Effect of area decrease in a food competition situation in captive wild boars (Sus scrofa)

The aim of the present study was to examine the effect of area reduction on the hierarchy-dependent behaviors of wild boars and crossbred sows (wild boar × Vietnamese pot-bellied pig) living in captivity, with regard to a food competition situation. We first defined the hierarchy system among 7 individuals, living together for more than a year, with a mathematical model based on wins and defeats. We then tested the possibility of a correspondence between the rank position and the age and/or weight. In a first experiment, we defined the frequency of dominant and submissive behavioral elements depending on the rank and on the group level in a food competition situation. We analyzed individually the time spent feeding. In a second experiment, we reduced the size of their living area and observed the potential modifications of the dominant and submissive elements’ frequency as well as the time spent feeding.We found a linear hierarchy among the sows. We did not find any relationship between the rank and the age or the rank and the weight of the animals. However, after excluding the youngest and the lightest leader from the analysis, significant correspondence was found among the aforementioned variables. In such cases, the older and heavier sows occupied the higher ranks in the hierarchy. We also observed that the sow with the higher rank position spent more time feeding and presenting aggressive behaviors compared with the other individuals, whereas the sow with the lowest rank position spent the most time displaying submissive behavior. Moreover, the frequency of dominant and submissive behavioral elements increased when reducing the size of the living area.Based on our results, we found that the area reduction and, therefore, the higher density increased the frequency of aggressive and submissive behavioral elements of the sows.     

Serological evidence of Neospora caninum infections in beef bulls in six counties of the Corrientes province,Argentina

The purpose of the present work was to identify Neospora caninum infections in beef bulls belonging to 19 herds from six counties located in the Corrientes province, Argentina. The presence of antibodies to N. caninum was evaluated in 305 serum samples of bulls (Bos taurus and Bos indicus). Age and breed were recorded. An indirect fluorescent antibody test was used to determine specific antibodies. The number of bulls with natural Neospora-infection was 15 of 305 (4.9%). No association between serologic status and breed (odds ratio (OR), 0.53; 95% CI, 0.18-1.53) was found. Neospora-infected beef bulls were identified in the present work. The bull role in bovine neosporosis and the risk of horizontal transmission for cows should be investigated.     

Pulse and continuous oral norfloxacin treatment of experimentally induced Escherichia coli infection in broiler chicks and turkey poults

Experimental colibacillosis was produced in 40 healthy, 7-day-old broiler chickens and turkeys by intratracheal injection of 1 x 10(8) CFU/chick and 1.23 x 10(9) CFU/poult bacteria of an O1:F11 strain of Escherichia coli, respectively. Two days before E. coli challenge all chicks were vaccinated with a live attenuated strain of infectious bronchitis virus (H-52). This model of infection--at least in chicken--proved to be useful for evaluating the efficacy of antimicrobial medication, by recording mortality, body weight gain, pathological alterations and frequency of reisolation of E. coli. Using this model, the efficacy of two different dosing methods of norfloxacin (continuous and pulse dosing) was evaluated. The once-per-day pulse dosing of norfloxacin administered via the drinking water at 15 mg/kg body weight proved to be more efficacious than the continuous dosing method of 100 mg/L for 5 days in chickens, while there were no convincing differences between the two treatment regimens in turkeys. The results confirmed earlier observations on the pharmacokinetic properties of norfloxacin in chicks and turkeys (Laczay et al., 1998).     

Seroepidemiology of beef and dairy herds and fetal study of Neospora caninum in Argentina

The purpose of the present work was to study the epidemiology of Neospora caninum in beef and dairy herds in the Humid Pampas of Argentina. The seroprevalence of N. caninum was evaluated in 2414 serum samples of cows from beef and dairy farms. An indirect fluorescent antibody test (IFAT) was used to determine specific antibodies. The sera was screened at a dilution >or=1:200 and >or=1:600 in cows with reproductive disease antecedents and without them, respectively. Cows without history of reproductive diseases from nine beef and fifteen dairy farms were grouped according to the percentage (> or the seroprevalence in beef and dairy cattle cohabiting in the same farm with these dogs was compared. Microscopic studies were performed in 188 aborted fetuses and/or their placentas. Formalin-fixed fetal tissues with microscopic lesions compatible with N. caninum were processed by immunohistochemistry (IHC). The seroprevalence in cows without reproductive diseases was 4.7% (19/400) for beef cattle and 16.6% (174/1048) for dairy cattle. The seroprevalence of N. caninum in dairy cattle was higher (P<0.05) in farms grouped according to the percentage (> or th N. caninum were observed in 43 of 188 (22.8%) fetuses and/or placentas evaluated. The protozoan was identified in 29 of 43 (67.4%) aborted specimens, being the largest number of positive results in dairy fetuses. The results obtained demonstrate a high association between neosporosis and dairy herds, however, our data also reveals that N. caninum is an important risk factor for reproductive losses in the extensively farmed beef cattle in the Humid Pampas of Argentina.     

Factors influencing pregnancy rate and late embryonic loss in dairy cattle.

This trial was conducted on three Hungarian dairy farms between March 2003 and April 2004. The aims of this study were to examine the effect of milk production and milk contents, the day after calving (DAC) and the sire for the pregnancy rate (PR) and late embryonic loss (LEL) in dairies. Five thousand three hundred and eighty insemination was carried out in this period. Pregnancies (n = 1969) were detected by BioPryn test from 3919 blood samples between 30-36 days post insemination (PI). Retention of pregnancy was determined by rectal palpation on Day 60. LEL has been determined by the optical density (OD) of blood samples/cutoff ratio and the serum progesterone (P4) concentration 30-36 days PI. According to serum progesterone concentration the authors predicted a presumed or possible embryonic loss or maintenance of the pregnancy. The efficiency of the artificial inseminations (AI) was significantly lower 60 days within post-partum. Significant positive correlation was found between the result of early and late PR and DAC and the milk protein/fat ratio. Significant negative correlation was detected between the early and late PR the milk protein and fat content. A later stage (60 days PI) of pregnancy the milk production has a negative effect for retaining of pregnancy. More data would be necessary to state that sires can influence the reproduction ability of their progenies. This is a really important issue, because the AI bulls have a great impact on the herds and the one-way selection may cause decreased fertility on breed level as well.     

Interspecific germ cell transplantation: a new light in the conservation of valuable Balkan trout genetic resources?

Interspecific transplantation of germ cells from the brown trout Salmo trutta m. fario and the European grayling Thymallus thymallus into rainbow trout Oncorhynchus mykiss recipients was carried out in order to improve current practices in conservation of genetic resources of endangered salmonid species in the Balkan Peninsula. Current conservation methods mainly include in situ efforts such as the maintenance of purebred individuals in isolated streams and restocking with purebred fingerlings; however, additional ex situ strategies such as surrogate production are needed. Steps required for transplantation such as isolation of high number of viable germ cells and fluorescent labeling of germ cells which are to be transplanted have been optimized. Isolated and labeled brown trout and grayling germ cells were intraperitoneally transplanted into 3 to 5 days post hatch rainbow trout larvae. Survival of the injected larvae was comparable to the controls. Sixty days after transplantation, fluorescently labeled donor cells were detected within the recipient gonads indicating successful incorporation of germ cells (brown trout spermatogonia and oogonia—27%; grayling spermatogonia—28%; grayling oogonia—23%). PCR amplification of donor mtDNA CR fragments within the recipient gonads additionally corroborated the success of incorporation. Overall, the transplantation method demonstrated in this study presents the first step and a possible onset of the application of the germ cell transplantation technology in conservation and revitalization of genetic resources of endangered and endemic species or populations of salmonid fish and thus give rise to new or improved management strategies for such species.     

白斑狗鱼耗氧率和窒息点研究

白斑狗鱼(Esoxlucius)属鲑形目(Salmoniformes)、狗鱼科(Esocidae)、狗鱼属(Esox),北半球北部亚冷水性大型凶猛淡水鱼类,我国仅产于新疆北部额尔齐斯河流域,如额尔齐斯河、布尔津河、哈巴河等及附属水体。鱼类大多数代谢活动都和氧的利用有关,耗氧率直接或间接地反映新陈代     

Improving the Reproductive Efficiency by Zoo-Technical Methods at a Dairy Farm

This trial was conducted on a Hungarian dairy farm between July 2001 and December 2004. The objective of this work was to improve the reproductive efficiency with relatively high milk production. At the beginning of this trial blood and fodder samples were taken for checking the metabolic status of the animals in order to determine their health condition. The nutritive value of the daily ration for all groups met with the requirements of the Hungarian National Standard and almost all serum metabolic parameters differed between the milking and pregnant animals. Early pregnancy detection (by ultrasound) and ovulation synchronizing methods were introduced to optimize reproductive performance. The oestrus cycle was also checked by ultrasound and open cows were treated by the appropriate method in order to inseminate them as soon as possible. Efficiency of artificial insemination (AI) followed by a single prostaglandin F2alpha (PGF2alpha) and Ovsynch treatment was similar (30.8% and 29%) and less effective than AI after natural heat detection (37.1%). Provsynch (Pre-synch followed by Ovsynch) was the most effective ovulation synchronization method (conception rate=42.6%; p<0.01). Although milk production increased between 2002 and 2004 by approximately 600 kg per cow, the calving period decreased by 20 days and the number of AIs per pregnancy was also improved (0.8 AI per conception). These findings are really beneficial economically because the decrease in the calving interval returns profit for the dairy farms; one open day costs euro2.5/cow. Economical analysis showed a high profit ratio from the reproductive 'investment' on this farm. Every invested euro yielded approximately euro10.