It has been demonstrated that heat stress has a detrimental effect on conception rate of dairy cows, via early embryonic death. To reduce heat stress, providing shade, fan, appropriate diet and application of ovulation induction agents (GnRH and hCG) is recomended. Endogen PGF2a has positive effect on ovulation. Repeat Breader. The aim of the present study was to evaluate the role of PGF2a injection on reproductive performance of Repeat Breader (RB) dairy cows in heat stress condition at artificial insemenation (AI). This study was conducted in two large dairy farms in Tehran province during the summer 1386-87. All cows were inseminated (A M -PM) based on heat detection at 12 hours after observed standing heat. Mean temperature and humidity were recorded throughout the study. In this study 150 RB cows were randomly divided into three groups. Group A(n=50) received PGF2a simultaneously with AI, group B (n=50) received GnRH at the time of AI and group C (n=50) did not receive any treatment and served as control. Based on rectal palpation on 40-50 days of AI, 5 cows of group A, 9 of group B and 10 of group C were pregnant. There were not any significant differences among groups (p>0.05). The results revealed that simultanous using of PGF2a or GnRH with AI has no beneficial effects on conception rate in RB cows.

Beak lesions were observed in 50-weeks-old broiler breeder roosters reared under a separate sex mash diet feeding, with low in protein and energy for roosters. All roosters kept with hens showed deformities in the upper and lower beak but the lesions were not found in roosters kept separately. Hens’ feed troughs had been covered with galvanized wire grids to exclude the males eating from hens’ troughs. There was approximately 5% mortality among roosters with the beak lesions. A marked reduction (23%) on hatchability was observed, but no change in egg production occurred. The beak lesions were the major cause of male’s culling in the flock. Histopathological examination of the lesions revealed that the epidermis, keratin layer and underlying connective tissue of the beaks were severely affected by necrosis. Bacteriological cultures yielded, mainly, growth of hemolytic Staphylococcus aureus, and hematological tests showed a mild increase in the number of the white blood cells. The case reported here appeared to be a management-related problem. These findings have implications for poultry industry.

The current study aimed to optimize artificial insemination in aged broiler breeder hens in two experiments. In the first experiment, the effect of (two) different diluted semen temperatures (5 and 25 °C) of Hubbard rooster (40 roosters, 58 weeks of age) on fertility, hatchability and sperm penetration (SP) rate in the perivitelline layer of Hubbard hen (180 hens) were investigated. In the second experiment, three (different) sperm concentrations (100 (C100), 200 (C200), and 400 (C400) million sperm in 0.25 mL per hen) of Hubbard roosters (40 roosters, 62 weeks of age) on fertility, hatchability and SP rate of Hubbard broiler breeder hens (270 hens) were explored. In the first experiment, the results showed that the temperature of 5 °C of diluted semen compared to the 25 °C, increased percentage of hatchability of set eggs, hatchability of fertile eggs, and SP and decreased early embryonic mortality. The results of the second experiment showed the highest percentage of fertility and SP rate were observed at treatment C400. Also, in this experiment that highest percentage of hatchability of set eggs and hatchability of fertile eggs and lowest early embryonic mortality were observed at treatment C400. Return on investment (ROI) of the treatments C200 and C400 was approximately 2.9 and 1.4, respectively. In overall, the results of this study showed that (in attention to ROI and hatchability) to optimize artificial insemination of aged broiler breeder hens we can use a sperm concentration of 200 to 400 million in 0.25 mL per hens at 5 °C.

Li2TiO3 as a tritium breeder has a significant role in nuclear fusion reactors. The aim of this study was the synthesis of Li2TiO3 powder by solution combustion in the explosive mode as an inexpensive and efficient method. Fuel type and nitric acid, as an oxidizer, have vital roles in this method. Hence, the effect of nitric acid content and citric acid, glucose, and glycine fuels were investigated. Results showed that the use of glucose fuel was not appropriate, because the combustion didn't occur, neither the desired phase was not synthesized. Moreover, synthesis in the presence of glycine fuel led to the synthesis of the desired product, however, no pure single-phase product was obtained. Contrary to the two mentioned fuels, citric acid was a suitable fuel for the synthesis of Li2TiO3 by solution combustion method, which resulted in a single-phase product. The optimum amount of nitric acid was determined to be 9 liters per mole of fuel. Using more than the optimal amount of nitric acid also resulted in LiTiO2 impurities being left. While using less than the optimal amount resulted in an incomplete combustion reaction.

The effects of increasing the laying period day-length from 13 to 16 hours were examined in Ross (308) broiler breeders. The birds reared on 8-h photoperiods and then were photo-stimulated at 21 weeks by in-creasing the photoperiods from 8 h of light, 16 h of darkness (8L: 16D) to 11L: 13D. Then the birds were given an additional 60 min of light per week cumulatively, such that in different experimental groups the 12L: 12D, 13L: 11D, 14L: 10D, 15L: 9D and 16L: 8D photoperiods were achieved in 22, 23, 24, 25 and 26 weeks of age, respectively. The photoperiods remained unchanged until the experiment was finished at 50 weeks of age. The 16L: 8D group had a poorer feed conversion and less egg production and egg mass than the other 3 groups (P<0. 05). The total settable egg percentage was significantly lower for 15L: 9D and 16L: 8D than for 13L: 11D and 14L: 10D birds (P<0. 05). The 13L: 11D and 14L: 10D h hens had more dou-ble-yolked and broken or abnormal eggs, followed by the 15L: 9D h birds, and the 16L h birds (P<0. 05). The mean egg weight of 14L: 10D birds was significantly more than for 16-L h birds (P<0. 05), with 13L: 11D and 14L: 10D birds were intermediated (P<0. 05). The percentage of hatchability was higher in 13L: 11D h hens followed by the 15L: 9D and the 16L: 8D birds (P<0. 05), with 14L: 10D h hens intermedi-ated between 13L: 11D and 15L: 9D groups. The findings of this study suggest that 13L: 11D was the opti-mal photoperiods for Ross 308 broiler breeders in the laying period up to 50 weeks of age.

Mycoplasma Synoviae is a major poultry pathogen which causes significant economic losses to the poultry industry. The aim of study was detection Mycoplasma synoviae infections in vaccinated broiler breeder flocks and their progeny. For this purpose, from 20 broiler breeder farms and their progeny 2 times in 40 and 60 weeks of age 20 tracheal swab and 20 blood samples from each broiler farm were collected. All 20 broiler breeder farms before vaccination against Myc.oplasma Synoviae were confirmed free from Mycoplasma synoviae infections. Tracheal swab transfered to cap tubes containing PPLO broth media and kept at 4°C less than 24 hrs send to laboratory for further proceeding. Antibody against Mycoplasma Synoviae was measured by rapid serum agglutination (RSA) and Elias tests. Tracheal swabs were examined by high resolution melting PCR (HRM PCR) for detection Mycoplasma Synoviae field isolate. The results showed that vaccination broiler farm against Mycoplasma Synoviae upto 40 weeks could protect all broiler breeder farms from Mycoplasma Synoviae field infection and produce good antibody titers. With increasing age and at age 60 weeks one farms and its progeny was positive for Mycoplasma Synoviae which was differ from Mycoplasma Synoviae included in live vaccine. This study showed vaccination by present vaccine against Mycoplasma Synoviae in broiler breeder farms could not protect older broiler breeder farms in older ages and probably Mycoplasma Synoviae infection transferred to progeny. Therefore vaccinated farms should be monitor by molecular methods.