جستجوی مقالات مرتبط با کلیدواژه « گوساله » در نشریات گروه « علوم دام »

In Suckling calves, due to the low development of rumen, the digestibility of food may decrease, so the energy of the diet can be increased by adding fat sources. The present experiment was conducted to investigate the effect of omega-3 and omega-6 fatty acids on feed intake and growth parameters of Holstein calves.

A total of 40 newborn calves (average age 3 days), for 60 days, in the form of a repeated design to 4 treatments including: (1) no supplemented fat source (control; CON), (2) 3% calcium-salts of soybean oil (Ca-SBO), (3) 3% calcium-salts of flaxseed oil (Ca-CO), and (4) 3% mixture of Ca-SBO and Ca-CO (1.5% each, DM basis; MIX). The study continued 66 days and the calves were gradually weaned during 61-65 days of age.

The starter intake during the period of 31 to 60 days for the control treatment was higher than the other treatments (p=0.05), but no differences were observed among the treatments in the entire experimental period. The daily weight gain in the periods of 31 to 60 days and the whole period for the treatment containing soybean oil supplement was better than the control treatment (p<0.05). Regarding body weight, soybean oil treatment had the highest weight at the end of the experiment. In terms of feed efficiency, mixed oil treatment had better performance than the control and flaxseed oil treatment, and it was not significantly difference with soybean oil treatment (p<0.05). Regarding blood metabolites, a significant differences were observed between experimental treatments in terms of glucose, total protein, cholesterol and other metabolites. Also, the liver enzyme concentration of aspartate aminotransferase for the treatment containing soybean oil on the 60th day of the experiment was the lowest compared to other treatments (p<0.01).

In general, the results showed that the use of soybean oil as a source of omega-3 fatty acids has more positive effects on the growth performance of Holstein suckling calves than flaxseed oil.

To be successful in rearing newborn calves, it is necessary to maximize feed efficiency and health status. One way is to use feed additives such as probiotics. Probiotics reduce the harmful microflora of the digestive tract (such as coliforms) and metabolic and infectious diseases and improve beneficial microbes, the defense system, nutrient absorption, feed consumption, and animal growth. However, the animal response to probiotics is not uniform. Therefore, if the conditions for the activity of probiotics in the digestive system are improved, it may be possible to increase the effectiveness of these microbial additives and achieve a more uniform and reproducible response. For this purpose, it may be possible to use biochar in diets containing probiotics. Biochar can absorb organic substances and gases, bind toxins, and provide a favorable environment for useful microorganisms, increasing fermentation efficiency and livestock performance. However, few findings are available on the effect of biochar, Saccharomyces boulardii (yeast), and different commercial lactobacilli mixtures in young calves. We hypothesized if biochar is included in diets containing probiotics, it could probably provide better conditions for the probiotic activity in the digestive system and thus improve the response of the calves to these additives. Therefore, this research investigated the effect of adding biochar (pomegranate and plum woods) in diets containing lactobacilli (L. plantarum, L. rhamnosus, and Enterococcus faecium mixture) and yeast (S. boulardii) on in vitro fermentation, microbial population, methane release, antioxidant capacity, as well as health indicators, rectum bacteria and blood enzymes of the pre- and post-weaning calves.
The experimental treatments were: 1. Basal diet without probiotics and biochar (control), 2. Diet + lactobacilli mixture, 3. Diet + S. boulardii, 4. Diet + biochar, 5. Diet +lactobacilli-biochar, and 6. Diet + S. Boulardii-biochar. The in vitro experiment was conducted with three replicates and two different runs. Digestibility coefficients were determined using Tilley and Terry method. A gas production technique was used to assess truly digestible substrate (TDS), partitioning factor (PF), microbial biomass production (MBP), cellulolytic bacteria, total protozoa, methane release, and antioxidant capacity. The in vivo experiment was done using 60 newborn Holstein calves (six treatments and 10 replicates) in a randomized complete block design. The start of the experiment was at the age of 10 d, weaning at 75 d, and the end of the experiment at 100 d. The daily intake and growth of the animals were recorded. In pre- and post-weaning calves, the rectum bacteria (coliforms, lactobacillus, and total aerobics), urinary and fecal pH, health score criteria (including scores of feces, nose, eye, ear, cough, temperature, navel, and joint), and total average health score were determined using standard methods. Moreover, the blood serum enzymes (alkaline phosphatase, Gamma-glutamyl transferase, aspartate aminotransferase, alanine transaminase, and lactate dehydrogenase) were assessed. Data were analyzed using the MIXED procedure of SAS.
Separate inclusion of the lactobacilli mixture, S. boulardii, and biochar in the diet improved in vitro digestibility, TDS, cellulolytic bacteria population, and antioxidant capacity compared to the control group (P<0.05) with maximum improvements when probiotic-biochar mixtures were used. The MBP and PF were improved by including the additives in the diet. Probiotics and probiotic-biochar mixtures decreased protozoa (P<0.05). Different additives decreased methane production, and the least methane was observed in diets containing lactobacilli-biochar and yeast-biochar (P<0.05). Probiotics provide better conditions for the growth and activity of appropriate microorganisms. In addition, the highly porous structure and high surface area of biochar increased the establishment, attachment, and growth of useful microbes. These properties improved cellulolytic bacteria, organic matter degradation, and MBP. The improved antioxidant status could be due to the effect of probiotics in eliminating oxidant compounds in the digestive system, and the activity of biochar in absorbing toxins and unfavorable factors in the fermentation environment. As a result, the simultaneous use of probiotics and biochar improved in vitro fermentation variables more effectively. The reduction of methane can be due to the decrease of protozoa and methanogens, and the increase of methanotrophs. The results of the second experiment (in vivo) showed the probiotics and biochar reduced the rectum coliforms and improved (reduced) the fecal score and average health score of pre- and post-weaning calves so that the greatest improvement was seen in probiotic-biochar treatments (P<0.05). Cough and body temperature scores also tended to improve by feeding additives. Alanine phosphatase, gamma-glutamyl transferase, aspartate aminotransferase, and alanine transferase were not affected by the treatments. However, lactate dehydrogenase in the pre-weaning period was lower in the additive treatments compared to the control group (P<0.05), and the minimum value was observed in probiotic-biochar groups. The use of probiotics can improve the rumen development, ruminal and intestinal population of useful microbes, and prevent diarrhea, which results in enhancing digestion, passage rate, feed consumption, and animal performance. Moreover, adding biochar enhances digestibility and microbial growth, binds toxins, reduces energy loss, and induces a suitable environment for beneficial microbes, resulting in better animal performance. The reduction of coliforms may be due to the binding of probiotics to the digestive system wall, nutrient competition, preventing harmful microbes, improving digesta flow, and changing the pH of the digestive tract. Moreover, biochar provides a suitable growth environment for beneficial microbes, removes toxins and unwanted substances from the digestion environment, reduces viscosity, and probably makes the digestive system unsuitable for harmful species including coliforms.
Separate inclusion of the lactobacilli mixture, S. boulardii, and biochar in the diet improved in vitro fermentation variables and the health status of pre and post-weaning Holstein calves, without negative effects on blood enzymes. The best in vitro and in vivo responses were observed when probiotics and biochar were used simultaneously. Therefore, the addition of biochar (1% of DM) to diets containing probiotics (lactobacilli and yeast; 2 g/d) can be recommended as a strategy to enhance the effectiveness of the probiotics in calves and to reduce environmental pollution due to the decreased methane emissions.

 To date, there is not any accurate estimation of calf mortality in the world; however, annual pre-weaning calves’ mortality was estimated to be around 7.8, 6.5, 5.5, and 2.6% in the United States, Iran, China, and Sweden, respectively. Raboisson et al. (2013) represented that most neonatal calf mortality happens at age under one month. Hill et al. (2011) reported that nutritional factors could modulate the calf immune system's functions. Studies on non-ruminants confirm that the consumption of polyunsaturated fatty acids (PUFA) relating to the n-3 FA can affect the immune response. In calves’ nutrition, using PUFA in milk or milk replacer (MR) had a pleasant effect on immune responses and antioxidant status. Supplementation n-3 FA, especially EPA and DHA, would increase the proportion of PUFA in the membrane phospholipids, which might change the performance of the immune system. The n-3 PUFA plays a critical role in influencing the immune system through various mechanisms described in detail by Calder (2012). Previous studies showed that adding n-3 PUFA to milk or MR decreases the symptoms of diarrhea and inflammatory diseases caused by viral or bacterial infections. So far, there are not enough reports regarding dietary n-3 PUFA on the APR in neonatal calves. Nevertheless, most research regarding FO supplementation and its anti-inflammatory effects on neonatal calves' health has been done on long-term consumption. As earlier mentioned, most calf mortality occurs at the first 30 days of age; consequently, long-term (more than one month) consumption of FO might not provide clear evidence to evaluate the anti-inflammatory effect of FO on the status of neonatal calves’ health. Therefore, the purpose of this study was the first evaluation of short-term supplementation of n-3 PUFA on the APR of neonatal calves.

Twenty-four bull calves, with a mean age of 34.5  3.7 days, were housed outdoors in individual pens bedded with wheat straw at the dairy farm facilities of Astan Quds Razavi Animal Husbandry and Agriculture Co. (Mashhad, Iran) in February 2019. The criteria for calf selection were, namely, the type of calf delivery (without any difficulty) and no history of disease or diarrhea. To achieve a quantitative similarity between calves, we used age and body weight as further criteria. The experiment's duration was 11 days (a week before LPS challenge and three days after LPS challenge) with an adaptation period (seven days). After the adaptation period, calves were weighed (57.5 ± 4.4 kg) and randomly assigned to 1 of 4 groups (six calves/group). Randomized calves received treatments during the study period according to the group they were already allocated: 1. negative control group (NC), 2. Positive control group (LPS challenge, PC), 3. Tallow 350 mg/kg BW group + LPS (TA), 4. Fish oil 350 mg/kg BW group + LPS (FO). All calves were fed the same diet, 5 L/d of whole milk, and had free access to freshwater during the experiment. The PC, FO, and TA groups were intravenously challenged with 0.5 μg/kg BW ultrapure LPS from E. coli serotype O111:B4 (Sigma–Aldrich: registered; product NO. L2630) on day eight. Treatments FO and TA were mixed with whole milk and were offered two times a day (at 0800 and 1700). FO and TA groups were isocaloric to compare the effect of manipulating fatty acid intake in the same level of energy intake on the APR of neonatal calves. The blood samples were collected at 1, 2, 3, 4, 6, 12, 24, 48, 72 h, post LPS challenge (p.c.) to evaluate inflammatory condition. The clinical signs (RT, RR, and HR) were recorded at 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 12, 18, 24 h p.c. According to Plessers et al.'s (2015) model, the appearance of behavioral phases (respiratory, depression, and recovery phase) was assessed. Data were analyzed as a completely randomized design by using JMP (13.2) software.

The results of this study confirm previous experiments that showed a significant increase of cytokines level by the LPS administration (26, 29). As expected, the IL-6 increased when the TNF-α decreased (Maximal level at 3 and 1 h p.c., respectively). There was no significant difference in cytokines and APPs between PC, FO, and TA, while the FO had the minimum level. The typical sickness behavior of LPS-challenged calves was distinguished as respiratory, depression, and recovery phases according to Plessers et al.'s (2015) model. In this study, there was no significant effect of decreasing n-6/n-3 FA ratio on sickness behavior. Besides, the level of inflammatory cytokines and acute-phase proteins were not affected by experimental groups. These results were in line with McDonnell et al., (2019) reported no FO effect on immune function during the pre-weaning period. Although the level of DHA + EPA requirement for calves has not been well known, studies represented that their highest level in humans is 5 g/d. Stanley et al. (2007) concluded that the n-6/n-3 FA ratio might not be a helpful concept and distracts attention from increasing absolute intakes of long-chain n-3 FA. In this regard, Flaga et al. (2019) represented that DHA-rich algae supplementation in milk replacer could decrease cytokines' mRNA expression. They suggested that 3 g/d DHA might be the maximum level in neonatal calves’ diet with an appropriate effect on the immune system. In the current study, NC, PC, and TA received 2 mg/d, and FO received 3 g/d DHA. It might be worthwhile considering the amount of DHA + EPA when FO is used as an n-3 PUFA source in calves’ diet.

The results showed that decreasing the n6/n3 FA ratio in diets by supplementing FO could not affect acute phase response in calves. Besides, short-term supplementation of FO could not improve calves' immune systems as no differences in cytokines and APP between PC and FO were observed. Although sickness behavior in FO finished sooner than PC, there was no significant difference between them. In this study, increasing MUFA intake could not affect APR in calve. It seems that more studies are needed to evaluate the effect of EPA and DHA on the performance and health status of calves.

Meat is an important source of protein and energy, which contains large amounts of essential amino acids and fats along with vitamins and minerals. The livestock industry is one of the most important sources of pollutants due to its high consumption of energy and water, as well as the production of excrement. In the present study, the environmental impact of cattle beef production in three industrial, semi-industrial and traditional breeding methods were evaluated using Life cycle assessment method in Mazandaran province. The environmental impacts of producing one ton of cattle beef were evaluated by IMPCAT 2002+ methods in the form of 15 midpoint environmental indicators and 4 endpoint environmental indicators. The results showed that in the industrial and semi-industrial production method, direct pollutants from livestock farm and in the traditional production method, the use of concentrate has the highest impact on creating intermediate environmental indicators. In different production methods, human health in the range of 1.72 to 1.92 Pt, ecosystem quality in the range of 13.36 to 17.5 Pt, climate change in the range of 1.41 to 1.62 Pt and the resources in the range of 0.31 to 0.46 Pt were changed. Also the final environmental indicator showed that the highest and lowest final environmental indicator occurs in the industrial and traditional production methods at the rate of 21.58 and Pt 16.81 per ton of live weight.

Introduction:

 The present study was conducted to investigate the efficacy of inclusion peppermint, thyme, cinnamon essential oils and also probiotic supplement (Protexin, Probiotics International Ltd., south Petherton, UK) when added to whole milk on performance, some blood parameters, skeletal growth, and nutrient digestibility of Holstein dairy calves.

Material and Methods :

A total of 25 Holstein dairy calves (10 females and 15 males; 1–10 days) with 42 ± 8 kg of average birth weight were used in a completely randomized design in which calves were randomly assigned to one of five different dietary treatments including 1) control diet without inclusion of any milk essential oil supplementation, 2, 3 and 4) control diet + 40 ml (20 ml in the morning and 20 ml in evening meals) per day of peppermint, thyme, cinnamon essential oils, respectively and 5) control diet + 0.5 g per day probiotic Protexin. Calves were individually housed and bedded with straw that was replaced every day. Feed and water were available ad libitum throughout the experiment. Calves were fed colostrum for 3 days and then fed with 10% of their birth weight until 80 days of age. The rations were iso-energetic. Ruminal fluid samples were collected by esophagus tube after morning feeding at the end of study. Starter intake was recorded individually and daily. The amount of feed consumed daily was calculated throughout the experiment from the difference between the feed poured and the remaining feed. Edible samples from calves were kept in the freezer (-20 °C) for approximate analysis experiments. Performance was analyzed in repeated measures of the mixed model (PROC MIXED) including initial BW as a covariate (covariate structure: compound symmetry) with treatment, week and their interaction as fixed components and animal as random effect. Structural growth data were evaluated by GLM. Gender was considered a block but was not significant and drop from the model. A mixed-effects regression analysis, which included calf and period as random effects and treatment and time relative to weaning (before or after) as fixed effects, was then performed. Analytical model was Yij = µ + Ti + Aij + β (BWij - x) + eij, where Yij was each observation, μ was the overall mean, Ti was the fixed effect of treatment i, Aij was the random effect of calve j in treatment i, β (BWij - x) was using initial BW as a covariate and eij was residual error. Treatments means were statistically compared by the test of Duncan.

Results and Discussion:

 The results showed that starter intake was not affected by the experimental treatments (p> 0.05). However, calves consuming cinnamon essential oil and probiotic Protexin had higher daily weight gain than other essential oils and control group (p <0.05). Calves fed milk without any additives had the lowest feed efficiency but it was highest for calves fed whole milk based on cinnamon essential oil or Protexin (p<0.05). Rumen parameters and ammonia nitrogen concentration were not affected by essential oils and probiotic intake (p> 0.05). Ruminal pH value was lower in calves were fed milk supplemented with different essential oils and Protexin than those fed control treatment (p<0.05). This decrease in pH by inclusion of essential oil and Protexin was probably due to increased ruminal propionate to acetate ratio. Addition of peppermint, thyme, cinnamon essential oils and probiotic Protexin to milk of Holstein calves had no detectable effect on the mean concentration of glucose, cholesterol, total protein, albumin, urea, aspartate-aminotransferase and alanine-aminotransferase (p> 0.05). The concentration of triglyceride in calves fed cinnamon essential oil was higher than that of other essential oils as well as probiotic Protexin (p <0.05). Inactivation of blood urea nitrogen concentration by the addition of essential oils was associated with a significant lack of ruminal ammonia nitrogen concentration. Increased ammonia nitrogen levels, more than the microbial requirement, lead to absorption through the rumen wall and hepatic vein, and most of it is converted into urea in the liver and ultimately increases in blood urea concentrations, which in this study did not affect the essential oils. Different effects of Protexin on ruminal ammonia nitrogen concentration resulted in no significant blood urea nitrogen concentration.Hip width, heart girth, body barrel and wither height were not affected by the addition of essential oils, as well as probiotic supplementation (p> 0.05). However, body length and hip heights were higher in the calves fed cinnamon essential oil than the control group. The apparent digestibility of dry matter and organic matter in calves consumed cinnamon essential oil tended to increase than the control group (p=0.06 and p=0.07, respectively). The digestibility of crude protein and neutral detergent fiber was not affected by the type of essential oil and Protexin supplementation in Holstein dairy calves.

Conclusion :

Overall, essential oils especially cinnamon and probiotic Protexin may improve growth and performance by increasing daily gain and feed efficiency of Holstein dairy calves.

Calf breeding has been one of the most important and sensitive management programs in cattle farms. Therefore, using the right nutrition strategies for their improved growth and health is very important. For this reason, antibiotics have long been used in many countries to increase the growth of livestock due to their inhibitory effect on harmful bacteria in the gastrointestinal tract. In the last decades antibiotics were used for stimulating growth and increasing viability in calves, because of improving antibiotic resistance finding new techniques for improving growth and viability and reducing weaning weight is necessary. Adding supplemental levels of probiotic and organic acids can increase the immune system and improve health of calf.

In this study, the effects of different levels of probiotic and organic acids additive were investigated on blood metabolites, immune response and health of Holstein calves.

In order to determine the effects of different levels of probiotic and organic acids on the performance, skeletal growth and feeding activity of infant calves, the experiment was conducted using 36 Holstein calves with a mean weight of 36 kg ± 2 in a completely randomized design with nine treatments and four replicates. The experiment lasted for 75 days in Moghan Agro-Industrial Company located in Parsabad city, Ardebil province. Treatments included: 1. basal diet without additive (control), 2. basal diet containing 2 g probiotic additive, 3.basal diet containing 3 g probiotic, 4. basal diet containing 3 g organic acid, 5. basal diet containing 4.5 g organic acid, 6. basal diet containing 2 g of probiotic and 3 g of organic acid, 7. basal diet containing 2 g of probiotic and 4.5 g of organic acid, 8. basal diet containing 3 g probiotics and 3 g of organic acid and 9. basal diet containing 3 g probiotic and 4.5 g organic acid. The study evaluated feed intake, body weight gain, feed conversion ratio, skeletal growth, nutrition behavior, blood parameters, immune response and the calves health state. The test results were analyzed in a completely randomized design with SAS statistical software version 9.1.

The results showed that experimental diets had a significant effect on feed intake and daily gain, blood glucose and cholesterol and improved the immune system and health status of calves (p <0.05). In contrast, the experimental diets do not have a significant effect on the final weight and feed conversion ratio. This study also showed that the addition of probiotic, organic acid and the combination of these additives did not affect skeletal growth and feed intake activity of Holstein calves. Experimental treatments at 60 days and the whole period had a significant effect on feed intake. In general, probiotics increase food intake through their effects on the processes of digestion and absorption of nutrients. The average daily weight gain in the first, second and whole months of the period was affected by experimental diets but the overall effect of treatments in time periods was not significant. Blood glucose concentrations were increased in calves receiving treatment 5, which could be attributed to the created suitable environment in the intestinal tract due to the consumption of organic acids, which may have contributed to the digestion and absorption of more nutrients and As a result, it increases the blood glucose levels. Experimental diets had a significant effect on the white blood cell percentage in both sampling times (45 and 75 days). In general, the improvement of the immune system by probiotics is done through three ways of increasing general antibodies, increasing macrophage activity and increasing the production of local antibodies on the mucosal surface of tissues such as the intestinal wall. The effect of organic acids on the immune system is still largely unknown, but in general it can be said that organic acids improve digestion and absorption of nutrients as well as reducing harmful bacteria and help the immune system improvement.

based on the obtained results dietary treatments do not have any adverse effect on calves' performance. Moreover, it can be concluded that feeding probiotic and organic acid to the calves could have positive effects on animal performance and health state, so supplementing the diets by these substances is a good mean to improve the calves’ growth.

This study was conducted to evaluate the effect of Aloe vera gel and conjugated linoleic acid supplement feeding on performance, blood metabolites and immune parameters in Holstein calves in a completely randomized design with a 2×2 factorial arrangement. This study was carried out using 24 male and female Holstein calves (with average age of 1-10 days and 38±8 kg weight) with four treatments and six replications for 60 days. The treatments were: (1) basal diet including starter and whole milk (control), (2) basal diet + 250 mg/kg body weight Aloe vera gel, (3) basal diet+20 g/kgDM complementary conjugated linoleic acid (CLA) and (4) Basal diet+250 mg/kg body weight Aloe vera gel+20 g/kgDM of CLA. The Dry matter intake, weight gain, feed conversion ratio, blood parameters and immune and health factors were measured. Results showed that there were no significant differences between the control and other groups in terms of feed intake and performance of Holstein calves. The interaction effect of Aloe vera gel and CLA was significant on blood glucose concentration and calves receiving 250 mg Aloe vera gel had the lowest glucose concentration (88.33 mg/dL) (P>0.05). On the other hand, the effect of time on white blood cell, lymphocyte and monocyte was significant (P<0.05) and using 20 g CLA increased blood monocyte (5.33%) compared with no CLA treatments (3.58%; (P<0.05). In general, the interaction effect of aloe vera gel and CLA supplementation was not significant on performance and health status of Holstein calves.

The objective of this study was to evaluate the effects of feed bunk space and forage particle size on feed intake and nutrient digestibility in growing Holstein female calves. Fourty Holstein female calves with an average age of 8-12 months (295.6 ± 32.8 kg) were used in a 2×2 factorial change-over design (with four treatments, four periods and four stalls), in which 10 calves were allocated to each stall. The current experiment lasted 4 months as one month allocated to each period. The experimental treatments were included: 1) 24 cm of feed bunk space and average forage particle size of 4.6 mm (24/fine); 2) 24 cm of feed bunk space and average forage particle size of 7.1 mm (24/coarse); 3) 48 cm of feed bunk space and average forage particle size of 4.6 mm (48/fine); 4) 48 cm of feed bunk space and average forage particle size of 7.1 mm (48/coarse). The results of this study showed that the apparent digestibilities of DM, CP and NDF for the 48/Coarse treatment was the highest, the treatment of 24/Coarse had an intermediate state, and for the treatment of 48/fine and 24/fine were the lowest. Also, apparent digestibilities of DM, CP and NDF were higher for treatments including coarse forage particles than treatments with fine forage particle size. Finally, it seems that feeding growing Holstein heifers with diets containing coarse forage particle size could result in better nutrient digestibility.

In order to evaluate the effect of adding butyric acid to whole milk on growth performance and blood parameters of Holstein calves, 36 calves were used in a completely randomized design. The experimental treatments were: 1) control group without any additive (B0); 2) B0 + 4 grams per day of added butyric acid in milk (B4); and 3) B0 + 8 grams per day of added butyric acid in milk (B8). The calves had free access to feed and water during the experiment. Body weight at weaning and end of experiment tended to increase in B4 and B8 compared to B0 (P = 0.08). Average daily gain was significantly (P < 0.01) affected by treatment during the pre-weaning, so that B0 had the lowest daily gain, but no difference was observed between B4 and B8. The starter intake was less in B0 compared to the other two groups during pre-weaning period (P < 0.01), post-weaning, (P = 0.04) and throughout study (P < 0.01), but there was no difference between B4 and B8. The serum concentrations of glucose, total protein and albumin within pre-weaning were not significantly different among treatments, but BHBA concentration was lower in B0 group than in other groups (P < 0.01). There was no difference among treatments in terms of average fecal score. In general, for the first time, the results of this study showed that adding butyric acid to the whole milk can have positive effects on improving performance.

In order to evaluate the effects of using mixture of probiotic bacteria applied as a freeze dried or fresh culture on feed intake, weight gain, structural growth measurement and health, and blood metabolites, twenty four female Holstein calves were used in a completely randomized design. Calves after birth were randomly assigned into one of three treatments as follow: 1) control (without any additive), 2) calves received probiotic as a fresh culture and 3) calves received probiotic as freeze dried. Determination of starter intake and fecal scoring were done daily, and weighing and Structural growth measurements were recorded weekly. Blood samples were taken at the age of 25, 50 and 70 days old. Rumen fluid was collected 4 hours after morning feeding on 30, 60 and 70 days. The results showed that there were no differences among treatments on average weaning age and structural growth indices (p>0.05). Neither fresh culture probiotic nor freeze dried probiotic had effect on initial, final and weaning weight (p>0.05). There was no significant difference between treatments in terms of pH and ammoniacal nitrogen concentration (p>0.05). Freeze dried or fresh culture of probiotic had no significant effect (p>0.05) on blod metabolites (glucose, triglyserid, total protein, β_Hydroxybutyrate and albumin). Totally, the loss of predictable response resulted using of powder and liquid probioticson weaning calves performance can be attributed to good managerial and sanitary condition in weaning calves.

This study was carried out to evaluate the effects of feeding rosemary, chavil and mixture of rosemary-chavil on growth and blood metabolites of suckling Holstein calves. Thirty two newborn calves from primiparous cows with an initial body weight of 36.24±3.04 kg and thirty two newborn calves from multiparous dairy cows with an initial body weight of 37.38±3.36 kg were used at 4 days to 60 days of age in a complete randomized design with a 2×4 factorial arrangement. Calves were fed with experimental diets including: 1- control diet, 2- control diet‏+ 5% Chavil, 3-control diet‏+5% rosemary, 4-control diet‏+ 2.5% chavil+ 2.5% rosemary. Results showed that dry matter intake (DMI) and weight gain were recorded bi-weekly and blood samples were collected on 30-days intervals entire the study. Glucose, Blood Urea Nitrogen (BUN), Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Beta-HydroxyButyricAcid (BHBA), Malondialdehyde (MDA) and Total antioxidant capacity (TAC) concentration was measured. The addition of chavil and mixture of rosemary- chavil to the diet improved dry matter intake (P<0.01), average daily gain (ADG) (P<0.05) and final body weigh (P<0.01). Blood glucose and insulin increased (P<0.05) in calves fed chavil and mixture of rosemary- chavil. Blood Alanine amino transferase (ALT) decreased (P<0.05) with addition of chavil to diet. Experimental treatments had no effect on blood Antioxidant defense. It was concluded that adding chavil to diet had favorable effects on growth performance of suckling Holstein calves from primiparous cows and multiparous dairy cows.

In this experiment, effects of injection of vitamin E (VE) and selenium (Se) solution and vitamin B12 (VB12) and iron (Fe) solution to transition dairy cows on colostrum quality and calves’ antioxidant capacity, concentrations of VE and VB12, Fe and Se, serum metabolites and blood cells were studied. Twentyprimiparous (607.09±60.26 kg of body weight) and twentymultiparous (712±55.54 kg of body weight) Holstein dairy cows were divided to 4 based on parity and body weight in a randomized completely block design. Experimental treatments consisted of 1) injection of 7 ml of NaCl % 0.9 (Control), 2) injection of 60 ml of VE and Se solution, 3) injection of 7 ml of VB12 and Fe solution and 4) injection of 60 ml of VE and Se solution with 7 ml VB12 and Fe solution. Solutions injected on 21 and 7 day prepartum and calves blood samples collected before and 24h after cholestrum feeding. Results indicated that treatments had no effect on calves’birth weight and colostrum concentrations of fat, protein, lactose and solid not fat, and immunoglobulinG. Serum concentrations of VE and B12, Se and Fe, serum activities of glutathione peroxidase, catalase, total antioxidant capacity and serum metabolites did not affected by the experimental treatments. Altogether, it can be concluded that injection of VE and Se solution and VB12 and Fe solution to transition dairy cows on days 21 and 7 prepartum had no effect on calves’immune system at first 24h of life.

The purpose of this study was to investigate the relationship between plasma leptin and blood testosterone concentration before and after puberty. Eight male Najdi calves with mean age of 7 months were used for this purpose. Blood samples were taken three times before and after reaching puberty. At each sampling period, a blood sample was collected to determine the plasma concentration of leptin from all 8 consecutive and 6 consecutive blood samples and at 20 min intervals from 4 animals to determine the plasma level of testosterone. The results of this study showed that the age of puberty in the Najdi race was 13-15 months old and the average weight was 120.08 ± 36.91 kg. Plasma leptin concentration was negatively correlated with testosterone (P <0.05, r = -0.43), age (P <0.01, r = -0.77), body weight (P <0.01, -0.39), testicular environment (r = -0.62, P <0.01) and testicular height (r = -0.72, P <0.01). In general, it can be concluded that with the onset of puberty and the increase in testosterone concentration, leptin concentration decreased due to the negative effect of testosterone on the production of leptin hormone in the body.

This study was aimed to investigate the effect of adding dried dairy wastes to the starter diet on growth performance in Holstein dairy calves. A total of 28 female newborn Holstein dairy calves were randomly allocated to four groups (n=7/group) and after two weeks of habituation to experimental conditions and diet, in a completely randomized design, individually fed starter diets containing 0 (control), 10, 20, or 30% dried dairy waste up to eight weeks of age. Feed intake, weight gain, and feed efficiency (gained weight/consumed feed) were measured weekly, during the experimental period. Results showed that body weight, weight gain, feed intake, and feed efficiency were not affected by the treatments. Interactive effect of treatments by week showed that the highest weight gain was for calves fed by the diet containing 10% dairy waste or control group at first week. However, the highest gain was recorded for those that received 30% dairy waste at week five of the experiment (P<0.05). In conclusion, the results of the present study revealed that the inclusion of dried dairy products up to 30% of calves’ starter diet had no adverse effect on performance, and therefore can be used as an affordable and valuable nutritional by-product of the dairy industry in the nutrition of calves.

In ruminant animals, the microbial population of the digestive tract can be controlled by several factors such as growth promoters, probiotics, periobacters, enzymes, essential oils, oligosaccharides and plant additives. Before weaning, dairy calves are susceptible to many pathogens and nutritional problems. For several years antibiotics have been used to overcome these
problems also to obtain economic benefits in terms of improved calves performance and reduced medication costs. However, the use of antibiotics in animal husbandry is in question because of antibiotic resistance of microorganisms. Research shows an association between the use of subtherapeutic dose of antibiotics and antibiotic-resistance organisms. Probiotics are live microbial feed supplements which beneficially affect the host animal by improving its microbial balance. Most of probiotic studies that were reported in the literatures used single or two strains probitics rather that multi strains bacteria, Prebiotics are non-digestible carbohydrates which are not metabolized in the small intestine and fermented in large intestine. reported that dietary chitosan oligosaccharides supplementation was effective in increasing the ileal digestibilities of nutrients and feed efficiency in broilers. Also reported that broilers fed diet supplemented with oligochitosan prebiotic had higher serum IgG, IgM and IgA concentration compared with broiler fed control diet. Dietary supplementation with Chinese herbal ultra-fine 3 powder as a prebiotic enhances cellular and humoral immunity in early weaned piglets. In this study, the effect of adding supplements to milk on functional parameters, blood metabolites, microbial population and inactivation of immunoglobulins to calves were investigated.

Sixteen newly-born Holstein male calves were used in four completely randomized treatments for 60 days.Treatments included: 1- control group (no additive milk) 2- probiotic group (milk + 2 gr probiotic) 3- prebiotic group (milk + 4 gr perbiotic) 4- synbiotic group (milk + 2 gr probiotic and 4 gr perbiotic). Calves were weighed at 3, 30 and 63 days of age after feeding the milk at the morning meal, and the feed intake was measured and recorded daily from  taken from the feces for microbial culture. Blood samples were taken at nine o'clock in the morning (two hours after the morning meal) on weekdays. To measure the concentration of metabolites, plasma samples were melting at room temperature to determine the serum levels of serum cholesterol, glucose, albumin, triglyceride and total protein plasma from a biosorbent kit and an autoanalyzer (model A15, France) with two replications measured. IgG concentrations were measured by  immunoturbidimetry method using the COBAS INTEGRA kit at a wavelength of 800- 400 nm on the fourth day of the course, the total activity was measured for 24 hours by direct observation (28 and 51). The duration of rumination and eating was considered as the duration of maturation, and the activity of rumination and eating every five minutes was recorded for 24 hours. The duration of rumination and eating from the product of the number of each observation was obtained at intervals of five minutes.

 In calves fed with a diet containing probiotic supplementThe lowest feed intake and the best feed conversion ratio were observed in all periods compared to other treatments.Glucose and Triglyceride, total cholesterol concentration, total plasma protein and plasma aliquin concentrations were not affected by probiotic and peri-biotic supplements in diets and no significant  differences were found between diets. Probiotic supplementation significantly reduced the concentration of triglycerides in the blood plasma of calves fed with supplement supplements (P <0.05). The highest concentration of triglyceride was in the control group, with a significant difference (P <0.05) with other groups. The lowest concentration of betahydroxybutyrate was in the control group, with a significant difference (P <0.05) with other groups. In the calf Fed with probioticThe total amount of bacteria increased slightly after feeding, but there was no significant difference between different age groups in the complementary recipient groups. The highest IgG levels were in the group that consumed probiotics and there was a significant difference between the control group and the synbiotic group (P <0.05), but it was only numerically higher than the prebiotic group and this trend All ages 3, 7 and 30 continued.

In general, the results showed that supplementation with probiotic additive could improve the livestock's economic indices

Zinc has a role in many cases such as rumen microbial activity, immunity, and blood metabolites. But, there is no sufficient information on the effect of nano and organic Zn supplements on microbial protein synthesis and immunity variables in Holstein calves. Thus, this study was conducted to assess the effect of using nano-ZnO and Zn-methionine instead of ZnO (equal to or twice NRC 2001-recommended level) on urinary purine derivatives, microbial protein, immunoglobulins and nitrogenous compounds of the blood in pre- and post-weaning calves.

Sixty suckling Holstein calves were assigned into one of the 6 experimental groups (10 replications) in a completely randomized design. The experimental treatments were the diets containing: 1- ZnO equal to NRC recommendation, 2- Zn-methionine equal to NRC recommendation, 3- nano-ZnO equal to NRC recommendation, 4- ZnO twice NRC recommendation, 5- Zn-methionine twice NRC recommendation, and 6- nano-ZnO twice NRC recommendation. During 7 to 30 days of age, the calves were fed with milk and starter concentrate according to the above treatments. From days 31 to 70, milk and mixed alfalfa-starter (at the ratio of 10:90) were provided for the calves. Weaning was done at 70 days of age and during post-weaning period (71 to 100 days of age), the calves were freely fed with experimental diets (alfalfa and starter concentrate at the ratio of 20:80). During pre- and post-weaning periods, the urinary purine derivatives, microbial N synthesis, total globulin, IgM, IgG, total protein, albumin, urea-N, creatinine and glucose of the blood were determined. Data were analyzed in a factorial experiment (3×2) using PROC MIXED of SAS (2001).

Urinary purine derivatives and microbial N synthesis were not affected by replacing ZnO with nano-ZnO and Zn-methionine during pre- and post-weaning periods. Zinc chemical form had no significant effect on the blood concentrations of total globulin, IgM and IgA. Total protein, albumin, urea-N, creatinine and glucose in the blood of the calves fed with inorganic, nano or organic Zn supplements were the same. Moreover, increasing Zn level in the diet had no effect on urinary purine derivatives, microbial N synthesis, total globulin, IgM, IgA, total protein, urea-N, creatinine and glucose.

Using nano-ZnO and Zn-methionine instead of ZnO and also the increasing dietary Zn level had no effect on microbial protein synthesis, IgM, IgA, nitrogenous compounds and glucose in the blood of the calves. Thus, feeding the conventional inorganic Zn source (ZnO) at the NRC-recommended level was sufficient to supply the calves’ requirement during pre- and post-weaning periods and the other sources are not recommended.

The aim of this study was to evaluate the effect of different levels of monensin on growth performance, body weight gain, feed efficiency and rumen volatile fatty acid in weaning Holstein male calves. This study were conducted using 66 weaning male calves (average body weight 103 ± 5 kg and average age 90 ± 5 days) that received experimental diets including A) control without monensin, B) control with 70 mg/d monensin and C) control with 140 mg/d monensin in a complete randomized design with periods of 90 days (days of 90 to 180). The effect of treatments was significant on dry matter intake (P= 0.01). Daily Feed intake was 5.99, 5.82 and 4.04 Kg respectively for 1 to 3 treatment that highest in 70 mg monensin and lowest in control group. Feed conversion ratio (FCR) improved in month 5 in calves fed monensin as compared with control group (P= 0.05). The results indicated that monensin increased final weight in calves fed monensin as compared with control group. Body weight in 70 mg monensin was highest as compared with others (P≤ 0.05). Average daily gain in month 5 was significant (P≤ 0.05) that highest in 140 mg monensin group. Average height gain was significantly different between experimental treatments that highest in 140 mg monensin group (12.65 am). Monensin had significant effect on propionate that highest in 70 mg monensin group.

The present study was performed to determine the effect of resistant starch as a type of prebiotic and phenolic compound extract on performance, hematological and blood parameters of suckling Holstein calf. For this, 54 suckling Holstein calves (27 male and 27 female) were randomly assigned in 9 treatments including: RS1 (8 g resistant starch), RS2 (16 g resistant starch), PE1 (1800 mg phenolic compounds), PE2 (3600 mg phenolic compounds), RS1+PE1 (8 g resistant starch+1800 mg phenolic compounds), RS1+PE2 (8 g resistant starch+3600 mg phenolic compounds), RS2+PE1 (16 g resistant starch+1800 mg phenolic compounds), RS2+PE2 (16 g resistant starch+3600 mg phenolic compounds) in a completely randomized factorial design with 9 treatments and 6 replications. The weight gain, feed intake and feed conversion ratio of calves, hematological and blood parameters were measured. The results showed that weight gain didn’t affected by experimental treatments and feeding of resistant starch and phenolic extracts had no effect on daily weight gain, daily feed intake and feed conversion ratio of Holstein calves. The hematological and metabolic parameters did not affected by experimental treatments. But the effect of period on blood glucose, triglyceride, cholesterol and total protein was significant.

The aim of this study was to examine the effect of Lactic acid bacteria based probiotic and its use schedule on Kurd male calves’ growth performance and white blood cell antimicrobial activity. The experimental period was 105 days after calves adapted to new environmental conditions. This study was carried out by 12 calves with an average body weight of 195 ± 10 kg and age of 240±10 days in a completely randomized design with three treatments and three replicate. Experimental groups included: 1) the control group was fed on a commercial basal diet (without probiotic). 2) was fed on basal diet and daily usage probiotic 3) was fed on basal diet and probiotic usage a day then skip 2 days and repeated. Growth performance and feed conversion rate were determined by measuring calves weight and feed intake on day 0, 52 and 105 of experiment after 14 h feed deprivation. For measurement of reactive oxygen species as anitimicrobial activity index in white Blood Cells, blood samples were taken from all of the calves at the end of experiment. Although body weight gain and feed conversion rate was not significantly different among any of the treatments 2 and 3 but increased and decreased respectively compared to control group in end of experiment (p<0.05). Feed intake significantly increased in treatment 3 compared 2 (p=0.0424). No differences in reactive oxygen mean were observed in calves fed probiotic-supplemented diets and control group. According to this results dietary supplementation with probiotic did not affect white blood cell antimicrobial activity although improved Kurd calves growth performance and feed conversion rate, also daily usage of probiotic can be replaced by usage a day then skip 2 days and repeated schedule.

In this study 43 calves (19 female and 24 male) from pure sistani cattle population were used in order to study the relationship between the calve's temperament at weaning time with performance, body type and some blood parameters. At weaning time, temperament was determined by using Pen Scores, Exit score and Chute Score methods. Calves were divided into three groups: calm, moderate and temperamental. The measured parameters included body temperature, heart rate, hand length, waist length, tail size, round the chest, the diameter of the hand and leg, forehead and the ear size as well as the concentration of glucose, total protein, creatinine, triglyceride, insulin, HDL, LDL, T3 and T4 in the serum. Statistical analysis of the results with R-3.3.2 software showed better growth rate and conversion coefficient in calm calves compared with other moderate and temperamental groups (P