s. hassani

The first purpose of treatment of periodontal disease and bone loss is to regenerate the lost structures and preserve the sound residual tissues. Different techniques and materials are utilized for alveolar bone loss treatment. This review summarizes the techniques and materials utilized for treatment of alveolar bone loss due to periodontitis.

A search was performed in PubMed, Cochrane Library, and Google Scholar databases from 1990 to 2021. Totally, 133 studies were collected and reviewed, and finally, 31 studies were selected for the analysis.

Of 31 papers, 13 were about intra-bony defects, and others were about furcation involvement defects. Each article suggested different techniques and materials. Clinical parameters such as plaque index, gingival index, probing pocket depth (PPD), clinical attachment loss (CAL), and gingival margin position had been measured in studies, and a few techniques showed better results than others. Treatment of furcation defects is difficult in periodontal therapy. We should note that surgical procedures do not have any superiority over non-surgical procedures.

In conclusion, to decide about the best technique, site of defect, severity of disease, the available materials, and the clinician’s knowledge should be considered.

Nanotechnology can be very effective in increasing productivity through food, nutrition, hygiene and breeding of livestock, poultry and aquatic animals. Nanotechnology has received a great attention within scientific and industrial communities in many countries including Iran. Nanotechnology, as a powerful new technology has the ability of creating massive revolution in feed supply and agricultural systems at global scale by improving diet quality and consequently health and growth performance (Buzea et al. 2007). One of the reasons for the extensive use of these particles in poultry units is due to their antimicrobial properties. Nanotechnology deals with structures that their dimensions are approximately between 1 to 100 nanometers (Sriram et al. 2010). Silver nanoparticles are among widely used nanoparticles. The interest in the use of silver based antimicrobial agents was primarily due to the emergence of antibiotic resistance among microbial populations and due to the fact that resistance to silver is not commonly encountered (Prestinaci et al. 2015). Nanoparticles according to their size, have new properties in comparison with mass materials. Silver nanoparticles in many characters are more effective compared with other metals. In addition, beneficial effects of silver nanoparticles are due to the size and resemblance of nanoparticles which caused their passage through the biological membrane and through the cell (Wang et al. 2015). Silver nanoparticles because of their small size for proper homogeneity can be coated by zeolite particles. Zeolite has been used in broiler feed due to its resistant chemical structure and it’s not digested and catalyzed by passing through the digestive tract. Also, zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earth cations. Among many properties attributed to zeolites, two of the most characteristics that relates to their effectiveness in animal nutrition are their ability to lose and gain water reversibly and being capable of exchanging selectively a variety of cations in their structure without much changes of structure (Wawrzyniak et al. 2017). Therefore, zeolite can be considered as an appropriate carrier for nanoparticles. Based on these facts, silver nanoparticles had been replaced instead of massive particles of silver and been more effective in different industry. Silver nanoparticles lead to the production of reactive oxygen species and oxidative stress in cells (Ahmadi and Kurdestani. 2010). Liver as the biggest gland in the body has several roles. In addition to digestive and metabolic activities, liver has immunological and detoxification activity (Maser et al. 1994). Silver nanoparticles can inter the cells and communicate with intracellular structures (Panzarini et al. 2018). The ability of silver nanoparticles to infiltrate into tissues led to resistance against their removal in blood and then, cause particles aggregation in utilizable tissues. Due to the reports of the aggregating and dangerous effects of silver nanoparticles, it seems necessary to histopathologically investigate liver and kidney of broiler chicken fed silver nanoparticles.

This experiment was performed at the Poultry Research Station Faculty of Animal Science at the Gorgan University of Agricultural and Natural Resources. This experiment was designed to evaluate the effect of silver nanoparticles coated on zeolite and organic acid on liver and kidney histology in broiler chickens. A total of 375 one-day old broiler chicks (Cobb 500) was randomly assigned into five treatment groups containing of five replicates with 15 birds in each replicate. Five dietary treatments groups were, (1) basal diet (control), (2) basal diet containing 1% zeolite, (3) basal diet containing 1% of zeolite-coated with 0.5% silver nanoparticles, (4) basal diet containing 0.15% organic acids and (5) basal diet containing 1% of zeolite-coated with 0.5% of silver nanoparticles and 0.15% a mixture of organic acid. The basal diet prepared for starter and growth periods, and composition of the experimental diets prepared according to the requirements prescribed for Cobb 500 (Cobb. 2012). Birds has ad libitum access to feed and water for all treatment groups and continuous lighting program was provided during the experiment. Two chickens per each replicate were slaughtered on day 42 for evaluating the histology of liver and kidney. The tissue samples were fixed in a 10% buffered formalin, processed through graded alcohols and xylene and embedded in paraffin blocks. Tissue sections were cut for 5 m at multiple levels and routinely stained with haematoxylin-eosin (H&E). Mounted slides were examined and photographed under a light microscope. Hepatocytes and kidney cells were evaluated for histopathologic lesions, focal point of lymph nodes in the liver parenchyma, around the portal region and focal point of heterophobia. Data were analyzed based on a completely randomized design using general linear method (GLM) procedure by using SAS (2003) software. Mean comparison was done by Duncan's multiple range tests at 5% level with values of P<0.05 being considered significantly different.

The experimental results didn’t show any significant difference between experimental treatments on liver and kidney histopathology in broiler chickens (P>0.05). Liver in the body as a detoxifying organ absorbs a significant part of toxins produced from harmful microbes and external particles into the blood. However, it was not possible to remove them completely in the tissues because of high ability of nanoparticles in dispersion in tissues of broiler chickens (Zargaran-Esfahani et al. 2010). Increased liver weight in the presence of nanoparticles due to inflammation in these organs has been reported in some studies. The results of this experiment didn’t show any significant difference between treatments on liver and kidney histopathology in broiler chickens and there were no toxicological effects of silver nanoparticles on liver and kidney tissues (P>0.05).

Nanoparticles coated on zeolite and with organic acid can be used as an additive supplement without any adverse effect on feeding and histopathological liver and kidney in broiler chickens.

Estimates of the amount of milk produced by lactating ewes provide information for the implementation of optimum management and feeding strategies for ewes and their lambs. Lamb survival and subsequent birth weight gains until weaning reflect milk production abilities of ewes. Genetic evaluation of milk yield traits in dairy sheep may be based on whole lactation records (Rahman Ahmad, 2010) or test day records (Horstick et al. 2001; Komprej et al. 2009; Carlos 2014). The random regression method of data analysis seems to be the most appropriated technique to apply in longitudinal data including growth and milk production and the corresponding models have been incorporated in animal breeding for the estimation of breeding values (Schaeffer, 2004). The main objective of this study was genetic analysis of test day milk records for Kurdi ewes of Shirvan Kodri sheep breeding station using fixed and random regression models. Matherial and Kordi sheep is an Iranian fat-tailed native breed developed mainly for meat production but produce milk and wool production as well. This breed is distributed in North Khorasan Province of Iran and is mainly grown traditionally by nomadic people in pastures. Kordi sheep breeding station is located in Shirvan city, North Khorasan Province, Iran. This station was established in 1988. The breeding system in this station is semi-intensive. Considering local weather conditions, lambs and ewes are usually sent to the pastures around the station for daily grazing in late April. Sheep are grazed in the pasture until early July and during the wheat and barley harvest in farm lands of the town. With the onset of the cold season the herd is transferred to the station, and by setting appropriate diets each animal group (pregnant ewes, male and female lambs and rams) is fed separately and manually three meals a day. Mating season is from mid August to late October and the lambing begins in early January and continues until late March (Saghi et al, 2014). Data included 1124 test day records of milk yields collected from 250 Kurdi ewes. Milking was carried out by hand combined with lamb suckling at 14 days intervals starting from May to August 2012. General linear model was used to identify effective fixed effects on the trait by SAS 9.1 software. Fixed effects of litter size, parity and month of recording and random effects of direct genetic and permanent environmental effects were included in the models. Variance and covariance components were estimated using restricted maximum likelihood procedure. Genetic analysis of milk yield was carried out using fixed and random regression models by Wombat software. Average milk yield of studied Kurdi ewes was 0.38 kg. Average heritability estimates of milk yield were 0.04 and 0.07 in fixed and random regression models, respectively. In random regression model, the highest and the lowest heritability estimates were found at 14 (0.18) and 84 (0.006) days, respectively. Heritability of milk yield was higher in the first than in the second part of lactation period. Repeatability of milk yield in different days of lactation was ranged from 0.51 (day 28) to 0.89 (day 126). Genetic correlations between milk yields at different days in milk were ranged from -0.942 to 0.999. Permanent environmental correlations between milk yields at different days in milk were ranged from -0.850 to 0.920. Milk yield additive genetic and permanent environmental correlations between adjacent test days were more than between distant test days. Kominakis et al. (2001) were found low heritabilities for milk yields in different days of lactation for dairy ewes (0.05 to 0.25). Komprej et al. (2013) were also reported estimated heritabilities of milk yields in different days for Slovenian dairy sheep ranged from 0.08 to 0.16. Lower genetic correlations between milk yields at different days with increase in intervals between test day records were also found by other researchers (Zavadilova et al. 2005; Madad et al. 2013). Results indicated that Kordi sheep has a relatively good potential for milk production among Iranian native sheep breeds. For milk yield in the studied population, orthogonal Legendre polynomials of order 2 and 3 for additive genetic and permanent environmental effects, respectively, was found the most appropriate model. Considering low heritability of milk yield, improvements in environmental conditions could result in increasing milk yield performance in the studied flock. Lower genetic correlations with increase in intervals between test-day records may suggest that different genes are involved in milk yield in different days of lactation.

The purpose of this research was the study of reproductive performance in postpartum dairy cows with different parities. Twenty Holstein dairy cows were assigned into two equal primiparous and multiparous groups. Body weight and body condition score (based on 1-5 scoring) were measured every other week, starting from two weeks before calving till pregnancy confirmation. Daily milk yield was also recorded. Reproductive parameters including days from calving to the uterus returning time, to the initiation time of clinical oestrus signs, to the first time of insemination and number of insemination per pregnancy were recorded. Meanwhile, blood serum concentrations of estrogen and progesterone were measured. Results indicated that, the mean (±SE) of body weight and milk production was significantly higher for multiparous cows. Blood serum concentration of estrogen (mean ±SE) was significantly lower for primiparous cows (61.86±17.91 vs. 71.39±17.02 pg/ml). The number of insemination per pregnancy and estrus frequency did not differ between both groups. However, the intervals (mean ±SE) of calving to the uterus returning time (40.0±5.41 vs. 24.0±5.41 days), to the first insemination (119.62±14.17 vs. 67.5±14.17 days) and the initiation of clinical oestrus signs (28.5±4.5 vs. 19.67±8.5 days) was significantly higher for primiparous than multiparous cows. In general, this study demonstrated that the effect of parity on postpartum reproductive performance is modulated through its effect of blood serum estrogen level, uterus returning time and estrus initiation time.

Data collected of lambs born from 1982 to 2006 in herd number one of Baluchi Sheep of Mashad Abbass Abad Sheep breeding station were used for the analysis. Animal breeding values were predicted using univariate analysis based on animal model. Genetic, phenotypic and environmental trends were estimated by regression of mean breeding value, mean phenotypic value and difference between phenotypic and breeding values on year, respectively. Total genetic progress of 22 years for birth weight (BW) and 24 years for weaning weight (WW), 6-month weight (6W), 9-month weight (9W) and 12-month weigh were 0.011, 1.488, 2.066, 2.062 and 2.034 kg, respectively. Genetic trend for BW, WW, 6W, 9W and 12W were 0.7±0.06, 55±1, 72±2, 77±2 and 88±3 gr per year, respectively. The phenotypic trends for BW, WW, 6W, 9W and 12W were 4±1, 3±9, -11±11, 15±11 and 118±14 gr per year and environmental trends estimates for respective weights were 3±1, -52±8, -83±9, -62±9 and 29±12 gr per year, respectively.

An experiment was carried out to compare the effects of ewe milk with commercial milk replacer and starter dirt with different levels of concentrate on the growth, feed intake and rumen development of suckling lambs. Thirty Dalagh breed male lambs were separated from their mothers at 3±1 days of age divided into 6 groups (5 lambs per treatment) and were fed with 6 treatments for 90 days age. Treatment consisted of 2 fluid feed (ewe milk and milk replacer) and 3 starter diets (diet 1: 100% concentrate, 2: 67% concentrate and 33% alfalfa hay, 3: 33% concentrate and 67% alfalfa hay). Lambs were fed ewe milk or milk replacer in 2 per day and starter diet 3 per day and their intake were measured. Data were analyzed as a randomized completely blocks design according to 2×3 factorial method. The end of experiment 18 lambs (3 per treatment) were slaughtered, stomach harvested, emptied, washed with water and rumen development characteristics were measured. Data for growth, feed intake, rumen development parameters were analyzed as a randomized completely block according to 2*3 factorial design. Results showed the average of daily weight gain (ADG), dry matter intake, feed efficiency, ratio rumen weight to stomach weight (percent) and rumen wall thickness (RWT) in lambs fed ewe milk and milk replacer did not show significant differences, but means of papillae length (PL), papillae width (PW) and papillae density (PC), were differences statically significant and higher on lambs fed ewe milk (P<0.01). Feeding starter diets affected on ADG (P<0.05), PL, PW, RWT and PC (P<0.01) and higher on lambs fed starter diet with 100% concentrate. This experiment demonstrated that lambs could be reared with milk replacer, without any problem on the growth, feed intake and rumen development. Feeding starter diet with high levels of concentrate on suckling lambs resulted in high growth and good rumen development.

To evaluate drought tolerance of tobacco cultivars by quantitative indices, a research was conducted using factorial experiment on the basis of completely randomized design, with six cultivars of Virginia tobacco in four replications in the potty conditions during 2005. Cultivars including K326F, C176, C347, C258, C319 and MN944F were compared in two levels of irrigation including irrigation at the level of field capacity (75% available water) and stress condition in the fast growth stage (irrigation at 25% available water). To evaluate drought tolerance of cultivars, some related indices such as mean productivity (MP), tolerance (TOL), stress susceptibility index (SSI), geometric mean productivity (GMP) and stress tolerance index (STI) were used. On the basis of their correlation with yield under stress and non-stress conditions, MP, GMP, STI were selected as the best indices to separate tolerant cultivars. In respect of these indices, among the cultivars of tobacco, K326F with high yield and drought tolerance characteristics was selected. Using biplot method and comparison of best indices measures for each cultivar, C347 was identified as the most sensitive cultivar to drought stress.

The effect of dietary protein level and feed restriction on performance, body temperature and hematological values was evaluated, using Ross 308 broiler chicks under heat stress. For this purpose, three dietary treatments were fed to broilers during 21 to 42 days of age. Two treatments consisted of diets with protein levels recommended by NRC, 1994 and 85% of NRC recommendation and were fed ad-lib during the experiment. The third treatment was a feed restriction group that was fed diet with protein level recommended by NRC, but chicks were deprived of feed for 6 hours during heat stress challenge. Birds had free access to water. Results indicated that lowering protein content or feed restriction had no significant effect on body weight gain (P>0.05). Feed restriction resulted in significantly decreased feed intake, improved feed conversion and energy efficiency ratio, and decreased body temperature after heat stress challenge at 24 and 32 days (P<0.05). Lowering protein of diet and feed restriction resulted in significantly decreased protein intake, improved protein efficiency ratio and increased hematocrit and blood uric acid (P<0.05). Sex had no significant effect on body temperature and hematological values (P>0.05). Heat stress significantly increased body temperature, hematocrit and glucose and uric acid values.