مجله تولیدات دامی
سال بیست و دوم شماره 2 (تابستان 1399)

The aim of the present study was to investigate the codon usage pattern and their relationship with gene expression for genes with different expression between pure and crossbreed Sistani and Montbeliared breed. In this study, the results of differential gene expression analysis using RNA-Seq technology between pure and crossbreed Sistani and Montbeliared breed (two pure and two its crossbreed) were used. For this purpose, after determining the ORF regions for these genes, CodonW software was used to estimate codon usage pattern indices including CAI, ENC, GC and GC3s. Results showed that there was a significant correlation between total GC and GC3s (0.74). There was also a significant correlation between ENC and GC and GC3s (0.65, 0.77), indicating the role of mutation in codon formation. Based on the results of this study, the factors such as nucleotide composition (GC content), mutation, and gene expression level played important roles in codon formation in the genes studied in this study. This study is the first comparison between pure and crossbreed Sistani and Monti-billiard samples, which helps to better understand the evolutionary mechanisms of codon usage pattern formation and its association with gene expression.

The aim of this study was the investigation of gene expression profile in Shal sheep ovarian tissue using RNA sequencing data. For this purpose, the ovaries of five Shal sheep were isolated after estrous synchronization and their RNA was sequenced using Illumina Hiseq 4000 technology. On average, the data obtained from the sequencing consisted of 26638311 read pairs with 81.08 unique mapping rate. The results of bioinformatic analyzes revealed the expression of 21085 genes in Shal sheep ovarian tissue, of which 15078 genes had expression mean above 10. Gene ontology analysis revealed the significant enrichment of 162 GO terms including 41 biological processes, 46 molecular functions and 75 cellular components. KEGG pathway analysis also identified 149 significant pathways (P <0.05), most important of which were estrogen signaling pathway, TGF-beta signaling pathway and oocyte meiosis. Investigating the expression of major genes for twining and reproduction, showed a high expression for INHA, INHBA and BMPR1B, so that INHA, an important paracrine factor in ovarian follicles, was one of the 10 genes with the highest expression. Also, FSHR, ESR1 and ESR2 showed medium expression and GDF9, BMP15 and PRLR showed low expression in the samples. For the first time, in this study the ovarian tissue transcriptome of Shal ewes was comprehensively studied using RNA-Seq technology and this study can provide a useful genetic basis for a better understanding of the genes and processes involved in the Shal sheep reproduction.

To study the effects of feeding rumen-protected ascorbic acid and salicylic acid on performance of dairy cows under heat stress conditions, forty four lactating dairy cows in early lactation were allocated in a completely randomized design with 4 treatments and 11 animals in each treatment for 30 days. Experimental treatments were: 1) control (diet without coated ascorbic acid and salicylic acid), 2) diet contained 30 g/d coated ascorbic acid, 3) diet contained 10 g/d coated salicylic acid and 4) diet contained 30 g/d coated ascorbic acid + 10 g/d coated salicylic acid. Cows were fed with salicylic acid supplement had a higher daily milk yield (51.47 kg/day) compared to other experimental groups (P<0.05). Feeding of coated ascorbic acid increased milk fat percent, glucose, BHBA, NEFA concentration and decreased somatic cell count compared to other treatments (P<0.05). Total milk's solids, energy and fat corrected milk and milk urea nitrogen were increased in coated ascorbic acid group compared to control (P<0.05). Blood urea concentration in coated ascorbic acid and salicylic acid group were less than control group (P<0.05). The results showed that feeding coated ascorbic acid and salicylic acid could improve performance of Holstein dairy cows in early lactating phase under heat stress conditions.

In order to evaluate the effect of cobalt on performance, some blood and ruminal fermentation parameters an experiment was performed using 24 three to four months old male lambs, with an average weight of 30 kg in a completely randomized design with four treatments and six replications. The experimental treatments consisted of: basic diet (control; containing 0.083 mg cobalt /kg DM); basal diet + 0.2 mg Cobalt /kg DM, basal diet + 0.4 mg cobalt /kg DM, and basal diet + 0.6 mg / kg of cobalt. In order to determine blood parameters on days 0, 45, 70, blood samples were collected from jugular vein and ruminal fluid through the esophagus were taken to evaluate ruminal fermentation parameters. Cobalt supplement had no significant effect on daily gain, dry matter intake, feed conversion ratio, serum B12, cholesterol, triglyceride and albumin and also alkaline phosphatase and alanine transaminase. Ruminal ammonia concentration increased at the level of 0.2 and 0.4 (P<0.05), but concentration of volatile fatty acids, rumen pH and protozoan population did not influence. The concentrations of cobalt, iron, zinc and copper minerals were not affected by treatments. The results of the present study showed that adding cobalt supplementation to the diet up to the level of 0.6, despite limited changes in some blood and ruminal parameters did not have a significant effect on the performance of lambs; it seems that the cobalt in the basic diet could be sufficient for the cobalt requirements of growing Sanjabi lambs.

The effect of flaxseed and soybean seed on the performance of Maque ewes during the transition period in a completely randomized design with four treatments and four replications and one ewe per replicate using 16 pregnant Maque ewes with average age of three years and weight (65 ± 2.4 kg) was investigated. Experimental treatments included: control diet (basal diet), diet containing 10% flaxseed; Contained 10% soybean seed and 50:50 dietary ratio of flaxseed and soybean seed. Experimental results showed no effect of treatments on feed intake of ewes before and after calving. Milk production of ewes fed flaxseed diets was higher (p<0.05) and ewes fed 50:50 diets containing flaxseed and soybean had the highest total serum protein concentration (p<0.05). Other serum metabolites were unaffected by experimental treatments. Rumen fluid valeric acid concentration was the highest in ewes fed diets containing soybean seed and soybean-flax seed mixture (p<0.05). Results of this experiment showed that using flaxseed and soybean seed up to 10% diet without adverse effect on feed intake improved ewes performance during the transition period and increased production in the early lactation period.

The aim of this study was to investigate the effect of bentonite, kaolin and activated carbon on the absorption of Cu, Fe and Mn by in vitro and in vivo methods in Baluchi lambs. In vitro experiment, the binders effect on the minerals absorption was investigated in a completely randomized design with factor arrangement with standard solutions of Cu, Fe and Mn with concentrations of 7, 20 and 30 mg/l, respectively, four levels of binders (no binders, 10, 20 and 40 g/l) and three pHs 5.5, 6.4 and 7.5 and incubation for 60 min. In vivo experiment, bentonite, kaolin and activated carbon including 0, 10 and 20 g/kg DM were added to diet of 36 fattening lambs (6-7 months) for 90d in a completely randomized design. Feed intake, weight gain and blood and wool concentration of Cu, Fe and Mn were measured on 0, 45 and 90d. In vitro experiment, activated carbon had the highest and kaolin had the lowest mineral absorption by increasing binders levels and pH (P<0.05). In vivo experiment, the effect of treatments on feed intake, body weight, weight gain, feed conversion ratio and blood and wool concentration of Fe were not significant.The concentration of Cu and Mn in the blood and wool in lambs fed with binder were lower than control treatment (P<0.05). In general, the use of binders, especially activated carbon at low concentrations, causes less absorption of minerals. In vitro methods can be used to select binders instead of animal experiments.

The objective of this study was to evaluate the effects of feed bunk space and forage particle size on feed intake and nutrient digestibility in growing Holstein female calves. Fourty Holstein female calves with an average age of 8-12 months (295.6 ± 32.8 kg) were used in a 2×2 factorial change-over design (with four treatments, four periods and four stalls), in which 10 calves were allocated to each stall. The current experiment lasted 4 months as one month allocated to each period. The experimental treatments were included: 1) 24 cm of feed bunk space and average forage particle size of 4.6 mm (24/fine); 2) 24 cm of feed bunk space and average forage particle size of 7.1 mm (24/coarse); 3) 48 cm of feed bunk space and average forage particle size of 4.6 mm (48/fine); 4) 48 cm of feed bunk space and average forage particle size of 7.1 mm (48/coarse). The results of this study showed that the apparent digestibilities of DM, CP and NDF for the 48/Coarse treatment was the highest, the treatment of 24/Coarse had an intermediate state, and for the treatment of 48/fine and 24/fine were the lowest. Also, apparent digestibilities of DM, CP and NDF were higher for treatments including coarse forage particles than treatments with fine forage particle size. Finally, it seems that feeding growing Holstein heifers with diets containing coarse forage particle size could result in better nutrient digestibility.

The effect of feeding L-carnitine during pre-puberty on the quality parameters of fresh and frozen-thawed semen by using 12 Ross broiler breeder males (12 weeks) for 18 weeks, in a completely randomized design with three treatments (0, 250 and 500 mg / kg of L-carnitine in the diet) and four replications was performed. From the age of 26 to 29 weeks, semen collection was performed using abdominal massage. The sperms taken each time after dilution (with Beltsville diluent) were divided into two parts, one section was frozen and the other part was immediately examined. Motility (total and forward), viability, morphology, membrane functionality and lipid peroxidation parameters were evaluated. In fresh sperm, the correlation between L-carnitine and abnormalities was negative linear, and with viability was positive linear (P<0.05). Quadratic analysis was significant in forward Motility and MDA concentration (P<0.05). Birds that use diets containing L-carnitine, In terms of forward motility, viability, morphology and MDA concentrations in fresh sperm, And these traits, with the total motility and integrity of the plasma membrane of frozen sperm, were higher in comparison to the control group (P<0.05). Also, in the sperm after frozen-thawed, the correlation between L-carnitine and Motility (total and forward), viability and membrane integrity were positive linear (P<0.05), and the correlation between L-carnitine and MDA concentration was negative linear (P<0.05). The correlation between L-carnitine and Motility (total and forward), membrane integrity and MDA concentration were quadratic (P<0.05). According to the results, Dietary L-carnitine supplementation in pre-puberty improves the qualitative traits of sperm before and after freezing in the breeder broilers.

The goal of this study was to determine regression equations to predict metabolizable energy of wheat samples given their chemical compositions using meta-analytical approach. A database compromising chemical compositions and apparent metabolizable energy corrected  for the nitrogen (AMEn) of 111 published sources of wheat strains was used. Sample information contains crude protein (CP), ether extract (EE), crude fiber (CF), ash and AMEn. Average values for AMEn was calculated as 2917.46 (kcal/kg), while for the CP, EE, CF, ash was calculated as 12.53, 2.12, 1.61and 1.56 (% dry matter), respectively. Meta-regression equations for predicting AMEn wheat based on chemical composition were developed and evaluated by means of provided database. Best equation obtained as: AMEn (kcal/kg)=1648+45.8 %CP+175.8 %EE+ 185.4 %CF. This equation can be used for predicting energy of wheat variates in feed-factories and poultry farms.

In this experiment, the effects of Hyssopus officinalis powder, Virginiamycine antibiotic and Aspirine on performance, immunity and ascites indexes of broiler chickens which subjected to cold stress were studied. In a completely randomized design, 500 male Ross-308 broiler chickens were allocated to 5 treatments with 5 replicates and 20 birds in each. The dietary treatments consisted of: 1) basal diet with no additive (control), 2 and 3) basal diet plus 300 g/tone Virginiamycine or Aspirine respectively and 4 and 5) basal diet containing 0.5 or 1 percent Hyssopus officinalis powder, respectively. As compared to control group, inclusion of 0.5 or 1 percent Hyssopus officinalis powder significantly increased feed intake, body weight gain and EPEF and improved FCR of broiler chickens. Feeding broiler chickens with diet containing Hyssopus officinalis powder or Aspirine decreased ascitic mortality, heamatocrite percentage and ascites indexe (relative weight of right ventricle to total weight of ventricles) at 42d of age. Dietary treatmens had no effect on antibody titer against New-Castle and influenza virus and relative weight of tymous, spleen and Burce of Fabrecoius of broiler chickens at 42d of age. Regards to the results of present experiment, addition of Hyssopus officinalis powder or Aspirine decreased ascytic incidence and its related mortality in broiler chickens under cold condition.

This experiment was conducted to evaluate the effect of Thyme essential oil on performance and some physiological parameters of broiler chickens fed diets containing wheat in a completely randomized design with a 2×3 factorial arrangement using 264 broilers (Ross 308) in ground floor. Treatments consisted of 2 levels of wheat (0 and 50% of the diet) and 3 levels of essential oil of Thyme (0, 200 and 400 ppm). Performance parameters were recorded weekly. Determination of micro-flora, carcass characteristics, and blood parameters were done on day 42. The results showed that adding the Thyme essential oil to the diet containing 50% wheat increased feed intake at the all period of experiment. Body weight gain was increased significantly in the birds that consumed 50% wheat with 400 ppm essence compared to the birds consumed the diet without wheat or without essence at the starter period. The birds consumed the diet without wheat with essence had lower blood concentration of LDL. Although, adding essence at the level of 400 ppm to the diet without wheat increased significantly blood concentration of HDL. The diet contained 50% wheat without essence had higher abdominal fat compared to the diet with 200 and 400 ppm of essence without wheat and also the diet contained 50% wheat with 400 ppm essence. Overall, the use of Thyme essence at the level of 400 ppm in wheat-based diet is recommended for increasing feed intake and improving some physiological parameters of broiler chickens.

In order to evaluate the effect of bi-partial toxin binder "Biotox" on health status and productive parameters, sixteen Holstein cows were classified into two groups, biotox (supplemented with Biotox) and control (without Biotox). Feed intake, dry matter intake, body weight, body condition score, rectal temperature, respiratory rate, heartbeat, milk yield and compounds and blood parameters were measured and recorded. In control group feed intake, dry matter intake, body weight and body condition score were significantly decreased from forth to seventh week, while rectal temperature, respiratory rate and heartbeat were increased (P≤0.05) during the entire period. The milk yieldincreased non-significantly during the entire period and significantly (P≤0.05) from fifth to seventh week in biotox group. Content of milk protein (P≤0.05) in biotox group and percent of fat (P≤0.05), percent of lactose (P≤0.05), somatic cell count and concentration of aflatoxin M1 (P≤0.05) in control group were increased. Milk solids content in the biotox group increased non-significantly during the entire period and significantly in the fifth to seventh week (P≤0.05). There were no significant difference in concentration of plasma glucose, total protein and creatinine during the entire period, but in control group, creatinine level increased during the late period. Plasma aspartate transaminase (P≤0.05) and alanine aminotransferase (P≤0.05) were higher in the control group. Overall, biotox use improves the health, milk production, and production parameters of lactating cows when the feed is exposed to multiple mycotoxin contamination.