مجله علوم دامی ایران
سال پنجاه و چهارم شماره 3 (پاییز 1402)

In the poultry industry, the heat stress caused by high environmental temperature has a negative influence on broiler chicken performance and has become a major challenge. Transcriptome profile analysis of the data and identification of patterns of differential gene expression in related tissues can be involved in the discovery of molecular mechanisms resistant to heat stress. The main purpose of this study was to use transcriptome profiles of three tissues brain, liver, and leg muscle of two groups of the control and heat stress broiler chickens to identify candidate genes associated with heat stress. By the analysis of microarray data to express the gene differences, 657 significant genes (P<0.05) were extracted, which a total of 94 genes showed significant expression differences (FDR < 0.05, Fold change > ± 2). Then, by studying the ontology of the relevant genes resulting from data analysis and literature mining as well as the reconstructed protein-protein interaction network, hub genes including NSDHL, DHCR24, LSS, FDPS, PCK1, ACTA1, HSP90AA1, HSPA2, HSPB1, HSF1, CRYAB, APOB, and IL6 were identified. Annotation results of these genes indicated that they have a role in the main process of metabolic and signaling pathways related to the ion transport system, steroid, antibodies, cholesterol biosynthesis, lipid metabolism, immune system function, and various signaling pathways such as MAP kinase, RET, and ERK. Overall, the present study can provide new insights into evidence of the pathways activated by these genes to identify effective genes and a better understanding of biological processes related to heat stress.

The aim of this study was to investigate the growth performance, water consuming pattern, digestibility, and carcass traits of Lori-Bakhtiari (LORI) and Romanov-Lori-Bakhtiari (CROSSbred) lambs under water restriction conditions. Twenty lambs (10 heads per genotype) with an average weight of 31±2.5 and an age of 8±2 months were used in four treatments with 5 replications in each in a completely randomized design with 2×2 factorial. Water-restricted (WR) lambs had free access to water for only one hour a day. All lambs were slaughtered after six weeks. Feed intake, daily weight gain and final weight were not affected by genotype and access to water, while water intake (p=0.001) and water to feed ratio (p=0.02) were significantly dropped with water restriction. Water-restricted lambs consumed almost 90 percent of their water intake in the first five minutes. Nutrients digestibility was not affected by the treatments, but the amount of fecal dry matter was significantly high in water restricted groups (p=0.03). Carcass weight and yield were not affected by the treatments, but the percentage and weight of tails in the CROSSbred lambs were lower (p≤0.0001), but part of this decrease was compensated by higher fat thickness (p=0.05) and visceral fat (p=0.03).  The overall results of this study showed that genotype and water restriction did not significantly affect growth performance, so CROSSbred lambs can be used in water restricted area.

The fertility of female cows is the main factor for the survival of dairy farming. This study was performed to determine the differentially expressed genes in fertility in Holstein cows using phenotypic data and next-generation sequencing (NGS) technology. Corpus luteum samples from 18 Holstein cows at up to two parturitions were used in two high and low fertility groups, three samples from each group were pooled together and a total of three biological samples from each were submitted for whole genome sequencing. The preparation and analysis steps were performed on the Galaxy 22.01 platform. DAVID (2021) database were used for gene ontology. The results of differential gene expression analysis in luteal tissue showed that 19 genes out of 13049 expressed transcripts had a significant difference in expression between high and low-fertility cows with an FDR-adjusted p-value (q-value) of less than 0.05. UBE3B, NIF3L1 and ORC2 genes were three functional marker genes that were more highly expressed in the corpus luteum of high-fertility cows. The UBE3B gene is involved in biological processes as a protein involved in the catabolic process of ubiquitin-dependent protein. NIF3L1 is involved in the biological process of neuronal differentiation, positive transcriptional regulation, DNA pattern, and negative transcriptional regulation by nucleic acid pattern. The ORC2 gene plays a role in the biological process of DNA replication. The genes KRT8, PHLDB3, PPT2, LOC787628, PPYR1, TOX, TP73, DHX8, KCNN1, CLEC6A, PXMP4, LRRC26, SLC34A3, and OR13C7 have been shown to be more highly expressed in the corpus luteum in low fertility cows. Among these genes, three genes PPT2, PPYR1 and CLEC6A were functional indicators. The loci UBE3B, NIF3L1 and ORC2, which were expressed more strongly in the corpus luteum of highly fertile cows, can be used as functional indicator genes in the genetic selection of dairy cows.

Copy number variation (CNVs) is one of the most important structural variations in the genome which play an important role in the genetic variance of economic traits. In this study, CNVs and copy number variation regions (CNVRs) on the sex chromosome were investigated in three native Iranian sheep breeds, including fat-tailed Baluchi and Lori-Bakhtiari breeds and thin-tailed Zel breed. 50K genotyped samples were obtained and CNVs were identified for each individual using PennCNV software. After identifying CNVs in each individual, the quality control of CNVs was performed with different filters, and CNVRs were identified by using the overlapping regions of CNVs using CNVRuler software. In total, 37, 11 and 4 CNVs of gain events were identified on the X chromosome of Baluchi, Zel and Lori-Bakhtiari sheep, respectively. The minimum, maximum and average length of identified CNVs were 94477, 1293154 and 447694 bp in Baluchi breed, 271819, 906644 and 674854 bp in Zel breed and 99705, 306525 and 167913 bp in Lori Bakhtiari breed, respectively. After merging the CNVs, 30, 10 and 4 CNVRs were identified in these three breeds, respectively, all of which were of the gain events. The analysis of genes in CNVR regions showed that some of these genes (VEGF, VAM21, TRPC5, NDUFA1, APLN and TNMD) were related to fat metabolism. Annotations of genes for molecular function were significantly enriched in the pathway of arylsulfatase activity, which plays a role in reproduction. Further studies on these CNV regions can help identify genes affecting fat metabolism in sheep.

This experiment was designed to determine the nutritive value and estimate the rumen protected-protein level of protanomix and phosphoprotanomix as two new protein sources and compare them with corn-steep liquor as a raw material used for the production of these products. These two powdery products are obtained by separating and drying precipitates produced by reaction of tannins with corn-steep liquor. Tannins and total phenolic compounds contents in raisin-stem extract were 22.37 and 30.07 percent of dry matter, respectively. The insoluble protein in protonomix and phosphoproteomix were 81.15 and 48.98 percent of crude protein, respectively; while this value was 13.10 percent in corn-steep liquor. Gas production throughout the incubation and potential of gas production were affected by the experimental treatments, so that the highest values were related to the control treatment (corn-steep liquor). All ruminal-fermentation parameters were affected by the experimental treatments, so that the lowest metabilizable energy (ME) and short chain fatty acids (SCFA) and the highest efficiency of microbial protein synthesis (EMPS) and pH belonged to phosphoprotanomix; the lowest amount of in vitro organic matter apparent digestibility (IVOMAD) and microbial protein synthesis (MPS) were related to protonomix; while the highest amount of in vitro truly degraded dry matter (IVTDDM) and ammonia nitrogen (N-NH3) and the lowest value of partitioning factor (PF) belonged to the control treatment.

The aim of this study was to investigate the incidence, cull, abortion, stillbirth and weight loss due to Foot and Mouth Disease (FMD) outbreak and their interaction in different parity (primiparous and multiparous) in Iranian dairy cows. A total of 49,400 records of 20,330 cows were used in the period of 2009 to 2019, which were prepared from nine industrial dairy farms in Isfahan, Golestan, Fars, South Khorasan, Khorasan Razavi and Chaharmahal and Bakhtiari provinces. The incidence and mortality of FMD with FREQ procedure were estimated to be 43% and 11%, respectively and within herd incidence ranged from 18% to 59% and cull from 1 to 18%. The LOGISTIC procedure in SAS software was used to estimate the effects of FMD on the incidence of abortion, stillbirth, and weight loss and their interactions. The chance of occurrence the disease increased during the cold seasons in primiparous cows that had abortions and were in skinny BCS. Significant changes in the condition of affected cows compared to healthy cows showed an average of 23% decrease in BCS, 5% increase in abortion and 4% increase in stillbirth. Significantly, the chances of abortion, stillbirth and weight loss in multiparous cows in the normal and fatty BCS group were lower than in the primiparous cows with the same BCS group. In contrast, the chances of losing weight in multiparous cows which were in skinny BCS group, were higher than primiparous cows. The results of this study can be useful in analyzing management strategies to control and prevent FMD.

Artificial insemination is one of the most accessible techniques for raising domestic animals. It has been proven that refrigeration significantly reduces the quality of sperm. The aim of this study is to investigate the effects of crocin on the storage of dog semen at 4 ºC during a period of 48 hours. In this study, 25 ejaculates were collected from 5 terrier dogs and diluted in a Tris-based diluent. Then, they were divided into 5 parts in control, control dissolve (Dimethyl sulfoxide 5%, dissolve of crocin) and treated with 0.5, 1 and 1.5 mM crocin groups. Sperm parameters including evaluation of total motility, progressive motility, motility characteristics and sperm viability were evaluated for 48 hours. The obtained results showed that progressive motility and total motility during 48 hours of storage were significantly higher in 1.5, 1, and 0.5 mM crocin concentrations compared to the control group. Also, the examination of motility characteristics, except for STR, showed that the addition of 1.5 mM crocin significantly improved the characteristics compared to the control group. Investigating sperm viability showed that the addition of 1.5, 1 and 0.5 mM crocin significantly improves sperm viability. As a result, the present study determined that the addition of crocin to dog semen can improve the parameters of dog semen after liquid storage.

High stocking density is known as a source of chronic stress, which has an adverse effect on the performance of laying hens. So, the aim of this study was to investigate the effect of different levels of autolyzed yeast on performance and egg quality traits of laying hens reared under high stocking density. This experiment was done using 2 levels of density (2 and 4 birds per cage with dimensions of 38×38 cm) and 4 levels of autolyzed yeast (0, 0.2, 0.4 and 0.6 percentage) with 192 laying hens Hy-line W-80 (35 weeks old) in a completely randomized design with factorial arrangement of 4×2 with 8 replicates. The results of the experiment showed that high stock density decreased the viability and reduced the feather score of birds, but autolyzed yeast increased the viability of birds in high stock density (P≤0.05). Dietary supplementation of autolyzed yeast was not affected feed intake (P≥0.05), but increased egg production and decreased feed conversion ratio (P≤0.05). The increase in egg weight showed a tendency to be significant (P=0.07). Dietary supplementation of autolyzed yeast decreased pH of excreta in laying hens (P≤0.05). Also, autolyzed yeast increased the primary and secondary antibody titer against sheep red blood cell at the 43 and 44 weeks old (P≤0.05). The results of this experiment showed that the supplementation of autolyzed yeast to the diet improved performance and the humoral immune system of laying hens reared at high stock density.