IRANIAN JOURNAL OF APPLIED ANIMAL SCIENCE
Year:2013 | Volume:3 | Issue:3|Papers Count:30

The variation in climatic variables like temperature, humidity and radiations were recognized as the potential hazards in the growth and production of all domestic livestock species. Thermal environment is a major factor that can negatively affect both production and reproduction in dairy animals, especially in animals of high genetic merit. Among the stressors, heat stress has been of major concern in reducing animal’s productivity in tropical, sub-tropical and arid areas. There are few effective strategies for reducing the effects of heat stress on animal’s health and performance. The major strategies providing elaborate housing involving shade, sprinklers, fans, air conditioner, etc. are capital intensive, not very efficient and are of limited use for small and medium-size dairies. Sweating, high respiration rate, vasodilation with increased blood flow to skin surface, elevated rectal temperature, reduced metabolic rate, decreased DM intake, efficiency of feed utilization and altered water metabolism are the physiological responses that are associated with negative impacts of heat stress on production and reproduction in dairy animals. This article aimed to review bio-chemical and physiological changes which occur during thermal stress in bovines.

In this review, we aim to examine the effect of extrinsic and intrinsic factors on spermatogenesis process taking into account a complex signaling pathway. Primarily, it is suggested that retinoic acid (RA) has a vital function in spermatogenesis process and it is considered to be essential for completion of spermatogonia into mature spermatozoa. In the present review, the key effects of retinoic acid (RA) on spermatogenesis process were evaluated in the perspective of studies done, particularly at molecular level. Thus, this review will provide re look the spermatogenesis process in an outlook of new studies.

Two experiments studied the effects of canola or sunflower seed supplementation on conjugated linoleic acid (CLA) concentration in milk fat of lactating cows. In each experiment, only eight cows in early lactation were available to assign to one of two treatments in a completely randomized design and were fed individually for 12 wk. Experiment 1 compared similar diets with or without the addition of ground canola seed [12.1 g/100 g dry matter (DM)]. Cows fed canola had highercis -9, trans -11 CLA in milk fat at wk 9 and 12 (P<0.05). In experiment 2, treatments were two levels of rolled sunflower seed: low (2.0 g/100 g DM) and high (11.4 g/100 g DM). In experiment 2, cows on the high sunflower diet had greater cis -9, trans -11 CLA in milk fat compared with that of the low sunflower treatment at wk 3 and 12; however, significant individual cow variation existed within the high sunflower treatment. Milk yield, milk composition, and dry matter intake (DMI) were not altered in either experiment. Even given this experiment was not robust, the oilseeds of canola and sunflower increased CLA content in milk fat of lactating cows without negatively affecting milk yield or milk fat concentration.

This study was conducted to investigate the effects of infrared processing of barley for 60, 90, 120 and 150 seconds (s) on protein hydrophobicity, in vitro protein digestibility, degradation characteristics of protein and starch and its feeding effect on ruminal pH of sheep. The surface hydrophobicity of protein increased (P<0.04) as processing time increased. The degradation rate and effective rumen degradability of protein and starch decreased up to 90 s and remains constant at higher processing times (P<0.05). In vitro protein digestibility of barley increased at processing time of 60 and 90 s, remain constant at 120 s, then decreased at 150 s (P<0.05). Electrophoretic analysis showed aggregation of barley proteins that remain undegradable for longer time in the rumen. Ruminal pH of sheep fed processed barley was higher (P<0.05) than those fed untreated sample. There were no significant differences in ruminal pH of sheep fed barley processed at times over 90 s. It was concluded that infrared processing for 90 s, as shortest time, could decrease rate and extent of protein and starch degradation of barley in the rumen.

This study investigated the effect of Rumex Sc (commercial product which includes of Saccharomyces cer-visiae, saponin and essential oils) on rumen fermentation, blood glucose, urea, milk yield and milk composition. Animals were offered a basal diet containing alfalfa hay (15.5%), corn silage (24%), beet pulp (7%) and concentrate (53.5%). Additionally, Rumex Sc was included in the experimental diet at a rate of 5 g/day/cow. Sampling of milk, ruminal liquid and blood was conducted for determination of milk composition, fermentation parameters and blood metabolites. Milk yield was significantly increased for the experimental group when compared to the control group (P<0.05), but milk composition was not affected by Rumex Sc. The number of protozoa, ammonia nitrogen concentration and pH in the rumen were decreased in the experimental group (P<0.05). Concentrations of volatile fatty acids in the rumen were affected to some extent by inclusion of Rumex Sc in the diet. Molar proportion of acetate was decreased and propionate was increased with a corresponding decrease in acetate: propionate ratio. In this study, blood glucose was significantly increased and urea decreased with the addition of Rumex Sc (P<0.05). It was concluded that using Rumex Sc can improve the milk yield performance of dairy cows, however further studies are needed.

The present study investigated serum cortisol in response to postpartum ovarian resumption and luteal function. Postpartum ovarian resumption was detected based on a rise in progesterone (P4) concentrations during three weeks after calving. Twenty two Holstein cows in a semi-closed dairy farm in Qena city, Egypt were used. The study was carried out from late March to early June; the period characterized by a good temperature humidity index (THI) and absence of heat stress. According to the concentrations of P4 in se-rum (P4>1.0 ng/mL), 11 of the 22 cows resumed the ovarian activity within three weeks after calving (ovarian resumption cows). No effect of THI was found during the postpartum period of study on the concentrations of P4, cortisol and cholesterol in the ovarian resumption or non-ovarian resumption group. In the former, cholesterol showed a significant correlation with both P4 (r=0.405, P<0.05) and cortisol (r=0.393, P<0.05). However, in the latter, cholesterol had a significant correlation with P4 (r=0.289, P<0.05) but showed no correlation with cortisol. In addition, cortisol showed a significant correlation with P4 (r=0.329, P<0.05) in the ovarian resumption group but showed no correlations in the non-resumption group. Our study suggests that cortisol plays a role in the function of corpus luteum and maintenance of luteal life span during this period.

The present study aimed to evaluate the effect of kisspeptin-10 (Kp10), a shorter variant of kisspeptin re-taining full biological activity, on the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) in cyclic adult cows, and the effect of plasma progesterone (P4) concentration on the response to Kp10 administration. The experiments were performed using five postpartum cows (4-5 years old) treated with a progesterone-releasing intravaginal device (PRID) for 7 days. The animals received a single intrave-nous (i.v.) injection of Kp10 (5 mg/kg b.w.: 3.85 nmol/kg b.w.) for three consecutive days after the device’s removal. Plasma concentrations of P4 were higher on the day of the PRID’s removal (day 0: 7.3±1.1 ng/mL) than 1 (day 1: 0.8±0.1 ng/mL) and 2 (day 2: 0.6±0.1 ng/mL) days later (P<0.05). Kp10 did not alter plasma LH concentrations significantly at day 0. However, it significantly stimulated the release of LH on day 1 and day 2 (P<0.05). Kp10 tended to stimulate the release of FSH at day 2; however, it did not alter the concentrations of FSH in plasma significantly throughout the experiment. The results showed that Kp10 stimulates the release of LH in postpartum cyclic cows, and suggested that high concentrations of P4 in plasma may reduce the effect of kisspeptin on the secretion of gonadotropins.

The present work was carried out to study the variation in biochemical properties of cervico-vaginal mucus of pregnant and non pregnant animals which could help to design suitable tool in future for early pregnancy diagnosis in buffaloes. Cervico-vaginal mucus samples were obtained from 30 buffaloes (12 pregnant and 18 non pregnant) and some biochemical parameters were compared. Means of pH, sodium, potassium and chloride had no significant difference between the estrous cycle and pregnancy. Total sugar content showed significant differences in pregnant and non pregnant animals from 6th to 21st day (P<0.05). In pregnant animals, continuously increasing trend was observed from day 0 to day 21 (25.22±0.5 mg/100 mL on day 0 to 130.5±1.1 mg/100 mLon day 6 and later 156.4±1.8 mg/100 mL on day 21) whereas in non pregnant animals the concentration of total sugar increased from day 0 to day 12 and then started decreasing (24.33±0.6 mg/100 mL on day 0, 118.1±1.7 mg/100 mL on day 6, 127.9±1.5 mg/100 mL on day 12 and then decreased to 90.8±1.2 mg/100 mL on day 21). Protein content of vaginal mucus was different in pregnant and non pregnant animals from 12 to 21 day of experiment. A continuously decreasing trend of protein content was observed in non pregnant group after 12th day (14.3±0.43 mg/mL on day 12 and 9.9±0.55 mg/mL on day 21) whereas in pregnant group, the concentration remained higher up to 21st day without any significant change (26.8±0.33 mg/mL on day 12 to 29.6±0.12 mg/mL on day 21). However, protein content initially increased in both pregnant (42.4±0.22 mg/mL) and non pregnant (40.2±0.03 mg/mL) group and showed highest values on third day. Consequently, significant variation in total sugar and protein in cervico-vaginal mucus could be helpful in designing future biochemical tool for early pregnancy diagnosis in buffalo.

This study aimed at determining the physico-morphological attributes, in vitro fertility and their interrelationships in semen of Sahiwal bulls. Semen samples were collected weekly for 6 weeks from ten mature Sahiwal bulls divided randomly into 5 groups. The mean (±SEM) of ejaculate volume (mL), mass activity (score 0-5), progressive sperm motility (%), sperm concentration (106/mL), live sperm (%), abnormal sperm (%), intact acrosome (%), hypo-osmotic swelling (HOS) positive sperm (%), sperm penetration distance (SPD, mm) were 4.28, 3.17, 76.73, 1185.53, 83.37, 9.97, 82.70, 79.00 and 56.85, respectively. The bulls varied significantly (P<0.05) in all their ejaculates characteristics Moreover, HOS positive sperm also had significant (P<0.01) positive correlation with mass activity (r=0.756), progressively motile sperm (r=0.374), live sperm (r=0.395) and SPD (r=0.681), and negative correlation with abnormal sperm (r=-0.463). Sperm penetration distance has significant (P<0.05) positive correlation with mass activity (r=0.776), progressively motile sperm (r=0.653), sperm concentration (r=0.365) and HOS positive sperm (r=0.681), and negative correlation with intact acrosome (r=-0.415). Overall semen quality of Sahiwal bulls was found optimum for use in breeding programme.

The objective of this study was to analyze the association of somatic cell score (SCS) with milk, fat and protein yields across parities. Records of production traits and somatic cell counts (SCC) from first, second and third parity that were collected by the Animal Breeding Center of Iran from 1993 to 2010 were used. All animals were grouped into six classes according to SCC and production traits were evaluated in these SCC classes. To obtain an approximate normal distribution, SCC records were transformed on the base of Loge to somatic cell score (LSCS, the lactation mean of the natural log of test-day somatic cell count). A single trait animal model that LSCS was fitted as covariate was used to assess relations of SCS with production traits in fist, second and third parities. Effect of SCS on production traits in all of parities was negative and significant (P<0.05). Ranges of depressing effects on milk, fat and protein production were 107.78-220.41, 2.32-7.08 and 2.1-5.2 kg per 1 unit increase in SCS.

CSN1S1is one of the major genes encoding milk proteins of mammals. In this study we determined allele frequencies of CSN1S1 -5’ flanking region as well as exon 17 variants and their effects on milk traits in three indigenous cattle breeds Mazandarani, Golpaygani (Bos indicus) and Sarabi (Bos taurus) and Holstein cattle in Iran. CSN1S1 *B variant was nearly fixed in Holstein but ranged from 0.40 to 0.66 in indigenous breeds. CSN1S1 *C allele had higher frequency in indigenous breeds, especially in Bos indicus. Four genetic variants of the promoter were found in all breeds in different frequencies with allele 2 being the prevalent in all breeds (frequency 0.359 to 0.711) and allele 4 the least frequent (0.074 to 0.011). Allele B of the coding region was found in combination with all four promoter alleles. Allele 4 of the promoter was not found in any cow having the exon 17 allele C in all breeds except Mazandarani. BC/23 genotype yielded the highest fat percentage (P<0.05) in Holstein but it had no significant effect in Golpaygani. There was not any homozygous CSN1S1 *CC cow, to investigate the influence of C variant for fat content. None of the genetic combinations had significant effect on fat yield, although variant ' 2' of promoter indicated a negative effect. No significant effect among various combined genotypes on milk yield was found, but CSN1S1 *B tended to higher milk production. Differences of allelic frequencies and milk production traits found among these breeds might be due to differences in origin of breeds or selection breeding programs.

The objective of the present study was to estimate genetic trends for lactation milk yield, persistency of milk yield, somatic cell count and interval between first and second calving in Holstein dairy cows of Iran. The dataset consisted of 210, 625 test day and 25, 883 first parity cows with milk yield recorded from July 2002 to September 2007 comprising 97 herds in Iran. Breeding values of animals were predicted with Best Linear Unbiased Prediction methodology under multi-trait animal model. Model included region, herd-year-season of calving and age at first calving as fixed effects and Holstein percentage (covariate) and random animal additive effect. Genetic trends of studied traits were estimated by regressing mean of breeding values on calving year. Phenotypic trends were estimated using annual averages of first lactation traits on calving year weighted by the number of animals in each year. Genetic trend was positive and significant for lactation milk yield (21 kg/yr; p<0.01). Although not significant, favorable genetic trends for most studied traits were reported. Considering that selection emphasis in Iran was on lactation milk yield, progress for this trait was low during the years of the study.

Considering different fertility traits 411 cows from 73 farms used for economic analyses. From these, 202 lactating cows were selected for evaluating the fertility status. Pre-tested data sheets were used to record the socioeconomic status of the farms including their assets, cost and return and productive and reproductive performance of the dairy cows. Targets were set considering the situations prevailing in Zebu and their crosses rearing countries. The best 20% of local farms were chosen during setting the targets. Delay at first calving caused a significant loss (P<0.01) of Tk.11051 (135.04 USD) /farm/year. The farms would have had the opportunity to earn in average Tk.22236 (171.73 USD) more/year if they could attain the targeted milk production. The opportunity from milk production had a significant effect on total farm earning. The milk production cost was Tk.11.70 (0.14 USD) /litre. The average lactation length was 246.1 days in contrast to the target of 304 days. The farms were suffering from a significant (P<0.05) loss of Tk.5651 (69.05 USD) /year due to shorter lactation length. The calf mortality was 30.33% resulting in a loss of Tk.304 (3.71 USD) /farm/year. In 46 artificial inseminations (AI) the first service conception rate was 51%. The overall conception rate and services per conception was 50% and 2.0, respectively. The days open was found to be of 164.03 days. The main problems of the small holding dairy farms were delayed age at first calving, low milk production, high production cost, low milk to concentrate feed ratio and poor reproductive performance. Farmer’s income would have increased by about Tk.39493 (482.62 USD) /far year, if the control measures of different reproductive and productive indices could be substantially improved through veterinary herd health control programme.

Essential amino acids such as methionine have been increasingly included into diets of lambs. However, few studies have determined the effects of methionine supplementation in the general performance and economic returns of lamb production. To address this question, 21 weaned male Rahmani lambs were allotted to 3 dietary treatments: control diet (C), control diet plus 3.30 g of methionine/kg concentrate feed mixture (T1), and control diet plus 3.63 g of methionine/kg concentrate feed mixture (T2). T1-fed lambs showed significantly higher (P<0.05) total body weight gain than those fed diets C. The digestibility coefficients of dry matter (DM), organic matter (OM), crude protein (CP), ether extract, (EE), and nitrogen free extract (NFE) for T1 and T2 were significantly better (P<0.05) than for C. Economically, dietary feed T1 and T2 increased the net profit by 329.64 Egyptian pounds EGP/lamb and 305.76 EGP/lamb, respectively, as com-pared with the control diet. In addition, the economic efficiency (average feed cost/kg of body weight gain) was 10.02 for C and T1 and 10.48 for T2. Total costs were similar between the 3 dietary treatments. In conclusion, feeding growing Rahmani lambs with 3.30 g of methionine/kg concentrate feed mixture improved their growth performance and raised their economic value.

Two experiments were performed to determine the effectiveness of different progestogens contained in intravaginal devices, different doses of eCG and subsequent hCG treatment on the reproductive performance of estrus-induced mature Lori ewes. In the first experiment, 88 ewes were allocated into two groups, and were treated with either fluorogestone acetate (FGA) sponges or Controlled Internal Drug Release de-vices (CIDR). The sponges were withdrawn 13 days after insertion and then ewes were treated with either 350 IU or 500 IU of eCG by intramuscular injection. There was no significant difference among treatments in the percentage of ewes in estrus or the interval to the onset of estrus. However, the conception rate and prolificacy of ewes treated with 350 IU eCG, in both the FGA and CIDR groups, was higher than ewes treated with 500 IU of eCG. In the second experiment 384 ewes were randomly divided into three groups and after synchronization with FGA sponges and 350 IU of eCG, 128 ewes in the first group (T1) were injected 250 IU hCG when artificially inseminated, 128 ewes in the second group (T2) were injected 250 IU hCG 12 days after AI and the 128 ewes in the third group (C) acted as the control group. Estrous was determined by monitoring 35 teaser rams to calculate estrous rate. Prolificacy and conception rate were assessed and serum progesterone (P4) concentrations were measured on days 12, 14 and 16 days after AI. Prolificacy was increased in the T1 group compared with control group (P<0.05) and conception rates were higher in hCG treatments (P<0.05). The weight of single lambs on the day of birth increased with the hCG injection on days 0 and 12 (P<0.05). The P4 concentration was higher in the hCG-treated groups compared with the control ewes on day 16 (P<0.05). It is concluded that CIDR and FGA sponges were equally effective for estrous induction in anestrous Lori ewes and P4 concentrations increased with 200 IU hCG given at the time of AI or 12 days after AI which could improve reproductive performance.

An experiment was conducted in Algerian desert goats to study the effect of age and season on blood bio-chemical and mineral profile during different physiological stages of the goats. Serum Ca, Mg and Na levels were significantly high at birth and decreases as the age advanced. The season had a significant effect on the decreased levels of Ca, Mg and K and inversely on the increased levels of Na during dry season. The Ca (80.02±4.84 mg/L), Mg (22.14±1.61 mg/L), Na (142±1.73 mEq/L) and K (6.43±0.40 mEq/L) in pregnant goats were significantly higher than in non-pregnant and lactating goats.

Lipid oxidation was studied in M. longissimus dorsi and M. semimembranosus in male lambs of Northeastern Bulgarian Fine Wool Breed and cross of this breed with Ile de France, reared indoors and on pasture. The oxidation of the lipids was determined by quantification of thiobarbituric acid reactive substances (TBARS), formed during the storage of the muscles at 4oC until 6th day and -20oC until 90th day. The way of the rearing had significant influence (P<0.01; 0.001) on the lipid oxidation in the muscles during the storage in both lambs of Northeastern Bulgarian Fine Wool Breed and the cross. The lipid oxidation was lower in the animals reared on pasture. The muscle type also had significant effect on the amounts of TBARS, as they were higher in M. semimembranosus. The dynamic of changes in TBARS contents on the muscles in both groups of animals from the breed and the cross showed influence of the duration of the storage on the lipid oxidation, as the highest values were achieved on the 90th day of samples storage.

In this study 71 head of conceiving ewe and their progeny (91 head) from the flock of Lori-Bakhtiari sheep (360 head), in Sholi Station were randomly selected to determine the relationship between the immunoglobulin (IgG) concentration in the ewe's serum and colostrum, and lamb's serum. Ewe blood sample, colostrum of ewe and blood of the lamb was taken 2 weeks before parturition, 1 to 8 hours after parturition and 36 hours after birth of lamb, respectively. The serum of samples was extracted and then IgG (mg/mL) was measured in samples based on single radial immunodiffusion test and total serum protein (gr/L) based on quantitative zinc sulfate turbidity method. Results showed that the overall mean of IgG were 21.33, 48.48 and 7.86 mg/mL for blood serum of ewe, serum colostrum of ewe and blood serum of the lamb and total serum protein were 71.98, 114.48 and 65.77 g/L, respectively. The effects of age of ewe, type of parturition, gender of lamb, body condition score and body weight of ewe on considered immunity traits were not significant (P>0.05). The correlation coefficients between IgG in serum of blood and serum of colostrum in ewe and serum of blood in lamb were medium to high (0.35 to 0.75) and significant (P<0.05). The regression coefficients of IgG concentration in lamb's serum on values in ewe's serum at 2 weeks before parturition was highly significant (P<0.01) and shows that IgG content in lamb's serum increase by 0.18 units per increasing one unit in IgG content in ewe's serum. Therefore, the level of IgG in lamb's serum could be affected by the IgG concentrations in ewe’s serum and colostrum. Also, the level of IgG in lamb's serum could be enhanced by improving the level of IgG concentration in ewe's serum at two weeks before lambing.

The objective of the present study was to evaluate the effects of inbreeding on average daily gains and Kleiber ratios in Moghani sheep. Traits included average daily gain from birth to 3 months (ADG1), aver-age daily gain from birth to 6 months (ADG2), average daily gain from 3 months to 6 months (ADG3), average daily gain from 3 months to 9 months (ADG4), average daily gain from 3 months to yearling (ADG5) and corresponding Kleiber ratios (KR1, KR2, KR3, KR4 and KR5, respectively). Data and pedigree information used in this study were collected at the Breeding Station of Moghani sheep during 1987-2005. All the animals were grouped into three classes according to the inbreeding coefficients obtained by their pedigree: the first class included non-inbred animals (F=0%); and the second and third classes included inbred animals (0<F£0.10 and F>0.10, respectively). There were significant regression coefficients of ADG5 and KR5 on inbreeding of all lambs for changing 1% inbreeding (P<0.01). Indeed, there were significant regression coefficients of ADG3 (P<0.01) and KR3 (P<0.05) on inbreeding of twin-born lambs for a change of 1% in inbreeding. In addition, there were significant regression coefficients of ADG1 (P<0.05) and ADG5 (P<0.05) on inbreeding of male lambs and significant regression coefficient of ADG2 (P<0.05) on inbreeding of female lambs for a change of 1% in inbreeding. Effects of inbreeding on average daily gains and Kleiber ratios in Moghani sheep was not very pronounced in the flock. Planned matings are, however, suggested to avoid accumulation of inbreeding and appearance of its deleterious effects.

Berari goats are medium sized animals reared mainly for meat purpose. They are predominantly brown and blackish brown in colour with glossy hair and found in Vidarbha region of Maharashtra state. Berari is not a recognized breed but a well established local population of goat which is yet to be fully explored for its phenotypic and genetic aspects. Within population genetic variation was examined in Berari goat popula-tion using microsatellite markers. The observed number of alleles varied from 4 (ILSTS05, OarJMP29) to 26 (OarFCB304) with a mean of 11.76 whereas the effective number of allele varied from 1.15 (OarJMP29) to 11 (ILSTS059) with a mean of 4.95. The effective number of allele is lesser than observed number at all the loci. Polymorphic information content ranged from 0.47 (OarJMP29) to 0.92 (OarFCB304) with the mean value of 0.82. Shannon’s information index which measures the level of diversity ranged from 0.32 (OarJMP29) to 2.61 (ILSTS059) with average of 1.76 ± 0.55. Observed heterozygosity ranged from 0.10 (OarJMP29) to 1 (RM088) with the average of 0.67 and the expected heterozygosity ranged from 0.13 (OarJMP29) to 0.91 (ILSTS059) with the average of 0.73. Six of the twenty five loci showed the negative inbreeding coefficient as also depicted by the Hd value for the same loci. The unbiased expected gene di-versity (Nei’s) ranged from 0.14 (OarJMP29) to 0.92 (ILSTS059) with the overall mean 0.73 ± 0.19. The L-shaped curve obtained indicates that Berari goat population has not undergone any recent bottleneck. The genetic variability exhibited by the Berari goats can be suitably exploited for its genetic improvement and sustainable conservation.

Genetic improvement programs may improve disease resistance in animal production. The best-characterized genetic control of disease resistance and immune response in animals is the one associated with the Major Histocompatibility Complex (MHC). The ovine lymphocyte antigen of DRB1 gene encodes cell surface glycoproteins that initiate immune responses by presenting processed antigenic peptides to CD4+T helper cells. DRB1 is the most polymorphic gene in sheep and it has been extensively evaluated as a candidate marker for associations with various ovine diseases and immunological traits. Aim of this study was to analyze exon 2 Ovar-DRB1 gene polymorphism in two Iranian native sheep breeds (Afshari and Zel). PCR products were characterized by the restriction fragment length polymorphism (RFLP) technique using two restriction enzymes, RsaI and HaeIII. In the studied groups of Afshari Sheep and Zel Sheep of Iran we were able to identify 9 restriction patterns (a, b, c, d, e, f, g, h and i) for the fragments of exon 2 Ovar-DRB1 gene with RsaI enzymatic digestion and 5 patterns (a, b, c, d and e) with HaeIII enzyme, in-cluding one previously unrecognized allele (c). Our results indicate that exon 2 of the Ovar-DRB1 gene is highly polymorphic in both breeds.

A 3×2 factorial experiment was conducted to investigate the effect of thymol+carvacrol (0, 100 and 200 mg/kg) on ileal microbial population and jejuna and ileal histomorphology of broilers fed Carboxy Methyl Cellulose (CMC: 0 and 2%) containing diet. Each of the 6 dietary treatments was replicated 5 times with 12 chicks each from 0 to 42 days of age. There was no interaction effect of CMC and thymol+carvacrol in any measured parameters. At d 42, the ileal population of lactobacilli and Bifidobacteria were greatest (P<0.05) in birds fed 200 mg/kg thymol+carvacrol but 100 mg/kg of additive had no significant difference with two others treatment. The E. coli population was significantly decreased in birds fed 100 and 200 mg/kg thymol+carvacrol. Supplementation of diet with CMC enhanced (P<0.05) ileal count of E. coli and reduced ileal counts of Lactobacilli and Bifidobacteria as compared to those in chicks fed control diet. Data showed that supplementation of diet with CMC decreased (P<0.05) intestinal histomorphology including jejunal and ileal villus height (VH), villus height to crypt depth (VH: CD) and increased jejunal and ileal villus width (VW), crypt depth (CD) at 21 and 42 days of age as compared to those in chicks fed control diet. Inclusion of 100 and 200 mg/kg thymol+carvacrol improved VH, villus surface (VS), VH: CD and muscular layer (MSL) of jejunum at 21 and 42 days of age and also increased ileal VH, VH: CD, MSL and GC at d 21 and MSL and GC at 42 days of age. Supplementation of diet with CMC decreased (P<0.05) jejunal histomorphology including VH, VH: CD and increased (P<0.05) VW and CD at 21 and 42 days of age as compared to those in chicks fed control diet. At d 21, dietary CMC decreased (P<0.05) VH and in-creased (P<0.05) VW but it did not affect the rest of ileal histomorphological parameters. At d 42, CMC supplementation significantly affected some ileal histomorphological parameters in terms of increasing VW and CD and decreasing VH and VH: CD but the other parameters were not influenced by CMC.

This experiment was conducted to study the effects of two kinds of sodium and calcium bentonite (NaB and CaB) on performance, blood biochemical parameters, carcass characteristics and tibia ash of broiler chick-ens. Two hundred and sixty day old broilers of male Ross 308 strain were allocated to 5 treatments with four replicatates and 13 broilers in each. The experiment was carried out in a completely randomized de-sign, where the treatments were: control (corn soybean meal based diet); 1% NaB; 1.5% NaB; 1% CaB; and 1.5% CaB. The results showed no significant difference between the experimental groups in starter and grower periods, but feed intake decreased, and feed conversion ratio was improved by adding 1% bentonite to the diet in finisher and total periods (P<0.05). Addition of bentonite to diet had not significant effect on the blood biochemical parameters, carcass characteristics and tibia ash. The results indicated that the use of each two kinds of bentonite in diets (1%) improved the broiler performance; however addition of 1.5% ben-tonite had no significant effect.

An experiment was conducted to determine the effect of different levels of potato replacing maize seed on performance characteristics and immunes system of broiler chicken in a completely randomized design. A total of 220 broiler chicks were randomly assigned to 5 treatment groups, with 4 replicates of 11 birds each. The chicks in the first group were fed basal diet (control), 2nd and 3rd groups were fed with the cooked potatoes (25 and 35% replacing maize) and 4th and 5th groups were fed raw potatoes (25 and 35% replacing Maize). Two methods were used for preparing the potatoes. In the first method whole potatoes were cooked and then dried in the sun. In the second method the potatoes dried in the sun only. At the end of experiment one bird from each replicate was slaughtered for carcass analysis. There were no significant differences in feed intake, daily feed intake, daily weight gain, feed conversion rate, mortality percentage, carcass percentage, liver percentage and breast, leg, thymus, spleen percentage, concentration of cholesterol, triglyceride, LDL and HDL between treatments (P>0.05). Treatment did however have a significant effect on starter weight gain, starter FCR, pancreas percentage, small intestine, duodenum, jejunum and ileum weight, bursa of fabricius weight percentage and concentration of serum glucose of grower (P<0.05). The use of potato in broiler diets decreased blood cholesterol and consequently reduced abdominal fat pad. Ac-cording to the results of this experiment, the level of 25% dried potato can replace maize seed without performance reduction of broilers. Replacing maize with potatoes caused a delay in growth rate at higher level.

This experiment was conducted to evaluate the effects of different levels of dried aerial parts powder and extract of pennyroyal (Mentha pulegium) medicinal plant on performance, egg traits, blood biochemical and immunity parameters of laying hens. Two-hundred-fifty-two Hi-line (W36 strain) laying hens from 46 until 58 weeks of age were used in a completely randomized design in 7 treatments and 3 replicates (12 birds per replicate). The treatment groups consisted of a control group (1) with no dried aerial parts powder or extract of pennyroyal supplementation, and experimental groups 2, 3 and 4 contained 0.5%, 1% and 1.5% of pennyroyal powder respectively, whereas experimental groups 5, 6 and 7 contained 0.1%, 0.2% and 0.3% of pennyroyal extract, respectively. Using different levels and forms of pennyroyal significantly affected the performance, egg traits, blood biochemical and immunity parameters of laying hens (P<0.05). By increasing the level of pennyroyal extract to 0.2% and 0.3% of rations, the performance of laying hens significantly decreased, whereas pennyroyal powder improved the performance of laying hens, consequently the best feed conversion ratio (2.46) was achieved by using 1.5% pennyroyal powder. The highest specific gravity (1.092) and Haugh unit (89.22) were resulted in groups 5 and 6, respectively. The lowest amount of blood triglyceride (270.4 mg/dL) and the highest amounts of albumin (3.05 mg/dL), total protein (5.40 mg/dL) and uric acid (5.39 mg/dL) were observed in group 7. The lowest percent of hetrophil (9.67%) and the highest percent of lymphocyte (90%) were observed in group 2 and the highest amount of white blood cells (266601/mm3) was resulted in group 5. The overall results showed that the use until 1.5% of dried aerial parts powder and 0.1% of pennyroyal (Mentha pulegium) extract compared with control group had positive effects on performance of laying hens. Using different levels of pennyroyal powder and extract could change the egg traits, blood biochemical parameters and immunity levels of laying hens.

The effect of ascorbic acid (AA) and butylated hydroxyanisole (BHA) supplementation on aflatoxicosis in broiler chickens (1 to 42 days of age) was investigated (250, 500, 1000 and 2000 ppm for AA and BHA) in diet containing 1 ppm total aflatoxin (AF: 76.45% AFB1, 10.52% AFB2, 9.89% AFG1 and 3.14% AFG2). A total of 300 day-old broiler chicks were divided into ten treatment groups (T1=control; T2=T1+1 ppm AF; T3=T1+250 ppm AA; T4=T1+500 ppm AA; T5=T2+250 ppm AA; T6=T2+5000 ppm BHA; T7=T1+1000 ppm BHA; T8=T1+2000 ppm BHA; T9=T2+1000 ppm BHA; T10=T2+2000 ppm BHA). The results showed that inclusion of 1 ppm of total aflatoxin in the diet resulted in a significant decrease in body weight gain (BWG). Supplementation of AA or BHA to the AF contaminated diets increased BWG of broilers (P<0.05). Additing AA at both levels to the aflatoxin contaminated diet did not ameliorate the adverse effects of aflatoxicosis on FC. Incorporation of AA and BHA each at both levels, in aflatoxin contaminated diet could not ameliorate the ill effects of aflatoxicosis on feed efficiency in broiler chickens. The serum protein content of group T5 did not differ significantly (P<0.05) from that of T2, however, serum protein content in T6 was significantly (P<0.05) higher than that of T2. Indicating that inclusion of 250 ppm AA in the aflatoxin contaminated diet did not improve serum cholesterol content significantly. Inclusion of 500 ppm AA in the aflatoxin contaminated diet improved (P<0.05) the serum cholesterol content, however, the value was lower (P<0.05) than that of control. Serum uric acid content in T6 was higher (P<0.05) than that of T2, however. The aspartate animotransferase (ASAT) values in groups T5, T6 and T9 did not differ significantly (P<0.05) from that of T2. The alanine aminotransferase (ALAT) values in groups T5, T6, T9 and T10 did not differ significantly (P>0.05) from to that of control, indicating that both AA and BHA each at both levels significantly (P<0.05) ameliorated the adverse effects of aflatoxicosis on ALAT activities. It is thus concluded that dietary supplementation of AA at 250 and 500 ppm; and BHA at 1000 and 2000 ppm levels provided partial protection from adverse effects of aflatoxico-sis caused by 1 ppm total AF in terms of BWG and blood biochemical parameters. However, inclusion of AA and BHA, each at both levels, in aflatoxin contaminated diet could not ameliorate the adverse effects of afla-toxicosis on feed efficiency. The present study further showed that BHA was more efficacious than AA in ameliorating the adverse effects of aflatoxicosis on BWG in broiler chickens.

A total of 700 day old female broiler chicks (Ross 308) were distributed into seven groups in a completely randomized design with five replicates, and 20 chicks in each replicate. Dietary treatments, time of the switch from an unsaturated sunflower oil (SFO) to a saturated tallow (T) dietary fat source, were: 1) SFO for the entire growth period (6 weeks), 2) SFO for 5 weeks followed by T for last week, 3) SFO for first 4 weeks followed by T for last 2 weeks, 4) SFO for first 3 weeks followed by T for last 3 weeks, 5) SFO for first 2 weeks followed by T for last 4 weeks, 6) SFO for first 1 week followed by T for last 5 weeks and 7) T for the entire growth period. Chicks had free access to water and experimental diets during the experimental periods. All diets were calculated to be isocaloric and isonitrogenous. Body weight and feed intake of chicks fed different diets were recorded at 21 and 42 days. At the end of experiment (on 42 day), two birds were randomly selected from each pen and slaughtered and then breast, leg and thigh muscles and abdominal fat were sampled to determine fatty acid profile. The SAS general linear models (GLM) procedure was used for the statistical analysis of data. There was statistically significant differences between dietary treatments for body weight, feed intake and feed conversion ratio during the period from 22 to 42 d and the entire growth period, with a higher values of body weight for chicks fed diets supplemented with SFO throughout the entire growth period (P<0.05). The lower feed conversion ratio was observed in chicks fed T-based diet for the entire growth period. Chicks with more access to T-based diet during the feeding program had significantly higher amounts of saturated and monounsaturated fatty acids in their carcass compared to those fed SFO based diets (P<0.05). Shifting from SFO to T diet just for a few weeks time was capable in altering the profile of fatty acids in tissues toward a more saturated pattern.

In the present study, the polymorphism of myostatin gene (MSTN) in native chickens of Western Azerbaijan Rearing and Breeding Institute was investigated. The blood samples were collected from eighty two randomly selected hens. Genomic DNA was extracted from blood samples and a fragment of myostatin including 599 bp in promoter and exon 1 was amplified using PCR method. Breeding values for body weight and carcass traits were predicted by univariate animal mixed model analysis, using WOMBAT software. The effects of different SSCP genotypes on breeding and phenotypic values of the studied traits were evaluated by general linear model analysis. Three different single strand conformational polymorphism (SSCP) genotypes as AA, AB and AC were identified, with frequencies of 0.244, 0.549 and 0.207, respectively. Shannon and Nei gene diversity indices and number of effective alleles in the studied population were 0.88, 0.53 and 2.2, respectively, which indicated a high diversity of the studied population. More-over, the studied population was not in Hardy-Weinberg equilibrium. The effect of the SSCP genotypes on breeding and phenotypic values was significant only in the case of breeding value for body weight at 12 weeks of age, whereas, the AC genotype individuals, significantly (P<0.05) had the lowest breeding value for body weight at 12 weeks of age. Based on the results obtained, it could be concluded that the studied fragment of myostatin gene is polymorphic in native chickens of Azerbaijan and could be used for marker assisted selection.

Infectious bronchitis virus (IBV) is a contagious pathogen in fowl that results in economic loss in the poul-try industry. In this study, the amino acids sequences of three structural proteins M, N, and S1 for five Iranian IBV isolated during 1998-2011 have been analyzed. Conserved and variable regions, hydrophobic characteristics and identity matrix were determined after alignment by Bioedit ver 7.0.4.1. The phylogenetic tree was obtained by using the neighbor-joining method within MEGA4. Similarity for M and S1 protein was lowest for IR-3654-VM and TW2575/98 isolate (0.862) and IR1061-PH and Georgia 1998 isolate/strain (0.41), respectively. For the N protein, highest similarity was found between Ur1/09 and Arkansas DPI (0.948). Four conserved regions for M and N proteins were recognized. In the S1 protein three hyper-variable regions were detected in 52-90, 124-150 and 265-315 residues. In a phylogeny analysis all proteins were distributed in three clusters. Iranian IBV belonged to Mass cluster in phylogeny tree of M and N proteins. But S1 protein showed a close relationship with the California serotype and was distantly related to Mass serotype. The results showed that the Iranian IBV isolate was probably diverted from Mass strain that might be brought to Iran as a vaccine strain.

In this study, we investigated the relationship between the genetic polymorphism of growth differentiation factor 9 (GDF9) genes and the litter size in 384 individuals of five breeds of black goats. Four pairs of primers were designed to detect single nucleotide polymorphism of GDF9 gene in goats by PCR-SSCP. The least square was used to analyze the relation between different genotypes and the litter size. The results showed that the PCR products from primer pair 1 (P1) displayed polymorphisms in three genotypes (AA, AB and BB) in big foot (BF) and Jintang (JT) black goats. For primer pairs of P2, P3 and P4, there was no polymorphism. The sequencing results revealed that there was a single nucleotide mutation (A792 ®G) in exon 2 of GDF9 gene in BF and JT black goats, and this mutation resulted in an amino acid change: valine®isoleucine. In BF and JT black goats, the average litter size in the third parity was significantly higher in genotype AA than both genotypes of AB and BB while the average little size of genotype AB was higher than that of genotype BB in the same parity. GDF9 gene could be therefore considered as a candidate gene for marker-assisted selection of litter size trait in goats.