BACKGROUND: In commercial hatcheries, chicks are deprived of feed and water for up to 72 h, which is a det-rimental effect on growth performance. OBJECTIVES: Two experiments were designed to investigate the effect of hatching parameters and feeding time on the body and organ weights of chickens. METHODS: In the first experiment, 300 of both early- and later-hatched broiler chicks received feed immedi-ately after hatching or 48 h later and were divided into four experimental groups. The body and internal organ weights of chicks were determined for up to seven days. In the second study, 370 embryos, which were incubated in a setter until the 18th day, were transferred to two hatchers, which differed their air and eggshell temperatures. Then, hatching and post-hatched parameters were followed. RESULTS: Comparing early-hatched chicks, later-hatched chicks had significantly greater weight (p <0.05) on day 3 and better yolk utilization and higher relative liver and intestine (p <0.01) weights on day 2. However, early-fed chicks indicated significantly higher body weight (p <0.0001) until day 7 and early yolk utilization and higher internal organ weights than later-fed chicks. In the second experiment, when the air temperature of hatcher A (control) was kept at 37.5ºC, its eggshell temperature was determined at 38.5ºC, while the eggshell temperature of hatcher B was optimized at 37.5ºC, and its air temperature showed 36.5ºC. Earlier hatchability was higher in the control hatcher (46.8%) than hatcher B (27.1%), but later hatchability was reversed. However, final hatchability was lower in hatcher B (96.6%) than the control hatcher (98.3%). CONCLUSIONS: Later-hatched and early-fed chicks showed greater body and internal organ weights, indicating better maturation of these chicks. The results of the second study indicated that the hatching window could be shorter and also shifted to the end of the incubation time by reducing the egg temperature.

BACKGROUND: Silver nanoparticles (AgNPs) are widely used in various products. On the other hand, they can cause a variety of toxicity in living organisms, such as biochemical changes and oxidative stress in the liver. Scroph-ularia striata plant can affect the toxicity of AgNPs in diverse parts of the body due to the potent antioxidant compounds. OBJECTIVES: The present study aimed to investigate the modulatory impact of the hydroalcoholic extract of Scrophularia striata on the hepatotoxicity and oxidative stress caused by AgNPs in male Wistar rats. The measured hepatic enzymes and serum biochemical metabolites included alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, gamma-glutamyl transferase, albumin, Globulin, total protein, blood urea nitrogen, creatinine, total bilirubin, and direct bilirubin. In addition, the assessed blood oxidative stress markers entailed malondialdehyde, total antioxidant capacity, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx). METHODS: A total of 30 male rats with an average weight of 200±20 g were randomly assigned to five experi-mental groups of six. Animals in group 1 as the negative control received 2 ml distilled water and in group 2 as positive control received 200 ppm AgNPs (i.e., hepatotoxic dose). The rats in groups 3, 4, and 5 received 20, 60, and 180 mg/kg Scrophularia striata extract and 200 ppm AgNPs in 30 days, respectively. The animals were sacri-ficed under slight anesthesia 24 h after the last treatment. RESULTS: Hepatic enzymes, serum biochemical metabolites, and oxidative stress markers, mainly CAT, SOD, and GPx in groups 4 and 5 were significantly different from the positive and negative control groups (p <0.05). CONCLUSIONS: Scrophularia striata plant owing to the presence of some special ingredients, such as flavonoids can compensate for the side effects of AgNPs in the body.

BACKGROUND: Prebiotics are non-digestible feed ingredients that improve the immune system. OBJECTIVES: The present study was designed to assess the changes caused by the addition of prebiotics to the feed on carcass characteristics and also chemical composition, physical characteristics, color, texture, and fatty acid profile of chicken pectoral muscles containing Eimeria species. METHODS: Forty-one-day-old male Ross 308 broiler chickens were assigned to four treatments, including nega-tive control (NC), positive control (PC), positive medicated with coxidine (COX), and positive medicated with prebiotics (PRE). After 42 days, carcass characteristics of the chickens were recorded, and also physical character-istics, chemical composition, color, texture, and fatty acid analysis of breast meat were determined. RESULTS: Infection with Eimeria species diminished carcass characteristics. PRE had higher final body weight, hot carcass weight, and breast and thigh muscle weights. Drip loss, pH, cooking loss, fat, ash, dry matter, and texture properties of broilers’ breast meat did not show any significant differences among the experimental groups. Dietary supplementation with prebiotics increased the crude protein content of breast meat. Infection with Eimeria species decreased the a-value of breast meat. Dietary supplementation with prebiotics decreased the amount of fatty acids 16:1 and 18:1 and monounsaturated fatty acids (MUFAs) compared to NC. CONCLUSIONS: Dietary supplementation with prebiotics is a promising strategy with the potential to compensate for the negative effects of infection with Eimeria spp. on carcass characteristics, protein content, and color of breast meat of broiler chickens.

BACKGROUND: Improving the reproductive performance of dairy cows requires estrus manipulation using estrus synchronization protocols. OBJECTIVES: The current study aimed to assess the effect of reducing the length of estrus synchronization pro-tocol by two doses of prostaglandin injection on the reproductive performance of Holstein dairy cows. METHODS: At first, all cows received GnRH (day 0) followed by PGF2α on day 7 and GnRH on day 17. Next, cows were assigned randomly to one of the three groups: Group 1) PGF2α injection on days 22 and 23, estradiol benzoate injection on day 24, Group 2) PGF2α injection on days 23 and 24, estradiol benzoate injection on day 25, and Group 3) Control group; injection of PGF2α on day 24, injection of estradiol benzoate on day 25. Estrus detec-tion was performed twice a day up to 48 h (AM/PM) based on the signs of estrus, and fixed time AI protocol was used after 48 h if not previously inseminated. RESULTS: The conception rate in group 2 was significantly higher than the control group (P≤0.05) and tended to be higher than group 1 (P=0.079). CONCLUSIONS: Our results confirmed the hypothesis that a decline in the period of follicle dominance by re-ducing the interval between GnRH and PGF2α through two PGF2α injections improved the fertility of lactating dairy cows.

BACKGROUND: It is essential to minimize the effect of time and temperature on the serum biochemical param-eters and determine the stability limits of each analyte in pre-centrifuged blood samples.OBJECTIVES: This study aimed to investigate the stability limits of 10 analytes in Turkoman racehorses blood samples stored in different temperatures and time points.METHODS: The whole blood samples from healthy horses (n=10) were stored for 2 h (baseline), 6, 12, 24, and 48 h at 25ºC or 4ºC. The commercial kits (Parsazmoon, Tehran, Iran) were used for the samples analysis.RESULTS: Albumin (ALB), total bilirubin (TB), and phosphorous (P) exhibited remarkable changes at 25ºC. The storage time for as long as 12 h at 25ºC had no significant effect on urea, total protein (TP), lactate dehydrogenase (LDH), creatinine, and alkaline phosphatase (ALP). The stability of alanine transaminase (ALT) in serum samples stored at 25ºC was for 24 h and for LDH was for 48 h at 4ºC. Aspartate transaminase (AST) was the most unstable analyte at different storage times at both temperatures. Urea, TP, ALB, TB, and P were stable at 4ºC for as long as 6 h. Creatinine and ALP were affected by 24 and 48 h storage times at both temperatures. There was a significant difference (P<0.05) in AST and ALT activities between two temperatures. No significant difference was observed in creatinine, urea, and TB concentrations between two storage temperatures at any of the storage times.CONCLUSIONS: This study showed that some analytes have acceptable stability in the clotted blood samples stored at 4°C for 6 h.

BACKGROUND: Escherichia coli (E.coli) is one of the most common and important causative bacterium of urinary tract infections (UTIs) in both dogs and humans. OBJECTIVES: This study aimed to identify virulence genes and a phylogenetic group of E. coli isolated from the urine of dogs suffering from UTIs. METHODS: E. coli were isolated from urine of dogs suffering from UTIs and tested for the presence of the virulence genes using conventional polymerase chain reaction (PCR) and sequencing method. On day 60 after immunization, half of the fish in each treatment was challenged intraperitoneally and the re- maining half of fish in the oral receiving bacterin groups were challenged by bath method with 1 LD50 and 1 LC50 of a Y. ruckeri local virulent isolate respectively. RESULTS: Out of a total of 103 samples, 25 were found to be positive for E. coli, of these 20 (80.0%) were identified as aer, 14(56.0%) as pap , 12(48.0%) as sfa, 8(32.0%) as afa, 5(20.0%) as hly and 5(20.0%) as cnf1 genes. None of the isolates carried cnf2 genes. CONCLUSIONS: The study demonstrated a high occurrence of virulence genes. The phylogenetic compar- isons of these gene sequences detected in uropathogenic E. coli isolated from dogs showed high similarity to those present in the urine of humans with urinary tract infection. Phylogenetic comparisons of the virulence genes revealed that hly, sfa , cnf1 and pap matched to group B2, afa to group A and aer to group B2 and D.

BACKGROUND: Mesobuthus eupeus is an indigenous scorpion species in Southwest Iran which is respon- sible for the majority of scorpion sting cases in Khuzestan province. OBJECTIVES: The effects of M. eupeus venom were investigated on the chief metabolic hormones in rats. METHODS: A total of 45 Albino male rats were divided into 3 equal groups: group 1 (control): 0.5 ml normal saline was administered intraperitoneally (IP); group 2 and 3: M. eupeus venom was administered with a dose of 1 and 2 mg/kg IP, respectively. Sampling was performed at 8, 24, and 48 hours after venom/ saline injection. RESULTS: The levels of thyroxine (T4) and triiodothyronine (T3) were significantly lower in both venom receiving groups (groups 2 and 3) than in the control group, dose-dependently, at all sampling times. There was a significant decrease in insulin level in both intoxicated groups compared to the control group at all sampling times. Glucagon, cortisol and subsequently glucose concentrations were significantly increased in both groups receiving the venom (groups 2 and 3) compared to the control group at 8 and 24 hours following envenomation. CONCLUSIONS: The findings of this study indicate that M. eupeus venom can suppress the secretion of essential metabolic hormones including T3, T4, and insulin and stimulate the release of glucagon, and cor- tisol, leading to hyperglycemia.

BACKGROUND: Neurotransmitters (NTS) are endogenous chemicals secreted from neural terminals into the synaptic cleft of the chemical neurons in order to affect their receptors. NTS play vital physiological role as stimulatory, inhibitory or modulatory compounds. OBJECTIVES: This review was aimed to summarize the roles of the most important NTS which regulate food intake in the avian species. RESULTS: Over 40 neurotransmitters are known as regulatory agents that control ingestion behavior in mammals and birds. Acetylcholine (Ach), epinephrine (EP), norepinephrine (NEP), histamine, gamma amino butyric acid (GABA), glycine, serotonin and glutamate have been identified as the mediatory agents about regulation of feeding behavior in birds. Based on the molecular weight and the type of efficacy, NTS have been categorized into the two main groups including “the small molecular weight fast-effective NTS and the large molecular wieght slow-effective neuropeptides. Various physiological functions have been presented for NTS and it seems many other unknown effects and even possible interactions among them are still questionable. Appetite control, mediatory role of ingestion behavior and regulation of food intake have recently been highlighted among various roles of NTS in chicken. CONCLUSIONS: Food intake regulation is a complex physiologic process that is under the control of the central and environmental signals. Considering of the involvement of feeding behavior in other major physiological processes such as the growth, immunity and production, it is necessary to realize the role of different mediators which are affecting and modulating food intake in avian species.

BACKGROUND:Due to the large proportion of iodine present in milk and dairy products, they have been one of the important sources of nutritional iodine in several countries. Information about variation in milk iodine concentration in Iran is limited. OBJECTIVES:The present study was conducted to determine the iodine concentration in Iranian milk and dairy milk products. METHODS: In the first step, 10 commercial dairy farms (five located in tropical and other located in cold region) were included in the study. In the second step, the iodine concentration of six samples of different milk products from the retail market was determined by Sandell-Kolthoff (acid-digestion) reaction. RESULTS: The average iodine concentration of milk samples from cold region was significantly lower (50.7 ± 24.3 %) than the iodine concentration of milk samples from the tropical region (P<0.05). Sterilized milk (282.0 ± 111.0 µg/l) had higher and raw milk (224.3 ± 116.9 µg/l) had lower iodine concentration  (P<0.05). There was no effect of milk fat class (whole and semi-skimmed) on milk iodine concentration (P>0.05). CONCLUSIONS: Based on Iranian dairy product intake, raw, pasteurized and sterilized milk provides on average, 74.6, 84.6, 96.0 µg of iodine, approximately 29.8, 33.8, 37.6 % of the adult recommended dietary allowance for this nutrient, respectively.

BACKGROUND: A limited number of studies have investigated the inclusion of amino acids in calf starter. OBJECTIVES: This study was aimed to evaluate different levels of crude protein in starter and supplement- ing some protected amino acids on efficiency, health status and blood metabolites of dairy calves and to com- pare it with unprotected amino acids. METHODS: Forty-eight 3-day-old Holstein calves were randomly allocated to four treatments in a complete- ly randomized design. Dietary treatments were (1) 18% Crude Protein starter without Amino Acid, (2) 18% Crude Protein with 0.0340% protected lysine and 0.016% protected methionine, (3) 18% Crude Protein starter with 0.215% un-protected lysine and 0.012% un-protected methionine, (4) 22% Crude Protein without Amino Acid. All calves received the same amount of whole milk, weaned on day 56; the study was finished on day 70. RESULTS: Calves in treatment 4 had the greatest starter intake, weaning weight and final weight (P<0.05) but their feed efficiency was not different among treatments. There were no significant differences in Immu- noglobulin G, total protein and Lysine and Methionine concentration in blood (P>0.05). Health score (eye, ear, nose and respiratory score), was not different among treatments but the fecal score revealed a significant difference (P<0.05). Starter diet with 22% Crude Protein resulted in higher serum urea concentration (P< 0.05) CONCLUSIONS: Results of the present study indicate that, the performance of calves received protected or un-protected amino acid in starter was not different. Also, higher Crude Protein levels in diet did not lead to a better gain to feed ratio.