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1.
Science ; 376(6598): 1215-1219, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35679394

RESUMO

Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community composition at such geographic scales remains unknown. Using standardized experiments that spanned 115° of latitude, at 36 nearshore sites along both coasts of the Americas, we found that marine predators have both higher consumption rates and consistently stronger impacts on biomass and species composition of marine invertebrate communities in warmer tropical waters, likely owing to fish predators. Our results provide robust support for a temperature-dependent gradient in interaction strength and have potential implications for how marine ecosystems will respond to ocean warming.


Assuntos
Organismos Aquáticos , Biomassa , Peixes , Temperatura Alta , Invertebrados , Comportamento Predatório , Animais , Aquecimento Global , Oceanos e Mares
2.
Animals (Basel) ; 10(11)2020 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-33233317

RESUMO

In Chile, selling animals through livestock markets is common. At markets, stressful events like loading, unloading and travel are at least duplicated. We described procedures associated with transport of calves at 20 markets and evaluated compliance with Chilean law by performing a survey of drivers who transport calves from origin farms to markets (OM) and from markets to destination (MD). During loading and unloading, we evaluated handling by stockpersons, facilities, fitness for transport, and behavioural indicators of the calves through direct observation using protocols. A total of 80% of drivers claimed having the training required by law. The mean travel time was 1 h 31 min for OM and 1 h 44 min for MD journeys (overall range 5 min-40.5 h). Most drivers used bedding material and provided adequate space availability. A total of 99.2% of the observed calves were assessed as fit to transport; slipping, turning back, vocalizing and balking were frequent behaviours observed during loading and unloading. Prohibited practices like prodding and hitting using driving devices were still observed, mainly during loading. Compliance with the law during transport of calves was adhered to; however, the associated handling within markets was still inadequate, evidencing need for training in order to improve animal welfare.

3.
Front Vet Sci ; 7: 471, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32851042

RESUMO

The welfare status of cull cows going through livestock markets was assessed in 12 premises in Chile, using behavioral and health indicators observed during unloading, auction, and loading (once in winter and once in summer). Groups of cows were observed by the same observer and the following indicators were recorded at each stage: slips, falls, balks, turns, jumps, and vocalizations of cows were considered as behavioral events and a proportion was calculated based on the number of observed events per group divided by the number of cows per group to give a behavioral event index (BEI). Health status of the cows was assessed during auction by recording the proportion of cows with low body condition, lameness, udder problems, tegumentary lesions, and tail abnormalities. Handler behavior was assessed using a count of negative tactile interactions (NTI) with the cows, like blows/hits, kicks, and pokes with the devices used to drive them, then a NTI index (NTII) was calculated as for BEI. Using the groups of cows as the statistical unit, statistical models were built and used to identify how NTII, some facilities features and comingling were associated with BEI registered during unloading, auction, and loading and also to calculate if the selling price was associated with the different health problems of cows, using the software MLwiN 3.03. A total of 1,103 groups of cows (n = 3,963 cows) were observed, finding a high percentage of slips and balks, whereas hitting and poking were frequent NTI. The highest mean BEI was observed during unloading in winter (1.10), whilst the lowest one was found during auction in summer (0.34). There was an increase of 0.11 in BEI for every extra unit increase in the NTII by the handlers. The BEI was negatively affected by the winter season compared to summer. Of 1,608 cows, 49.8% had a low body condition, 28.3% had udder problems, 24% were lame, 8.7% presented tegumentary lesions, and 3.1% tail abnormalities. It can be concluded that the health of the cull cows is already compromised when leaving the farms; cow behavior and handler tactile interactions with the cows are useful indicators to assess the welfare of cull cows at livestock markets.

4.
Animals (Basel) ; 9(5)2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31083363

RESUMO

Long distance transport of livestock from Patagonia to central Chile involves both road and sea transport and has a potential impact on the welfare of animals. Fifty Bos taurus cattle of approximate age six months were exposed to a journey of four days, with both the sea and road components undertaken in a truck (roll-off roll-on system) with two pens of different dimensions. Thirty-two and eighteen cattle were randomly allocated to two treatment groups: Low and High welfare standards, which were provided 0.66 m2/head and 0.86 m2/head, respectively, and a fixed amount of feed and water daily to each pen, 1.25 kg hay/head and 3.1 L water/head in the Low welfare treatment and 2.22 kg/head and 5.6 L/head in the High welfare treatment, respectively. Low welfare animals had increased plasma total protein and albumin, which is suggested to be due to limited water availability, and also haptoglobin, suggesting inflammatory responses. Cattle in the High welfare treatment spent more time eating and ruminating than those in the Low space allowance, but they had increased cortisol at the end of the journey, perhaps reflecting increased fighting with more space. Cattle welfare in both treatments was adversely affected by the limited feed and water supplies, with increased beta-hydroxybutyrate at the end of the voyage; total protein was increased in just the low welfare standard group where low space allowance and less food and water was provided. Creatine phosphokinase also increased after the journey, compared with before, indicating bruising. Limiting feed and water availability to cattle in the low welfare treatment resulted in physiological evidence of undernutrition and low hydration status, but it also reduced the stress response, probably because there was less fighting.

5.
Animals (Basel) ; 9(6)2019 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-31181788

RESUMO

Marketing cattle through auctions increases marketing time, exposing animals to more stressful events. Within Chile, 37% of auctioned cattle are "calves". To assess factors that may be affecting the welfare of calves during movement and penning, twelve markets were visited to evaluate behavioral indicators of welfare, handling, and facilities. Behavioral indicators during movement were classified into movement and other behaviors, and indicators during penning were classified into positive or negative behavioral welfare indicators. For each group of calves, an index was calculated based on a proportion of observed behavioral indicators. Statistical models were built to identify variables associated with changes in these indices. Presence of inappropriate driving, inadequate lighting, and slippery floor was associated with a movement index increase (poorer welfare). Negative tactile interactions were associated with an increase, and group size was associated with a decrease in movement index and other behavior indices. During penning, not mixing animals from different sources was associated with an increase and stocking density with a decrease in positive welfare index. Number of auctioned cattle, observation number, and not mixing with incompatible and/or with calves from different sources were factors associated with a decrease in negative welfare index, and the presence of males was associated with an increase. Behavioral welfare indicators were mostly associated with handling.

6.
Animals (Basel) ; 8(10)2018 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-30282905

RESUMO

Marketing is a stressful process for beef calves, because they are removed from their environment, often weaned just before loading, loaded, transported, and unloaded. It also involves extended periods without food and water and mixing with unfamiliar animals in an unknown environment. Some studies have shown that calves sold through markets are exposed to extended fasting periods even when they undergo only short transportation times. The aim of this controlled study was to determine the consequences for beef calves of a short transportation time followed by a prolonged time without food and water on their tympanic temperature (TT), maximum eye temperature (MET), blood variables related to stress, and live weight. Ten calves were transported for 3 h and then kept in an outdoor pen for 21 h, completing a 24 h fasting period. Sampling took place before loading, after transport and unloading, and then after completing 24 h without food and water. TT, MET, blood glucose, and creatine kinase (CK) increased significantly after transportation. Live weight decreased across sample times (mean of 10 kg per calf after 24 h of fasting), which was consistent with the higher concentration of ß-HB found after fasting. Further studies to measure the actual consequences of true, commercial marketing on calf welfare and productivity are needed.

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