مجله پژوهش در نشخوار کنندگان
سال ششم شماره 2 (تابستان 1397)

Pro- inflammatory cytokines are small proteins that are released by different tissues and cause an inflammatory condition in body. Conjugated linoleic acid (CLA) is a common name for fatty acids with 18-carbon and a conjugated double bond. Conjugated linoleic acid can affect pro-inflammatory cytokines production. Since pro-inflammatory cytokines can affect different physiological processes, this study investigated effects of conjugated linoleic acid supplementation during transition period on gene expression of pro-inflammatory cytokines in mammary gland, uterus and subcutaneous fat of Holstein cows. Twenty-four cows with body condition scores of 3.2±0.20 (SEM±mean) and lactation number of 3.2±1.80 were allocated to four treatments (six heads per treatment): feeding palm oil (75g/d) from -21 d to +21 d (C21) or +42 d (C42) relative to parturition, feeding rumen protected CLA (75g/d) from -21 d to +21 d (CLA21) or +42 d (CLA42) relative to parturition. Rumen protected CLA provided 7.5 g/d each of trans-10, cis-12 CLA and cis-9, trans-11 isomers. Tissue samples were taken from mammary gland, uterus and subcutaneous fat at 21 and 42 days postpartum. Mammary gland samples were taken from the sampling site in rear udder, 6-8 cm bottom to udder and skin junction and 3 cm of udder cleft using a medical semi-automatic sampling device. Uterus samples were taken by passing a sampling device through cervix and conducting uterus body via rectum. By making an incision through the skin of around pin, subcutaneous fat samples were taken. Expression of tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2) enzyme and toll like receptor-4 (TLR-4) were measured by real time-PCR. Feeding rumen protected CLA during transition period decreased TNF-α gene expression in mammary gland (P˂0.05). In mammary gland, effect of time and interaction of time in treatment were nonsignificant for TNF-α. Conjugated linoleic acid increased expression of COX-2 gene in uterus of CLA42 cows (P˂0.01). In uterus, effect of time was significant for COX-2 (P=0.05). Feeding rumen protected CLA during transition period significantly increased COX-2 gene expression, but had no effects on gene expression of TNF-α and TLR-4 in subcutaneous fat. Results of this experiment showed that adding CLA supplementation to dairy cow’s ration during transition period can alter expression of some pro-inflammatory cytokine genes in mammary gland uterus and subcutaneous fat. Results of this study provide preliminary findings that can be used in ongoing mechanistic studies investigating CLA effects on some tissues in dairy cows

 

Trace minerals, as metabolic modifier agents, increase nutrients utilization efficiency in domestic animals. Selenium has important metabolic and antioxidant functions in animal cells. However, there is not enough information regarding selenium requirements of Iranian local sheep. Therefore, the aims of this study were to investigate the effects of feeding selenium-methionine (Se-Met) supplement on growth performance, nutrients digestibility, ruminal fermentation status and some blood metabolites of fattening male lambs.

Fifteen Kermani male lambs with average body weight of 32.2 ± 1.09 kg were assigned to 3 treatments with 5 replicates each, as a completely randomized design for 10 weeks including 2 weeks of adaptation and 8 weeks of data collection. The experimental treatments were (1) basal diet without supplemental Se, (2) basal diet plus 0.5 mg/kg diet of Se-Met, and (3) basal diet supplemented with 1 mg/kg of Se-Met. Daily feed intake and body weight were measured. The nutrients digestibility was determined via total feces collection method at the end of study. Sampling from the rumen fluid was done on the last day of the final week of the experiment just two hours after morning feeding using the esophagus-tube connected to vacuum pump for pH and ammonia nitrogen determination. Blood samples were also drawn from jugular vein at the end of experiment and serum was used for metabolite analysis. The statistical analysis of data was done by using SAS software.

Based on the results, average daily feed intake and gain were not affected by the experimental treatments (P>0.05). However, lambs fed 0.5 mg Se-Met tended to have improved feed conversion efficiency compared with those on the control diet (P=0.07). Feeding male lambs with 1 mg/kg of Se-Met supplement increased dry matter and organic matter digestibility compared to the control lambs (P<0.05). Despite the higher values for fat as well as neutral and acid detergent insoluble fiber digestibility, their difference with that of the control was not statistically significant. Moreover, NH3-N concentration and pH of ruminal fluid were not affected by the experimental treatments (P>0.05). Feeding 1 mg/kg of Se-Met increased serum glucose concentration (P=0.03), however, serum total protein, triglyceride and urea concentrations were not different among experimental groups (P>0.05).

It can be concluded that dietary supplementation of 0.5 mg Se-Met/kg of diet improves feed conversion efficiency and 1 mg Se-Met increases dry matter and organic matter digestibility as well as blood glucose of fattening lambs without any adverse effects on ruminal pH and ammonia nitrogen concentration

Milk consumption is one of the most important factors affecting growth and survival of calves in the pre-weaning period. Usually due to the higher cost of milk for feeding calves, it is recommended that the amount of milk intake be maintained at about 10% of body weight (4 liters per day), so that the calf is more encouraged to intake starter diet. In recent years, researchers have been looking for the best milking pattern to support the growth of calf more economically .The aim of this study was to compare the effect of two milk intake patterns, including conventional (4 kg / day) and free milk intake on the performance, skeletal growth, and blood metabolites of Holstein female calves. Thirty newborn Holstein female calves with average BW of 42.7 ± 2.2 kg were used in a completely randomize design. Experimental treatments included of conventional (4 Kg/d) and ad libitum milk intake. The experiment carried out in two periods: pre-weaning (day 1 to day 60) and post-weaning period (day 61 to day 120). Calves fed milk twice daily in the morning and the afternoon and had free access to starter diet and water. Starter intake was measured daily and ADG was calculated in a weekly basis. Skeletal parameters including body length, withers height and pin distance were taken at weaning (day 60) and end of the experiment (day 120). Blood metabolites including glucose, total protein, triglyceride and cholesterol were measured on days 30 and 60 of the study. The results showed that calves fed ad libitum milk intake had lower pre-weaning starter intake (P<0.01) and greater starter intake (P<0.01) during post-weaning and overall periods than those fed conventional milk intake. In calves fed ad libitum milk intake, average daily gain was higher (P<0.01) than the calves fed conventional milk intake during pre-weaning and overall periods but it was lower (P<0.01) during post-weaning period. Feed efficiency was higher during pre-weaning (P=0.05) and lower during pre-weaning period (P<0.01) in calves fed ad libitum than those fed conventional milk but it was insignificant in the overall period (P>0.05). Body weight of calves fed ad libitum milk intake was greater during pre-weaning, post-weaning and overall periods than those fed conventional milk intake (P<0.01). Calves fed ad libitum milk intake had greater (P<0.05) body length than those fed conventional milk intake. Plasma glucose and cholesterol concentrations were greater (P<0.05) in calves fed ad libitum milk intake than those fed conventional milk intake in day 30 of experiment. Plasma total protein and cholesterol concentrations were not affected by milk intake pattern (P>0.05). It is concluded that ad libitum milk intake resulted in better performance of dairy calves

In previous studies in low-protein diets, mostly used pure sources of protected methionine or combined lysine and methionine used. It has been used in limited studies of the pure source of protected lysine to balance the dietary amino acids. It seems that investigating the effect of protected lysine and methionine supplementation alone and in combination, in low-protein diets, especially in early lactation, is useful to achieve maximum performance. Therefore, the purpose of this study was to investigate the effects of reducing dietary crude protein (CP) concentration and alone and in combination use of protected lysine and methionine amino acids on milk yield and milk composition and concentration of blood chemical metabolites in Holstein lactating cows during early lactation. In this study, 8 Holstein lactating cows with average 89±37 days in milk were used in a repeated measurement design two 21 day periods; each period contains 17 day for adaptation and 4 day for sampling. Treatments were: 1) a formulated diet with 17.8% CP, 2) a formulated diet with 16.5% CP plus 6-gram per day protected lysine, 3) a formulated diet with 16.5% CP plus 13-gram head per day protected methionine, 4) a formulated diet with 16.5% CP plus 6-gram lysine and 13-gram protected methionine per head day. The results of this study showed that dry matter intake, the percentage of milk fat and protein, molar proportion of volatile fatty acids, pH of rumen fluid and apparent digestibility of nutrients were not affected by experimental treatments. (P > 0.05). The results of independent comparisons in milk yield and feed efficiency indicated that by reducing the dietary protein concentration and the addition of protected methionine (alone and in combination with lysine) led to significantly increased in milk yield and feed efficiency, relative to the control group (P < 0.05). But in independent comparisons inside the treatments there was no significant difference between protected lysine and methionine in milk production and feed efficiency (P > 0.05). The addition protected lysine and methionine, alone and in combination resulted in a significant decrease (P < 0.05) in the milk concentration of urea nitrogen, relative to the control (respectively 12/36, 12/74, 13/12, to 15/37). Crude protein intake in the supplemented protected methionine and lysine, alone and in combination, group compared to the control group was significantly decreased (P < 0.05). Methionine and lysine supplementation (alone and in combination) resulted in an increase (P < 0.05) in the serum albumin total protein concentration, compared to the control group. In cattle receiving protected methionine serum urea nitrogen concentration was lower than that of control (P < 0.05). The addition of protected methionine (alone and in combination with lysine) led to significantly increase (P < 0.05) in serum glucose concentration in early lactation. The results of this study indicate that by decreasing the amount of protein in the diet from 17.8% to 16.5% in early lactation and the use of protected amino acids without adversely affecting on the nutrients. Also, the results of the present study showed that combined use of protected lysine and methionine compared to their individual use, one more effective to improve the performance of Holstein lactating cows during early lactation

The transition period for a dairy cow is from 3 to 2 weeks prepartum until 2 to 3 weeks postpartum. Transition cow nutrition and management have received much attention in the research and popular-based literature in recent years because of the recognition of its importance in the productivity and health of cows. Also, Application of different source of minerals and their metabolism performance a current issue in animal science and research centers. The objective of this study was to selenium nanoparticles synthesis and investigate its effect compared with selenium source of sodium selenite on milk yield and composition and the blood parameters associated with inflammation and energy statues of Holstein dairy cow dairy cows. In this study 16 Holstein cows were selected (days in milk 5 ± 2) and assigned them randomly within one of the two experimental treatments in tie-stall pens for 35 days. These treatments were including: 1) diet with sodium selenite source (0.3 ppm sodium selenite), and 2) diet with selenium nanoparticles (0.3 ppm selenium nanoparticles). Milk yield and composition were measured for all cows. Blood parameters, including albumin, bilirubin, total cholesterol, beta hydroxide butyrate acid, non-esterified fatty acid, glucose, total protein, globulin and blood urea nitrogen, were collected at 3day intervals in 1, 14, 30 periods of experiment. Also, liver functionality index of cows was calculated. Except of milk protein percentage, no significant differences were observed in milk yield and composition. Milk protein percentage of cows was higher fed with diet with selenium nanoparticles compared to cows fed with sodium selenite diet (P-Value=0.05). There was no significant difference in plasma urea concentration between the two treatments in the present experiment. However, numerically plasma urea was lower in cows fed with diet with selenium nanoparticles compared to cows fed with sodium selenite diet. Statistically, blood plasma total protein of cows (P-Value=0.06) and globulin (P-Value=0.1) tended to significant. There was no significant difference in blood parameters related to liver function among experimental treatments. As there was no significant difference in serum cholesterol, bilirubin and albumin in blood plasma in cows fed from diet with sodium selenite compared to cows fed from diets with selenium nanoparticles. When the values of these parameters were placed in the formula of the liver functionality index. The results of the present experiment showed that diet with selenium nanoparticles had a positive effect on milk protein. Also, a glance at the results of blood parameters revealed no significant differences in blood parameters of cows fed selenium with nanoparticles or sodium selenite source. It seems, due to experience the metabolic complexity of dairy cows during the transition and fresh periods, judgment must be thinkable in order that nanoparticles can have a positive or negative effect on the metabolic function and ultimately the production performance, and it is necessary to study further studies on the nutrition of selenium nanoparticles in dairy cows.

Mutton production in Iran, as the main source of red meat, does not satisfy the increasing demand of the consumers. Estimation of genetic parameters of economic important traits are necessary for determining breeding goal and selection index. In this study, data were collected from 1996 to 2014 at the Makooei Sheep Breeding Station (Makoo) in west-Azerbaijan province were used to estimate the genetic parameters for growth traits and Kleiber ratios. Traits studied were birth weight (BW), weaning weight (WW), six month weight (6MW) and yearling weight (YW), Average daily gain from birth to weaning (ADGa), Average daily gain from weaning to six months of age (ADGb), Kleiber ratio from birth to weaning (KRa), and Kleiber ratio from weaning to six months of age (KRb). (Co) variance components were obtained fitting different animal models using a restricted maximum likelihood (REML) procedure via ASREML program. The most appropriate model for each trait was determined based on log likelihood ratio tests. The most appropriate model for birth weight trait model 3 (direct and maternal genetic effects, without considering covariance between them), weaning weight, six month weight and Average daily gain from birth to weaning Model 2 (direct additive genetic effects and maternal permanent environment) and yearling weight, Average daily gain from weaning to six months, Kleiber ratio from birth to weaning, and Kleiber ratio from weaning to six months of age Model 1 (direct effects). Direct estimate of heritability for BW, WW, 6MW, YW, ADGa, ADGb, KRa and KRb was 0.15±0.04, 0.16±0.03, 0.21±0.04, 0.22±0.06, 0.13±0.05, 0.14±.04, 0.06±0.03 and 0.03±0.02, respectively. The estimate of maternal heritability for BW was 0.08±0.02. Genetic correlations were ranged 0.13 (between YW with KRb) to 0.94 (between WW with KRa). The results of this study indicated that selection for Kleiber ratio can result in genetic improvement of growth rate as well as feed efficiency.Genetic parameter estimates of local breeds are important. Genetic parameter estimates of local breeds are important for conservation purposes, defining breeding objectives, and programs. The traits having economic value such as growth
rate and Kleiber ratio are influenced by individual direct genetic, maternal effects, and environment which animal is raised Profitability of a sheep production system can be influenced by growth rate of the lambs in different ages. Normally, the lambs having more growth rate are more capable of reaching market weight. Growth rate is defined as the average daily gain of an individual in a specific period and can be classified as from birth to weaning, from birth to 6 months of age, from weaning to 6 months of age

 

One of the pivotal technology for genetic resorviors preservation is the freezing of semen. As freezing causes a reduction in sperm fertility, adding some components to semen to preserve its ferility would be important. Since beginning the time of artificial insemination technique, different diluents have been used to preservation semen in liquid and frozen condition. Therefore, the goal of this stady was to investigate the effect of adding different levels of raffinose and milk, Tris-chicken egg yolk and Tris-soybean lecithin extenders on ovine semen characteristics after freezing and thawing.

Samples were collected from four mature Dalagh rams and extended by different extenders and then raffinose was added. Semen samples were aspirated into 0.5 ml straws and cooled to 4°C within 150 min and then frozen in liquid nitrogen Frozen straws were transferred to a tank containing liquid nitrogen. After thawing spermatozoa quality parameters including percentage of sperm motility, viability, membrane integrity and sperm normality were evaluated. This study was performed in a 4×3 factorial experiment with a completely randomized arrangement. Treatments were four levels of raffinose (0, 60, 70 and 80 mmol) and also three kinds of extenders (milk, tris-egg yolk and tris-soy lecithin). The obtained data from this study were analyzed by ANOVA procedure of Statistical Analysis System SAS (version 9.1). Comparison of data means were performed by Tukey test at the level of %1 error.

Results showed that adding raffinose had a significant effect on sperm viability and mobility (P<0.01), but did not significantly affect on sperm memberane integrity and normal morphology percentages. Effect of extender on percentages of motility, viability, membrane integrity and normal morphology of sperms was significant (P<0.01). The interaction between raffinose levels and extenders on percentages of motility, membrane integrity and normal morphology of sperms was significant while it was not for viability percentage. The greatest sperm mobility (35.00±2.09%) was in tris-egg yolk extender containing 60 mmol raffinose while that greatest sperm viabilty (74.40±1.88%) was in tris-egg yolk extender containing 80 mmol raffinose but also the most percentages of membrane integrity (66.40±2.60%) was in Tris-chicken egg yolk containing 0 mM raffinose. The greatest sperm normal morphology (74.80±2.82%) was observed in tris-soy lecithin extender containing 60 mmol raffinose.

Findings of the study showed that sperm characteristics including mobility and normal morphology percentages in level 60ml raffinose, membrane integrity percentages in level 0ml raffinose wihle for viability percentage were better preserved in 80ml level. In the other hand, tris-egg yolk extender had more prominant effect on preservation of sperm characteristics.

Today, use of feed and vitamin additives has been prevailed to improve immune system of ruminants and their growth performance. Conjugated linoleic acid is a general name for some fatty acids with 18 carbons and conjugated double bond. Vitamin C is a water soluble vitamin that has antioxidant property and can remove free radicals from the cells. Both conjugated linoleic acid and vitamin C involve in several physiologic processes and their supplementation for suckling calves may have some health effects. The aim of this study was to investigate the effects of conjugated linoleic acid and vitamin C supplements on growth performance, concentration of some blood metabolites and blood cell counts of Holstein suckling calves.
Material and For this experiment, 28 newly-born Holstein (average age of 1-8 days, and body weight 39±2 kg) were allocated to four treatments and 7 replications for each treatment in a randomized complete design with 2×2 factorial arrangement of treatments. The experimental treatments were: 1) Basal diet (starter and whole milk), 2) Basal diet + 10 g per day of rumen protected conjugated linoleic acid, 3) Basal diet + 600 mg per day vitamin C, 4) Basal diet + 600 mg per day Vitamin C + 10 g per day of rumen protected conjugated linoleic acid. The results showed that vitamin C supplement increased starter intake in first month significantly (P<0.05). Starter intake was not affected by feeding conjugated linoleic acid. Vitamin C supplementation improved significantly daily weight gain of calves in the first month (P<0.05). Dairy weight gain of calves in the second month was affected by the interaction effect of vitamin C by conjugated linoleic acid so, calves received vitamin C and conjugated linoleic acid supplements had higher weight gain during second month of life (P <0.05). Final body weight and feed conversion ratio were not affected by the addition of conjugated linoleic acid and vitamin C during rearing periods. The results showed that adding conjugated linoleic acid and vitamin C did not affected blood parameters (glucose, cholesterol, triglyceride, total protein, albumin) of claves (P>0.05). The addition of conjugated linoleic acid increased significantly red blood cells and lymphocytes counts (P <0.05). Calves fed 600 mg of vitamin C had higher white blood cell counts than control group (P <0.05). Based on the results of this study, supplementation of vitamin C and conjugated linoleic acid could have beneficial effects on the growth and health of suckling calves

Today, artificial insemination plays an important role in improving production efficiency and improving genetic progress. In order to realize many of the potential benefits of artificial insemination, semen storage for a long-term is considered a necessary step by freezing process. The freezing process, including the freezing process, leads to morphological changes, damage to the natural functions of the sperm and ultimately reduced fertility. Therefore, improving the thawing method of ram semen is related to the sperm quality indicators and is of considerable importance. The purpose of this study was to compare the effects of two thawing rates on microscopic parameters and enzyme activity of ram semen after freeze-thawing process. In this study, semen samples were collected from five Ghezel ram using an artificial vagina twice a week. To eliminate the individual effects of animals, semen samples were pooled after each sampling. Then diluted with Tris diluent. The diluted semen samples were frozen in nitrogen vapor and eventually stored in a tank containing liquid nitrogen until evaluation. The straws containing 0.25 ml semen were thawed at water bath temperatures at (i) 37ºC for 30s and (ii) 60ºC for 6 s. Following the freeze-thawing process, the effects of time exposure and thawing temperature on the kinematic features (CASA), viability, plasma membrane integrity (HOS test), morphological abnormalities, malondialdehyde (MDA) concentration, antioxidant activity (GPx, SOD) and total antioxidant capacity (TAC) were evaluated. The experiment was conducted as a completely randomized and the statistical model includes the effect of temperature and thawing time. The data were analyzed by the general linear model (GLM) procedure and statistical differences between the various group means were determined by Tukey's test. Significant differences were reported at the level of (P<0/05). The results showed that sperm motility parameters such as PM, VSL, VCL were improved at 37°C, but this increase was not statistically significant. The viability and plasma membrane integrity was improved at 37°C for 30 s compared 60°C for 6 s, but it was no significant. Also, total abnormality did not improve at high thawing rates than low rates. In addition, the results of the comparison of lipid peroxidation (MDA), glutathione peroxidase (GPX), superoxide dismutase (SOD) and total antioxidant capacity (TAC) were no significant at two thawing rates. According to the results obtained from thawing methods, the thawing at 60°C for 6s cannot be a suitable alternative for semen thawing at 37°C for 30 seconds.

Thyroid hormones are effective on reproductive performance of animals, especially in response to photoperiod. In different animal species, changes in serum concentrations of these hormones have been observed throughout the year. According to available data, by determining the serum level changes of these hormones, the sensitivity of the livestock species and breeds to photoperiod was predicted. The aim of this study was to compare the sensitivity of imported breeds (Saanen and Alpine) and indigenous goats (Mahabadi and native Semnan) to photoperiod change in the year, using thyroid hormones. This experiment conductedin the south of Damghan (Semnan province: 36 ° North and 54 ° East), at a height of 950 m above sea level, that has a warm summer and cold and dry winter. Sixteen male goats of 3 to 4 years old were selected from four Saanen, Alpine, Mahabadi and native goats of Semnan province. From the beginning of March, every 15 days, sampling was done from jugular vein. Serum T3, T4 was measured by ELISA method. The effect of breed and photoperiod on hormonal concentrations was analyzed by repeated measures method in a completely randomized design. T3 and T4 levels had changes during each year (p≤0.01). In all four breeds, T3 was high in autumn and winter and peaked in March. The T3 variation pattern was the same in four breeds, but the Saanen breed showed the most variation in T3. Differences in inter-species variation in some months were significant (p≤0.01), but in general, there was no significant difference in the maximum and minimum points of T3 between Saanen, Alpine and Mahabadi breeds. This difference was only significant for Semnan goats with other breeds (p≤0.01). Hormone level was significantly lower in Semnan native goats than in other breeds in March, April, November and December (p≤0.01). The level of T4 has also been influenced by variations in the photoperiod. Concentration of this hormone was highest in winter and autumn and in summer it was the lowest (p≤0.01). There was a significant difference between breeds in terms of sensitivity of changes in T4 concentration to changes in photoperiod (p≤0.01). In the months of the heat season (July, August and September); the concentration of T4 in Semnani goats was significantly higher From Saanen and Alpine goats (p≤0.01). Semnani goats were less influenced in the amount of thyroxin during photoperiodic changes. The results of this test showed that male Saanen goats more than Alpines were affected by changes in photoperiodic changes and climatic conditions in the southern foothills of Alborz mountain. There was no significant difference between two indigenous genetic populations in response to climatic conditions and photoperiodic changes. According to these results, it seems that the Alpine breed is a more appropriate option for use in these climatic conditions in our country.