فصلنامه پژوهشهای تولیدات دامی
پیاپی 41 (پاییز 1402)

The banning of equine chorionic gonadotropin (eCG) application for estrus synchronization by ethics committee for protection of animal rights, has caused the development of alternative protocols. One of the alternative protocols based on a short-term progesterone treatment and single dose injection of GnRH after termination of progesterone treatment. Half-life of GnRH is very short and it is rapidly degraded by peptidases and cleared by glomerular filtration. One of the suggested approaches is to prolong the action of GnRH and protect it against peptidases. Propyleneglycol and aluminum-hydroxide-gel nanoparticles absorb protein compounds and reduce their release rate. Therefore, the aim of this study was to compare the effect of GnRH dissolved in aluminum-hydroxide-gel nanoparticles or propyleneglycol on estrus synchronization, ovulation induction and fertility outcome after artificial insemination in Mehraban ewes.

In the breeding season total of 67 non-pregnant ewes (with weight average of 57.72±5.33 Kg, aged 2-4 years and BCS 3-3.5) were selected and treated by progesterone impregnated sponge for a 7 days period. All of ewes were received 5 mg PGF2α (Dynoprost) with sponge removal and were divided into four treatments, randomly. Each ewe in T1 was received 400 IU eCG (i.m) immediately after removing the sponge. Ewes in T2 and T3 were received 50 µg of GnRH (s.c) dissolved in aluminum-hydroxide-gel and propyleneglycol 36 h after removing the sponge, respectively. Each ewe in T4 was received 50 µg of GnRH (i.m) dissolved in distilled water 56 h after removing the sponge. All of the ewes were inseminated laparoscopically at 56 h after removing the sponge. During insemination, ewes with estrus signs were determined and uterine status were scored by uterine tone. Blood plasma estradiol (E2) concentration was evaluated at 36 and 56 after removing the sponge. Ovulation rate and plasma progesterone (P4) concentration was measured 11 days after insemination. Conception rate, fecundity and prolificacy were calculated after parturition.

Percentage of estrus, estrus quality, occurrence of ovulation, ovulation rate, and plasma P4 concentration were similar among groups. Plasma E2 concentration in T1 was significantly higher 36 after removing the sponge (P<0.05) but, it was similar among groups at 56 after removing the sponge. Conception rate with regards to ovulated ewes was higher in T3 compared to T2 (P<0.05). Conception rate with regards to inseminated ewes, lambing rate and fecundity were higher in T3 compared to other groups although these differences were not statistically significant.

Slowing and extending the release of GnRH by dissolving in propyleneglycol or aluminum-hydroxide-gel nanoparticles induces estrus and ovulation similar to eCG. However, propyleneglycol has better efficiency in synchronizing the animals for artificial insemination.

Vermi humus refers to the final product of organic material decomposition by earthworms, which contains compounds such as humic substances (humic acids, fulvic acid, and humin). The present study aimed to investigate the effect of vermi_humus supplement on performance, quantitative and qualitative characteristics of eggs, serum biochemical parameters, and microbial population in the small intestine of laying quails.

The experiment was conducted for eight weeks using 160 laying quails in a completely randomized design with eight treatments, four replications, and five female quails per cage. The experimental groups consisted of different levels of vermi humus (0, 0.25, 0.50, 0.75, 1.5, and 2%) and virginiamycin antibiotic (7.0%). During the experiment, all eggs in each cage were collected daily, counted, weighed, and recorded. Feed consumption for each cage was calculated on a weekly basis throughout the entire experimental period. The feed conversion ratio was calculated by dividing the daily feed intake by the average daily egg mass of each quail. Some qualitative egg traits were measured, including shell thickness, shell percentage, shell strength, yolk percentage, albumen height, IQU unit, and yolk oxidation. At the end of the experiment, five birds from each treatment group were randomly selected and slaughtered after weighing using the neck bone displacement method, and one gram of ileum contents was taken for microbiological population analysis.

According to the results, different levels of vermi humus did not have any effect on the performance of egg-laying quails. The effect of vermi humus supplement on the percentage of shell thickness, shell percentage, shell strength, and yolk percentage was not statistically significant. By increasing the level of vermi humus supplement, the height of the albumen and IQU unit decreased. Different levels of vermi humus supplements had no effect on the amount of calcium, total protein, cholesterol, glucose, and albumin in blood serum. The results indicated that the effect of different levels of vermi humus supplement on the microbial population of quail's small intestine was significant. With increasing levels of vermi-humus supplement, the degree of oxidation of fresh and stored quail egg yolks changed linearly and in the second degree.

Conclusion :

In general, the results showed that the consumption of vermi humus as a natural food substance improved the performance and egg weight, and enhanced the quality characteristics of Japanese quail eggs at levels of 0.5% and 1.5%. Furthermore, the consumption of vermi humus at a level of 0.5% led to an improvement in the antioxidant status of the yolk and a decrease in the population of undesirable microorganisms in the small intestine of quails.

Sunflower is primarily an oil crop but the plant itself and its crop residues are used as animal feed. This study was to investigate the replacing of sunflower head wastes with wheat straw.

This research was conducted in the form of two experiments. In the first experiment, in order to determine the degradability of dry matter and neutral detergent fibre (NDF) of sunflower heads, three rams of Dalagh breed with rumen fistula were used and in the second experiment, 8 male Afshari lambs with an average live weight of 30±4.5 kg were tested in the change-over design with zero, 7, 14 and 21% in the diet. In this research, feed intake, digestibility, blood parameters, and chewing activity were measured.

The results showed that degradation percentage of DM and NDF was 20.41 and 25.59, respectively at time zero, and at 96 hour later it reached to the highest level of degradation equal to 73.47% and 46.40%, respectively. In this study dry matter intake (DM) was influenced by the experimental treatments (P=0.003). Replacing wheat straw with sunflower head improved digestibility of dry matter, organic matter and neutral detergent fiber but not significant. The feed conversion rate was improved with sunflower head treatments but not significant. Lambs that were used sunflower head residues, had more weight gain compared to the control group. None of the treatments containing sunflower head residues had a significant effect on blood parameters. Eating and chewing activity and whole chewing activity were influenced by the experimental treatments (p=0.01). The highest rumination activity per kg neutral detergent fiber, was related to the control treatment.

In general, replacing wheat straw with sunflower head residues up to 21 percent in the diet, can be done successfully. In general, according to daily weight gain, sunflower head residues can be replaced up to 21% levels in the diet by wheat straw.

The latest major advances in transcriptomics technologies, especially next-generation sequencing technologies and advanced bioinformatics tools, allows deeper exploration of messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs), including miRNAs. These technologies have offered important chance for a deeper study of miRNA association in farm animal diseases, as well as livestock productivity and welfare. Since the discovery of lin‑4 and let‑7, many microRNAs have been identified in farm animal species and deposited in miRNA databases. miRNA can be used as biomarkers in the context of farm animal disease diagnostics, prediction, and therapeutic purposes, for the management of livestock diseases. By the sequencing of Bos Taurus (cattle) genome, we have an opportunity to discover novel miRNAs in this species. However, the experimental determination of miRNA sequence and structure is both expensive and time-consuming, therefore, computational and machine learning-based approaches have been adopted to predict novel microRNAs in the Bos Taurus (cattle) genome.

Finding an accurate method for Identification of miRNA molecules can help for understanding of regulatory processes. Currently, computational methods based on learning algorithms have been extensively applied for miRNA prediction.Inspired by the work of predecessors, we proposed an improved computational model based on random forest (RF) for identifying real miRNA precursor sequences (pre-miRNAs). First, the occurrence frequencies of the dinucleotide of pre-miRNAs genes, and the percentage of G+C content were calculated. The observed dinucleotide composition was calculated as the structural features of the sequence composition for each miRNA gene. A total of cattle (Bos Taurus) dinucleotide compositions with their genomic G+C contents for 1064 genes encoding miRNA and non-miRNA sequences were calculated. In the next step two classification models based on machine learning approach were trained to identify real and pseudo bovine pre-miRNAs. One set of 17 optimized features related to sequence structures were used to train the models. These models were trained and validated with 10-fold cross validation method.

Our goal was to investigate the predictive performance of RNA features in distinguishing pre-miRNAs from pseudo hairpins. Our model achieved 99% precision, and 97.9% MCC using Bos Taurus datasets.

Computational methods of Artificial intelligence can detect novel potential miRNAs in the bovine genome, some of which to have previously undetected in this genome. As a result, it seems necessary to use computational methods to identify these regulatory RNAs in livestock for breeding purposes. Our discoveries support that dinucleotide features will be beneficial to achieve the highest accuracies for miRNA sequences prediction.

Animal nutritionists are looking for alternative compounds with the ability to improve the fermentation process. Probiotics and medicinal plants can be mentioned among these alternative compounds. Yarrow and ginger can be mentioned among medicinal plants that have antimicrobial properties. The aim of this study was to investigate the effects of yarrow and ginger powder on the digestibility and gas production of sainfoin and alfalfa hay in laboratory conditions.

For this purpose, the in vitro digestibility of sainfoin and alfalfa hay and a mixture of 50% alfalfa and 50% sainfoin were measured due to the use of yarrow and ginger powder by Tilley and Terry's modified Holden method. So that different levels of yarrow and ginger powder at three levels of zero, 1.5 and 3% were added to 100 ml syringes containing alfalfa, sainfoin, and a mixture of alfalfa and sainfoin, and the amount of gas produced by incubating the syringes at times 2, 4, 6, 8, 12, 24, 48, 72 and 96 hours of measurement and the resulting data were analyzed in a completely randomized design.

The results showed that the addition of 3% of ginger and Yarrow powder in sainfoin hay increased the digestibility of dry matter from 55.71 to 68.76 and 74.65% (P=0.0458), the digestibility of organic matter in dry matter from 52.62 to 64.95 and 62.09 percent (P=0.0468) and metabolizable energy increased from 8.42 to 10.39 and 9.93 MJ kg-1 DM (P=0.0489) by Holden's method, respectively. While the use of ginger and yarrow powder did not have a significant effect on the digestibility of organic matter, the digestibility of organic matter in dry matter and metabolizable energy of alfalfa and alfalfa- sainfoin mixture. The results related to the digestibility according to the McNiven method showed that the addition of 1.5 and 3% of yarrow and ginger powder in sainfoin and alfalfa hay could reduce the amount of gas production at times 3, 6, 12, 24, 48, 72, 96 and 120 hours of incubation. However, the addition of yarrow and ginger powder to alfalfa- sainfoin mixture did not have a significant effect on the amount of gas produced. The results of the gas test method showed that the addition of 1.5% and 3% of yarrow and ginger in sainfoin and alfalfa hay reduced the digestibility of organic matter, total short chain fatty acids and metabolizable energy compared to the control group. Among these, 3% of ginger has the most significant reducing effect on the digestibility of organic matter from 67.80 to 50.14 and 45.99% (P=0.0092), total short chain fatty acids from 1.77 to 0.76 and 0.66 milli moles (p=0.0183) and metabolizable energy from 9.88 to 7.47 and 6.79 MJ kg-1 DM (P=0.0167) respectively in sainfoin hay. Also, this similar decreasing trend continued in alfalfa hay for the nutritional parameters of the gas test. A mixture of alfalfa and sainfoin was not affected by the addition of different levels of yarrow and ginger.

It is concluded that the addition of 1.5 and 3% levels of yarrow and ginger powder in sainfoin and alfalfa hay could not improve the amount of gas production.

In recent decades, with the ban on the use of antibiotics in the poultry industry, the use of new alternatives such as probiotics and prebiotics have increased. Some of these alternatives can improve the growth and health of birds by creating optimal changes in the microbial population of the digestive tract. Therefore, the present experiment was conducted to investigate the effect of kappa-carrageenan polysacharid and primalac probiotic on the growth response and health of broilers.

240 one-day-old broilers of Ross 308 strain in a completely randomized design with 2× 2 factorial arrangement, including two levels of probiotic additive (zero and 0.1 % of food ration) and two levels of kappa-carrageenan additive (zero and 0.1 % of food ration) distributed in 24 cages (six replicates each containing ten birds) and reared on floor system for 24 days.

The growth performance of birds was not affected by the interaction of probiotics and kappa-carrageenan in the diet. However, the use of kappa-carrageenan in diets significantly increased the body weight gain of birds during 1 to 10 days of age. Feed intake of the birds was not affected by the experimental treatments and dietar levels of probiotic and kappa-carrageenan, but the feed conversion ratio was improved by adding 0.1% of probiotic in the diet at day 24 (P< 0.05). The relative weight of thigh in birds that received kappa-carrageenan was higher compared to the zero level of kappa-carrageenan in the diet (P< 0.05). Probiotic supplementation alone in the diet increased the relative weight of the liver of birds. Also, the relative weight of the liver was significantly lower in the birds that received diets containing kappa-carrageenan. In broilers fed with kappa-garakinan, the villus length increased in the duodenum and decreased the crypts depth in the ileum. The use of 0.1% of probiotics significantly increased the population of lactic acid bacteria in the ileum of birds. The population of lactic acid bacteria in the ileum of birds under 0.1% of probiotic increased significantly. Consumption of kappa-carrageenan and probiotics separately or mixed in the diet reduced the population of coliforms in the cecum (P< 0.05). Using a mixture of kappa-carrageenan and probiotic in the diet the activity of superoxide desmutase enzyme improved compared to the treatment containing kappa-carrageenan (P< 0.05).

The results of the present experiment showed that the use of probiotics and kappa-carrageenan in the diet of young broiler chickens can be effective in improving some parameters of the growth response during separate periods of rearing and optimally changing the microbial population of the digestive tract.

Genetic architecture of sheep reproduction is increasingly gaining scientific interest due to the major impact on sheep production systems. The present study aimed to conduct for identifying the loci associated with total number of progeny born and first lambing age in highly prolific Chios sheep using the 50K arrays.

In this research, phenotypic and genotypic data related to total number of lambs born and first lambing age in lifetime and first lambing age were obtained from 538 highly prolific sheep. The gene set analysis consists basically in three different steps: the assignment of SNPs to genes, the assignment of genes to functional categories and finally the association analysis between each functional category and the phenotype of interest. Genome wide association study was performed with reproductive traits using GEMMA software. Using the biomaRt2 R package the SNP were assigned to genes if they were within the genomic sequence of the gene or within a flanking region of 15 kb up- and downstream of the gene. Finally, a gene enrichment analysis was performed with the KOBAS platform from online bioinformatics databases for the assignment of the genes to functional categories, the GO, KEGG, DAVID and PANTHER databases were used.

In this research, 11 SNP markers on chromosomes 1, 2, 5, 7, 8, 10, 13, 15, 17, 22 and 23 were identified. Also, we identified different sets of candidate genes related to reproductive traits: QULP1, AURKA, TEX12, DLG1T, ACVR1, LCP2 and PPFIA2 in Chios sheep. Some of these genes identified in this research were consistent with previous studies. In the enrichment analysis of gene sets, 19 biological pathways related to reproduction traits were identified. Some of these pathways have important role in fertilization, ovulation rate, estrogen biosynthesis, conception rate, skeletal muscle development, early development of the fetus and puberty.

The results of this research can further reveal the role of genetic mechanisms affecting reproductive traits. Considering the conformation of previous genomic region and the new genomic regions identified in this study, the findings of this research can be used more confidently in breeding programs for important economic traits in sheep.

 Efficient forage preservation as silage requires minimizing losses during the ensiling, storage, and feed-out phases. The penetration of air into the silage is one of the important factors that stimulate aerobic bacteria, yeasts, and molds. This process severely impact silage quality and causes aerobic deterioration. Also, these conditions reduce the amount of dry matter and nutritional value of silage, and with the increase of pathogenic microorganisms and mycotoxins in silage, it will ultimately reduce the consumption of dry matter of silage in livestock. Polyethylene has been used for many years as a silage isolate and preservation. This study was to evaluate the chemical composition and microbial population of whole-crop barley silage preserved by different covers in laboratory conditions. 

Whole forage barley with dry matter of approximately 31% was harvested and cut into 30 to 50 mm long pieces. Then they were ensiled 1) in polyethylene laboratory tubes with screw lids with rubber rings, 2) in polyethylene bags and 3) in plastic bags, with an approximate weight of 10 kg in 4 repetitions, and kept in the closed environment of the laboratory for 60 days.

The results of the experiment showed the silages that were stored in polyethylene bags, compared to the silages that were ensiled in polyethylene tubes, the acidity index (3.79 vs. 3.53) and the yeast population (0.50 versus against 1.14 cfu/g of silage), were significantly increased (p=0.001), while in the silages that were ensiled in plastic bags, more changes occurred than in the silages that were ensiled in polyethylene tubes, and amount of dry matter (31.80% versus 31.24%; p=0.018), insoluble fibers in neutral detergent (61.89 percent of DM versus 59.8 percent of DM; p=0.014) and the mold population (1.95 versus 1.13 cfu/g of silage; p=0.046) also changed significantly. Aerobic stability in silages ensiled in polyethylene pipes was the highest (95 hours), while this index was significantly (P=0.001) less (62.5 hours) in silage covered with plastic bags than other silages. The recovery of dry matter after opening the ensiles and after 7 days of aerobic exposure also significantly (P=0.001) decreased rather than other silages (81.50 percent of DM versus 87.84 and 88.10 percent of DM).

According to the results of this experiment, the use of Polyethylene bags rather than plastic bags for ensiling small packages of forage can provide more favorable condition for the preservation of silage quality.

Recent studies have shown that consuming different sources of omega-3 fatty acids can play an important role in improving sperm quality in different species. The purpose of this study was to investigate the effects of using different sources of omega-3 fatty acids in the diet of Qezel ram, on volume and concentration of semen, fatty acid profile and characteristics of fresh and frozen-thawed sperm.

In this study, which was carried out for three months, 16 adult rams of Qezel breed were selected and randomly divided into 4 groups, and each group received one of the diets, all of which were isocaloric and isonitrogenous. The first group: diet without oil (control), the second group: diet with palm oil, the third group: diet with flax oil and the fourth group: diet with fish oil. After habituation of the rams, sperm collection was done weekly with an artificial vagina for 13 weeks. After evaluating the appearance and measuring the sperm volume, sperm concentration and motility in the fresh sperm samples, the sperm samples were frozen packing in straws. Physiological and biochemical characteristics of sperms after freezing-thawing, including sperm motility parameters (CASA), viability percentage, HOST and Hancock test and fatty acid profile were evaluated.

The results showed that the concentration, viability and integrity of sperm plasma membrane in the third and fourth groups were significantly increased compared to the control and second groups (P<0.01). Also, the abnormal morphology in the third and fourth groups was significantly reduced compared to the control and palm oil receiving groups (P<0.01). Motility parameters such as total motility, straight line velocity (VSL), curvilinear velocity (VCL) and average path velocity (VAP) in the third and fourth groups showed a significant increase compared to the control and the second group (P<0.05). Also, there was a significant increase in progressive motility in the fourth group compared to the first and second groups, and in the third group compared to the second group (P<0.05). Diet containing palm oil caused a significant increase in sperm palmitic acid in week 12 (P<0.05). Eicosapentaenoic and docosahexaenoic fatty acids increased significantly in the groups receiving fish oil and flax compared to the group receiving palm oil and control (without oil) (P<0.01). The rest of the measured fatty acids did not show any significant changes.

The results showed that adding fish and flax oil to the diet of Qezel rams for 3 months improves the quality of physico-chemical characteristics and improves the freezing ability of sperm.

The rapid development of sequencing technologies and bioinformatic tools has made it possible to sequence the entire genome of many species, providing a starting point for exploring the genome-wide genetic diversity of organisms. The buffalo is one of the most important domesticated animals in the world and has great economic value for humans, being used for milk, meat, leather and most importantly as labor. Khuzestani buffalo are among the most important buffalo in Iran. These animals are scattered in western and southwestern Iran. The largest population of this breed is in the Khuzestan province and they are fully adapted to the geographical features of this region

In this study, whole genome sequencing of the Khuzestan buffalo was performed in paired-end format using Illumina technology. Quality control of the readings obtained met all quality parameters and processing of the readings showed that all samples were of high quality. The BWA-MEM software package was then used to match the data to the reference genome. Genome variants were obtained with the Freebayes software. The final filtering of the variant file then took place. This filtering serves to increase the quality of the analysis and to sort out inferior variants.

The alignment percentage for all samples was over 97.44% and also the coverage in the sequenced samples ranged from x 4.3 to x 9.12, indicating reasonable quality of the reads. Also, in this study we identified 76,676,529 million variants fairly evenly distributed on the chromosomes of the Khuzestan buffalo. The highest and the lowest number of variants were observed on chromosome 1 chromosome 28, repectively. In this study, the total number of translocation and inversion mutations in the genome level was 298,193,017 and 135,694,466, respectively. In addition, the ratio of transitions to transversion was estimated at 2.1989 (Ts/Tv).

The presence of genetic diversity in the native population of Iranian buffalos are valuable parameters that can be studied to evaluate the genetic potential of economic traits in these populations in order to design suitable breeding programs.

Silver nanoparticles are one of the new achievements in nanotechnology, which are used in medicine, veterinary medicine, agriculture, and pharmaceuticals due to their antimicrobial activity. Silver nanoparticles can react with biological macromolecules and induce apoptosis by disrupting intracellular homeostasis. Hence, the aim of this study was to the effect of zeolite, organic acid and silver nanoparticles coated on zeolite on the expression of BAX and Bcl2 apoptosis genes in broiler chickens.

The number of 450 one-day- old broiler chicks (Cobb 500) were used in five treatments and six repetitions with 15 chicks per replicate in the form of a completely random design. Experimental diets were: control or basal diet (1), a basal diet supplemented by 1% zeolite (2), a basal diet supplemented by 1% zeolite coated with 0.5% nanosilver (3), a basal diet supplemented by 0.15% organic acid (4) and a basal diet supplemented by 1% zeolite coated with 0.5% nanosilver and 0.15% organic (5). The experiment was conducted with broiler chicken from 1 to 42 days old. The expression of the BCL2 and BAX apoptosis genes, liver sampling was done on the 21st and 42nd days of the breeding period.

The results of this experiment showed that in broiler chicks receiving zeolite treatment (Z) on d 21 and silver nanoparticles coated on zeolite treatment (NS) on d 42 of the breeding period the expression level of Bcl2 gene in liver tissue was significantly increased (P<0.05) compared to the control treatment (C Also, the expression of the BAX gene in the liver tissue in NS and NSOA treatments on d 42 of the breeding period increased significantly compared to the control treatment (P<0.05).

In conclusion, the results of this experiment showed that zeolite and NS and NSOA treatments have an increasing effect on the expression of Bcl2 and BAX genes, while this effect was not observed in organic acid treatment.

Heat stress is one of the serious issue in poultry industry which causes significant economic losses. Decreasing feed consumption, increasing excretion and decreasing the bioavailability of nutrients during heat stress reduces the performance and immune response. Selenium is an essential trace element for humans and animals that plays a role in improving the antioxidant status and the immune system and inflammatory response. The goal of this study was to investigate the effects of different selenium sources [2-hydroxy-4- methyl seleno butanoic acid, selenomethionine and sodium selenite) on performance, carcass characteristics, antioxidant and immune response and blood characteristics in broiler under heat stress condition.

This experiment was conducted in a completely random designs with 240 Arbor Acres (Male) broilers chicks. Chicks were randomly distributed in 4 treatments and 6 replicates (10 chicks in each replicate). The experimental treatments include that: (1) basal diet + 0.3 mg 2-hydroxy-4- methyl seleno butanoic acid; (2) basal diet + 0.3 mg selenomethionine per kilogram of diet; (3) basal diet + 0.3 mg sodium selenite per kilogram of diet; (4) The basal diet that did not have any additives. The birds were kept at 32-340C (10.00 to 16.00; for 6 hours) from 22 to 42 days.

The results of this experiment showed that feed intake, body weight gains and feed conservation ratio were not affected by the experimental diets. The use of different sources of selenium had no significant effect on blood biochemical factors in broiler chickens under heat stress. dding selenium source with 0.3 mg/kg 2-hydroxy-4- methyl seleno butanoic acid significantly affected immunoglobulin G in comparison to other treatments. Diets containing selenium sources significantly increased the relative weight of the spleen compared to the control treatment (P < 0.05). The treatments of 2-hydroxy-4- methyl seleno butanoic acid and selenomethionine significantly decreased liver weight percent. The concentration of glutathione peroxidase, superoxide dismutase and catalase enzymes in blood were significantly increased by selenium sources in different treatments.

The use of selenium source improved the immune system and blood antioxidant status in broiler chickens.