مجله تولیدات دامی
سال بیست و پنجم شماره 4 (زمستان 1402)

This research was conducted to compare the effect of different zinc sources on in vitro microbial populations, hydrolytic enzymes and ruminal fermentation products in sheep. Five diets without zinc supplement (control) or containing ZnSO4, ZnO, nano-ZnO and Zn-methionine were assessed. The 24 and 72-h gas tests were conducted in a completely randomized design where the microbial populations, hydrolytic enzymes, methane, antioxidant activity, organic matter digestibility (OMD), metabolizable energy (ME), truly degraded substrate (TDS), microbial biomass, partitioning factor (PF) and volatile fatty acids (VFA) were determined. Total proteolytic bacteria count and protease activity decreased due to the usage of organic, inorganic and nano-particle sources of zinc (P<0.05). The use of methionine, oxide and sulfate sources of zinc increased alpha-amylase activity (P<0.05). Total protozoa number in the 24-h incubation tended to decrease owing to dietary zinc supplements. Total cellulolytic bacteria, carboxymethyl-cellulase, microcrystalline-cellulase, filter paper-degrading activity, antioxidant capacity, microbial biomass and PF were the same among treatments. Zinc methionine, oxide and sulfate supplements increased OMD, ME, TDS and total VFA, whereas decreased ammonia and acetate:propionate ratio (P<0.05). Also, 24-h methane production decreased with the use of zinc supplements (P<0.05). Overall, the dietary addition of sulfate, oxide and methionine- sources of zinc is recommended with the aim of improving alpha-amylase activity and digestibility and reducing proteolytic activity, ammonia accumulation and methane, but feeding nano-ZnO is not recommended. More research is needed on the effect of zinc sources on rumen microorganisms and enzymes in different dietary conditions.

In order to investigate the chemical and nutritional characteristics of pea pod silage (PPS) and its effect on the performance of fattening lambs, 24 Zandi male lambs (initial BW, 33.5 ±1.5 kg) were used in a completely randomized design over 75 days. Experimental treatments were: 1) control; (basal diet) 2- pea pod silage (PPS replaced wheat straw and alfalfa in the basal diet). The amount of dry matter (DM), crude protein, ether extract, ash, neutral detergent fiber and acid detergent fiber of PPS were determined 20, 11.8, 1.8, 8, 62 and 20.2 percent, respectively, and pH was 6.02. The rumen degradability potential of DM and in vitro gas production potential of PPS after 96 h of incubation were estimated 83 and 58.6 percent, respectively. The use of PPS in fattening lambs rations improved the final body weight and increased the daily weight gain (P<0.05). The amount of DM digestibility was affected by the treatment (P<0.05), but digestibility of other nutrients was not affected by the experimental treatment. Blood parameters (cholesterol, triglyceride, HDL and LDL) were not affected by the experimental treatments, except for the glucose, which significantly decreased by feeding PPS (P<0.05). The experimental treatments had no significant effect on carcass traits. Based on the results of this study, the use of pea pod silage as a cost-effective alternative forage in replacement with common forages such as wheat straw and alfalfa can improve the performance of fattening lambs.

In order to investigate the effect of feeding milk enriched with garlic powder on performance, digestibility of nutrients, diarrhea status and blood parameters in suckling lambs, twenty-four newborn lambs (birth weight 3.7±0.5) were randomly placed in three treatments and eight replications. The lambs of the control group were fed with milk without garlic powder and the other groups were fed with 1.5 and 3 grams of garlic powder per day, respectively, for 45 days. The results obtained from this research showed that consumption of garlic powder in suckling lambs led to improvement in daily weight gain, final weight and starter feed consumption (P<0.05). Also, treatments caused a significant increase in digestibility of nutrients (P<0.05). The use of garlic powder in experimental lambs improved stool consistency and significantly reduced the number of lambs with diarrhea and the average days of diarrhea (P<0.05). By adding garlic powder, the concentration of glucose and high-density lipoprotein increased (P<0.05). In addition, garlic powder caused a significant decrease in the level of triglyceride, cholesterol and low density lipoprotein in plasma (P<0.05). However, different levels of garlic powder did not make a significant difference on the concentration of urea, albumin, globulin and the ratio of albumin to globulin. According to the present results, it is possible to use garlic powder up to the level of at least 1.5 grams per day as a food additive to improve the performance and health of suckling lambs.

Sixteen male Markhoz kids (13.2±1.6 kg live body weight, 3 months old) were used to evaluate the effects of a commercial bacterial probiotic supplement on growth performance, nutrients digestibility, meat quality attributes and fatty acid profile of triceps brachii muscle and omental fat based on a completely randomized design with two treatments and eight replicates. The Primalak probiotic was fed daily in the amount of two grams to each kid in the respective treatment. Growth performance parameters, including average daily feed intake, average daily weight gain, and feed conversion ratio were not affected by bacterial probiotic feeding. Digestibility of diet’s chemical components showed no significant difference between treatments. Similarly, the quality attributes of triceps brachii muscle, including pH24, drip loss, water holding capacity, and chemical composition had similar values in both experimental treatments. Kids with access to bacterial probiotic had significantly lower saturated fatty acids, higher mono-unsaturated fatty acids and greater unsaturated to saturated fatty acids ratio in examined muscle (P<0.05). However, with the exception of lower C15:0 concentration in kids receiving bacterial probiotic (P<0.05), fatty acids profile in omental fat tissue did not change in response to probiotic consumption. It can be concluded that Primalak multi-strain probiotic with the mentioned dosage (2g/d/h) is not an effective additive to make significant changes in nutrients digestibility, Markhoz kid’s performance, meat quality attributes and fatty acids profile of different fat tissues.

In this experiment, the effect of two types of zinc-methionine (Zn-Met) chelate on performance and bone characteristics of broiler chickens were considered in a completely randomized design, using 490 Ross-308 broiler chickens (one-d-old, mixed sexes) with 7 treatments, 5 replicates and 14 birds in each replicate. Treatment consisted of: 1) control (basal diet), 2-4) control + 0.2, 0.4 and 0.8 mg/kg Zn-Meth of Zin-Pro® respectively and 5-7), control + 0.2, 0.4 and 0.8 mg/kg zn-Met synthetized by Ilam University. Results showed that as compared to group, none of zn-Met source had significant effect on broiler chickens feed intake, body weight, FCR and EPEF, carcass and breast and thigh percentages, serum glucose, triglyceride, cholesterol, LDL-cholesterol and HDL-cholesterol, triglyceride and Ca concentrations, activity of Alkaline phosphatase, Aspartate transaminase and Alanine aminotransferase enzymes and tibia characteristics including weight, dry matter and ash percentages, length, width and diameter and P and Ca percentages (P < 0.05) while broilers fed diet containing Zn-Meth had higher serum and tibia Zn concentration, higher villous height and villous height to crypt depth ratio and lower villous width in ileum and jejunum as compared to negative control group (P < 0.05). Generally, both of the chelates had similar effects on broiler chicken’s performance, small intestine morphology and tibia traits and Iranian kind of Zn-Meth has capability to substitution with foreign source of it although needs to further investigations.

Effect of different sources of probiotic and prebiotic on growth performance, carcass characteristics, intestinal microflora, and blood metabolites using 720 Ross 308 commercial male broiler chickens in a 3×3 factorial experiment with three levels of probiotic (without probiotic, probiotic type I and type 2) and three levels of prebiotic (without prebiotic, prebiotic type 1 and type II), in a completely randomized design with nine experimental groups (four replications and 20 birds were studied in each replication. Birds that were fed with diets containing type 2 probiotics had a lower conversion factor (P<0.05). Diets containing prebiotic type 1 as well as diets containing probiotic type II and diets containing probiotic type II and two prebiotics under test reduced serum cholesterol and LDL concentrations (P < 0.05). The effect of the experimental treatments on carcass fat was not significant, but the birds fed diets containing prebiotic type 1 had less abdominal fat (P<0.05). At 21 days old, the population of E. coli in the ileum and ceca of birds that received probiotics, prebiotics, and their combinations decreased (P < 0.05). At 38 days of age, feeding the birds with probiotics and prebiotics and a combination of them reduced the population of E. coli in the ceca and increased lactobacillus in the ileum (P < 0.05). The results of this experiment showed that probiotics or prebiotics assayed in this study have positive effects on the increase of beneficial intestinal bacteria (Acid lactic bacteria), blood biochemical traits, and FCR in broiler chickens.

To investigate the effects of using fennel root powder in the diet on the productive performance, immune responses, and meat quality of Arian broiler day-old chicks, an experiment was carried out in a completely randomized design with six treatments, four replicates and 20 (male and female) in each, for 42 days. The experimental groups include: 1- basic diet (control) 2- basic diet + 2 g/kg fennel root powder 3- basic diet + 4 g/kg fennel root powder 4- basic diet + 6 g/kg fennel root powder 5- basic diet + 250 mg/kg antibiotic and 6- basic diet + 200 mg/kg probiotic. The live weight , livability percentage , the production index and carcass characteristics were not affected by the experimental treatments during the whole period. In contrast, the average feed consumption in the whole period was affected by the treatments containing fennel and antibiotics (P<0.05). The antibodies against sheep red blood cells (SRBC) and immunoglobulin G were higher in the treatments using fennel root powder compared to the control treatment (P<0.05). The use of fennel root powder at all levels, reduced MDA after seven days of keeping meat in the refrigerator at 4 degrees Celsius (P<0.05). In conclution, regarding the positive effects of using fennel root powder on the immune responses and meat preservation of broilers, it is recommended to use it at the rate of 2 grams per kilogram of diets.

In order to investigate the effects of using live, autolyzed yeast and their combination on performance, and intestinal histology in Japanese quail, 360 of one-day-old chicks were used. Birds were randomly divided into 4 experimental groups in a completely randomized design with 6 replicates. The experimental groups included the control group: fed with basal diet without additives, the second group: fed with basal diet containing 0.4% live yeast, the third group: fed with basal diet containing 0.4% autolyzed yeast and the fourth group: fed with basal diet containing 0.2% live yeast and 0.2% autolyzed yeast. The results showed that the addition of autolyzed yeast caused the greatest increase in body weight gain compared to the control and their mixture in the whole period of experiment (P<0.05). The weight of thigh and pancreas as well as the length of duodenum increased significantly in birds fed with autolyzed yeast compared to live yeast and their mixture (P<0.05). The highest height of duodenal villi was observed in birds fed with autolyzed yeast and live yeast compared to the control treatment and their mixture. Birds fed with autolyzed yeast showed a significant decrease in E. coli bacteria and an increase in Lactobacillus bacteria (P<0.05). The results showed that the use of autolyzed yeast as well as live yeast can be useful in feeding Japanese quails due to improving performance, increasing the height of duodenal villi, reducing the microbial population of E. coli and increasing the cecal population of Lactobacillus.

The aim of the current study was to improve the reproductive performance and birth weight of lambs using vitamin E and selenium (Ese) injection in estrus-synchronized Moghani ewes. In this research, a total of 200 Moghani ewes were divided into two groups in a completely randomized design. In the control group, only estrus synchronization was performed, but the second group was received two intramuscular injections of Ese (5 ml) on the days of sponging and sponge removal. Synchronization of estrus was done by inserting intravaginal sponges for 14 days followed by 400 IU eCG at sponge withdrawal. Two days after sponge withdrawal, ewes were joined with fertile rams. Twenty ewes from each group were selected randomly and their blood was sampled. The first and second blood samplings were done before inserting intravaginal sponges and three weeks after ram exposure, respectively. Then, some blood plasma metabolites were determined. After parturition, reproductive traits were calculated in each group. According to the results, lambing rate, fecundity rate, lamb production efficiency and twinning rate were higher in Ese group (88, 111, 126.1, 21.6 respectively) compared to control (73, 84, 112.3, 12.3 respectively). The birth weight of lambs did not significantly differ between the groups. Glucose and cholesterol concentration of blood were significantly higher in group receiving Ese three weeks after mating. In conclusion Ese injection improved the reproduction performance in Moghani ewes.