مجله پژوهش در نشخوار کنندگان
سال نهم شماره 2 (تابستان 1400)

Ruminal digesta is the nutrients consumed by the animal prior to slaughter, which is processed almost exclusively by rumination and exposure to the various enzymes and protozoa present in the rumen and a complete, ready-to-digest feed. After being processed, it is possible to re-feed it to ruminant animals. The use of digestive leftovers from slaughtered cattle could be a cheap, nutritious, and accessible alternative to the conventional feed ingredients. Therefore, the purpose of this study was to evaluate the effects of replacing cattle and sheep rumen digesta with alternative feed ingredients on the growth performance, carcass quantitative and qualitative traits, and some blood parameters of Dalagh fattening lambs.

A total of 24 Dalagh fattening male lambs at the age of 4.5 months, with a mean live weight of 27 ± 2.0 kg, were assigned to 6 treatments and four replications in individual cages for 90 days. Experimental treatments consisted of: 1) control, without rumen digesta of cattle and sheep, 2) 15% rumen digesta of cattle, 3) 30% rumen digesta of cattle, 4) 15% rumen digesta of sheep, 5) 30% rumen digesta of sheep, and 6) 15% rumen digesta of cattle, and 15% rumen digesta of sheep.

The results showed that daily gain and FCR were significantly different between treatments at the end of experiment (P <0.05). The highest daily weight gain and final body weight as well as the improving feed conversion ratio were observed in the treatment containing 30% rumen digesta of sheep. The results of body biometric showed that body length was significantly higher in the treatment contaning 30% rumen digesta of sheep, compared to the control (P <0.05). The results of quantitative carcass traits showed that treatment containing 30% rumen digesta of sheep in hot carcass weight, cold carcass weight, and crustacean were significantly higher than the control treatment (P <0.05). The results of some blood parameters of day 90 showed that there was a significant difference in the concentrations of glucose, cholesterol, BUN, and total protein between the experimental treatments (P <0.05). Therefore, in the treatment containing 30% of rumen digesta of sheep, the concentration of desired parameters was higher.

The results of this study showed that the use of rumen dried digesta in the diet of fattening lamb was effective in improving growth performance; especially live weight gain, FCR and carcass traits. Consumption of dried rumen digesta of sheep also had a significant effect on some blood parameters of experimental lambs. Similarly, 30% of rumen digesta of sheep had a better performance than other levels.

Flax products (seeds and meal) are one of the sources of energy and protein for ruminants. Flaxseed is an vegetable oil that contains 45-40% of oil and 23-30% of protein. In addition to extracting oil, its meal can be used as a protein source in animal feed diets. Although flaxseed is a very inexpensive and affordable source of omega-3s, more than 50 percent of its fatty acids are made from alpha-linolenic acid, but it cannot be used at high levels due to its anti-nutritional properties. Flaxseed processing improves nutrient consumption while reducing the negative effects of anti-nutritional substances such as lintine and makes food more palatable. This study was conducted to investigate the effect of processing type and level of flaxseed on the nutrient digestibility and blood parameters and safety of infant calves.

In order to investigate the effect of processing type and flaxseed level on the digestibility of nutrients and blood parameters and safety of infant calves, was used from 20 newborn Holstein male (with an initial weight of 41±5.4 kg). This experiment was performed in the form of a 2 × 2 factorial design with 4 treatments and 5 replications. Treatments included: 1- Treatments containing 5% micronized flaxseed, 2- Treatment containing 10% micronized flaxseed, 3- Treatment containing 5% extruded flaxseed and 4- Treatment containing 10% extruded flaxseed. The rations were provided to calves as pellets and were adjusted. The entire trial period was 60 days, including 14 days of habituation. Feed and fecal samples were collected in the last 5 days of each treatment period to determine nutrient digestibility. On the last day of the blood test, each of the treatments was performed to determine blood and immune parameters. Flaxseed replaced corn and soybean meal in the starter diet. Given that the effect of treatments on the amount of dry matter, daily weight gain, final weight of calves and also due to improved digestibility of nutrients was not significant, It is recommended to use flaxseed in the diet of infant calves at the level of 5% as a source of energy and protein.

Based on the results of this experiment, different levels of processed grains had a significant effect on the digestibility of dry matter, organic matter, crude protein, insoluble fiber in neutral detergent, insoluble fiber in acidic detergent and crude fat (P <0.05). so that the highest digestibility of nutrients belonged to treatments containing 10% extruded flax and 10% micronized flaxseed. Also Experimental treatments also had a significant effect on blood urea nitrogen (P <0.05), but other blood and immune supplements such as cholesterol, triglycerides, glucose, crude protein, albumin, HDL, LDL, VLDL, IGG, and the number of blood cells White, neutrophils, lymphocytes, monocytes, and the ratio of neutrophils to lymphocytes were not affected by experimental treatments (P <0.05).

Considering that the results of this experiment show that using processed flaxseed at the 10% level improves the digestibility of nutrients, We can use 10% extruded flaxseed as a source of energy and protein in the diets of infants.

The effects of lactic acid bacteria as a microbial additive on the fermentation properties of silage are mainly due to the production of beneficial metabolites that can inhibit the growth of pathogenic and destructive microorganisms. Therefore, the ability of a strain to use numerous substrates in forage plants and produced different metabolites can be useful in competition with other microorganisms. This ability can be used as a principle for selecting inoculants. Nevertheless, research has shown that published articles on inoculant selection to limit the growth of these destructive and pathogenic microorganisms are still scarce. Some researchers have reported the effects of microbial inoculants on silage fermentation. However, despite numerous articles on the effects of inoculants on silage fermentation, there is little descriptions for the systematic selection of strains. The aim of this study was to isolate, identify and select strains of lactic acid bacteria with the ability to improve fermentation properties and prevent the growth of pathogenic and destructive microorganisms and evaluate the effect of inoculation of these strains on nutritional value and aerobic stability of maize silages.

This study was performed to select the lactic acid bacterial (LAB) strains isolated from different sources and evaluate their effect on the quality of maize silage. Lactic acid bacteria strains were inoculated to evaluate metabolite production and pH reduction in aqueous extract obtained from maize forage. One hundred and twenty-one strains were isolated from various sources in the laboratory. All isolated strains were gram-positive, catalase-negative and mainly lactic acid-producing, which were considered lactic acid bacteria. 16S ribosomal DNA sequence analysis of 22 representative strains was used to confirm the presence of dominant groups. The sequences of different isolates of lactic acid bacteria had a high degree of similarity to the GeneBank type strains, which showed between 99 and 100% similarity. Four strains of lactic acid bacteria that showed the best results were evaluated in experimental silos. This experiment was performed in a completely randomized design with five treatments (four strains of lactic acid bacteria and one control without inoculum) and nine replications. Inoculants were used in 106 colony forming unit/g of fresh forage to chopped maize forage, which were then ensiled for 105 days. After opening the silos, silages were sampled for analysis of chemical compositions and fermentation products.

Inoculation of lactic acid bacterial strains affected the chemical composition, fermentation properties and microbial population. Inoculation of lactic acid bacterial strains significantly affected the chemical composition and concentration of lactic and acetic acids, ethanol and 1,2-propandiol of silage. Among all treatments, silages inoculated with Lactobacillus fermentum had higher acetate concentration (p < 0.0001), but lactate concentration (p < 0.008) and yeast counts (p < 0.0001) were lower than other silages. Also, inoculation of silage with L. fermentum (strain 16) resulted in silage with higher lactic acid bacterial population and improved aerobic stability after air exposure (p < 0.0001). Silages inoculated with L. fermentum and fallowed by with L. salivarius contained the lowest number of yeasts (p < 0.0001) and filamentous fungi during fermentation. Between silages, silage inoculated with L. fermentum showed higher aerobic stability (p < 0.0001).

The pre-selection method based on the production of metabolites was efficient in selecting new inoculation strains along good correlation with experiments in laboratory silos. Inoculation of lactic acid bacterial strains in maize silage resulted in differences in nutritional value or population of pathogenic and destructive microorganisms. Strains 16 and 7, identified as Lactobacillus fermentum and Lactobacillus salivarius, were considered promising sources for use as inoculants in maize silages because they provide silages with better fermentation properties and improve aerobic stability after exposure to air.

Crossbred lactating cows were hypothesized to outperform Holsteins under environmental stresses . The objective of this study was , therefore, to compare production, reproduction, metabolism and health of purebred Holstein cows vs . crossbred Holstein × Montbeliarde and Holstein×Simmental cows under hot and humid conditions of north of Iran ( Sari , Mazandaran ) .

Dairy crosses were produced by crossing Holstein ( H ) cows with Montbeliarde ( M ) and Simmental ( S ) bulls’ semen . The performance and health of 70 primiparous cows from each breed ( 210 cows in total) were compared during their first lactation . Blood samples were taken from 15 primiparous cows from each breed at stages of close-up , calving , 21 days after calving. Samples were analyzed for glucose , BHBA, NEFA, calcium and mangium . Statistical analyses were performed using SAS programs ( GLM and MIXED procedures ).

Results showed that Montbeliarde × Holstein and Simmental×Holstein crossbred cows were not different (P> 0.05) from pure Holsteins in rectal temperature , fertility and other reproductive indices , 305-d milk yield, milk fat and protein yield, stillbirth, mastitis, and laminitis rates and close-up blood metabolites. However , Montbeliarde × Holstein cows had greater calving difficulty than did Simmental×Holstein cows (P < 0.05 ) . Also , both crossbred groups had higher incidence of metritis compared to purebred Holstein cows ( P < 0.05 ) . The purebred Holsteins exhibited more desirable udder traits than did crossbred cows (P < 0.05). The crossbred cows had more body condition score ( BCS ) during the transition period than did the pure Holsteins (p < 0.05 ). However, stature of Simmental × Holstein crossbred cows was shorter than pure Holstein . Foot angle was steeper for Holstein×Simmental and Holstein × Montbeliarde crossbred cows , but Holstein × Montbeliarde crossbred cows were similar to pure Holstein cows for hoof measurements .

findings of this study suggest that Holstein×Simmental and Holstein × Montbeliarde crossbred cows did not outperform first - lactation purebred Holstein cows, and that they experienced higher rates of dystocia and metritis under stressful hot and humid conditions .

Pomegranate (Punica granatum) seed pulp is one of the wastes of agricultural conversion industries that has been increasingly used in recent years due to its antioxidant properties in animal nutrition. Pomegranate seed pulp contains polyphenolic compounds that mainly contain ellagic acid, punicalagin and punicallin, which have antioxidant properties and prevent the peroxidation of fats and the activity of free radicals. In addition to polyphenolic compounds, pomegranate seeds contain estrogens such as "estradiol, estrone and estriol" and in lower concentrations also contain testosterone, beta-sitosterol and coumestrol, but there are many reports about its side effects on the physiology and metabolism of ruminants. Due to the role of estrogens in lipid metabolism, pomegranate seed pulp as an estrogen-rich plant source may be able to mimic the regulatory role of endogenous estrogens on metabolism and reproduction. In this study, the estrogenic effects of pomegranate seed pulp on serum estradiol concentration and other blood and antioxidant variables of dry non-pregnant Saanen goats were investigated.

In this experiment, 18 non-pregnant dry Saanen goats in 3rd to 4th parity number with average weight of 44.85 ± 5.16 kg were used in a completely randomized design with 3 treatments and 6 replications. Experimental treatments included: 1) control treatment 2) Basal diet with 12% of pomegranate seed pulp 3) Basal diet with 12% of pomegranate seed pulp + ozone gas (estrogen removal agent from pomegranate). Blood parameters of estradiol, albumin, direct bilirubin, total bilirubin, creatinine, glucose, betahydroxybutyrate, urea, uric acid, blood urea nitrogen, alkaline phosphatase, aspartate and alanine aminotransferase, Triglycerides, HDL, LDL and plasma antioxidant factors of MDA and TAC were measured. Experimental data were statistically analyzed by SAS software with mixed procedure as repeated data over time.

Based on the results, the parameters of standard estradiol concentration and the area under the serum estradiol concentration curve increased (33.36 pg.ml-1 and 605.12 cm2 respectively) significantly during the estrus cycle under the influence of treatment 2 (p <0.05). Ozone gas in treatment 3 significantly reduced these variables (28.13 and 543.91) compared to treatment 2 and was not significantly different from the control (25.56 and 515.12). Blood parameters other than phosphorus and some antioxidant variables were not significantly affected by experimental treatments, indicating insufficient estrogen intake to disrupt homeostasis of blood parameters at level of 12% Replacement of pomegranate seed pulp with wheat bran.

Generally, the level of 12% of pomegranate seed pulp in the studied physiological stage, did not have significant negative effects on normal metabolic parameters of Saanen goats. Elimination of the effect of estrogen in treatment 3 indicates that ozone gas is able to diminish the effect of dietary phytoestrogens.

In recent years, various tools for reproductive management have been introduced, the most important of which are drugs that regulate estrus time and mating of sheep and goats. Due to the poor reproductive management of nomadic herds and in order to improve the existing conditions, one of the main needs of this project is to study the use of estrus synchronization methods and create controlled off-season reproductions in one of the herds. Nomadic herds in order to observe the objective results in the same herd and also to introduce and model these methods in other herds in the region. This study was performed to investigate the increase in twinning and to determine the best amount of PMSG on fertility and calving in Kurdish sheep. Therefore, due to the weak reproductive management of nomadic herds and in order to improve the existing conditions, one of the main necessities of this project is to study the use of synchronous estrus methods and create controlled out-of-breeding reproductive seasons in one of the herds. Nomads are in order to observe the objective results in the same herd and also to introduce and model these methods in other herds in the region. Therefore, in this project, the effects of the duration of cider progestogen use (14 days) along with injection of different amounts and times of PMSG hormone in sheep in two nomadic herds of the province were investigated.

In this experiment, 90 Kurdish ewes aged 3 and 4 years were used in nomadic herds in 3 experimental groups in Golestan province. Cider was used to synchronize the herd for 14 days. Simultaneously with cider withdrawal, each experimental group received different amounts of PMSG muscle intramuscularly. 36 hours after CIDR ejaculation, the ewes showed estrus and were placed in front of the ram for mating for 7 days. It was recorded on ovulation day and calving day, and finally the effect of different amounts of hormone on the performance of each treatment was investigated. Data were analyzed using SAS software using Duncan's method and GLM procedure at 5% alpha level.

No significant level was observed between the treatments that received 400 and 500 units of PMSG, but the weight of the three-month-old lamb in the group that received 400 and 500 units of PMSG compared to the group that received 600 units of PMSG was significant. Has been.

The results showed that with increasing the amount of PMSG, the number of ewes that showed estrus, estrus percentage, number of pregnant ewes, average weight of three-month-old lamb and weight of production lambs per treatment increased and the average weight of three lambs increased. The month showed a significant increase.

One of the most important goals of dairy cows breeding is to increase profitability by reducing production costs. Cost analysis is one of the basic needs to calculate the economic efficiency of cattle breeding to reduce the cost of milk. Considering that the study of the present subject has not been seriously considered by researchers and officials, we conducted a study aimed at investigating the economic aspects of milk production in Holstein herds in Iran compared it to other countries in the world.

For this purpose, economic and returns indicators, and affecting factors on milk production costs in five Isfahan dairy herds as a sample in 1396 over one year was calculated. Data were collected through a questionnaire and economic analyses were performed by using the TIPI-CAL model which was developed by the IFCN Dairy World Network, and statistical analyses were performed using SAS software. IFCN Dairy is an international farm Comparison network that economically and productively analyzes the information of best farms from more than 100 countries, and for a more accurate and comprehensive understanding of the dairy world with compiles, a milk global map Compares together.

Studies showed that the highest cost of the dairy herd with an average of 68% in Iran and 55% on a world scale was related to feed. The labour costs had a 7% share and the share of depreciation on machinery and buildings was 7.8% of total costs. In typical farms, per 100 kg energy-corrected milk (ECM), an average of Feed cost was 26.0 USD, Vet & medicine cost was 4.1 USD, machinery and buildings costs was 3.1 USD and the labor costs had an average of 2.8 USD. On average, Cash costs were adjusted to 36 USD, depreciation, and lost opportunity costs were also 1.7 and 0.7 USD/100 kg ECM. The average cost of producing milk only in typical farms was 29.8 USD/100 kg ECM. World milk price indicator, world feed price indicator, and IFCN sustainability indicator were calculated on IRAN and global scale in the last 10 years, and also was seen in 1396 typical farms with 1.2 sustainability indicator were financially justified and profitable.

The results of the study indicate the existence of profitability and financial and economic justification in the studied farms, which was estimated by examining the factors affecting the cost of milk and also calculating economic indicators. The financial and economic study of dairy farms can better identify the location of these farms and increase the level of awareness of policymakers and investors of agricultural activities to make principled decisions or solve existing problems. The results of this research can provide a new approach to comparing dairy herds in different countries and compare it with dairy farms in Iran by using the economic, return, and profitability indicators to dairy farmers and experts.

The use of bio-waste in animal feed, in addition to reducing the cost of feed, reduces environmental pollution resulting from the disposal of this waste. Feathers make up about 10% of a bird's weight. 90% of full weight contains creatine, which is rich in the serine amino acids cysteine, glycine, alanine and threonine. The strength of fibrous protein is due to its high hydrogen, disulfide bonds and low hydrophilicity, which makes creatine insoluble and stable against degradation by enzymes such as trypsin and pepsin. Although the poultry industry in the country is expanding day to day, there are no plans to process and return this valuable product to the production cycle. Therefore, the purpose of this project is Processing of Feather meal using ozone (o3) gas and evaluation of its nutritional value using in vitro and in situ nylon bags techniques.

To process the Feather meal with ozone gas, for this purpose a reactor with a capacity to withstand twice the pressure was designed and built. The processing reactor was a double-walled steel tank with a steel surface with a capacity of 1 kg. An ozone generator with a capacity of ten grams of ozone per hour was connected to it and an oxygen capsule was used to supply the oxygen needed by the device and also to increase the pressure inside the reactor. Experimental treatments include: control (without processing), ozone-processed Feather meal in 30 minutes, ozone-processed Feather meal in 60 minutes, ozone-processed Feather meal in 90 minutes and ozone-processed Feather meal in The time was 180 minutes. In order to determine the degradability coefficients of dry matter, three fistulated Holstein male steers were used to prepare and incubation of the samples in situ within the rumen. In order to determine the effect of processing on the amount of gas produced in the laboratory, the pressure of the produced gas was determined in three separate cycles and three repetitions per sample in each run.

Feather meal dry matter under the influence of ozone gas showed a significant decrease in treatments of 60, 90 and 180 minutes (P <0.05) The amount of crude fat under the influence of ozone gas processing showed significantly increased in treatments 60, 90 and 180 Minute (p < 0.05). The amount of crude protein in 180 minutes treatment showed a significant increase compared to the control (P <0.05) but no significant difference was observed in other treatments. The amount of ash was not affected by ozone treatment. Ozone gas processing increased the amount of gas production (P <0.05). The gas production of insoluble part showed a significant increase in all processing times compared to the control (P <0.05). The decomposition rate constant showed a significant decrease in the 180-minute treatment (P <0.05). There was a significant increase in methane production volume and dry matter digestibility of all treatments (P <0.05). The pH value was not significant. The protozoan population in 90 and 180 min treatments showed a significant increase compared to the control (P <0.05). Dry matter degradability showed a significant increase in all treatments (P <0.05). The insoluble part showed a significant increase with increasing frequency (P <0.05). Effective degradability in all passage rate constants showed a significant increase with increasing processing time (P <0.05).

According to the results of this experiment, it can be concluded that processing of Feather meal using ozone gas releases peptides and amino acids and consequently increases its degradability and nutritional value. However, further studies are needed to increase the processing time, use of oxygen in the air,

The last month of pregnancy is one of the critical stages for cattle. Providing the nutrients and energy needed at this time is vital, as In sufficient energy supply at this time increases the risk of metabolic diseases in livestock, which can be greatly prevented by increasing the energy density of the diet using oilseeds. Therefore, this experiment was performed to investigate Nutritional effects of cannula and soybean as a fat supplement on performance of Ghezel ewes during the transition period

This experiment was carried in a completely randomized design using 16 ghezel ewes with an average age of three years and an average weight of ±59.8 kg in a 74-day period (14 days of adapting and 60 days of experiment). Treatments included: 1. Control (diet without fat supplementation) 2. Base diet containing 5% milled cannula as a source fat supplementation, 3. Base diet it contained 5% of milled soybean source fat supplementation and 4. Base diet containing 5% mixture of cannula and soybean at 50:50. The rations were given to the cattle in a completely mixed manner at 6:00 and 18:00. The weight gain of lambs in the postpartum period was measured daily using a digital scale. In order to determine the milk produced and the composition of ewes' milk, milk samples were collected on two consecutive days and analyzed using a Milco-scanner. Rumen fluid sample was taken to evaluate the parameters of ruminal fermentation on the twentieth day after delivery using esophageal catheter. Intravenous blood samples were taken from the venous vein on the twentieth day after delivery to measure blood counts.

The results showed that the birth weight of lambs, the amount of feed intake and daily changes in the weight of ewes before and after calving were not affected by experimental treatments (p < 0.05). Weight gain of lambs did not show a significant difference between treatments. Milk production was significantly higher in the diet of cannula (p < 0.05). There was no significant difference in the amount of milk compounds (P <0.05). There was no significant difference in blood triglyceride, cholesterol and beta-hydroxybutyrate levels between different experimental treatments. The amount of glucose and total blood protein in the postpartum period showed a significant difference between treatments (p < 0.05). However, the amount of blood urea nitrogen in the postpartum period was higher in soybean treatment than other treatments (P <0.05). There was no significant difference in pH and the amount of major volatile fatty acids in the rumen including acetic acid, propionic acid, butyric acid and iso valeric acid (P <0.05). The control treatment had the lowest digestibility of protein and the highest digestibility of insoluble fibers in neutral detergent among the treatments (p < 0.05).

According to the results of this study, the use of oilseed cannula as a fat source at the level of 5% can improve milk production without changing the composition of milk and feed intake. However, more studies are needed in this area.