مجله پژوهش در نشخوار کنندگان
سال نهم شماره 3 (پاییز 1400)

Intake of poor quality plants of rangelands and pasture grasses and agriculture by products by ruminants is usually low to maintain animal performance because of their poor digestibility and nutrient deficiency. So, it seems essential to explore new feed resources, which may have potential as an animal feedstuff. So, one possible way to reduce this alimentary deficit is to use of naturally growing forages including Gundelia tournefortii (G. tournefortii). G. tournefortii is one of the most important rangeland plants that can be used to feed livestock. G. tournefortii are known to be a plant with high nutritional value and water content, and are therefore likely to be highly selective for consumption by native herbivores. It is very resistant to cold and dry weather and tolerates high temperature changes. Therefore, due to their diversity, they are able to propagate in large ecological areas and can be dry and semi-arid areas, often as part of forage and even a relatively good source of protein for ruminants. The aim of this study was to evaluate the effect of adding different additives on chemical composition, fermentation characteristics, gas production and digestibility parameters of G. tournefortii silage in a completely randomized design.

Whole forage Gundelia tournefortii were harvested and chopped with a conventional forage harvester under farm condition to length of 3-4 cm. Representative of Gundelia tournefortii forage samples were packed manually, in triplicate into plastic bags. The filled silos were stored at ambient temperature and allowed to ensile for 3, 7, 21 and 45 days. The following treatments were: 1) Gundelia tournefortii silage without any additives (control), 2) control + molasses (5% of DM), 3) control + organic acid (1% of DM), 4) control + barley meal (10% of DM) and 5) control + barley silage (20% of DM). After designated ensiling times, silos were opened and the ensiled forage was mixed thoroughly and then were dried at a 60°C in oven for 48 h and then ground to pass through a 2 mm screen for later analysis.

Results showed that different additives had effect on chemical composition of G. tournefortii silage significantly (p<0.05). Treatment G. tournefortii + barley meal had highest dry matter (DM) and organic matter (OM) content compared with others. Fermentation characteristics of silage were affected by different additives (p<0.05) and G. tournefortii treated with molasses had lowest pH. The highest and lowest aerobic stability was observed in organic acid treated silage (42 h) and barley treated silage (31/5), respectively. There were significantly differences among treatments on gas production parameters (P<0.05) and barley meal treated silage (on day 3) had highest gas production potential, organic matter digestibility (OMD) and short chain fatty acid (SCFA). In vitro digestibility of DM and OM were affected by additives (P<0.05). Treatment control (on day 7) had highest partitioning factor, and microbial crud protein efficiency.

Overall, these results indicated that in vitro gas production and digesibilty of G. tournefortii silage were improved by the application of molasses and barley silage as additive and its aerobic stability was improved by using acis asetic.

The prevalence of zoonotic parasitic diseases in large and small ruminants, which provide an acceptable percentage of protein sources of animal origin, is significant. In the meantime, liver parasites have a special place, because they can cause a lot of economic losses and also cause a lot of direct and indirect damages. Parasitic diseases have created many problems for the development of effective vaccines due to different epidemiological and biological characteristics, including the wide spread and diversity of antibodies and having extremely diverse and complex mechanisms against the immune system. These diseases often occur chronically and show no obvious clinical signs, cause less mortality in the herd, and mainly cause significant economic losses over time. This study aimed to determine the prevalence of various parasitic infections in the liver (Hydatid cyst, Cysticercosis, Fasciola, and Dicrocoelium) and lungs (Hydatid cyst and Strongyloides) of slaughtered animals in industrial slaughterhouses in Qazvin province.

This descriptive-analytical study was carried out in four seasons of spring, summer, autumn and winter in Qazvin province. A total of 95,156 head of livestock, including 54,864 sheep, 22,579 goats and 17,713 cattle, were inspected after slaughter. During this study, the liver and lungs of slaughtered animals were inspected by macroscopic observation.

The pollution rate of liver parasites (Hydatid cyst, Cysticercosis, Fasciola, and Dicrocoelium) and lung parasites (Hydatid cyst and Strongyloides) in sheep, goat, and cattle were 4.81 percent, 1.92 percent, and 1.93 percent respectively. The sheep with the highest pollution rate, have a significant difference compared to cattle and goats (P<0.05). Also, liver and lung parasites' pollution rate was 6.17 percent in spring, 7.80 percent in summer, 10.77 percent in autumn, and 10.50 percent in winter. Also, liver and lung parasites' pollution rate was 6.17 percent in spring, 7.80 percent in summer, 10.77 percent in autumn, and 10.50 percent in winter. The highest and lowest rate of infection was observed in autumn and spring (P≤0.05). In inspected livers, the highest rate of parasitic infection was related to dicrocoeliasis; it’s prevalence in sheep, goats, and cattle was 6.02 percent, 5.34 percent, and 6.78 percent respectively. Also, in inspected lungs, the most lesions were related to hydatid disease, the prevalence in sheep, goats, and cattle was 0.51 percent, 0.52 percent, and 0.58 percent respectively.

This study shows the prevalence of parasitic diseases in large and small ruminants in this region. Due to these diseases zoonotic nature, the use of appropriate management methods to prevent or control these diseases is crucial.

Mastitis is an inflammatory disease in dairy cows that occurs in response to infectious factors. This inflammatory disease have a high negative economic impact on dairy industry. In recent decades, somatic cell score has been used as an indirect method to control mastitis. Resistance to infection disease may be defined as the ability of an animal to have an immune response to prevent the spread of pathogens after infection. Previous studies showed that animals differ in their genetic ability for immune competence. Genetic resistance to mastitis involves interconnected biological mechanisms that result from differences in the response to mastitis that activate and regulate different levels of the immune response. A better understanding of the immune system and the metabolic pathways involved in responding to various pathogens may be used as a complementary approach to control of the disease. Several studies have been evaluated genetic mechanisms affecting somatic cells score in dairy cows. Many candidate genes affecting somatic cells score has been introduced. But the complex relationships between genes and pathways that affect them have not been fully identified yet. The main purpose of this study is to integrate the results of recent genome-wide association studies on somatic cells score using meta-analysis to obtain a set of important genes and pathways.

In this study, a search for the genome-wide association studies dataset in Google Scholar was performed using the keywords Dairy cows, Genome wide association studies, and Somatic cells score. Gene sets were available in different populations of dairy cow breeds (Holstein and Friesian breeds and red cows) in 11 independent studies from 2011 to 2019. 218 candidate genes for somatic cells score were found from genome-wide association studies. The number of common genes in dairy cows was examined using Venn diagram. Then, all available genes were combined and evaluated using meta-analysis. The ClueGO v2.5.4 plugin were used to conduct gene ontology analysis and KEGG pathways. The CluePedia v1.5.4 plugin in Cytoscape v3.7.2 were used to visualize genes and protein-protein interactions.

The results showed that U6, DCK, and NPFFR2 genes as the key candidate genes have an important role in combating infection and pathogens in the development of mastitis. Some biological processes, cellular components, molecular functions, and related pathways were identified. The most important biological process, cellular components and molecular function pathways were mesenchymal cell development (P=3.92e-04), apical plasma membrane (P=2.83e-03), and solute: cation symporter activity (P=3.71e-04), respectively.

Generally, the results of this study showed that meta-analysis based on a large number of original data revealed the most important candidate genes involved in the fight against mastitis pathways, this information provides a solid foundation for the development of new treatments for mastitis. Therefore, identification of important genes and gene ontology term enrichment (with high power and accuracy) can play an effective role in genomic evaluation and design of breeding programs aimed at controlling mastitis in dairy cows.

Primiparous cows are generally more sensitive to low pH, higher concentrations of volatile fatty acids, and postpartum ruminal acidosis than multiparous cows, possibly due to differences in feeding patterns and variation in nutrient intake. The aim of this study was to evaluate the ratio of omega-6 and omega-3 fatty acids in diets with or without pomegranate peel as a rich source of antioxidants, on nutrient intake, chewing behavior, and sorting activity of primiparous Holstein cows.

Primiparous Holstein cows (n = 12) were randomly divided into a Latin square design with a 2 × 2 factorial arrangement of treatments. Each period lasted 28 days with 21 days of adaptation to the diet and 7 days for data collection and sampling. The diet (1.5% dry matter) contained calcium salts of fish oil (CAFO) or palmitic acid-enriched fat (PAF) with (+ PP, 8.7% dry matter) or without (-PP) pomegranate peel.

Fats and nonstructural carbohydrate intakes were greater in palmitic acid-enriched fat -fed cows thancalcium salts of fish oil -fed cows. Also, intake of dry matter, energy, organic matter, protein, neutral detergent fiber, nonstructural carbohydrate and fats in cows supplemented with +PP diets were greater than cows fed –PP diets. Consumption of particles retained on 8-mm sieve, pan, peNDF8 in cows on +PP diets were greater than those in -PP cows. Cows fed palmitic acid-enriched fat treatment had less rumination time per kg of neutral detergent fiber, peNDF8 and peNDF1.18 than calcium salts of fish oil -fed cows. Also, palmitic acid-enriched fat treated cows had less chewing time per kg of peNDF8 and peNDF1.18 than cows in calcium salts of fish oil treatments. Sorting activity against long particle and peNDF1.18 and in favor of medium particle were higher in cows fed –PP diets than those in cows fed +PP treatments. Eating meal number per day increased and time between meals and duration of each meal decreased in –PP-fed cows than those in +PP-fed cows. Rumination and chewing time per kg of peNDF1.18 intakes were greater in –PP cows than +PP cows.

Under the conditions of this experiment and in primiparous cows, palmitic acid-enriched fat -fed cows had less chewing and rumination times per kg of peNDF intake than calcium salts of fish oil treatment however, the sorting activity and chewing pattern were not affected. Pomegranate peel increased nutrients intake, reduced sorting against long portions and fiber, as well as reduced the meals number and increased the duration of each meal.

Applying low-calcium to control milk fever have many problems in practice. Dietary Ca levels should be reduced by quantitative and qualitative methods such as limiting feed intake, which negatively affects the milk production and health of the cows. Anionic salts are also expensive and should be consumed before calving for a long period. It is also difficult to produce a homogeneous diet for selected cows in special section of a farm. In addition, add these salts to cows' diets reduces the palatability of the diet, decrease dry matter intake, conversely, increase negative energy balance and the concentration of non-esterified plasma fatty acids. Therefore, as an important goal of this research, it seems vital to introduce a method that solves the problems and have many advantages to improve productive traits and health related factors of fresh cows during a hot full stressed summer.

Study was performed by 60 Holstein cows near calving in 3 experimental groups using a completely randomized statistical design with repeated measurements in time. Study was done in summer season, adaptation and experimental period were 15 and 45 days from -15 to +30 after calving time, respectively. Experimental diets including: 1) Low-Ca or control diet (Ca=0.44%), 2) Anionic diet (Ca=1%), 3) Control +enriched Zeolite diet. From second week after calving the cows were fed with a fresh milking diet The DCAD of diets were +100, -100, +100 mEq/kg DM respectively. The Anionic and Zeolite supplementation were used at level of 2.8 and 1.5% based on daily DMI of cows. Experimental traits were included milk production and compositions, total and ionized plasma calcium and some reproductive disorders.

According to the results, consumption of DM and energy between diets were significantly different. Fat percentage of zeolite diet was higher than others but raw and corrected milk yield of anionic diet was the highest (P≤0.01). Plasma and ionized Ca concentration of zeolite diet were the same with two other diets at calving time but at 6, 12 and 24 hours after that were significantly higher than others (P≤0.01). The frequency of severe and subclinical hypocalcaemia was higher in control diet and older cows, but in zeolite diet was lower than others (P≤0.01). The highest BCS was for zeolite (2.98) and the lowest (2.86) for control diet (P≤0.01). The frequency of postpartum disorders (calving difficulty, retained placenta, endometritis, and abomasum displacement) was significantly lower in zeolite and anionic diets than control (P≤0.01). Highest percent of ssuccessful pregnancy, inversely, lowest percent of culled cows from herd observed in zeolits and anionic diets (P≤0.01).

According to the results, improved dry matter and energy consumption was observed in zeolite diet compared to anionic which had a direct effect on milk productive traits. Improved total and ionized Ca plasma concentrations during calving and after that and better control on hypocalcaemia and related problems in the herd, with highest BCS and a significant reduction in the frequency of postpartum disorders are of the advantages of zeolite diet. So the proposed method of calcium restriction using zeolite supplement seems to be successful and can be used as an alternative for common methods.

Zinc is involved in the regulation of many metabolic processes and zinc deficiency resulting in low appetite, consequently decreased feed intake. Also, zinc deficiency decreases the growth and weight gain of the animal. It has been reported that the daily requirement of zinc for suckling calves is 33 mg/kg DM. While, the amount of this element in cow’s milk is 3-5 mg/kg. Therefore, zinc supplementation may improve the performance of suckling calves. So, this study was performed to investigate the effect of different levels of zinc on performance and some blood and ruminal parameters in Holstein suckling calves.

This study was conducted using 18 newborn Holstein calves from 4 days of age to weaning (70 days) in a completely randomized design. Experimental treatments were treatment 1 (control, basal diet), treatment 2 (basal diet plus 30 mg / kg DM as zinc sulfate) and treatment 3 (basal diet plus 60 mg/ kg DM as zinc sulfate). The calves were housed in individual pens with cement floors and were offered with whole milk (approximately at 10% of weight) in two equal meals daily at 8:00 and 19:00 during the experimental period. They had free access to the pelleted starter and fresh-water. After 15 days, chopped wheat straw (5 %) and alfalfa (5%) were added to their starter. Daily feed and ort were measured to estimate daily dry matter intake and animals were weighed fortnightly to obtain average daily gain. Blood samples were taken from the jugular vein at the end of the trial (day 70) before the morning feeding for measurement of blood mineral (Zn, Ca, P, Fe, and Cu) status and the hematological parameters (hemoglobin concentration, red blood cell count, white blood cell count and hematocrit %). Also, the ruminal fluid samples were collected on day 70, 3 h after the morning feeding, by stomach tube and a vacuum pump for determination of ruminal volatile fatty acids concentrations.

The results showed that the use of different levels of zinc had no significant effect on feed conversion ratio in weaning calves. However, average daily gain in treatments 2 and 3 (724.29 and 765.00 g / day, respectively) and dry matter intake in treatment 3 (1692.41 g / day), were significantly (P<0.05) higher than the control treatment (628.29 and 1532.83 g / day, respectively). Supplementation of zinc significantly increased (P<0.05) serum zinc concentration in treatments 2 and 3 (1.184 and 1.168 mg / l, respectively). However, no significant differences were observed among treatments for the concentration of other minerals in blood serum (calcium, phosphorus, iron and copper). Also, supplementation of zinc had no significant effect on blood hematological parameters. Ruminal total volatile fatty acids, acetic acid, propionic acid, and butyric acid concentrations, and acetic acid: propionic acid ratio were not affected by zinc supplementation.

Generally, the results showed that a basal diet containing 29.68 mg Zn/kg DM can supply the zinc requirement of Holstein suckling calves. But, zinc supplementation improved the performance of these animals.

The use of conventional feed sources in livestock diets has caused that in addition to increasing demand, prices and imports also increase. On the other hand, the use of feed industry residues and their processing can provide reliable sources of nutrients in livestock diets. Therefore, this experiment was performed to investigate the processing of microwave electromagnetic waves on poultry byproduct meal on growth performance, rumen parameters, microbial protein production and nitrogen retention in fattening lambs.

Fifteen mixed male lambs with an average weight of 29.3±2.7 were used in a completely randomized design with 3 feed treatments and 5 replications. Treatments include: 1- Soybean meal, 2- poultry byproduct meal, 3- Microwave poultry byproduct meal. The experiment consisted of 14 days of adaptation and 70 days of fattening. Weighing was done every 14 days. Feeding was done at 7:00 and 19:00. Daily feed intake, initial weight, final weight were measured and recorded. Measurement of microbial protein produced in the rumen was calculated by estimating purine derivatives excreted through urine collection. On the last day of the experiment, three hours after the morning feeding, ruminal fluids were taken using a stomach tube and a vacuum pump. Then it was used to calculate the population of bacteria and protozoa, to determine the concentration of volatile fatty acids using standard internal solution and gas chromatography, to determine the concentration of ammonia nitrogen and the pH of ruminal fluid.

The use of microwave poultry byproduct meal in the diet instead of soybean meal in dry matter intake was not significantly different. Daily weight gain and total weight gain in microwave poultry byproduct meal treatment was against treatment of process without 324.3 and 22.7 kg versus 0.277 and 19.4 kg, respectively, with significant difference and improved traits (P <0.05). Also, feed conversion rate and feed efficiency between treatments 3 and 2 were 7.446, 0.135 and 8.455, 0.119, respectively, which showed a significant difference at the level of P <0.07 and P <0.08. The highest bacterial population (28.8*109 ml) was observed in soybean meal treatment and was significantly different from other treatments (P <0.05) but no significant difference was observed between treatments in protozoan population. Rumen pH between treatments 1 and 3 were 6.73 and 5.79 respectively (P <0.05). There was no significant difference in ammonia nitrogen concentration in ruminal fluid between treatments. The percentage of acetate, propionate and the ratio of acetate to propionate in treatment of processed poultry byproduct meal are 65.8, 18.8 and 3.5, respectively, which are the lowest, highest and lowest traits in comparison with other treatments, respectively (P<0.05). There was no significant difference in microbial protein production between treatments. The apparent nitrogen retention in the microwave treatment was 27.129 g / day which was not significantly different from other treatments and its lowest amount (24.861 g / day) was for soybean meal treatment and its highest amount was for conventional treatments with poultry byproduct meal was 32.148 g / day (P> 0.06).

This study showed that the effect of poultry byproduct meal processing by microwave method on growth performance traits was better than poultry byproduct meal without processing. Microwave replacement of conventional poultry byproduct meal with soybean meal did not differ significantly in growth performance traits. Also, replacing microwave and microwave poultry byproduct meal with soybean meal in the diet of fattening lambs without creating unfavorable conditions on rumen parameters and apparent nitrogen retention can replace soybean meal with up to 10% dry matter, reduce soybean meal demand and imports.

One of the most important economic indicators in the process of agricultural production is efficiency index. Due to the increasing competition and complexity of economic relations between production units, today measuring the efficiency of production, especially in livestock units to create the necessary planning and make optimal decisions in the management process of such units is of great importance. The aim of this study was to evaluate the technical, allocative and economic efficiencies and determine the factors affecting them in industrial farms in Kurdistan province.

The data of this research is related to the year 2019, in which statistics and information were collected through documentary study and face-to-face interviews. In this study, Deap 2.1 and Eviews 9 software were used to analyze the performance and determine the factors affecting them. To design the data envelopment analysis model, the main variables used in the study, including herd size, feed and concentrate, manpower, health, milk production and livestock manure production and the sum of different incomes were determined. The efficiency of industrial farms was evaluated in the framework of technical efficiency with constant return to scale, technical efficiency with variable return to scale, scale efficiency, allocation efficiency and economic efficiency. Performance calculations were performed assuming the minimization of production costs in the form of performance of industrial farms in Kurdistan province and the results were obtained annually. To determine the factors affecting the amount of performance obtained, Tobit regression analysis and parent statistics were used.

The results showed that technical efficiency with constant efficiency compared to the scale is 0.814 and with variable efficiency compared to the scale is 0.943. The scale efficiency of these livestock units was calculated to be 0.859 in which 22 dairy cattle breeding units with incremental returns to scale and 2 units with decreasing returns to scale were reported. The amount of technical efficiency in general was calculated as 0.824, allocation efficiency as 0.818 and economic efficiency as 0.680. In the general evaluation, milk production efficiency in Bijar city had the highest and in Qorveh city the lowest amount among other cities of this province. Decreasing the age of managers and increasing household manpower in technical efficiency as well as decreasing age and increasing fixed and current investments in economic efficiency had a positive and significant effect.

In general, in Kurdistan province, in terms of technical efficiency of 34%, allocation efficiency of 14% and economic efficiency of 24%, dairy cattle breeding units are operating at an efficient level and the rest of the units are inefficient. Given the conditions of farms and the current state of the Iranian economy in the short term, it is better for livestock units to reduce their herd size by selling older dairy cattle and native heifers and optimally reviewing the supply and allocation of production inputs. Do the necessary.