مجله تولیدات دامی
سال بیست و دوم شماره 3 (پاییز 1399)

The aim of this study was to identify the molecular pathways related to litter size in sheep using gene set enrichment analysis. For this purpose, information of high prolificacy sheep breeds including Wadi, Hu, Icelandic, Finnsheep, and Romanov and low prolificacy including Texel and Rahmani were used for genome wide association studies and gene set enrichment analysis. Genome-wide association study was conducted using GenABEL package of R program. Gene set enrichment analysis was performed with the goseq R package to identify the biological pathways associated with candidate genes. We identified different sets of candidate genes related to litter size: BMP5, DHCR24, BMPR1B, ESR1, ESR2 and PLCB1 in Wadi and Romanov; SMAD1, SMAD2, INSR and PTGS2 in Finnsheep and Hu; BMP7, NCOA1 and ERBB4 in Icelandic; BMP4, MSRB3 and SPP1 in Texel; BMP7, EGFR and KCNMA1 in Rahmani. According to pathway analysis, 30 pathways were associated with the litter size trait. Among biological pathways, the TGF-β signaling, Oxytocin signaling, Estrogen signaling, Prolactin signaling, and Insulin signaling pathways have significant association with ovulation rate and litter size trait. Overall, this study supported previous results from GWAS for litter size, also revealed additional regions in the sheep genome associated with litter size in sheep. These findings could potentially be useful for selective breeding for more litter size in sheep.

The objective of this study was to identify known intergenic lncRNAs related to biological pathways of acidosis in Holstein calves using ruminal tissue. Two groups of healthy calves (N=3) and affected by acidosis (N=3) were compared. Paired-end sequencing method was performed using the Hiseq2500 illumine platform. Hisat2 software was used to align reads to the bovine reference genome and StringTie software package was used to assemble read files into transcripts. Using next generation sequencing, 1636 genes belonging to known intergenic lncRNAs were identified, of which 56 genes showed significant differential expression (P≤0.05). Neighbor genes of known intergenic lncRNAs were determined on bovine genome. Analysis of biological pathways and molecular function showed that five biological pathways were significantly (P≤0.05) enriched. These pathways were Apelin signaling pathway, Gap junction, Glucagon signaling pathway, Renin secretion, and AGE-RAGE signaling pathway. Moreover, two molecular functions including gap junction channel activity, and phosphatidyl inositol phospholipase C activity were significantly (P≤0.05) enriched. Some lncRNAs have different expression in healthy and acidosis samples, and the decreased pH acts as a stimulus to activate some biological signaling pathways. In conclusion, it was indicated that lncRNAs with differential expression between the control group and the group affected by acidosis are associated with pathways related to rumen energy metabolism and signaling. Identified differentially expressed lncRNAs could be used as prognostic in acidosis and biomarkers or promising candidates in animal breeding.

The objective of present study was to investigate the effect of different levels of sesame meal in early lactation cow's ration on dry matter intake, milk yield and composition, apparent digestibility of nutrients and blood metabolites. Six dairy lactating Holstein cows with average DIM 26± 3 (n=3 primiparous and n=3 multiparous cows) were randomly assigned to 1 of 3 experimental treatments (different levels of sesame meal) in repeated 3×3 Latin square design. Experimental treatments were control (without sesame meal), 4.33% sesame meal and 8.66% sesame meal (DM basis). The experimental periods consisted of 21 d with the first 14 days as adaptation and the last 7 days as sampling days. Increasing level of sesame meal in early lactation rations did not affect dry matter intake, milk yield and composition (fat, protein and lactose), feed utilization efficiency, apparent digestibility of nutrients and blood metabolites (P  0.05), while milk urea nitrogen decreased with increasing the level of sesame meal (P<0.05). Blood urea nitrogen concentrations also tended (P = 0.1) to decrease with increasing levels of sesame oil. In general, the lack of response in feed intake and milk yield with increasing the levels of sesame meal in early lactation cow's ration showed that sesame meal could be a proper protein source in early lactation cow's ration.

Present study was designed to investigate the effect of Artichoke (Cynara Scolymus) extract on performance and some blood and anti-oxidantparameters of Sanjabi lambs. Eighteen Sanjabi lambs were randomly allocated to three experimental treatments with six replicates in each individualcage for 75 days. The experimental treatments were: 1) control group including basal diet without Artichoke extract, 2) basal diet plus 5 ml ofartichoke extract, and 3) basal diet plus 10 ml of artichoke extract per kilogram dry matter. The blood samples were collected from jugular vein oflambs before feeding at morning monthly. The concentration of glucose, cholesterol, total protein, urea, albumin, and the activity of glutathioneperoxidase, superoxide dismutase, alkaline phosphatase, alanine aminotransferase enzymes and malondialdehyde were measured. The results of thisexperiment showed that artichoke extract had no significant effect on lambs' performance and growth parameters, but significantly decreased bloodconcentration of cholesterol, triglyceride and malondialdehyde index at the level of 10 ml extract per Kg/DM of diet. The urea and cholesterolconcentrations affected by time and at days 40 of experiment, the amount of this parameters was lower than other times. In general, it can beconcluded that artichoke extract at the level of 10 ml extract had no significant effect on average daily gain and growth performance of lambs butimproved some blood parameters.

In order to study the effects of sunflower oil and Konar leaves addition on performance, meat quality and fatty acids profile, an experiment wasconducted using 32 Adani male goat kids, with 17.8 ± 2.2 kg initial BW in a completely randomized design with a 2×2 factorial arrangement for 75days. Goat kids were randomly assigned to one of four treatments: 1- control, 2- 20% Konar leaves, 3- 2.5 % sunflower oil and, 4- 2.5 % sunflower oil+ 20% Konar leaves. The results showed that treatments had no effect on feed intake and final body weight of goat kids. Oil inclusion in the diettended to increase daily weight gain (P=0.06) and tended to decrease feed conversion ratio (P=0.07) of goat kids. Dry matter, ash, and crude proteinconcentrations, color indices, malondialdehyde concentration and pH of longissimus dorsi (LD) muscle were not affected by treatments. Totalsaturated fatty acids (P<0.05) and total N6 fatty acids (P<0.01) of LD are affected by interaction of oil and Konar leaves supplementation. Inclusion ofkonar leaves in the diet increased the polyunsaturated fatty acids to saturated fatty acids ratio in LD muscle of goat kids (P<0.05). The fat of LDmuscle increased with the inclusion of oil to the diets (P<0.01). The results of this study showed that the use of Konar leaves and sunflower oil in thediet of Adani goat kids can improve the nutritive value of their meat by reducing saturated fatty acids and increasing polyunsaturated fatty acids.

This study was conducted to evaluate the effects of treating ground barley grain with lactic acid (LA) in starter diets on feed intake, average daily gain,feed efficiency, nutrient digestibility, skeletal growth, and blood metabolites of pre-weaned dairy calves. Thirty male Holstein calves with averageinitial body weight of 45.06±2.25 were randomly allocated to one of the 3 treatments. Starter containing 41% ground barley grain from day 4 to 65 ofbirth. Experimental treatments include: 1) diet containing treated barley in tap water (No LA), 2) diet containing treated barley in 0.5% LA solution,and 3) diet containing treated barley with 1% LA solution. Feed intake was recorded daily. Body weight and skeletal growth measures were recordedon day 4, day 35, and day 56. Calves blood samples were collected on day 4, 35, and 65. Total tract dry matter digestibility and feed efficiency weregreater in calves fed diet containing lactic acid treated barley (P ≤0.05). No effects on dry matter intake, average daily gain, and blood metabolites wasobserved. At day 35 of the experiment the withers height and body length were greater in calves received LA-treated barely (P ≤0.05). It seems thattreating barley grain with lactic acid decreased starch digestion in the rumen and increased starch flow to the small intestine; accordingly, feedefficiency was improved. Using higher levels of lactic acid may have a positive effect on calf performance.

The effects of increasing levels of L-leucine supplementation on performance, carcass traits, breast meat production and determination of digestibleleucine requirement broilers during the grower period (15 to 30 days) using 240 Ross males broiler chickens in a completely randomized design withsix dietary treatments (five repetitions and eight chicks per repetition) was investigated. Treatments include; a basal diet with 1.53% digestible leucineand five diets containing 1.63, 1.73, 1.83, 1.93, and 2.03% digestible leucine by adding synthetic L-leucine to the basal diet. By increasing the levels ofdigetible Leucin, body wieght gain, carcass and breast muscle percentage were increased, but feed conversion ratio and abominal fat percentage weredecreasd (P<0.05). The response trends to increasing levels of digestible leucine were quadratic for weight gain, feed conversion ratio, the relativeweight of carcass, relative weight of breast muscle and relative weight of abdominal fat ( P<0.05). Due to the better fit of the quadratic model to theresponse criteria, digestible Leucine requirements were estimated at 1.70, 1.72, 1.724, and 1.735% for body weight gain, feed conversion ratio, therelative weight of carcass and breast muscle; respectively. Based on the average of these estimates, the suggested digestible Leucine requirements ofbroilers in the grower period is 1.72%.

The aim of this study was to evaluate the efficacy of Bacillus subtilis bacteria capable to produce phytase enzyme on improving broiler chickenperformance and to evaluate its effect on gastrointestinal organs, and tibia strength in broiler chickens. This experiment was done using 200 one-dayold broiler chicks (Ross 308), in a completely randomized design with 5 treatments, 4 replicates and 10 chicks per replicate for 42 days. Thetreatments include: 1) positive control diet containing sufficient phosphorus level; 2) negative control diet with 30% less phosphorus; 3) negativecontrol diet supplemented with phytase enzyme; 4) negative control diet supplemented with a commercial probiotic; 5) negative control dietsupplemented with Bacillus subtilis SH17-3. Feeding broiler chickens with a diet containing Bacillus subtilis bacteria SH17-3 significantly reducedfeed intake and mean body weight gain (BWG) in the total rearing period (P<0.05). Feeding broiler chickens with a diet containing phytase enzymesignificantly increased feed intake and BWG (P<0.05). The strength of tibia was significantly increased in birds received phytase enzyme, comparedto other groups (P<0.05). Based on the results the use of phytase enzyme in diets with phosphorus deficiency, improves performance in broilers; butBacillus subtilis bacteria SH 17-3 could not be a good alternative for probiotic and also phytase enzyme.

This experiment was conducted to investigate the effect of processed date pit on broiler performance. In this experiment, 280 broiler chicks were usedin a completely randomized design with seven treatments and four replicates. The experimental treatments were: 1- control (diet without date pit), 2-10 percent raw date pit, and treatments 3 to 7- were 10 percent date pit that processed with steam pressure, NaOH, and fermented with Lactobacillusfermentum, Bacillus subtilis, and Aspergillus niger respectively. The crude protein content of processed date pit was higher, and the ether extractcontent was lower (exept NaOH) than raw date pit (P<0.05). The feed intake, body weight gain, feed conversion ratio and cecal microbial populationof broiler chickens were not affected by experimental treatments. The small intestine length of birds that fed diets containing processed date pit withsteam pressure and NaoH was significantly reduced in comparison with birds resived diets containing fermented date pit with Aspergillus niger andwithout date pit (P<0.05). The highest amount of litter dry matter and lowest amount of excreta ash was observed in groups fed diet containing rawdate pit (P<0.05). According to the results of this study, the processing methods of date pit has no effect on broiler performance and cecal microbialpopulation. Therefore, due to the high cost of processing, and the favorable effects of feeding raw date pit on broiler litter quality, the use of raw datepit in broilers diet is recommended.

This study was conducted to determine the effects of Propolis on growth performance, carcass characteristics and some blood parameters in broilerchickens in response to heat stress condition. A total of 160 one day-old male broiler chicks (Ross 308) were randomly divided into four treatmentgroups in a completely randomized design with four replicates of 10 birds each. The experimental treatments including: 1) control (basal diet), 2) thebasal diet with Neomycin (200 g/ton), 3) 150 mg/kg Propolis, 4) 200 mg/kg Propolis in diet. Birds submitted to heat stress (32±2ºC from 10.00 AMto 6.00 PM) from 15 to 42 d of age. The results showed that, average mortality was lower in Propolis groups than in the control group (P < 0.05).None of the feed intake data was influenced by treatments during different periods. Birds receiving diet supplemented with 200 mg/kg Propolis had asignificantly (P < 0.05) higher body weight compared to the control group at the finisher feeding phase and whole period. In the finisher phase andwhole period, the lowest (P < 0.05) fed conversion ratio (FCR) was observed in chickens fed 200 mg/kg Propolis. Cholesterol and LDL level werelower in chickens fed diet with Propolis compared to control (p < 0.05). In conclusion, the addition of Propolis at a rate of 200 mg/kg to the diet couldreduce the negative effects of heat stress in broiler chickens.

This study was conducted to investigate the weight changes, age and weight at first laying, the outer and inner egg characteristics of breeding stationof Isfahan native chickens. Three hundred-day old native chickens were used in this survey. The experiment was started from the first day to the endof the 12 weeks of egg production (32 wks. of age). The results indicated that average age and weight of the first laying hens were 152.6 days and2061.46 g, respectively. The overall average of the egg weight was 45.47 g in whole production period. The average number of eggs produced byeach hen in 12 weeks of production period was 42. The range of hen production percentage in each week was 5.83 to 61.99 with an average of 45.44.The regression curves of height and diameter of yolk with production weeks were in order of second; with the weight of the hen's body, the white andyolk weight, and the shell thickness were of third order and with the rest of the traits were in forth order. Correlation of age at first egg with shellweight was high (r =0.99) and highly significant (P <0.001), but with total egg weight, the length and weight of the egg, and the height of yolk wasnegative and significant (P <0.05). The results of this experiment indicated the good production potential in some of these birds which proper breedingprograms may led to improve their productivity.

The aim of this study was to compare feedlot performance, carcass characteristics, blood metabolites, and economic profits between pure andcrossbreeds Holstein calves. Crossbreeds were produced by crossing Holstein (H) cows with Angus (A), Charolais (C), Limousin (L) and INRA 95 (I)bull’s semen. The performance of 25 calves of each breed (125 calves in total) was compared in a fattening period of eleven months. The averagedaily gain was significantly higher in crossbred calves compared to pure Holstein calves. The interaction of breed and time was significant (P<0.01).The Charolais crossbred calves and pure Holstein had significantly lower dry matter intake than other crossbreeds, and feed conversion ratio in theC×H calves was remarkably more favorable than other groups (P<0.01). Dressing percentage and saleable meat yield for C×H, L×H and I×Hcrossbreeds were higher than for pure Holstein and A×H. Concentrations of plasma urea of Charolais crossbred calves was more than other groups(P<0.01). Economic calculations demonstrated that the respective highest profit for the whole fattening period belonged to crossbreeds of C×H, I×H,L×H, A×H, and pure Holsteins. In conclusion, the calves from Holstein-beef crosses had higher feedlot performance, dressing percentage andeconomic productivity than pure Holstein calves.

This study was designed to add the reduced glutathione to a lecithin nanoparticle-based extender and evaluate the quality of bull sperm after freezingand thawing. In the present study, the effect of four different levels of glutathione (0, 1, 2.5 and 5 mM) in extender-based on lecithin nanoparticles wasevaluated. The lecithin nanoparticles were prepared and the particle size was reduced by using a sonicator device. During three weeks, 48 ejaculatesfrom six Holstein bulls were collected and frozen. Properties evaluated after freezing and thawing were kinetic parameters (CASA), membraneactivity (HOST), membrane integrity (eosin-nigrosine) and morphology (Hancock solution). The results showed that using 2.5 mM glutathione in theextender significantly increased total and progressive motility (63.38±1.5 and 43.1±1.1 respectively, P <0.05). The results of eosin-nigrosine stainingand Host test showed that the highest viability and cell membrane functionality were related to 2.5 mM treatment (64.8±1.5 and 58.1±1.1 respectively)(P<0.05). In general, 2.5 mM glutathione could improve the quality of bull sperm compared with other concentrations after freezing and thawingprocess. It seems that the 2.5 mM glutathione is optimum concentration for bull extender based on the lecithin nanoparticles.

The effect of diets containing different sources of fat on milk production and composition, and mammary gland morphology of the 40 primiparousSaanen does was studied during the last two months of pregnancy to 12 weeks after kidding. Goats were divided into four groups of 10 each, based onthe average initial live weight and were assigned to one of four experimental diets. The diets included a non-fat diet, diet containing saturated fat, dietcontaining roasted soybeans, and a diet containing extruded flaxseed. The results showed that during the whole experimental period, milk productionin goats fed with diet containing flaxseed was higher than in goats fed with non- fat diet or saturated fat diet (P<0.05). The average daily milkproduction of goats fed a diet containing flaxseed in the first, second, third, ninth, tenth, and twelfth weeks of lactation was higher than that of goatsfed non-fat diet or saturated fat (P<0.05). The percentage of protein, lactose, solids not fat, and milk solids in non-fat diet goats were higher than theother groups (P<0.05). The percentage of fat to protein ratio in goats fed a diet containing unsaturated fat was higher than in other groups (P<0.05).Consumption of diets containing unsaturated fats improved the volume, environment, and size of mammary gland quarters (P<0.05). In general, theuse of fat supplements rich in unsaturated fatty acids such as soybeans or flaxseed, in the close-up and early lactation diets could improve lactationperformance in primiparous Sannen goats.

This study was conducted to evaluate the effect of various concentrations of lipopolysaccharide (LPS) in maritaruta medium on oocyte maturation, oocyte developmental competence and metabolites related to maturation medium including glucose, pyruvate, lactate and glutamine. The experimental treatments were 0 (control), 0.01, 0.1, 1 and 10 μg/ml of LPS in oocyte maturation medium. The cumulus oocytes complex (COC) were cultured with various concentrations of lipopolysaccharide. After 24 h of oocyte maturation, the medium was collected and the rates of oocyte maturation, cleaved oocyte and oocytes reached to blastocyst stage were analyzed. Oocyte maturation rate was lowest in the treatment with 10 μg/ml of LPS (P<0.05). Among the measured metabolites, only glucose concentration was linearly decreased in response to increasing levels of LPS in the maturation medium (P<0.05) as treatment with 10 μg/ml of LPS had lower glucose concentration comparing to other treatments. The percentage of oocyte cleavage was significantly lower in treatment with highest level of LPS compared to other treatments (P<0.05). In addition, the treatment with 1 and 10 μg/ml of LPS significantly reduced blastocyst rate compared to control group (P<0.05). According to results of this study, lipopolysaccharide could have detrimental effects on oocyte development and these influences seems to be mediated through pathways related to energy metabolism. Acquiring managerial approaches to control LPS enhancing agents during reproductive season could prevent animal's reproductive failure.