مجله علوم دامی ایران
سال پنجاه و سوم شماره 1 (بهار 1401)

This experiment was performed to compare the absorption kinetics and utilization of different methionine (Met) sources including synthetic-free crystalline DL-Met (DL-Met), L-methionine (L-Met) and dipeptide (Met-Met) and protein-bound methionine (PB-Met) in broilers with single-meal feed consumption. A total of 100 female Ross 308 broiler chickens were fed in a completely randomized design with five experimental diets (basal, DL-Met2.0, L-Met2.0, Met-Met2.0 and PB-Met2.0) in accordance with compliance to the single-meal broiler breeder from 39 to 60 days of age. During experimental period, 90 grams of pellet feed was given per chicken once a day, which was consumed within 17±2.5 minutes. The results showed that dietary supplementation with PB-Met2.0 caused a significant improvement (P<0.01) in growth performance, compared to the consumption of synthetic amino acids. The maximum blood plasma methionine concentration was observed at 1 hour after consumption of diets containing DL-Met2.0 and Met-Met2.0 and 2 hours after consumption of diets containing PB-Met2.0 and L-Met2.0 (P<0.01). The highest carcass protein content and protein utilization efficiency (P<0.01) and also the lowest excreta nitrogen content (P<0.05) were observed in treatment containing PB-Met2.0. The efficacy of essential amino acids, especially methionine was increased in chickens fed diet containig PB-Met (P<0.01). As a result, it seems that DL-Met and Met-Met have less efficiency in broilers with single-meal feed consumption, due to the lack of absorption synchronization with other amino acids. Therefore, the absorption synchronization of methionine using appropriate sources increases its efficiency. In conclusion, PB-Met is recommended as a preferred source of methionine in diet of broilers with single-meal feed consumption.

The aim of this study was to evaluate the effect of different source of magnesium in prepartum diets on productive performance, blood metabolites, insulin resistance and health disorders in transition cows. Sixty cows from 21 days prepartum were randomly assigned to 4 experimental treatments. Treatments were control treatment (Mg at NRC recommendation), magnesium sulfate treatment, magnesium carbonate treatment and magnesium oxide treatment (Mg was 0.60% of ration DM). Experimental diets increased DM and NDF digestibility (P<0.05). However, Calf and placenta weight, body weight changes and BCS were not affected by treatments. The incidence of retained placenta and hypomagnesemia decreased in experimental treatments (P<0.05). Magnesium oxide and carbonate treatments tended to increase milk yield (P=0.08). Milk fat increased in the control diet (P<0.05). Experimental diets decreased plasma NEFA and cholesterol and improved plasma Mg and Ca (P<0.05). Control treatment had the lowest rate of glucose CR (%) and RQUICKI (P<0.05).

In the present study, the effect of vanillic acid in comparison with vitamin E+C on the semen characteristics of Zel's ram under short and long-term preservation, was investigated. The experimental groups consisted of different concentrations of vanillic acid (0, 1, 10 and 100 μg/mL), a mixture of alpha-tocopherol and ascorbic acid (vitamin E+C), and dimethyl sulfoxide (DMSO) (as alpha-tocopherol solvent). The samples were evaluated at 0, 24, 48 and 72 hours after storage at 4 °C and following the freeze-thawing process. During the cold storage, sperm quality traits (motility, viability and membrane integrity) and mitochondrial activity increased significantly (P<0.05) at concentrations of 1 and 10 μg/ml vanillic acid in comparison with control and vitamin E+C groups. Our results revealed that the total motility and percentage of spermatozoids in the concentration of 1 μg/ml of vanillic acid were higher than control and vitamin E+C groups (P<0.05). Also, plasma membrane integrity and morphology of spermatozoid were higher in concentrations of 1 and 10 μg/ml of vanillic acid than control group. Concentration of 1 μg/ml of vanillic acid showed the highest mitochondrial activity than vitamin E+C treatment (P<0.05). Our findings showed that addition of vanillic acid at the concentrations of 1 and 10 μg/mL to the semen extender improved the quality of spermatozoid in the Zel breed sheep.

An experiment was performed to investigate the effects of using saturated and unsaturated fatty acids calcium salts on the production performance and some physiological traits of finishing lambs fattened under heat stress condition. Thirty-two cross bred Lori-BakhtiariÍRomanov lambs were randomly divided into 4 groups. Lambs were fed individually with the following experimental diets for 6 weeks (early July to mid-August): 1) Basal diet without supplemental fat (control), 2) Basal diet supplemented with 2% (on DM basis) of fish oil calcium salt, 3) Basal diet supplemented with 2% (on DM basis) of olive oil calcium salt and 4) Basal diet supplemented with 2% (on DM basis) of saturated fat calcium salt. Daily feed intake was recorded and lambs body weight was measured weekly. Rectal temperature and respiration rate were measured once per week. Using calcium salts of fish oil, olive oil and saturated fats in the diet significantly increased daily weight gain and reduced the lambs feed conversion ratio compared to control group (P≤ 0.05), but had no effect on dry matter intake of the Lambs. Regardless of fatty acid origin, supplementing lambs with calcium salts of fatty acids, reduced rectal temperature and respiration rate of lambs exposed to heat stress, compared to control group (P≤ 0.01). Also, using calcium salts of Fish oil, olive oil and saturated fat had no effect on DM, CP and EE digestibility, however, EE digestibility was higher in lambs consumed fat-supplemented diets than the control group. NDF digestibility was significantly higher in the control group lambs than the other groups. The results of this study showed that diet supplementation with calcium salts of unsaturated fatty acids of fish and olives and saturated fatty acids, improved the production performance of finishing lambs exposed to heat stress. No difference was detected between fat supplements with different fatty acid patterns, in this investigation.

The Helmeted Guineafowls were originated from West Africa and spread widely across the world, due to their ability to adapt to different environmental conditions. The main goal of this investigation was to identify the single nucleotide variations (SNVs) in order to explain the genetic structure of Helmeted Guineafowl in Iran. The whole genome of six Guineafowl ecotypes (18 samples) including Tabriz (blue and grey), Rasht, Tabriz (white), Rasht×Tabriz cross, Shiraz and Lar were sequenced. Paired-end libraries with 125 bp of Guineafowl samples were sequenced by whole genome Illumina platform. The phylogenetic tree analysis based on the maximum likelihood and neighbor joining was constructed. Runs of homozygosity (ROHs) were detected across all individual genomes by PLINK software. In the current study, around 14.48 million SNVs were detected. To evaluate the phylogenic relationships among all Guineafowl ecotypes, we applied two different phylogenic methods based on neighbor-joining and maximum-likelihood methods. Similar results were reported by these methods, all Helmeted Guineafowl ecotypes were classified separately except Shiraz and Lar ecotypes, which showed the most amount of genetic similarities. The results of runs of homozygosity (ROH) analysis indicated that the highest level of inbreeding at all levels of ROH were observed in the white Tabriz ecotype, in contrast Tabriz (blue and grey) ecotype showed the lowest level of inbreeding at all levels of ROH. These findings can provide new insight into genetic structure of Helmeted Guineafowl ecotypes in order to develop the breeding programs.

In order to understand the causes of bovine embryo mortality and viability, it is necessary to identify different pathways between the embryonic fission and the blastocyst. The enriched sets of genes from a bovine embryonic cell to a 16-cell and blastocyst stage were examined. The raw DNA microarray data was downloaded from the GEO database. Then differentially expressed probes were enriched with the online software agriGO v2 by means of singular enrichment analysis (SEA). The results of this study showed that a total of 5 genes with increased expression, including KPNA7, RGS2, TESC, MLLT11, BMP15 and 5 genes with decreased expression, including KRT8, CLDN6, PLAC8, FN1, KRT18 had the highest differentially expressed pattern (P ≤0.05). In addition, 39 gene sets in various molecular metabolic pathways, including NADP metabolism, tRNA, ATP, phospholipid catabolism, apoptosis and cell growth, glycolysis, mitosis; 13 gene sets on the path of molecular functions, including manganese ion, RRNA, cytochrome C oxidation activities, translation primers, ATP and ATPase activity and at the level of the cellular components of 12 gene sets on the path of the cytoplasmic cavesicle membrane, endoplasmic reticulum membrane, microtubules and Spindles and plasma membrane showed the highest enrichment (P ≤0.05). As a result, the gene sets enriched with blastocysts indicate the beginning of cell differentiation and the transition from the blastocyst state to the implantation process. Ultimately, at this stage, gene sets are expressed, the interaction of which is likely to result in the survival or analysis of the embryo.