نشریه علوم دامی (پژوهش و سازندگی)
پیاپی 137 (زمستان 1401)

The study was conducted to evaluate the effect of different programs of feed restriction on performance and ascites syndrome occurrence in Arian broiler chickens under cold stress. Four hundred Arian male broiler chicks were used in a completely randomized design with four experimental groups (control (no restriction feed); feed restriction as 25 gram feed per chick since 9 until 14 days old; feed restriction as 8 hour per day since 9 until 24 days old; intermittent feed restriction since 9 until 18 days old) and four replicates of twenty five chicks (totally 16 pens) under stress condition. The house temperature was gradually decreased from 32°C and reached to 25, 20, 15 and 15 °C respectively in the end of 1st, 2nd, 3rd and until 6th weeks to induce cold stress and the development of ascites syndrome. Results indicated feed restriction programs decreased body weight, body weight gain, feed intake, and feed conversion ratio in some periods. However, in the period of 1 to 42 days, these effects weren’t significant except for feed intake with feed restriction as 25-gram feed per chick (since 9 until 14 days old). Effect of the programs was respectively insignificant on total mortality, carcass traits percentages and haematocrit amount and significant on decreasing ascites mortality rate with the intermittent feed restriction. In conclusion, the feed restriction programs especially the intermittent feed restriction are effective in decreasing of ascites mortality and feed intake without any negative effect on the performance of broilers under cold stress.

In order to investigate the effect of alfalfa physical shape and barley grain processing on yield, ruminal parameters and microbial protein synthesis in Dalagh fattening lambs, 30 male lambs of 3.5±1.2 months old with an average live weight of 17±1.1 kg were used.This experiment was performed in factorial form (3×2) based on a completely randomized design with two factors including: physical form of forage and processing of barley grain in 98 days with 6 treatments and 5 replications. Experimental diets included: 1- Chopped alfalfa with whole barley grains 2- Chopped alfalfa with ground barley grains 3- Chopped alfalfa with flaky barley grains 4- Pellet alfalfa with whole barley grains 5- Pellet alfalfa with barley grains Grinded 6- Pellet alfalfa with barley flakes. The daily feed and its residue were weighed and recorded daily for each animal. Rumen fluid sampling was performed on day 84 at 3 hours after feeding. From day 70 of the experiment, the volume of urine produced by each animal was recorded daily for 6 days.The results showed that alfalfa forage in the form of pellets increased the dry matter consumption, increased daily weight, increased propionate content, increased nitrogen, increased microbial protein and decreased acetate and pH (P <0.05). Also, flaxseed and ground barley processing compared to whole barley grain increased daily weight gain and increased propionate, nitrogen and microbial protein levels and decreased ammonia and pH (P <0.05).Keywords: Physical form, Processing, Rumen parameters, Microbial protein, Fattening lambs.

Survival records and pedigree information from Rayeni kids born between 1993 and 2009 from breeding station of Rayeni Cashmere goat, located in the Baft city, were used. Also, by completing questionnaire from breeding station of Rayeni Chashmere goat and flock nongovernmental, in Kerman province environmental factors affecting survival and survival rate were obtained. 11 herds with geographical diversity and different herd sizes in Kerman province were selected. The highest and lowest percentages of kid removal were related to fattening surplus (54.2%) and defective removal (0.4%), respectively. Death due to disease after fattening surplus was the most common cause of kid removal (22.3%). Survival rate in these herds was 89.94 percent. according to the results overall mean of lifetime cumulative was 310.3 days. The effect of fixed factors year and month of birth, sex of kid and kid’s birth weight as quadratic were significant. The estimates of heritability in logarithmic scale were low to medium (0.14 to 0.40), original scale were medium to high (0.25 to 0.70) and effective heritability were medium (0.23 to 0.61). Since the estimated genetic parameters for survival of goats are moderate, to improve the survival of goats from birth to one year of age and increase the economic profit of the farmer, while improving nutritional and managerial conditions, genetic selection within the breed can be considered.

In this study, the role of bacteriocin produced by Lactobacillus plantarum TA013 (Plantarsin which has the most effect against Listeria monocytogenes) in the persistence of lactic cheese (LCh) was investigated. Groups: 1) LCh without probiotic bacteria and bacteriocin as a control 2) Probiotic LCh containing L. plantarum 3) LCh containing Plantarsin and 4 (LCh containing Nisin were considered. Physicochemical and microbiological properties of cheese in each treatment were determined in terms of pH, dry matter, fat, protein, salt, aflatoxin M1, fatty acid profile, and the growth inhibition of L. monocytogenes during 60 days storage in the refrigerator. Statistical analysis of this design was performed in a completely randomized design. The results showed that the reduction of L. monocytogenes in the treatment of LCh containing nisin in comparison with the control group was 3.05 Log(CFU/g), which was significantly different from the control group. in other treatments containing probiotics and Plantarisin, the rate of reduction of this pathogen compared to the control treatment was 2.76 and 1.79 Log(CFU/g) respectively, but no significant difference was observed between the two samples. Also, the survival rate of probiotics at the end of storage was 107 CFU/ g in the refrigerator and only two Log(CFU/g) were reduced. The results showed that cheese containing probiotics had superior properties over other treatments. Therefore, environmental conditions such as pasteurization are not sufficient to completely eliminate L. monocytogenes in lactic cheese, and it is necessary to use natural additives to create favorable conditions in different stages of production and storage.

Nanotechnology brings new solution for improving ruminal fermentation. Meta-analysis study of the effect of nanoparticles on ruminal fermentation can help to better understand how to manipulate ruminal fermentation. After searching and selecting appropriate articles, data related to ruminal fermentation parameters were extracted. Meta-analyses were carried out using the Comprehensive Meta-Analysis package, version 3. The effect sizes of across studies were calculated with fixed and random effect models. Possible publication bias was evaluated with funnel plot and statistical tests. The results of meta-analysis showed that the administration of nanoparticles in the diet, has a positive effect on gas production, total VFAs concentration and apparent dry matter digestibility. Addition of nanoparticles in the diet decrease N-NH3 concentration. The values of I2 for GP and TVFAs indicated moderate and values of I2 for N-NH3 concentration and apparent dry matter digestibility effect size indicated high heterogeneity, respectively. Administration of nanoparticles can improve ruminal fermentation process due to its positive effects on microbial growth, fiber degradation, DM digestibility, TVFAs concentration, and reduce the ratio of acetate to propionate and methane production.

The present study was conducted to evaluate the interactions between forage source (alfalfa hay vs. wheat straw) and particle size (fine vs. large) on growth performance, starter intake and ruminal fermentation of Holstein dairy calves. For this purpose, 48 Holstein dairy calves in a completely randomized block design (6 males and 6 females for each treatment) with 2 × 2 factorial arrangements were allocated to experimental diets including: 1) alfalfa hay with fine particle size, 2) alfalfa hay with long particle size, 3) wheat straw with fine particle size, and 4) wheat straw with long particle size. Calves entered the trial on d 4 and the trial lasted on d 70 of the age. Results showed that there was no interaction between forage source and particle size on growth performance, starter intake and feed efficiency of Holstein dairy calves during the all three periods. Skeletal growth characteristics were not affected by experimental diets. Results indicate that ruminal pH, total volatile fatty acids, acetate, propionate, butyrate and valerate molar proportions were similar across treatments. In general, our findings indicate that the different source and particle size of forage had similar effects on performance, skeletal growth and ruminal fermentation in the Holstein dairy calves.

A total of 500 one-day old broiler chicks (as hatched) were assigned to 4 treatments with 5 replicates and 25 chickens in each replicate. Experimental design was a completely randomized block design in a 2×2 factorial arrangements with 2 levels of citric acid (0 and 0.4 % of diet; A0 and A1, respectively) and 2 levels of phytase (0 and 2000 FTU/kg diet; P0 and P1, respectively) in three phases including starter (1-10d), grower (11-24d) and finisher (25-42d). During grower, finisher and overall period of experiment feed intake and body weight gain was increased by dietary citric acid addition. Dietary phytase supplementation increased feed intake at finisher and overall period of experiment (P>0.05) and increased body weight gain during grower and overall period of experiment (P>0.05). The interaction effect of phytase and citric acid was significant for feed intake and body weight gain through the experimental period (P<0.01). Serum phosphorous was increased by phytase supplementation and alkaline phosphatase decreased by inclusion of citric acid to the diet (P>0.05). The interaction effect of phytase and citric acid significantly increased serum calcium, alkalin phosphatase and phosphorous in A0P0, A1P0 and A1P1 treatments, respectively (P>0.05). Crypt depth and villi length were significantly higher in A1P1 and A1P0 treatments, respectively (P<0.05). it was concluded that dietary addition of phytase improves broiler performance and intestinal morphology and the effect was more pronounced by supplementation of citric acid.

In the present study, the effects of peppermint essential oil (PEO) and artifier in low energy diets on production index, feed cost, blood biochemical parameters and shelf life of meat of broiler chickens was investigated. A total of 240 male Ross broiler were used in a completely randomized design with 2×2 factorial method and compared with the control treatment (5 treatments) and 4 replications. Experimental treatments were include 1. control treatment and treatments containing low energy diets (150 kcal / kg less than the control diet) supplemented with 2. without additives 3. 150 ppm PEO 4. 300 ppm artifiers and 5. 150 ppm PEO + 300 ppm artifiers. The results showed that among broiler chickens fed low energy diets, the use of PEO + artifier in the diet increased body weight, production index (P=0.11) and decreased feed price (P<0.05) in the whole period. No difference was observed between birds fed control diet and birds fed low energy diet containing PEO + artifier in body weight, production index, survival percentage and feed price. Also, birds fed low energy diets containing PEO + artifier had lower serum cholesterol, low-density lipoproteins, triglyceride and meat malondialdehyde, and greater total antioxidant capacity, as compared to control diet. Finally, it can be concluded that the simultaneous use of 150 ppm PEO and 300 ppm artifier in low energy diets of broiler chickens compared to the control diet had the same performance and feed cost and improved blood biochemistry parameters and meat shelf life.

In this experiment, the effect organic forms of zinc, copper, manganese and iron on growth performance, morphology and microbial population of small intestinal using 360 one-day-old Ross 308 male broilers in a Completely randomized design with 6 groups and 6 replicates from 1 to 42 days of age under heat stress conditions. The experimental groups were: 1- basal diet (control), 2- basal diet + 5mg copper-methionine, 20mg manganese-methionine and 5mg iron-methionine (CuMnFe) 3-basal diet + 40mg zinc-methionine, 20mg manganese-methionine, 5 mg iron-methionine (ZnMnFe) 4-basal diet + 40mg zinc-methionine, 5mg copper-methionine, 5mg iron- Methionine (ZnCuFe) 5-basal diet +40mg zinc-methionin, 5mg copper-methionine, 20mg manganese-methionine (ZnCuMn) and 6-basal diet +40mg zinc-methionine, 5mg copper-methionine, 20mg manganese-methionine and 5mg iron-methionine (ZnCuMnFe). The consumption of CuMnFe and ZnCuMn groups increased the villus height as compared to other groups. The birds of all groups had the lower abdominal fat weight, higher muscle layer thickness and lower coliform population in ileum compared to control birds. The number of Lactobacillus bacteria in ZnMnFe and ZnCuMn birds was higher than that of the birds in other groups. In conclusion, consumption of ZnCuFe group in broiler diet under heat stress condition causes the decreased harmful microbial population in intestine and improved performance and breast and thigh weights.

The Effect of different level of sesame meal with internal enzyme was evaluated on performance, egg quality and some related blood parameters in layer quails. A total of 600 lying quail, used in CRD design with 5 treatments and 4 replicate (30 hens in each replicate). Five experimental treatments consisted of 1) Control diet (soybean-corn), 2) Diet with 10 % sesame meal, 3) Diet with 10 % sesame meal with 500 mg/Kg kemzyme, 4) Diet with 20% sesame meal, 5) Diet with 20% sesame meal with 500 mg/Kg kemzyme. Egg production was differing among experimental group significantluy. Experimental treatments had no significant effect on egg weight and feed conversion ratio significantly (P>0.05). Feed intake was tended to reduce by sesame meal inclusion significantly. Egg white and yolk were not affected significantly by experimental treatments (P>0.05). Different sesame meal inclusions with or without kemzyme did not affect significantly blood metabolite parameters such as total cholesterol, triglyceride, LDL, HDL, VLDL. Villus height, villus height to crypt depth ratio and Villus surface area, was affected significantly by experimental treatments (P<0.05). Control and enzyme consumed groups had higher villus height; it was differ significantly with SM groups. In conclusion, the inclusion of 10 sesame meal had no negative effect on production performance and egg quality traits in the early production phase of laying quail. Generally, the use of multi enzyme at 500 mg/Kg in diet with 20 percentage sesame meal was particularly affect to improve performance traits and feed intake parameters.