Huber D.,Veterinary Faculty
International Zoo Yearbook | Year: 2010
Bears need to learn appropriate survival and behavioural skills in the first 1 or 2 years of life. They can acquire those skills fully only if raised by their mothers in the natural habitat. Releasing captive-born and/or hand-reared cubs threatens their life expectancy because individuals will have problems finding food and shelter, and experience intra- and inter-specific predation. Additionally, bears reared in captivity may cause behavioural and genetic pollution of the indigenous free-living population. The release of bears cannot be called 'reintroduction'. The surplus of bears currently in captivity should be resolved by control of reproduction and investment in efforts to prevent situations whereby wild-born bears become orphaned and captive. The existing captive population should be given the best possible care and be used as ambassadors to raise public awareness about situation of free-living conspecifics. The above statements are corroborated by experiences with European brown bears Ursus arctos. © 2010 The Authors. Journal compilation © 2010 The Zoological Society of London.
Meikle A.,Laboratory of Nuclear Techniques |
Adrien M.D.L.,Veterinary Faculty |
Mattiauda D.A.,Agronomy Faculty |
Chilibroste P.,Agronomy Faculty
Animal Feed Science and Technology | Year: 2013
The effect of different sward herbage allowances and a total mixed ration (TMR) management on milk production, body condition, first postpartum ovulation and endocrine/metabolic parameters were investigated. Primiparous Holstein dairy cows ( n=44) were randomly assigned to one of the following grazing treatments ( n=11 each): high (HA, 30. kg), medium (MA, 15. kg) and low (LA, 7.5. kg) estimated grass DM available/cow/d and a TMR group fed ad-lib from calving to 56 days after calving. Body condition score (BCS) was registered every 15 days from one month before to two months after calving. Non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), cholesterol, plasma protein, albumin, urea, insulin, insulin like growth factor-I (IGF-I) and leptin were determined in plasma every 15 days from 15 days before to 56 days after calving. Progesterone was determined 2 times per week after parturition to determine first ovulation. TMR group had higher milk production in the first 56 days in milk than the HA and MA groups (P<0.05) which did not differ, and were in turn greater than LA cows (P<0.01). Overall, the TMR and HA groups had a greater BCS, protein and albumin concentrations than the other groups, suggesting a better energy balance. While HA cows presented a better metabolic status (smaller BCS losses, lower plasma NEFA and greater urea concentrations) than MA cows during the early postpartum period (15-30 days postpartum, dpp, P<0.05), HA cows differed (greater plasma cholesterol, albumin and urea concentrations) from LA cows later on (45-60. dpp, P<0.05). Greater plasma insulin and IGF-I concentrations were found in the TMR group (P<0.05), which is consistent with the higher nutrient density offered to this group. The reinitiation of ovarian cyclicity was delayed in MA cows one month after calving when compared to TMR and HA cows (P<0.05), which is consistent with the greater NEFA and lower urea concentrations in this period. The lowest probability of first ovulation throughout the study was observed in LA cows (P<0.05), which was associated with their endocrine and metabolic profile. In conclusion, sward allowance affects metabolic signals which in turn are associated with a different productive and reproductive performance. © 2013 Elsevier B.V.
De Clercq E.M.,Catholic University of Louvain |
Leta S.,Adami Tullu Agricultural Research Center |
Estrada-Pena A.,Veterinary Faculty |
Madder M.,Institute of Tropical Medicine |
And 3 more authors.
Preventive Veterinary Medicine | Year: 2015
Rhipicephalus microplus is one of the most widely distributed and economically important ticks, transmitting Babesia bigemina, B. bovis and A. naplasma marginale. It was recently introduced to West Africa on live animals originating from Brazil. Knowing the precise environmental suitability for the tick would allow veterinary health officials to draft vector control strategies for different regions of the country. To test the performance of modelling algorithms and different sets of environmental explanatory variables, species distribution models for this tick species in Benin were developed using generalized linear models, linear discriminant analysis and random forests. The training data for these models were a dataset containing reported absence or presence in 104 farms, randomly selected across Benin. These farms were sampled at the end of the rainy season, which corresponds with an annual peak in tick abundance. Two environmental datasets for the country of Benin were compared: one based on interpolated climate data (WorldClim) and one based on remotely sensed images (MODIS). The pixel size for both environmental datasets was 1. km. Highly suitable areas occurred mainly along the warmer and humid coast extending northwards to central Benin. The northern hot and drier areas were found to be unsuitable. The models developed and tested on data from the entire country were generally found to perform well, having an AUC value greater than 0.92. Although statistically significant, only small differences in accuracy measures were found between the modelling algorithms, or between the environmental datasets. The resulting risk maps differed nonetheless. Models based on interpolated climate suggested gradual variations in habitat suitability, while those based on remotely sensed data indicated a sharper contrast between suitable and unsuitable areas, and a patchy distribution of the suitable areas. Remotely sensed data yielded more spatial detail in the predictions. When computing accuracy measures on a subset of data along the invasion front, the modelling technique Random Forest outperformed the other modelling approaches, and results with MODIS-derived variables were better than those using WorldClim data. © 2014 The Authors.
Landi H.,National University of Central Buenos Aires |
Barros L.,Veterinary Faculty |
Micheo C.,National University of Central Buenos Aires
Livestock Research for Rural Development | Year: 2011
An evaluation of the production and milk composition under different production biotypes, and nutrition methods in three commercial systems for a single production cycle was made. The effects of biotype, grazing management and different methods of feeding on milk composition were assessed. The results indicated that cows with a small biotype seem more appropriate for milk production based on pasture. The difference in body condition of grazing Holstein cows indicated an insufficient intake of herbage dry matter. Differences in milk production and composition as fat, protein, non-fat solids, casein fraction, and insoluble fractions in particular, can be attributed to the small biotype and to herd management.
Anzano J.,University of Zaragoza |
Lasheras R.-J.,University of Zaragoza |
Bonilla B.,University of Zaragoza |
Bonilla A.,University of Zaragoza |
And 5 more authors.
Green Chemistry Letters and Reviews | Year: 2011
In the present work, metals (cadmium, lead, copper, nickel, tin, selenium, and mercury) have been estimated in the Ebro River (Spain) using the zebra mussel (Dreissena polymorpha) as an environmental bio-indicator. In two sequential studies, in 2006 and 2008, concentrations of metals were calculated in water as well as in the shells and fleshes of the zebra mussels. Samples were collected from assorted locations of the river. Metals were determined successfully at trace levels through voltamperometry, a sensitive technique. It has been noted that analysis of bioaccumulators like zebra mussels can be helpful in evaluating metal pollution in water. © 2011 Taylor & Francis.