ANIMAL SCIENCE RESEARCHES (FACULTY OF AGRICULTURE, UNIVERSITY OF TABRIZ)
Year:2015 | Volume:25 | Issue:4|Papers Count:21

BACKGROUND: Study of heritability, genetic and phenotypic correlations of internal egg quality traits.OBJECTIVES: The aim of this study was to evaluate of heritability, genetic and phenotypic correlations of internal egg quality traits in Azerbaijan native fowls.METHODS: Statistical models for all traits were fitted using GLM procedure of SAS software. Fixed effects including generation and incubation time were significant (P < 0.01) for all traits except for yolk hright. In the first section, eight univariate animal models were compared for estimation of heritability and other genetic parameters and the most appropriate model for each trait was determined based on deviance information criterion (DIC). The genetic and phenotypic correlations between certain traits were also estimated through a multivariate animal model.RESULTS: Results showed that direct heritability estimations for egg quality traits ranged from 0.12 for Haugh unit to 0.46 for yolk depth. There were high positive genetic and phenotypic correlations between albumen height and Haugh unit (0.96) as well as between egg weight and albumen weight (0.87).CONCLUSIONS: Egg quality traits especially Haugh unit as a trait in the selection index, could be useful to improve internal egg quality in eggs of Azerbaijan native fowls.

BACKGROUND: Use of cooling systems can improve blood anti-oxidants of dairy cows during the hot weather.OBJECTIVES: This study was conducted to evaluate the advantages of cooling systems on immunity, oxidative status and cell blood counts of early lactating dairy cows during hot weather. METHODES: Forty six multiparous Holstein dairy cows were blocked according to milk yield and parity into two treatments after parturition as follows: group 1, the heat stressed cows and group 2, cows were housed in individual roofed boxes and were cooled 8 hours per day with sprinkle and fan.RESULTS: The production of oxygen free radicals (P<0.001), malonaldehyde (P<0.01) and activity of glutathione peroxidase (P<0.001) and superoxide dismutase (P<0.001) and total antioxidant capacity (P<0.05) were higher in group 1 in compared with group 2. But the concentrations of immunoglobulin A (P<0.01), immunoglobulin G (P<0.001), interlukin-1 (P<0.01) and tumor necrosis factor-alpha (P<0.001) in group 2 were greater than group 1. Furthermore, the hematological factors such as white blood cells (P<0.01), lymphocytes (P<0.05), monocytes (P<0.05), red blood cells (P<0.01), hemoglobin (p<0.05) and hematocrit percentage (P<0.001) were better for cows in group 2.CONCLUSIONS: With regard to these results, using of cooling systems can improve oxidative situation, immunity and hematological profiles of lactating dairy cows during hot weather.

Background: Increasing population and growing demand for dairy products and protein has led to paying more attention by policymakers in livestock sector on increasing efficiency. Objective: The purpose of this study is measuring technical and environmental efficiency of dairy farms in Sarab County and determining effective factors influencing them.Methods: Required data collected using simple random sampling and filling 51 questionnaires at year 1394.Results: Using Data Envelopment Analysis, average technical, scale and environmental efficiency calculated 95%, 55% and 88%, respectively. The Kruskal-Wallis test used to the statistical comparison of the difference between technical and environmental efficiency, Results confirm significant difference between them. Also, the result of Spearman's rank correlation coefficient show that the higher the technical efficiency of the farm, the less the pollution emitted and then the farm has high environmental efficiency.Conclusions: Finally, education and milk yield per cow determined as the effective factors influencing the environmental efficiency of dairy farms.

Background: livestock production as a protein source for human hasnot an equal elevation along with world population growth. Whereas different animal diseases have more confining effects on livestock production. Cystic echinococcosis as a zoonotic disease has direct and indirect influence on human health and meat production system, respectively. Objective: We investigated effect of time and area variables on economic losses of cystic echinococcosis based on hydatidosis data report of three abattoirs in south of Kerman province from 2011 to 2014.Methods: Database was registered information of three slaughterhouses of three cities from south of Kerman province. Economic losses evaluation was based on discarded offal price and indirect financial losses of meat and wool production decline resulted from hydatidosis disease. Result: The disease rate average was 5.4% during 4 years. Contaminated carcass rate was significantly different between three cities and different seasons (P<0.01). Disease had the most outbreaks during fall and winter seasons. Total economic losses were 58345080 Rial. Maximum and minimum loss was 64% for offal discards and 5% for wool production. Conclusion: although disease rate in these regions showed a decreasing trend, but total disease rate was partly critical. More disease control during farm animal production, exact carcass inspection and enhancement of public information about cystic echinococcosis for disease prevention is recommended.

BACKGROUND: The Subsidy Reform Plan (SRP) was implemented in 2010 in order to replace the subsidies on energy, food and etc with targeted social assistance.OBJECTIVES: Given the importance of dairy industry in human nutrition, the aim of this study is to evaluate the impact of ISRP on the efficiency and productivity of dairy farms.METHODS: Data were collected from a sample of 65 industrial dairy farms by using proportionate stratification sampling method, through face-to-face interviews based on a structured questionnaire. The calculation method of efficiency and productivity respectively are data envelopment analysis (DEA) and Malmquist index.RESULTS: The results show that respectively decrease and increase in technical and allocative efficiency of farms. In addition, farm productivity has declined in this period, but there was no significant difference between periods. There were significant differences between productivity and technical, allocative and economic efficiency of farms with different size. Furthermore, farms with more than 1,000 head of cattle has been less affected by the ISRP.CONCLUSIONS: In order to improve the dairy farm productivity and efficiency, and the farmer’s motivation, it is important to removal of the output price distortions and enhancing farmers' access to input markets.

BACKGROUND: By studying lipid and lipoprotein concentrations changes in the pregnant camels, methods can be found to reduce fertility problems and enhance reproduction efficiency in the species Bactrian camels.OBJECTIVES: This experiment was carried out to evaluate the effect of age, sex and pregnancy on serum lipid and lipoproteins in two humped Camels.METHODS: blood samples were collected from the jugular veins of 20 healthy camels according to their age (<10, 10-4 and >4 years), sex and pregnancy. Serum concentrations of total cholesterol (TC), triglyceride (TG), total lipid (TL), LDL-cholesterol, HDL-cholesterol and VLDL-cholesterol were evaluated.RESULTS: The concentrations of TG, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol in different age groups was significantly different (P<0.05). Age had a significant effect on the level of serum TG, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol of the camels, as in advanced ages, these parameters were lower except LDL-cholesterol. The concentration of LDL-cholesterol in immature camels was lower than adult ones. The concentration of TC was higher in male camels compared with females and this difference was significant (P<0.05). Tthe concentration of HDLcholesterol was higher in non-pregnant camels as compared with pregnant camels.CONCLUSIONS: Probably activation of sexual hormones during the puberty and hormonal interactions in the hypothalamus – pituitary - Gonadal axis (HPG) is the main reason for this phenomenon.

BACKGROUND: In this study, 2554 calving records from 1484 Holstein cows were used.METHODS: The data were collected from one of the East Azerbaijan herds, during 2009 to 2013. The studied traits were production traits (305 d milk and 305 d fat yields) and reproduction disorders (dystocia and retained placenta).OBJECTIVES: Estimation of genetic parameters was performed by repeatability animal linear (305 d milk and 305 d fat yields) and threshold models (dystocia and retained placenta), by single and two-trait analyses.Results: Heritability for 305 d milk yield and 305 d fat with single-trait analysis were estimated 0.33 and 0.23, respectively and the repeatability of these traits were estimated 0.35 and 0.25, respectively. Heritability of dystocia and retained placenta were estimated 0.09 and 0.1, respectively and the repeatability for both was estimated 0.11. Genetic correlation between production traits were estimated 0.98 and genetic correlation between reproduction disorders were estimated 0.51. Estimated genetic correlations between production traits and reproduction disorders were from -0.85 (305 d fat and retained placenta) to 0.21 (305 d milk yield and dystocia). CONCLUSION: Considering negative genetic correlation between milk production and dystocia and a relatively strong positive correlation between these two reproductive disorders, planning of selection programs in dairy cows based on a combination of production and reproduction traits is recommendable. Also ignoring these relationships in selection may negatively influence overall performance in a long term.

BACKGROUND: L-carnitine and choline affected lipid metabolism and deposition of fat in the carcass and liver.OBJECTIVES: An experiment was conducted to determinate the effects of rumen protected choline (RPC) and L-carnitine on growth performance, carcass characteristics and apparent digestibility of finishing male calves.METHODS: 28 Holstein male calves (average initial weigh 300±24 kg) used in 4 treatments with 7 replicates in a completely randomized design for 100 days. Treatments included: 1) without L-carnitine and RPC or control, 2) 4g L-carnitine d-1 head-1, 3) 5 g RPC d-1 head-1 and 4) 4 g L-carnitine d-1 head-1 and 5 g RPC d-1 head-1. Calves had free access to balanced TMR and water. Monthly body weight changes and daily individual feed intake recorded. Carcass characteristics were measured on the day of slaughter.RESULTS: There were no differences among diets for DMI, ADG and feed efficiency. Apparent digestibility of dry matter, organic matter and natural detergent fiber numerically decreased in calves fed RPC (P<0.08). Extra carcass fat and back fat thickness decreased significantly in calves fed L-carnitine and RPC (P<0.05). Pelvic, kidney, heart and rumen and intestine fats were not affected by treatments. Hot carcass, femur, liver, kidney, heart, spleen, lung and trachea, skin and empty rumen weights and carcass length were not affected by L-carnitine and RPC.CONCLUSIONS: This study showed that L-carnitine and RPC supplements cannot affect growth performance in Holstein young bulls, but lipid metabolism may be affected by L-carnitine and RPC.

BACKGROUND: Optimum use of almond hull in fattens sheep feed. OBJECTIVE: In this study ruminal degradabilities of three varieties of paper shell, Mamaie and stone shell almond hull and their effects on fattening performance of sheep were determined.METHODDS: In order to effect of almond hull on fattening performance of sheep, 28 of ram lambs after weaning and three diets containing level of 0, 20, 40 and 60 percent of almond hull substituted with roughage, were used.RESULTS: Means of almond hulls degradabilities test had significant differences (P<0.05) in incubation time of 0, 4, 8 and 16 h, but lack of significant differences in 24, 48 72 and 96 h. Average daily gain in groups of control, 1, 2 and 3 with consumption of 0, 20, 40 and 60 percent of almond hull were 220, 223, 235 and 262 g and feed conversion ratio were 9.3, 8.7, 8.9, and 7.2, respectively that were significant differences (P<0.05) between control and treatment 3 for both traits. COCLUSION: In general not only use of almond hull had any bad effect on fattening performance, but also with consider of suitable degradability and positive result on fattening performance, it can be used to 60 percent substitute with roughage in diet of sheep.

BACKGROUND: Oxytocin and prostaglandin F2a are effective on male reproductive function.OBJECTIVES: This experiment was carried out to evaluate the effects of oxytocin and prostaglandin F2a injection on reproductive activity of Arabian rams.METHODS: In breeding season, twelve Arabian rams with the nearly same age (average 2.5 years old), weight (average 64 Kg) and similar feeding conditions were assigned as a completely randomized design into three treatments: 1- control (without hormone injection), 2- oxytocin injection (7 IU, IV) and 3- PGF2a injection (4 mg dinoprost, IM). About 15 minutes after each injection, semen (with ejaculator) and blood samples were taken. Testicular circumference and height were measured. The time interval between the beginning of electrical stimulation to ejaculation was recorded. This experiment was repeated weekly for 4 weeks (16 observations for each treatment). The testosterone concentration in seminal and blood plasma was determined using radioimmunoassay.RESULTS: The testis dimensions were not affected by treatments. The time interval stimulation to ejaculation in hormonal treatments was higher than control (P<0.05). The Highest and lowest values of the semen volume, spermatozoa density, total numbers of spermatozoa and spermatozoa progressive motility were related to oxytocin and control treatments, respectively (P<0.05). Furthermore, the amount of these parameters in prostaglandin treatment was less than the oxytocin group (P<0.05). The percentage of live sperms in oxytocin treatment was higher than others (P<0.05). Both of the hormones caused the higher spermatozoa morphological defects than control (P<0.05). There were no significant differences in blood and seminal plasma testosterone values among treatments.CONCLUSIONS: In general, the oxytocin and prostaglandin F2a injection to Arabian ram in breeding season, reduced the time interval stimulation to ejaculation and improved the most quantity and quality parameters of spermatozoa.

BACKGROUND: poultry by-product meals are a excellent source of protein in diet because of their high protein content and sensible price. Although incorporating them in animal diets need to proper determination of their protein quality.OBJECTIVES: In the present study amino acid profile, Cornell Net Carbohydrate and Protein system (CNCPS) fractioning of protein and in vitro digestibility of three poultry by-product meals (Makian (M), Iran-Teyhoo (IT) and Kooshan (K)) samples were determined and compared.METHODS: In vitro digestbilities of DM and OM also were determined using three rumen-fistulated sheep. Protein contents of samples were 50.7, 55.5 and 62.6% for M, IT and K, respectively (P < 0.05). The CNCPS analysis showed that fractions A and B2 were similar in the samples studied, however, B1, B3 and C fractions differed among them. The K samples had the greatest B3 and C fractions among the samples.RESULTS: Both IVDMD and IVOMD were differed for three samples of poultry by-product meals (P < 0.05). The amino acids arginine, cysteine, leucin, threonine and valine were differed among treatments, but histidine, isoleucin, lysine, methionin, phenylalanine and tryptophane were similar among them. The results indicate that there were considerable variations among the poultry by-product meals with regard to chemical composition, CNCPS protein fractions and amino acid profiles.CONCLUSIONS: The results showed, chemical composition of poultry-by product meal has to determine before being included in animal rations.

BACKGROUND: Pregnancy and parturition are the important physiological conditions that could affect the body metabolism in ruminants.OBJECTIVES: The present experiment was carried out to investigate the variations of thyroid hormones and metabolite levels during pre-conception, pregnancy months and post parturition in Arabic ewes.METHODS: Estrus synchronization and natural mating were done in 20 healthy Arabic ewes with the ages of 3 to 5 years and they were reared under the same breeding and feeding conditions. Blood samples were taken before gestation, consecutive months of pregnancy and 45 days after delivery and blood sera levels of thyroid hormones and metabolites were determined. Data were analyzed using the SAS software in a completely randomized design by Proc Mixed.RESULTS: The blood sera concentration of T3 before the pregnancy was lower than that in post parturition (P<0.05). The amount of T4 in the last month of pregnancy was the lowest (P<0.05). T3/T4 ratio in various periods was not significantly different (P>0.05). Blood sera glucose in pre pregnancy was higher than its amount in gestation months and post parturition (P<0.05). Triglyceride concentration in the last month of pregnancy was the highest (P<0.05). Total protein concentration in the last month of pregnancy showed a significant decrease in comparison with other months of the pregnancy and before pregnancy (P<0.05). Albumin concentration of the blood sera was not affected by the time intervals of the study (P>0.05). Sera globulin concentration in the fourth month of pregnancy reached the highest value when compared to pre pregnancy and post parturition (P<0.05).CONCLUSIONS: The results of this study showed that the levels of thyroid hormones and some blood serum parameters of Arabic ewe in pre-conception, months of pregnancy and post parturition periods were different.

BACKGROUND: Agricultural waste due to their high nutritive potential can be useful food for animal nutrition. OBJECTIVE: The present study was designed to determine the effects of different microwave irradiation time on chemical composition, content of phenolic compounds, DM, CP and OM digestibilities, ruminal degradability parameters of DM, CP and in vitro gas production kinetics and parameters.METHODS: Chick pea pre-cleaning was processed for 3, 5 and 7 minuts with microwave irradiation after sampling.RESULTS: Results showed effectiveness of microwave irradiation in reduction of chick pea anti-nutritional factors. Greatest reduction in contents of total phenolics and total tannine (51.67 and 53.31, respectively) was belong to microwave irradiation for 7 minutes. Increasing irradiation time significantly decreased soluble protein fraction which reduces rapidly degradable protein fraction (P 0.05). Microwave irradiation for 5 and 7 minutes compared with control group reduced (P0.05) rapidly degradable protein fraction by 12.87 and 17.81%, respectively.CONCLUTION: Results of present study confirmed the ability of microwave irradiation in protection of CP form extensive ruminal degradation.

BACKGROUND: Placenta has an important interface between the fetus and the mother. It plays a special role in the exchange of metabolic and hormonal substances between mother and fetus.OBJECTIVES: The effect of relationship between maternal factors and placenta properties on birth weight, survival and average daily gain of Ghezel lambs was examined.METHODS: Placentas of 35 ewes were collected after delivery and target parameters were evaluated.RESULTS: Litter size had a significant effect (P<0.01) on placenta weight, large and small cotyledons count, cotyledonal density, placenta efficiency, large cotyledon length, birth weight, average daily gain and survival of lambs, while parity just had a significant effect (P<0.01) on placenta eject and large cotyledons length. There was a significant positive correlation between placenta efficiency and cotyledon density (r=0.47, P<0.05), number of cotyledons and cotyledonal density (r=0.7, P<0.01), birth weight and placenta weight (r=0.46, P<0.05), average daily gain and placenta weight (r=0.54, P<0.05) and a negative correlation between placenta weight and placenta efficiency (r=-0.68, P<0.01), placenta weight and cotyledonal density (r=-0.7, P<0.01) in single lambs but there was a positive significant correlation between cotyledon number and cotyledonal density (r=0.74, P<0.01) and negative correlation between placenta weight and placenta efficiency (r=-0.81, P<0.01) in twin lambs.CONCLUSIONS: Our results showed that birth weight, mortality rate and average daily gain of lambs are influenced by maternal factors and placenta properties, but more studies are required to elucidate effects of placenta properties specifically placenta efficiency and cotyledonal density on lambs health and survival.

BACKGROUND: There are many discrepancies about positive or negative effects of corpus luteum (CL) and unequal activity of sides of the reproductive system.OBJECTIVES: the initial aim of this study was to assess the developmental competence of bovine oocytes originating from right or left ovaries bearing a CL (R.CL+-oocytes or L.CL+-oocytes) or not bearing a CL (R.CL--oocytes or L.CL--oocytes) using the brilliant cresyl blue (BCB) test as a selection criterion (experiment 1).METHODS: In experiment 1, collected oocytes exposed to BCB and separated as growing (BCB-) and grown oocytes (BCB+, more competent). Then, all of the oocytes were subjected to the in vitro embryo production (IVEP) processes.RESULTS: Results of this experiment showed no differences in the embryonic development due to effects of side of ovaries (i.e., right vs. left) or BCB selection (i.e., BCB+ vs. BCB−). However, in case of R.CL⁺-oocytes, there was a heterogeneity in the developmental competence of oocytes and the percentage of oocytes classified as BCB+ was greater (P< 0. 05) than that of BCB- (57.6% versus 42.4%, respectively). Furthermore, the percentages of cleavage and blastocyst obtained of CL+-oocytes were lower than those of CL--oocytes (P< 0.001). The second objective was to evaluate heterogeneity in the developmental potential of oocytes in relation to presence or absence of CL and follicle size. After ovarian classification based on presence or absence of CL, sample follicles were placed in three groups according to their diameter, i.e., small, medium and large or big and collected oocytes in each group subjected to the IVEP processes. Results showed that CL+.B-oocytes were not influenced by negative effects of CL as much as CL+.S-oocytes did.CONCLUSIONS: Therefore, it can be concluded that using oocytes originating from large follicles of ovaries not bearing a CL may decrease problems associated with IVEP of bovine embryos.