فصلنامه تحقیقات تولیدات دامی
سال هفتم شماره 1 (بهار 1397)

A study was conducted in order to compare the nutritive value, fermentation and degradability parameters of mountainous and plain alfalfa areas at different growth stages (before flowering, flowering and after flowering) at secondary harvest in four experiments.Alfalfa samples were randomly taken from a second species of the mountainous region (Mountain alfalfa meadows of Barfchal in Minoodasht) and plain (alfalfa plain around the Gonbad Kavous) collected and then transferred to the laboratory. The samples were dried for 48 h at 65°C and with a two-millimeter sieve were milled. Results showed that mountainous alfalfa compared with mountainous alfalfa had higher ether extract, organic matter and crude protein. Extent and rate of gas production were highest at before flowering stage in both mountainous and plain Alfalfa (P

The optimum proportion of urea to molasses in order to enrich forage part of the ruminant ration has been assumed as an important enhancer of the livestock animal performance. This proportion could change depending on type or chemical composition of the forage part. Therefore, the purpose of the current study was to investigate whether digestibility and composition of the Tumbleweed (Gundelia tournefortii) forage could be affected by treating with different proportions of urea and molasses during ensiling process. The first experiment was designed as a 3×3 factorial experiment in completely randomized design with five replicates to study the chemical composition and in vitro digestibility of TF regarding to enriching them by different levels of urea (0, 4% and 6%) and molasses (0, 5 and 10%) for 45 days. In the second experiment, in vivo digestibility of selected ensiling treatments was measured. The results of the first experiment showed that NDF and ADF contents of silages decreased significantly due to enriching by "4% urea% molasses" and "6% urea% molasses", compared to control. Moreover, dry matter digestibility and digestible organic matter of the dry matter were higher significantly in the groups which treated by "4% urea 10% molasses" and"4% urea 5% molasses" compared to untreated control group. According to the result of second experiment, CP and NDF digestibilities were improved by enriching silages with "4% urea% molasses" in comparison with dry tumbleweed. It was concluded that the treatment of silages with 4% urea plus 5 or 10% of molasses would be the best ratio for the enrichment of tumbleweed silages.

The aim of present experiment was to find the appropriate amount of post-harvested bean by-products (bean residues) in diet of finishing lambs, when was replaced with corn silage or wheat straw in the diet. In this experiment, to determine the nutritional value of bean residues, its chemical composition was measured by standard methods. Then, nine experimental rations were selected as treatment, in which 0, 25, 50, 75 and 100 percent residues of beans were replaced with wheat straw or corn silage. The method of gas production and two-stage digestion was used to determine digestibility and fermentation of these diets. The protein and fat concentrations of bean residues, wheat straw and corn silage used in the present experiment were 6.9, 3.6 and 7.4, and 0.9, 1.8 and 0.3 percent, respectively. Replacing 75 and 100 percent residues of beans with wheat straw and all replacement levels with corn silage, resulted in a significant increase in gas production. The rate of gas production during the replacement of 75% and 100% of the bean residues with corn silage or 25 and 50% with wheat straws were increased compared to the control. The microbial biomass production efficiency was the highest and significantly different with control diet (65 vs. 60.5%, respectively) when replacement of 100% bean residues with wheat straw was done. The replacement of bean residues did not affect the digestibility of dry matter and neutral detergent fiber. Therefore, the 75 and 100% replacement of the bean residues with wheat straw or 25 and 50% with corn silage showed the best result and could be recommended for use in lambs finishing feeding.

As the resources are limited, improving efficiency of sheep farming is of high importance in Iran. In the present study, the technical efficiency of Moghani sheep flocks was investigated using the method of data envelopment analysis, considering constant (CRS) or variable (VRS) returns to scale. Data of year 2015 on inputs for the amount of concentrate, forage and labor as well as outputs including the amount of meat, milk, wool and fertilizer were collected from 214 Moghani sheep flocks through interviews and questionnaires. Data analysis was performed using Deap 2.1 software. The average technical efficiencies with CRS and VRS were 0.978 and 0.977, respectively, showing high efficiency in studied flocks. With CRS and VRS, there were 14 and 25 flocks being technically efficient, respectively, and could be introduced as reference flocks to inefficient ones. The results showed that with VRS, some reduction in flock size, labor, forage, concentrate, rangelands roughages and health costs as 2.99, 2.99, 2.63, 2.79, 2.73 and 6.41 percent, respectively, would let inefficient flocks to become efficient, while maintaining the same level of previous production. The estimates of return to scale showed that most of Moghani sheep flocks had an increasing return to scale, and are able to benefit from scale-based savings and lowered cost per output unit.

The objective of this study was to determine ileal digestibility of amino acids (AA) of canola meal using the standardized ileal digestibility (SID, ad libitum-fed), and a precision-fed ileal broiler assay (force-fed). For the SID, sixteen male Ross 308 broilers were fed a semipurified diet with 20% crude protein and containing canola meal as the only source of protein from 17 to 21 d, with ileal digesta collected at 21 d. For the precision-fed, sixteen )four groups of four chicks( 21-d-old male Ross 308 broilers were precision-fed by 10 g of semipurified diet containing canola meal mixed with chromic oxide, and ileal digesta were collected at 4 h post feeding. Then, ileal digesta samples were lyophilized, AA and chromic oxide concentration determined and standardized ileal digestibility of AA was calculated. Results showed that digestibility values for Lys, Val and His for SID assay were greater than precision-fed assay, and these values were greater for Thr, Phe and Asp for precision-fed assay than SID assay (P

In order to assess the effects of Silibum marianum seed(SMS) and Thymus vulgaris (TM)powderson carcass traits, some blood metabolites and immune system responses of chickens which fed by aflatoxin B1 (AFB1) contaminated diet (2 mg/kg) during 1 to 21 d of age, a total of 200 male broilers (Ross 308) were used in completely randomized design with five treatments and four replicates (10 birds per replicate). The experimental dietary treatments included: 1) control diet (without contamination, negative control), 2) AFB1 contaminated diet (positive control), 3) AFB1 contaminated diet 1% SMS, 4) AFB1 contaminated diet 1 % TM, 5) AFB1 contaminated diet 1% SMS 1 % TM. The results of current study indicated that feeding AFB1 containing diet increased liver weight compared with 1 and 3 groups and supplementation of AFB1 contaminated diet with SMS attenuated effects of AFB1 on liver weight (P0.05), while supplementation of AFB1 contaminated diets with SMS and SMS and TM combination significantly increased lymphocyte proliferation test and respiratory burst in monocytes (P

This experiment was conducted to investigate the effect of using 2% untreated and treated corn gluten meal with protease enzyme (300 mg/kg) at three different times (120, 180 and 240 minutes) on broiler chicks performance, carcass characteristics and some blood parameters. 240 commercial strains Ross 308 male broiler chicks with five treatments including: 1. control diet, 2. control diet containing 2% corn gluten, 3, 4, and 5. control diet containing 2% corn gluten meal processed with protease enzyme at 120, 180 and 240 minutes, respectively, four replicates and 12 chicks in each replicate in a completely randomized design were reared for 38 days. During the experiment, feed intake, body weight gain and feed conversion ratio were measured. To evaluate blood parameters and carcass components at 38 d, eight birds from each treatment were selected and after blood samples collection, some blood parameters such as glucose, total protein, albumin, globulin, triglycerides, cholesterol, HDL-C, LDL-C and VLDL-C were measured and also, carcass components including weights of carcass, thighs, breast, abdominal fat, liver, pancreas, spleen and Bursa Fabricius were determined. Results of this study indicated that treatments containing 2% corn gluten meal with protease enzyme processing at different times, increased feed intake (3801.98, 3848.59 and 3850.42 vs. control diet 3769/82 g), body weight gain (2000.88, 2020.16 and 2033.27 vs. control diet 1888.82 g), and reduced feed conversion ratio (1.90, 1.90 and 1.89 vs. control diet 1.99) in total period of the experiment (P

This experiment was conducted to investigate the interaction effects of ginger root and red pepper powders in wheat based diet on performance and immune response of layer hens. In this experiment 288 hy-line W-36 laying hens in post-molting phase (78 weeks) were assigned to 36 groups in a factorial arrangement with nine treatments and four replicates based on completely randomized design. The experimental factors were included three levels of red pepper (0, 1 and 2% of diet) and three levels of ginger root powder (0, 1 and 2% of diet). Results showed that pepper levels were significantly increased egg production and egg mass of birds (P