationships in this study.