فصلنامه پژوهشهای تولیدات دامی
پیاپی 25 (پاییز 1398)

Studying broiler preference to feed color is important for improving comfort and welfare of broilers and it may be beneficial for improving performance. The aim of the first experiment was to examine day-old chick's preference in different light colors to different feed colors. One hundred and sixty Ross 308 newly hatched broilers, never exposed to feed, were allocated into pens illuminated with different light colors: white, yellow, green and red. Under each color of light four colored feed choices (red, green, yellow and control) were offered. Choice was recorded the moment the bird attempted to obtain feed. In the second experiment, 80 chicks were chosen and separated equally in four pens illuminated with white color. Light intensities were the same in all pens at both experiment. The pens were separated using black plastic to keep stray light from interfering with neighboring pens. In each pens there were 4 dishes containing different feed color and chicks were allowed to choose the preferred color of feed for consumption. All chicks were fed a standard NRC ration and all pens were given ad libitum access to feed and water. The amount of feed intake from each colored feed in each pen was determined as a proportion of total pen feed intake until 21th days of rearing period. The results indicated that there were no significant differences between preferences of chicks to different feed colors. However, it was observed that under white light chicks tend to prefer green feed compared to control (P=0.08). The results in the second part of experiment showed that the feed intake from green feed were significantly higher compared to other colored feeds. Also, birds had the lowest proportion of feed intake from the red-colored ration under white lighting.

This experiment was conducted to investigate the effects of supplementation of different levels of peribiotic of mannan oligosaccharide (MOS) (Celmanax) on performance and some blood parameters of broiler chicks under induced ascites. 320 day-old Ross 308 male chicks were randomly divided into 4 treatments with 4 replicates. The dietary treatments included: positive control (corn – soybean meal basal diet), negative control (induced ascites with sodium chloride supplementation in the drinking water), negative control with supplementation of (2 and 4 ml per liter of drinking water of mannan oligosaccharide. Feed intake, Body weight and feed conversion ratio were measured at the end of the experimental period (42 d). Dead birds were dissected for ascites symptoms. Blood and ascites parameters (Right ventricular weight to total ventricles ratio (RV/TV) were also measured at 42 days of age. The statistical analysis of the data was done by using SAS software and comparison of the means were done by Tukey test at a significant level of 5%. The results showed MOS increased weight gain and decreased feed conversion ratio in birds with ascites (P <0.05). Both MOS levels significantly decreased the hemoglobin, red blood cells count, protein and hematocrit content of  birds reared under induced ascites (P <0.05). In addition, supplementation of 4cc/l  MOS on drinking water significantly decreased mortality rate caused by ascites (3.3%) and RV/TV index (P <0.05). In Conclusion, the supplementation of 4 cc MOS per liter of drinking water can improve growth performance of broiler chickens and can reduce the mortality rate of chickens reard unedr induced ascites.

In livestock nutrition management to increase productivity, finding inexpensive sources of food is a fundamental solution. .The sub-sectors of the agricultural industry in the feeding of ruminant animals make it possible to use them for the production of valuable products such as meat and milk. The purpose of this study was to investigate the effects of using citrus and sugar beet pulp in diet on ruminal performance and fermentation of Baluchi lambs. This research was carried out in a completely randomized design on 40 Baluchi lamb with 4 treatments and 10 lambs pretreatment with an average weight of 30 kg ± 1.5. The trial period was 75 days. Treatments were: 1) control group (base diet + 0 % citrus pulp per head at day 2( base diet + 10 % citrus pulp per head at day 3( base diet + 20 % sugar beet pulp dry per head at day 4) basal diet + 10% citrus pulp + 5% beet pulp dry per head at day. There was a significant difference between the mean daily weight gain in the whole period between different diets (P <0.05). The best conversion coefficient was for the group that consumed citrus (6.25) and the control group with the highest conversion factor (7.75), which had a significant difference with other groups (P <0.05). The results of this study showed that there was no significant difference between the average duration of chewing time, rumination and eating among different diets. According to the results of this study, the use of citrus pulp as a sub.

The NorFor is a semi-mechanistic system, which predicts nutrient supply and requirements for maintenance, milk production, growth and pregnancy in catlle. This research aimed to evaluate the effects of grinding, pelleting and steam-flaking of corn grain on protein characteristic using NorFor model according to a completely randomized design. Degradability of dry matter and protein of the processed corn were determined at 0, 2,4,8,16,24 and 48 hours after feeding with technique of nylon bags using three mature rams of Zel breed. By using the data gathered from the measurement of ruminal degradability of crude protein of corn, including soluble crude protein (sCP), potentially degradable crude protein (pdCP), degradation rate of potentially degradable crude protein (kdCP), indigestible crude protein (iCP) in feedstuff was estimated in NorFor system it was shown that effective degradability (%) of dry matter and protein steam-flaking of corn grain was higher than grinding, pelleting. Also, the slow fraction of grinding of corn grain was higher, both in dry matter and protein degradation. Corn steam-flaking increased soluble protein (sCP) and total soluble protein (sCP+ pdCP) and potential degradation protein, and reduce the kdCP, comparing with corn pletting (397 in contrast of 816) was significantly different (P<0.0 .(In this sdtudy, indigestibility of crude protein (iCP) was very low. The overall findings of this study indicated that increased rumen degradability of dry matter and protein as well as the total soluble protein (sCP+ pdCP) steam-flaking of corn grain was high.

This study investigated the effect of different levels of barley wet brewers on performance, rumen degradability, some blood parameters and gas production in fattening Zell male lambs. In the first experiment, in order to investigate different levels of barley wet brewers on performance and some blood parameters, in a completely randomized design with 4 experimental diets containing 0, 10, 20 and 30% barley wet brewers were used in 16 lambs with an mean weight of 30± 2 kg and age of about five months for 90 days. The experimental diets were isocaloric and isonitrogenous. The results showed that there was a statistically significant difference between experimental treatments in daily feed intake in the whole period (P<0.05). There was no significant difference between body weight gain, feed conversion ratio and blood parameters in experimental treatments. The mean apparent digestibility results of the nutrients were significantly affected by the experimental treatments, so that by increasing the level of barley wet brewers to 30%, the apparent digestibility of crude fat significantly increased, but the apparent digestibility of dry matter, crude protein and NDF, significantly decreased. In the second experiment, rumen degradability of dry matter, crude protein and NDF of experimental diets were measured using a nylon bag method with 3 fistulated Zell male sheep that were fed in the maintenance level. The incubation times were 0, 4, 8, 16, 24, 36, 48, 72 and 96 h. Significant differences were observed in degradability of dry matter, crude protein and NDF between experimental treatments (P<0.05). The degradability of the samples decreased significantly in all of parts, except in the rapidly degradable CP fraction that increased. There were significant differences in vitro of gas production rate between treatments (P<0.05). The overall result of this study showed that the use of 30% of wet barley brewers significantly reduced feed intake of lambs in the whole experiment period and its use in feeding lambs without negative effect on growth performance and diet nutrient digestibility is recommended.

The purpose of this experiment was to compare the effects of essential oils blend with probiotic and Flavomycin as antibiotic growth promoter on humoral immunity, meat quality, and some blood parameters in broiler chickens. A total of 288 day-old Ross 308 strain broiler chicks based on a completely randomized design was allocated to four treatments with four replicates and 18 birds in each replicate. Treatments were included: 1) control (a basal diet containing corn and soybean meal without additive), 2) basal diet + 150 mg/ kg essential oils, 3) basal diet +200 mg/ kg probiotic Gallipro®, and 4) basal diet +150 mg/ kg Flavomycin. In order to evaluate humoral immune response, antibody titers of sheep red blood cells (SRBC) were measured by hemagglutination method at 26 and 33days. In order to evaluate blood parameters and meat quality, two birds per replicate were slaughtered and blood samples were collected.  Humoral immune response was not significantly different between groups (P >0.05). Redness index (a*) in thigh muscle and pH of breast muscle 24 h after slaughter decreased (P<0.05) in treatments 2 and 3 compared with 1 and 4. Plasma concentration of HDL was significantly lower by 4 treatment than other groups (P < 0.05). Generally, the results of this study showed that dietary supplementation of essential oils blend, probiotic and Flavomycin to broiler chickens did not affect immune response of the birds, but pH of meat was improved after slaughter. In addition, Flavomycin supplementation of diet had a negative effect on blood HDL concentration.

Primarily the purpose of this study was to determine the chemical composition and the in vitro fermentation parameters of banana peel (BP) in comparison with wheat straw and alfalfa hay. Then, substitutional effects of BP with levels of 0, 50, 100, 150, and 200 g/kg in dry matter (DM) In Vitro Fermentation Parameters were investigated. Results showed that BP had higher crude protein (CP) content compared to wheat straw, but it was lower than alfalfa (P<0.05). However, neutral detergent fibre (NDF), acid detergent fibre (ADF) and lignin content of BP were lower compared to other experimental feeds (P<0.05). Greater ether extract and non-fibre carbohydrate contents were observed in BP compared to other experimental feeds (P<0.05). Potential of GP (b coefficient) and ruminal organic matter disappearance of BP were greater than wheat straw, but they were lower compared to alfalfa (P<0.05). Alfalfa and BP had similar total GP (TGP) and DM disappearance (P>0.05). Microbial protein production (MPP) increased with BP incubation compared other feeds (P<0.05). Two-stage DM and ADF digestibility were lower in BP than alfalfa (P<0.05), while their NDF digestibility was not significant (P>0.05). A linear reduction in ammonia-N concentration and a linear increase in MPP and partitioning factor were observed as BP dietary level was elevated (P<0.05). Other fermentation parameters and ruminal DM and OM digestibility were similar among experimental diets (P>0.05). In conclusion, results of present study indicated that banana peel has a better nutritive value in comparison with wheat straw and is comparable to alfalfa. In addition, it can be used in dry nutrition up to 20 % DM without any negative effects on in vitro fermentation parameters.

Artificial insemination is a reproductive technology that uses the best male breeders. Successful artificial insemination is affected by several factors, one of the most important of which is the availability of fertile sperm after the freezing-thawing process. The purpose of this study was to investigate the effect of different concentrations of naringenin after the freezing process. Sperm collection was performed twice a week using abdominal masage. After adding the diluent to the semen samples, the samples were placed in the refrigerator at a temperature of 4°C for equilibration. Samples were then transferred to freezing straws and exposed to nitrogen vapor, then stored in a tank containing liquid nitrogen. After thawing, several parameters containing motility, viability, abnormality, membrane integrity, MDA production, SOD and GPX enzymes and total antioxidant capacity were evaluated. The results indicate that the total and progressive cavity in 100 μM naringenin treatment significantly increased compared to control treatment. The percentage of sperm with morphological abnormalities in different concentrations of naringenin did not differ significantly (p<0.05). The viability and membrane integrity of the sperm cells at 100 μm concentration increased significantly compared to the control group. The results of this experiment indicate that 100 μm naringenin treatment increased glutathione peroxidase and total antioxidant capacity and reduced MDA levels compared to control group. Based on the results of this study, naringenin at 100 μm in a diluent medium improves rooster sperm quality after freeze-thawing.

Previous studies have indicated the positive impact of dietary supplementation of arginine on meat quality and growth, though there is no report regarding the effect of in ovo injection of arginine on meat quality. So, the aim of this study was to evaluate the effect of in ovo injection of different levels of L-arginine on hatchability, growth performance, and meat quality of Ross 308 broiler chickens. In this research, 300 fertile eggs were used in a completely randomized design with three experimental treatments (levels of 0.5 and 1% of L- arginine and total control). Experimental groups included: 1) in ovo injection of 0.5% L-arginine, 2- in ovo injection of 1% L-arginine, 3) total control group {collected control 1 (injection of distilled water) and control 2 (no injection)}, which were injected on d 14 of incubation. After hatching, broiler chicks of arginine treatments and total control group were divided each into four equal groups and placed randomly into four cages (replicates of the experiment). The rearing period continued from hatching to d 24. In order to investigate the quality of meat, on day 24, three chicks from each replicate (12 chicks per each treatment) were weighed, slaughtered and their breast muscles were used for meat quality evaluation. Based on the results, in ovo injection of different levels of L- arginine did not significantly affect 1, 10 and 24 day-old birds’ weight, daily weight gain, feed intake, feed conversion ratio, and relative weight of scalped carcass and breast muscle (P >0.05). Although, meat pH, meat fat and Ash content, and meat color indexes (a*, b*, L*, H) were not affected by L- arginine in ovo injection treatments (P>0.05), meat water loss, ΔD, and C indexes were significantly affected by experimental treatments (P˂0.05). Based on the overall results of this study, in ovo injection with different levels of L- arginine could not have a significantly noticeable effect on growth performance, meat production and/or meat quality of 24 day- old broiler chickens.

The objective of this study was to compare first service conception rate before and after milking and changes in metabolite and hormones during four times realted to milking in lactating dairy cow. 300 High producing Holstein cows (> 30 Kg/d and BCS) were randomlly selected and assigned into two groups: 1- insemination before morning milking (0700 a.m, n = 150) and 2- insemination after morning milking (0900 a.m, n=150). Milking was performed at 8 a.m. All cows were synchronized with G7G-Ovsynch protocol started at d 30 postpartum. Blood samples collected from subsample of cows (n = 45 per group) and at four times (before milking, with milking, 1 h after milking and 2 h after milking) for measauring glucose, triglyceride, free fatty acids, albumin andcortisol concentrations. Results showed that Glucose, trigyceride, free fatty acids, abumin and cortiso concentrastions were affected by miking time (P<0.05) and significanty increased with milking compared to before milking (P<0.05) but significanty decreased 1 h after milking compared to milking and before milking. Conception rate at d 32 and 60 after AI were greater in cows inseminated after milking in comparsin with before milking. In conclusion results of the present study showed insemination of cows after milking compared to before miking resulted in increased fertility.

In-ovo injection of anti-aromatase compounds with the aim of achieving a higher male to female sex ratio, higher economic impact, higher growth rates and better feed conversion ratio in broiler industry has been taken into consideration by researchers. The present study was conducted to find out if in ovo injection of aqueous and alcoholic extract of tomato can affect sex differentiation, sex ratio, hatchability, and performance of broiler chickens Therefore, 600 fertilized eggs were divided into 6 treatments, each with 4 replicates and 25 eggs per each replicate. Treatments included in ovo injection of tomato aqueous extract on the levels of 0.3 and 0.6 mL (TWE0.3, TWE0.6), tomato alcoholic extract on the same levels (TAE0.3, TAE0.6), in ovo injection of 0.1 mL of saline (Sham group: SG), and control group without any injection (Cont). On day 5 of incubation, the eggs were injected at the narrow end of the eggs using 1mL-syringes. Hatched chicks were reared (separated-sex) for 6 weeks to evaluate their general performances. Complete randomized block design was used and data analysis was performed using SAS software. The results showed that injection of 0.3 ml of alcoholic extract and 0.6 ml of aqueous extract lead to a significant increase in male chicken percentage at hatching compared to control group (P <0.05), without any negative effect on hatchability and performance (P >0.05). Data obtained from rearing period revealed significant improvement in some performance parameters such as average daily gain and average daily feed intake (P< 0.05). In conclusion, in ovo administration of tomato extract which contains flavonoids with anti-aromatase properties, caused higher percentage of male chicks followed by higher profit achievement. However, for more precise statement, there should be more tissue samples for histological studies and more diverse doses of tomato extracts as compounds containing anti-aromatase substances.

Due to the importance of conservation and preserving indigenous breeds, Baluchi sheep as the most populous breed of Iranian sheep with reliable pedigree was selected. In this study genetic variations were analyzed with 15 microsatellites markers (BM737, BM1815, BMS332, BMS995, BMS2721, KD101, LSCV36, LSCV38, McM63, McM139, McM214, McMA1, McMA10, OarVH110, TGLA231) in a population of Baluchi sheep. Whole blood samples were randomly collected from 140 sheep at Abbas Abad Breeding Station (Mashhad). After PCR reactions, McM139 locus wasn't amplified and LSCV38 locus was ignored for many null Alleles. Thirteen microsatellites loci were %100 polymorphic. Number of alleles, observed and expected heterozygosity, polymorphic information content (PIC) and Shannon index were calculated. Highest and lowest allele numbers was observed in OarVH110 locus with 12 alleles and 6 alleles in BM737, BMS332, McMA10, respectively. Effective number of allele was between 3.51 (LSCV36) to 8.66 (OarVH110). The highest and the lowest heterozygosity belonged to 0.89 (OarVH110) and 0.71 (LSCV36), respectively. OarVH110 locus indicated the highest PIC (0.873) and LSCV36 locus indicated the lowest PIC (0.669). The highest and lowest Shannon index were belonged to 2.21 (OarVH110) and 0.66 (LSCV36), respectively. These results verify high efficiency of microsatellites marker for screening of population's structure in Iranian native sheep and in future study for QTL mapping. So, presence of new alleles and allele range indicates difference between Baluchi sheep population structure with foreign Sheep breeds.

The present study was conducted to estimate the genetic and phenotypic parameters of productive and reproductive traits of Holstein cows in Mazandaran Holstein dairy cattle. To this purpose, data 39792 records of Holstein cows collected at Mahdasht Milk and Meat Company in sari during 1986 to 2015 were used. Productive traits included corrected 305 days milk records, fat and protein production, and reproductive traits were age at first calving, calving interval, dry period and days open. Genetic parameters were estimated by THRGIBBS1F90 software under single trait animal model using Bayesian statistical method based on Gibbs sampling approach. A total of 200000 cycles were implemented among which the first, 20000 cycles were considered as burn-in period. Heritabilities obtained as 0.34, 0.68, 0.65, 0.17, 0.007, 0.07 and 0.07 for milk production, fat production, protein production, age at first calving, calving interval, dry period and days open, respectively. The genetic correlation between milk production and fat production was 0.48. Genetic correlation between milk production, fat production and protein production with age at first calving was -0.003, 0.14 and 0.39, respectively, Genetic correlation between milk and protein production with calving interval was estimated to be 0.23 and 0.55, respectively. According to the results, correlations between production and reproduction traits could be considered in breeding programs.

The objective of this study was to compare introgression and synthetic breed strategies for litter size trait improvement in sheep using computer simulation. For this purpose, a trait with heritability of 0.1, consisting of two chromosomes was simulated. On chromosome 1, a single QTL as the major gene was created that accounted for 40% of the total genetic variance. The effect of favorable and unfavorable alleles for the QTL was fixed after seven generations in both A and B breeds, respectively. The introgression and synthetic breed strategies were compared using Classical and Classical with gene-assisted selection (GasClassical) methods. The genetic gain in introgression and synthetic breed strategies using GasClassical method was 39% and 16% higher than that of Classical method, respectively. The mean of inbreeding coefficient in the fifth generation in introgression strategy was 0.049 and 0.077 using the Classical and GasClassical methods, respectively, and in synthetic breed strategy was 0.11 and 0.008, respectively. The results of this study showed that the GasClassical method in comparison with the Classical method led to an increasing frequency of favorable allele (major gene) and genetic gain in both introgression and synthetic breed strategies. However, the genetic gain for one percent increase in inbreeding in the synthetic breed strategy was greater than that of introgression strategy, and as a result, the synthetic breed strategy performs better than introgression strategy.

Climatic variables are among the factors influencing the performance of various crop and livestock products. Considering the advanced climate change, the impact of climate indicators on livestock production can present serious challenge for producers. Crop yields prediction is one of the most important issues in the food security debate to increase the economic efficiency of livestock production. In this research, the relationship between climatic elements and indicators with honey bee function in Shahindej was investigated. The length of the statistical period was 12 years from 2007 to 2018. First, elements and climatic indices that were highly correlated with product yield were identified. Then, by default, the honey yield prediction model was presented. The validity of the model is based on the linearity of the relationship between independent and dependent variables, then the normal distribution of the error values and the independence of the error values. In the end, the normal distribution of the dependent variable was tested. Output of the model results showed that product performance with temperature was significant. The accuracy of the honey performance model with a RMSE was 11%. Therefore, it can be said with great accuracy that the effect of climate change on a half-degree increase in temperature will reduce honey performance by about 40 tons per year. The results of the study of the trend of cold and cold climate indicators presented by the World Meteorological Organization's Climate Change Detection Panel, Indicates that the region under study is experiencing a warming process. Therefore, changes in bee function were mainly influenced by climatic factors.