مجله تولیدات دامی
سال چهاردهم شماره 2 (پاییز و زمستان 1391)

The effects of phytase and glycosidase supplementation to diets containing rice bran on broiler performance were investigated by using 200 day old (308 Ross) broiler chicks in a completely randomized design with five treatments and four replicates. The five dietary treatments were as: corn-soybean meal based diet; diet containing rice bran; diet containing rice bran supplemented with Natafous; diet containing rice bran supplemented with Safizyme، and diet containing rice bran supplemented with Natafous and Safizyme. The dietary levels of rice bran were 15، 20 and 25 percent for the starting، growing and finishing diets، respectively. Birds fed on rice bran + enzyme added diets consumed less feed (P< 0. 05) than those fed on unsupplemented rice bran contained diets. The enzyme addition to rice bran containing diets improved the villi length and weight gain of birds at different rearing periods (P< 0. 05). In conclusion، results showed that the Natafous or Safizyme supplementation in diets could improve the performance of broiler chicks when rice bran was used at a level of 15، 20 and 25 percent in starter، grower and finisher diets، respectively.

The effect of Aspergillus niger waste، a by product of citric acid extraction (yeast waste) on in vitro digestibility of alfalfa hay at different times of incubation (24 and 48h) and fattening performance of male lambs studies. Different levels (five، 10، 15 and 20 percent) of yeast waste were added to alfalfa hay and subjected to the in vitro digestibility trial. In fattening trial، twenty Sanjabi lambs (20. 8 kg initial BW، three months of age) divided into two groups in a CRD design. The use of yeast waste of different levels، increased Dry matter (DM) and organic matter (OM) digestibility of alfalfa hay at initial 24 h of incubation (P< 0. 05) but the difference in digestibility at the last 48 h of incubation was not significant. Average daily gain، FCR and DM intake and carcass parts between treatments were not significant.

The current study was designed to estimate the frequency of IGF-I gene 1 polymorphism and investigate if their polymorphisms have association with biometric traits in Moghani sheep by PCR-SSCP method. For this purpose، a number of 100 sheep were randomly chosen from Moghani sheep Jafarabad، Moghan breeding station that located in Ardabil state and blood samples were collected from the left jugular vein using vacuum tubes. DNA were extracted from blood samples that using the salting-out procedure and amplified a fragment of 279 bp in size from IGF-I gene exon 1. The Single-Strand Conformation Polymorphism (SSCP) method was used for genotyping. Electrophoresis of PCR products were done on acrylamide gel that observed the polymorphic in this region. Based on SSCP patterns، three genotypes BC، BD and BB obtained with frequencies of 65، 26 and nine percent، respectively. The genotypes in this locus deviated from HWE. The traits data were analyzed using the SAS program. The BB genotype were associated with Leg girth but no association of the other genotypes with the withers height، back height، body length، breast girth other examined biometric traits were found (P< 0. 05).

The chemical composition and digestibility characteristics of bread waste were determined and the effect of it on feedlot performance studied on 100 Sarabi steers. Dry matter، organic matter، ether extract، crude protein and NDF digestibility of bread waste were 87. 2، 84. 5، 76. 7، 62. 2 and 82. 9 percent، respectively. Degradability parameters of bread waste including a، b and c compartments were 19. 5 and 74. 6 percent and 0. 5 percent/hour، respectively. Metabolizable energy (ME)، organic matter digestibility (OMD) and short chain fatty acid (SCFA) amount calculated using gas production technique and were 9. 7 MJ/kg، 51. 3 percent and 1. 18 ml/200 mg DM of bread waste respectively. The difference of feed conversion ratio and dressing percentage of carcass of the steers were significant (P< 0. 01). The ration containing 30 percent of bread waste had the best feed conversion ratio (P< 0. 01).

Expression of the Growth Hormone receptor (GHR) gene which is located on the sixteenth chromosome of sheep and its binding with GH is essential for growth and fat metabolism. In this study، blood samples were collected from the jugular vein from 88 sheep of Kermani breed. DNA was extracted from blood sample using the modified salting out method for amplification of 155 bp fragment containing a part of exon 10 of GHR genes. Single Strand Conformation Polymorphism (SSCP) was used for genotyping. The vertical electrophoresis of PCR products was performed on 12 percent polyacrylamide gel، at 300 V، for 17 h at 4 ˚C. The silver-staining of gels، resulted identification of six genotypic patterns: 1، 2، 3، 4، 5 and 6 with frequencies of 9. 09، 4. 54، 13. 63، 9. 09، 35. 22 and 28. 40 percent، respectively. Analysis of variance was performed using SAS software and association of different patterns was not significant with growth traits.

The fresh Pomegranate seed pulp (PSP، containing 47. 5 percent dry matter) was ensiled within plastic buckets (three kg weight) for 70 days and then chemical composition، phenolic compounds concentration and DM ruminal degradability parameters and ruminal، post-ruminal and total tract digestibility of DM were measured. The results showed that ensiling significantly decreased total phenolic compounds، total tannins، gallic acid، tannic acid، penicillin and punicalagin A content of PSP but condensed tannins، ellagic acid and punicalagin B content were not affected by preservation method. DM ruminal degradability parameters، rapidly and slowly potentially degradable fractions and effective degradability on passage rate of 0. 02، 0. 05 and 0. 08 per h were not significantly affected by treatments but ensiling increased the ruminal and total tract digestibility of DM and decreased the DM degradability rate constant and DM post-ruminal digestibility. Based on the results of this study ensiling could improve the nutritional value of PSP.