مجله تولیدات دامی
سال بیست و یکم شماره 3 (پاییز 1398)

This research was conducted to investigate the effects of corn and sorghum silages particle size on feed intake, digestibility, rumen parameters and feed intake behavior in Kermani sheep. Around 1000 kg of fresh corn and sorghum forages were chopped into two coarse and fine particle sizes and ensiled for 45 days. Four male Kermani sheep, 34.0±0.8 kg average BW, were used in this experiment which was conducted in a completely randomized design, with a 2 × 2 factorial experiment. There were four experimental periods and each of which lasted 21d, with 14d adaptation, 7d of sample collection. The ratio of forage to concentrate was 60: 40. Experimental diets were: 1) coarse corn silage diet, 2) fine corn silage diet, 3) coarse sorghum silage diet and 4) fine sorghum silage diet. The NDF content was higher in the sorghum silages than corn silages (p<0.05). In diets containing fine silage, ruminal pH tended to decrease after two hours of intake. Population of Holotrich and Cellulolytic protozoa increased when coarse silages were fed to animals (P<0.05). The maximum microbial protein synthesis in the rumen was achieved in diets containing fine silage(P<0.05). Duration of feed intake, rumination and chewing activity were higher in coarse silage diets (P<0.05). The types of silage did not have significant effect on animals’ performance and dietary feed intake behavior. In conclusion, corn silage can be replaced by sorghum silage, without any negative effect on feed intake, digestibility, and rumen parameters in sheep.

The aim of this study was to investigate the effect of replacing alfalfa hay (AH) with corn silage (CS) in the finely ground starter diet on health status and blood biochemical parameters of male Holstein calves during pre-weaning period. Thirty (3-d old) newborn calves (40.2 ± 1.28 kg body weight) were assigned randomly to three experimental groups receiving starter diets containing 10% (on dry matter basis) AH (Control), 5% AH and 5% CS, and 10% CS. The starter diets had the same nutrient composition but dry matter content was highest and lowest in Control and 10% CS groups, respectively. Blood concentration of albumin was higher in calves fed 5% CS diet compared with calves fed Control or 10% CS diets (P ≤ 0.05). Compared with calves on other treatments, calves on Control group were more susceptible to develop diarrhea or pneumonia (P ≤ 0.05) and thereby had lower chance to be treated. No difference was observed among treatment groups for frequency and medication days of diarrhea or pneumonia, but duration of diarrhea was higher in calves on Control group compared with other treatments (P ≤ 0.05). Based on obtained results, feeding CS containing diets (5 or 10%) to male Holstein calves during the preweaning period may have a potential to improve calf health and to decrease costs related to drugs and medication

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.

The goal of the present study was to determine the true metabolizable energy corrected for nitrogen (TMEn) content, chemical compositions of the poultry by – product meal (PBPM), the relationship between their chemical compounds and TMEn in adult roosters. To examine the nutritional values of PBPM, a total of 30 fresh samples were collected from different slaughterhouses in the country. For TMEn estimation, each sample (25 g) was used to force feed to the 4 birds raised in individual metabolic cages. Dry matter (DM), gross energy (GE), crude fat (EE), crude protein (CP), ash and total volatile nitrogen (TVN) were measured according to standard methods. Average values for DM, EE, ash, CP, TVN and TMEn were obtained as 90.05%, 22.10%, 7.50%, 60.30%, 220 mgN/100g, and 3907 kcal/kg, respectively. There was a positive correlation between TMEn and EE, while the correlation between ash and TMEn was negative. Compared with EE and ash, the CP was less correlated (P<0.05) with TMEn, while the TVN had no significant effect. The determined values of chemical composition and TMEn were used in fitting the simple regression equations, which can be in practice used to predict energy contents of PBPM samples in factory and production farms.

This study was carried out to evaluate the effect of different levels of dietary crude protein and protease enzyme on growth performance, carcass characteristics, and protein digestibility in Japanese quails. Four hundred fifty day-old quails were randomly distributed into nine experimental groups in a completely randomized design with 3 × 3 factorial arrangement including 3 levels of protein (18, 20 and 22%) and 3 levels of protease enzyme supplementation (0, 200 and 400 mg/kg) with five replicates and 10 birds per replicates. In 1 to 21 days of age, the highest weight gain and feed intake were achieved in birds fed diet with 22% crude protein (P<0.05). Also, birds fed with the diet supplemented with 200 ppm protease enzyme showed higher feed intake and weight gain, in comparison to the birds fed no enzyme supplemented diet (P>0.05). But, the best feed conversion ratio was seen in birds fed a diet contained 400 ppm enzyme. In 22 to 35 days of age, different dietary treatments have no significant effect on growth performance. Carcass percentage of quails fed with diets contained 20 and 22% CP was significantly higher than those fed 18% CP diet (P<0.05). Also, enzyme supplementation had beneficial effects on the carcass, breast, and thigh relative weights (P<0.05). In the 13-15 days period, CP digestibility coefficient was significantly decreased by increasing the CP level from 18 or 20 to 22%. Also, protease enzyme supplementation at 200 ppm level had significantly a positive effect on CP digestibility (P<0.05). It could be concluded that the optimal dietary CP level for growing Japanese quails for 1- 21 and 22-35 days of the growing period is 22 and 18%, respectively. Also, dietary supplementation with protease enzyme at 200 ppm level could be beneficial at 1 to 21 days of age.

This research was carried out in order to investigate the effect of peppermint, thyme and tarragon essential oils on the performance and antibody titer of broilers. In this experiment, a total number of 240 Cobb 500 broiler chickens were used in a completely randomized design with eight treatment groups. Each treatment was replicated five times with six birds per replicate. Dietary treatments included; control, 200 mg/kg virginiamycin antibiotic, 150 and 200 mg/kg peppermint, thyme and tarragon essential oils. Chickens fed diets supplemented with antibiotic and 200 mg/kg thyme essential oil had significantly higher daily weight gain in comparison to control diet at the period of 21-42 days and 1- 42 days. Feed conversion ratio in birds fed the diets supplemented with 200 mg/kg peppermint essential oil and antibiotic was significantly improved in comparison to control diet. The highest ileum length and the best antibody titer against bronchitis and Gumboro in 42 days old chickens were recorded in150 mg/kg tarragon essential oil, 200 and 150 mg/kg peppermint essential oils, respectively. Therefore, it is recommended to supplement 200 mg/kg peppermint or thyme essential oils instead of dietary antibiotics in order to improve performance and antibody titer in broilers.

The effect of essential oils blend, probiotic and flavomycin on performance, gastrointestinal tract (GIT) characteristics, cecal microbial population and blood parameters was studied with 288 day-old chickens, Ross 308 broilers from 1 to 42 days of age in a completely randomized design by 4 treatments, 4 replicates and 18 chickens in each replication. The experimental treatments were: 1) basal diet as control group (without additive), 2) basal diet + 150 mg/kg essential oils blend, 3) basal diet + 200 mg/kg Gallipro® probiotic, and 4) basal diet + 150 mg/kg flavomycin. The results showed that feed intake was lower in the control group than other treatments (P<0.05). In the whole trial period, the weight gain of chickens fed with the diet containing flavomycin was higher than other birds and had a better feed conversion ratio than control birds or fed with the diet contains probiotic (P<0.05). The effect of treatments was not significant on relative weight of internal organs, pH of the GIT digesta and Lactobacillus and Escherichia coli population in the ceca. The relative weight of the breast was greater in chickens fed with flavomycin than control group or birds that received essential oils blend (P<0.05). There was no difference between treatments in terms of plasma cholesterol, glucose and triglyceride concentrations, but HDL concentration was lower in the plasma of birds receiving flavomycin compared to other treatments (P<0.05). Based on the results of this study, adding essential oils blend to the diet improved performance and can be used as a growth promoter instead of flavomycin in broilers diet.

The objective of this experiment was to investigate the effect of hydroalcoholic extract of Ferulago angulata (FA) as a substitute for common feed additive on performance and blood biochemical and hematological parameters of Ross 308 broilers. A total of 450 one-day-old male broiler chickens were used in a completely randomized design with six treatments and five replicates per treatment. The experimental treatments consisted of the basal diet with no additives (control); the basal diet containing Salinomycine antibiotic (500 mg/kg); Primalak® probiotic (recommended level), vitamin and mineral mixture (200 mg/kg of E and C vitamins and 0.3 mg/kg of selenium) and hydroalcoholic extract of FA at the levels of 200 and 400 mg/kg. During the entire experimental period, the birds fed diets with additives had better body weight gain and feed conversion ratio compared with the control birds (P<0.05). Feeding broiler chickens with experimental diets, except for the diet containing antibiotic, resulted in decreased concentrations of serum triglyceride and cholesterol compared with the control diet (P<0.05). The heterophil percentage and the heterophil to lymphocyte ratio decreased in the birds fed diets with evaluated additives, except for treatment containing 200 mg/kg of FA extract (P<0.05). Based on the results of this study, the FA extract, especially at the level of 400 mg/kg of diet, could be used as a suitable substitute for commercial dietary feed additives to improve growth performance and blood hematological and biochemical parameters of broilers.

The effect of addition of different concentrations of folic acid (vitamin B9) to the culture medium on in vitro maturation of bovine oocytes was investigated in two experiments. Optimization of bovine oocyte maturation medium is one of the strategies affecting quality of maturity and fertility, ultimately resulting in increasing the quality of produced bovine embryos. In the 1st experiment, to specify the concentrations of folic acid and homocysteine, ovarian follicles were divided into two categories including follicles with more or less than eight mm of diameter. Then, the concentrations were measured in both follicle groups as well as a commercial culture medium. In the second experiment, bovine ovaries were transferred to the laboratory immediately after slaughter and the cumulus-oocyte complexes were collected by aspiration from 2-8 mm diameter follicles. Oocytes were randomly divided into four groups and different levels of folic acid (0, 10, 100 and 1000 ng/ml) were added to maturation medium based on the results of the first experiment. Following incubation of oocytes, the percentage of mature oocytes was determined by Hoechst staining. The concentrations of folic acid and homocysteine in follicles with diameter of less than eight mm was higher than those with diameter of greater than eight mm, as well as the culture medium Supplementation of maturation medium with 100 ng/ml folic acid increased the percentage of metaphase-II oocytes compared to the control (P <0.05). Considering the concentrations of folic acid and homocysteine in the medium, results showed that the addition of folic acid improves in vitro maturation of bovine oocytes.

The effect of Pioglitazone and Curcumin on lipid metabolism and plasma metabolites of broiler breeder was investigated as a completely randomized design with three treatments and four replications by using of 60 hens at age 45 weeks during 10 weeks. Experimental treatments including: 1) Control (basal diet), 2) Adding 20 mg/bird/day Pioglitazone to diet and, 3) Adding 20 mg/bird/day Curcumin to diet. At the end of experiment, blood samples were collected, and birds were slaughtered. The results showed that hens receiving Pioglitazone or Curcumin had higher egg production and shell thickness when compared with control group (p<0.05). However, the yolk and egg weight of birds in the control group were higher than two another groups (p<0.05). Plasma concentrations of glucose, triglycerides and cholesterol were lower in hens feeding Pioglitazone or Curcumin than control (p<0.05). Liver and abdominal fat weight and adipocyte diameter were lower in birds receiving Pioglitazone or Curcumin (p<0.05). Based on current results, dietary supplementation of Pioglitazone or Curcumin, through lowering plasma lipids and subsequently positive influence on abdominal fat tissue and liver, could improve production in broiler breeders.

The effects of two different extenders were investigated (Tris- egg yolk and Andromed extenders) on semen quality and sex ratio during the dilution and freezing process in Holstien bull by using the real-time qPCR technique. The experiment was conducted using four 4-years old Holstien bulls for a period of four weeks in a completely randomized design. The PLP and SRY genes were amplified to isolate the specific fragments of X- and Y- chromosome sequences, respectively. Using Andromed diluent in comparison with Tris- eggs yolk improved semen quality during freezing and thawing. Using Andromed extender significantly increased the PLP gene expression (1.43±0.16), (P= 0/01) and reduced SRY gene expression (0.64±0.11), (P= 0/009). Using Tris- egg yolk extender led to a significant reduced in expression of PLP gene (0.3±0.06), (P< 0/0001) and s increased SRY gene expression during freezing (1.19±0.05), (P= 0/001). Based on the results, sperm dilution with Andromed extender and frozen semen with Tris-egg yolk increase birth of female and male in dairy cow herd, respectively.