IRANIAN JOURNAL OF APPLIED ANIMAL SCIENCE
Year:2012 | Volume:2 | Issue:3|Papers Count:15

A genetic marker is a gene or DNA sequence with known localization on a chromosome. It can be de-scribed as a variation that can be measured or detected by a suitable method, and can be used subsequently to detect the presence of a specific genotype. Such variations occurring at chromosomal or DNA level can serve as genetic markers. The progress in development of molecular markers suggests their potential use for genetic improvement in livestock species. Animal fertility is a measure of reproductive success. In males, it can be defined as the ability of a male to produce semen that will result in a successful pregnancy. In females, it can be defined as the ability of female to cycle and conceive normally to produce a viable off-spring. Such a complex feature is under the influence of numerous genes, working together to produce functional gametes, promote early embryonic and fetal development and finally the delivery of a healthy off-spring. The heritability is relatively low for fertility so reproductive traits in general are well-suited for application of marker-assisted selection (MAS). Animal fertility is one of the most important economical traits in animal production. Reproductive performance is controlled by the genetic make-up of the female and male, but in general it is largely affected by environment. Phenotypic selection for reproductive traits can only be carried out after puberty while marker-assisted selection could be a tool of choice to improve animal fertility. The possibility of exerting selection criteria at the molecular level shortens the generation interval as the selection decision can take place early in the life of an animal. Moreover, in consideration of the sex-limited nature of reproductive traits, genotypic information could allow for selection in the gender in which the trait cannot be directly observed. Accordingly, there has been considerable interest in mapping and identifying genes involved in the regulation of reproductive traits and in elucidating their expression patterns. The current review aimed to discuss the efforts being made and the approaches currently used in the field of molecular markers and their application to fertility in farm animals.

Greenhouse gases have been of serious global concern to environmentalists. Enteric ruminal fermentation and manure are seen to be responsible for global warming. Based on a better understanding of positive tan-nin effects on ruminant nutrition, the feeding value of browse trees and shrubs containing tannin, their roles on methanogen rumen microbes in overcoming the production of enteric fermentation gases and the methods of efficient manure handling are presented in this review.

Bacteria play an important role in the initiation and progression of diseases (not only in disease but affect health status of individual). Populations of digestive microflora in chicken gut change with age and also affected by diet, stressors, and performance enhancers as well as in disease conditions. The aim of the pre-sent study was to know bacterial makeup in chicken gut, using denaturing gradient gel electrophore-sis (DGGE). DGGE results showed 11 different band patterns from the six birds (P1-P6). A total of 11 bands were cloned and sequenced and similarities to known 16S rDNA sequences were examined. All the sequences had 93 to 100% similarity to 16S rDNA database sequences. In P1 birds, total 8 bands were ob-served; which had varying degree of homology with Proteus mirabilis, Gallibacterium anatis, uncultured bacterium, bacteroidetes bacterium, rumen bacterium and Bacillus subtilis. Similarly in second bird (P2), one clone was showing 98% similarities with uncultured bacterium. Further one clone from P3 was similar to uncultured prokaryote clone (93%). Likewise in P4, one clone was similar (100%) to Escherichia spe-cies. Moreover, in P5 and P6 birds, DGGE bands were having some common migration pattern to those that were observed in other four birds (P1-P4). These results may help poultry producers to develop more cost-effective health management strategies as well as differences in the composition of the gut microbial com-munity with improved performance, which implies that the presence of specific beneficial and / or absence of specific detrimental bacterial species may contribute to the improved performance of the birds.

A territorial isolation is a danger to the game population, causing deterioration called the inbreeding depression. The typical signs are anomalous body proportions, such as short lower jaw, shortened lifetime, weak physique and lower birth rate. This is caused by low number of game in the community. White colored deer is in the location of the Czech Republic bred in separation since 18th century. For their preservation, it was necessary to refresh the population by 'wild colored' Cervus elaphus. By this way, it was reduced the in-breeding depression and population was saved. Simultaneously white colored, beige colored, red colored, combined colored and spotted individuals started to appear. For further breeding development (retention of good health condition, fertility, inbreeding reduction and increase of white colored deer population), practical exploitation of molecular genetics methods were made by deer identification and verification of family relationships. Proven results were used for compilation of breeding groups with target of gradual reduction in: inbreeding, negative consequences of inbreeding depression and increase of white deer population (the origin from Kashmir or Persia). These breeding mechanisms are considered as breeding with controlled reproduction. This project is researching genetic variances within separated white deer population in game-preserve Zleby from 2004 to 2010. The idiotypes have been determined for thirteen microsatellite frequencies (BM888, OarFCB5, RM188, RT1, RT13, T26, T156, T193) and the genetic diversity, heterozygote contribution, polymorphic information content (PIC) and inbreeding factor (f) have been assessed during the project elaboration. Software Power Marker V 3.25 was used for elaboration of obtained results. The project results demonstrated the exploitation of molecular genetic methods for controlled game reproduction.

The present investigation aimed to conduct a genetic study of dairy cattle and buffalo bulls based on eco-nomic traits and their phenotypic correlation. The means of various economic traits in both the species are presented. Cattle bulls reported a better libido score, Flehmen response, requirement of mounting stimulus and semen volume, conception rate and expected predicted difference for milk production. Significant differences were observed between cattle and buffalo in growth traits (birth weight, 3 months body weight, 6 months body weight), reproduction traits (individual semen motility, post thaw semen motility and requirement of mounting stimulus). Association studies conducted among various growth, reproduction and production traits revealed that, a positively high and significant association existed among growth traits and individual motility with the number of semen doses per collection in crossbred bulls. Three month body weight was associated significantly with expected predicted difference (P<0.05) in crossbred bulls. How-ever in the case of Murrah bulls, a significantly high correlation was observed among body weights at birth and at three months of age.

The present study was undertaken to examine the efficacy of a treatment regime using a controlled internal drug release (CIDR) device in conjunction with injections of gonadotropin releasing hormone (GnRH) and prostaglandin F2a (PGF2a) on conception rate of repeat-breeding Iraqi buffaloes. Data were collected from 100 buffaloes with repeat breeding in Nineveh province housed at six private dairy farms. All buffalo cows were characterized as repeat breeding of more than three natural services with regular oestrous cycles with-out any signs of pregnancy. Any buffalo with abnormal vaginal discharge and >12% of polymorphonuclear cells in uterine smears was excluded from this study. Buffaloes were randomly assigned to four treatment groups of 25 cows each. Buffaloes in treatment 1 were injected with estradiol benzoate 1 mg and GnRH 250 mg on day 0, a CIDR in the anterior vagina from day 0 to 8, on injection with 25 mg of PGF2a on day 7 and GnRH (250 mg) on day 9. Buffaloes in treatment 2 received GnRH (250 mg) on day 0, a CIDR, from day 0 to 7 and 25 mg of PGF2a on day 7. Buffaloes in treatment 3 received a CIDR from day 0 to 7 and 25 mg of PGF2a on day 7. Treatment 4, a control group received no treatments. All buffaloes were mated dur-ing oestrus and pregnancy status was diagnosed by palpation of uterine contents at day 45. Pregnancy rates in treatments 1 to 4 were 44%, 52%, 24% and 8%, respectively. On average, Buffaloes treated with differ-ent CIDR protocols had higher pregnancy rate than control group. It could be concluded that the use of different CIDR protocols can be applied to improve fertility of repeat breeder Iraqi buffaloes.

Heritability, environmental and genetic correlations between body weight at hatch (BW0), eight (BW8) and twelve (BW12) weeks of age, body weight at sexual maturity (BWM), age at sexual maturity (AFE), the weight of the first egg laid by the hen (EWM), the mean egg weight from 28 to 32 wks (EW28-32) and egg numbers (ENs) were estimated by the restricted maximum likelihood method under an animal model. Data were from six generations (generation ten to fifteen) of hens kept at the Mazandaran Breeding Center of Iran. Heritability estimates for BW0, BW8, BW12, BWM, AFE, EWM, EW28-32 and ENs were 0.134, 0.235, 0.296, 0.247, 0.344, 0.125, 0.240 and 0.156, respectively. Genetic correlations between pairs of body weight measures were moderate with a range from 0.17 to 0.43. Generally, correlations of body weight traits with AFE were weak. Genetic correlation between BW8 and AFE was low, but favorable (-0.17). Egg numbers has unfavorable genetic correlation with BWM (-0.47). However, egg weight traits had favorable genetic correlation with body weight traits, except BW0, which was almost equal to zero. Age at first egg had negative genetic correlation with egg numbers, but positive correlations with egg weight traits. The absolute value of environmental correlations between traits varied from 0.00 to 0.39. The strongest environmental correlation was found between AFE and EWM. There was moderate and positive environmental correlation between BW8 and BW12 as well as between BW12 and BWM. The results showed that there are considerable genetic variations in important traits of Mazandaran native hens, and that selection on BW8, ENs and EWM, which are the most economically important traits in this breed, could be effective.

This study describes the management and products of the Gasconne cattle in two neighbouring countries (Spain and France), as a model study in trans-border breeds, analysing if they are significantly different depending on the place where they are located. Fifty-seven Gasconne breeders were interviewed (32 in Spain and 25 in France). The survey examined several aspects of the productive farming system and trading procedures. Descriptive statistics and multivariate analysis were used to understand the relationships between variables and establish the difference between countries. The herd size was similar in both countries but not the animal age distribution. Moreover, statistical differences were found in the replacement rate and age at weaning, both higher in France. Different reproductive management was also found between countries. Thus, seasonal reproductive control and the use of artificial insemination were only common in France. The herd production system was, in general terms, more intensive in France than in Spain. There was significant percentage of breeders, in both countries, which carried out their own fattening. The main products supplied and their trading channels were also different. Thus, yearlings and calves were the most common products in Spain whereas in France the focus was on cows, young calves for fattening and oxen. With respect to the trading channel, the sale of live animals directly to other breeders or slaughterhouses, was the most common option used in Spain compared to the sales to cooperatives, intermediaries and butchers reported in France. It has been demonstrated that there are significant differences among productive systems of the same breed even between neighbouring regions.

Potential growth of dairy sector is highest and more reliable compared to crop sector, indicating that dairy sector can play vital role to increase income among farmers in rural areas than crop sector in Sri Lanka. Credit and farmer training in management ability have been major concerns of dairy development efforts. Therefore, this study was conducted to assess the impact of credit and farmer training on small holder dairy sector and to estimate its contribution to farmer’s income. The study was carried out in southern region of Sri Lanka. Purposive sampling approach was adopted and data were collected from 119 farmers through pre-tested structured questionnaire by personnel interview. Twenty one percents of respondents had taken credit and 72% of farmers had received subsidies to develop their dairy production capacity. Almost 97% of farmers had received knowledge for different activities in dairy production and 45% of them had partici-pated for trainings which related to dairy. The milk yield of studied sample had correlation with credit amount (r=0.500, p=0.018), value of subsidy (r=0.350, p=0.003) and extension and training (r=0.453, p=0.000) which received by farmers. The farmers with higher level knowledge on management practices were acquiring and demanding of credit and farmer training compared to farmers with low knowledge. Fur-ther herd size had strong positive correlation with the amount of credit obtained. The results clearly illus-trated credit and farmer training in dairy sector could considerably facilitate to increase income of dairy farmers and assists to develop dairy sector in small holder context.

We reported here data from a productivity veterinary service that was participatory planned and delivered on farms at the Kanihari Union belongs to Mymensingh District of Bangladesh. We used a set of five forms and a breeding calendar on farm visit once in a month to guide service delivery and acquisition of data and to keep the records on general cattle health, reproduction, udder health and feeding management of the farms. Once information were entered into a database application, a summary sheet was produced, which was taken into the farm to guide the activities in follow-up visits. On average, 72% anoestrous cows and heifers resumed their estrous cycle and 64% of repeat breeding cows and heifers conceived when treated. When GnRH was injected at the time of artificial insemination (AI), 73% repeat breeder cows conceived. Sixty four percent cows recovered from mastitis and 87% sick animals recovered when treatment was given based on clinical diagnosis. Majority of clinically diagnosed diseases were endoparasitic infections (19.0%) and anorexia (11.9%). More than 80% farms that received the service had an income increase ranging from US $ 1.0 to $ 43.9 monthly per cattle. Productivity veterinary services increase farmers’ monthly income per cattle and number of cows for breeding.

The study was designed to investigate the haematological parameters of intensively and semi-intensively kept chicken. 60 males and 60 females chickens were randomly selected from farmers in the area of study. Age of birds were ascertained from farmers and blood samples (one including anticoagulant, one whole blood) collected through wing venepuncture. Significant (P<0.001) age group effect was observed on packed cell volume (PCV), red blood cell (RBC) and white blood cell (WBC). The 150 d age group re-corded the highest (P<0.001) PCV value (28.74±1.07%). Higher (P<0.001) RBC value (273.70±214 mm) was observed for age group 90 d. For WBC, the 90 d age group had the highest (P<0.001) effect (245.40±5.21 mm3) and 150 d (229.16±7.40 mm3) respectively while 60 d (155.30±5.21 mm3) and 104 d (154.90±5.21 mm3) had the least (P<0.001) respectively. A significant (P<0.001) sex effect was observed with males having higher (P<0.001) values on PCV (27.05±0.44%) and RBC (271.12±1.24 mm), and fe-males recording higher (P<0.001) (214.20±3.01 mm3) values on WBC. There was a significant (P<0.01) effect related to the management system evident for PCV indicating a higher (P<0.01) (25.14±0.57%) effect on semi-intensively kept chicken. A significant (P<0.001) age group effect was also observed for mean corpuscular haemoglobin concentration (MCHC) and mean corpuscular volume (MCV). Significant (P<0.001) sex effect was evident with females having highest (P<0.001) value on MCHC (17.84±0.26 g/dL) while males had higher (P<0.001) MCV (0.10±1.31 x 1015 fl). A significant (P<0.01) management system effect was also observed on MCHC indicating higher (P<0.01) value (17.52±0.30 g/dL) on inten-sively kept chicken. A similar significant (P<0.001) management system effect was observed for MCV (0.10±1.63 x 1015 fl) for semi-intensively kept chicken recording higher values. A significant (P<0.01) age effect was evident for power of hydrogen (PH) with the highest value recorded for 150 d (7.91±0.12) and 60 d had least value (7.31±0.09). A significant (P<0.001) sex effect was observed on PH with males having higher (P<0.01) value (7.72±0.05) and on haemoglobin concentration (Hbc) (42.40±0.60 g/dL) respec-tively. Generally, blood parameter values increase with age in birds while males had higher values than females.

Safety and beneficence of farm animal nutrition plays a great role in their healthy life which in turn have impact on human nutrition via diary or meat products. Assessing safety and beneficence of Vicia varibilis Freyn and Sint. Which is chosen intrinsically by domesticated animals of Kohgiluyeh and Boyerahmad Iran is the aim of the present work. Our results not only show no cytotoxic activity in 3-(4,5-dimethylthiazol-2-yl)-2,4-diphenyltetrazolium bromide (MTT) assay but also admit the antioxidant activity of the species through scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals confirmed in DPPH assay.

The study was undertaken to elucidate the beneficial effects of goat follicular fluid (g FF) added to maturation and culture media on in vitro maturation, fertilization and post-fertilization development of oocytes in Black Bengal goats. Follicular fluid and oocytes were collected from slaughter house goat’s ovaries using the aspiration technique. Media were prepared using TCM-199 supplemented with 0.5% bovine serum al bomin (BSA) plus four levels of g FF at concentrations of 0%, 5%, 10% and 15%. Oocytes were matured for 27 h, fertilized with capacitated fresh semen in Brackett and Oliphant (BO) medium for 6 h and then cultured up to 7 days, at 38.5oC with 5% CO2 under humidified air. It was observed with 0% to 15% of g FF that 53.8-75.0% of the oocytes reached the cumulus cell expansion level-3, 41.5-67.8% reached meta-phase-II; 28.6-38.4% exhibited normal fertilization (formation of 2-pronuclei), 12.3-33.7% were 2-cell embryos. The development of embryos was arrested at the 2-cell stage in control media and at the 8-cell stage in 5% media, though morula and blastocyst stages developed in 10% (14.1% and 9.3%, respectively) and 15% g FF media (18.0% and 10.0%, respectively). In comparison, it was observed that the results in all stages of in vitro production of embryos could be significantly increased (P<0.05) by adding 5% g FF to control media. The results could further be improved (P<0.05) by increasing the level of g FF to 10% but no further increment (P>0.05) occurred when g FF increased to 15% level. It is concluded that g FF has a positive effect on in vitro production of embryos in Black Bengal goats and a 10% level of g FF is recommended based on the improvements observed and the associated economic benefits.

The present study was conducted to see the effect of non-specific genital infections and ovulatory distur-bances on clinical signs of oestrus namely oestrus duration, tonicity of uterus, relaxation of cervix and per-sistence of follicle. The mean values of oestrus duration, tonicity of uterus and relaxation of cervix varied significantly (P<0.05) among the group of impaired ovulation (anovulation and delayed ovulation) and normal ovulation. Following the onset of oestrus, follicle was palpated up to 144 hrs in all anovulation ani-mals, 72.00±4.17 hrs in case of delayed ovulation, 36.89±0.62 hrs in case of normal ovulation with infec-tion and 36.71±1.61 hrs in the control group (normal ovulation without infection). The study revealed that oestrus duration and status of reproductive organs are important criteria in the diagnosis of ovulatory dis-turbances in repeat breeding cattle.

An attempt has been made to analyze the distribution of the beta-lactoglobulin genotype in swamp buffa-loes and Murrah buffaloes utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Blood samples were taken from 50 swamp buffaloes and 50 Murrah buffaloes. The DNA was extracted by the phenol-chloroform method. The PCR-RFLP was performed using beta-lactoglobulin gene primers and a single restriction enzyme, Hae III. The enzyme digested products were separated by electro-phoresis on 2.5% agarose gel. All the 100 DNA samples of swamp and Murrah buffaloes resulted in 398 bp product on amplifying beta-lactoglobulin gene. Those PCR products (398 bp fragment) were digested with Hae III produced only one type of restriction pattern yielding five fragments of 113, 99, 89, 73 and 24 bp. One hundred DNA samples of swamp and Murrah buffalo were examined in this study and revealed no polymorphism at the beta-lactoglobulin gene locus.