Comparing the behavioural thermoregulation response to heat stress by Atlantic salmon parr (Salmo salar) in two rivers     

Emily Corey  Tommi Linnansaari  Stephen J. Dugdale  Normand Bergeron  Jean-François Gendron  Michel Lapointe  Richard A. Cunjak 《Ecology of Freshwater Fish》2020,29(1):50-62

Climate change is expected to increase the frequency and magnitude of extreme thermal events in rivers. The Little Southwest Miramichi River (LSWM) and the Ouelle River (OR) are two Atlantic salmon (Salmo salar) rivers located in eastern Canada, where in recent years, water temperatures have exceeded known thermal limits (~23°C). Once temperature surpasses this threshold, juvenile salmon exploit thermal heterogeneity to behaviourally thermoregulate, forming aggregations in coolwater refuges. This study aimed to determine whether the behavioural thermoregulation response is universal across rivers, arising from common thermal cues. We detailed the temperature and discharge patterns of two geographically distinct rivers from 2010 to 2012 and compared these with aggregation onset temperature. PIT telemetry and snorkelling were used to confirm the presence of aggregations. Mean daily maximum temperature in 2010 was significantly greater in the OR versus the LSWM (p = 0.005), but not in other years (p = 0.090–0.353). Aggregations occurred on 14 and 9 occasions in the OR and LSWM respectively. Temperature at onset of aggregation was significantly greater in the OR (T_onset = 28.3°C) than in the LSWM (T_onset = 27.3°C; p = 0.049). Logistic regression models varied by river and were able to predict the probability of aggregation based on the preceding number of hours >23°C (R² = 0.61 & 0.65; P₅₀ = 27.4°C & 28.9°C; in the OR and LSWM respectively). These results imply the preceding local thermal regime may influence behaviour and indicate a degree of phenotypic plasticity, illustrating a need for localised management strategies.  相似文献   

Acute outbreak of porcine parvovirus infection in mozambique     

E. Rivera  C. Concha  M. Bragança  A. Gunnarsson  K. A. Karlsson 《Tropical animal health and production》1995,27(4):217-220

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Effect of dietary protein content on live and carcase performance of heterozygous naked neck and normally feathered broilers     

S. Yalçin  S. Özkan  Z. Açikgöz  K. Özkan 《British poultry science》1996,37(5):963-969

1. An experiment was conducted to determine the effect of different dietary protein contents on the performance of naked neck (Na/na) and normally feathered (na/na) broilers.

2. Chicks from the two genotypes were reared in wire‐floored cages and divided at random into 3 groups. Birds were fed on high protein (HP, 12.99 MJ ME, 238 g crude protein/kg and 12.94 MJ ME, 216 g crude protein/kg from 0 to 3 and 3 to 7 weeks, respectively), medium protein (MP, 12.99 MJ ME, 219 g crude protein/kg and 12.87 MJ ME, 201 g crude protein/kg from 0 to 3 and 3 to 7 weeks), and low protein (LP, 12.94 MJ ME, 205 g crude protein/kg and 12.75 MJ ME, 184 g protein/kg from 0 to 3 and 3 to 7 weeks) diets.

3. The LP diets resulted in a significantly lower daily body weight gain of males from 0 to 3 weeks. Dietary protein content had no effect on body weight gain from 3 to 7 weeks, body weight at 7 weeks, and the food intake of birds. Carcase composition of birds from both genotypes was unaffected by dietary protein.

4. Naked neck birds had significandy higher body weights at 7 weeks. Yields of carcase and breast of Na/na males were significantly higher than those of na/na males. There were no significant differences between females from the two genotypes as regards carcase yield.

5. It was concluded that the dietary protein requirements of naked neck birds were similar to those for normally feathered birds.  相似文献   

Genetic relationship, inbreeding and generation interval in registered Gir cattle in Brazil     

Queiroz SA  Lôbo RB 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》1993,110(1-6):228-233

SUMMARY: Two-hundred random pedigrees of cows and fifty of sires born in 1987 from the Gir herdbook of the Brazilian Association of Zebu Breeders were analized. The bull Chave de Ouro DGR no. 2851 was the most influential animal with a 7% direct relationship to the breed. Total average inbreeding was 3.62 and 3.25 for the female and male sample, respectively. The subdivision of total inbreeding into current and non-current components resulted in values of 1.62, 1.25, 2.00 and 2.00 for the female and male sample, respectively. Long-term inbreeding was the principal component of non-current inbreeding, with values of 1.52% and 1.26%, respectively. Inbreeding due to strain formation strain due formation was less important (0.48% and 0.74%, respectively). The average generation interval was 8.02 years. The breed appears not yet to be subdivided into strains but this process may be starting. The average generation interval for the pedigree population was very high. Culling of old bulls could decrease this interval. ZUSAMMENFASSUNG: Verwandtschaft, Inzucht und Generationsintervall bei Gir Herdbuchrindern in Brasilien 200 zuf?llige Stammb?ume von Kühen und 50 von 1987 geborenen Stieren wurden vom Gir Herdbuch des brasilianischen Zebu Zuchtverbandes genommen. Der Stier Chave de Ouro DGR Nr. 2851 war das einflu?reichste Tier mit einer 7%igen direkten Verwandtschaft zur Rasse. Der gesamte Inzuchtkoeffizient war 3.6 und 3.25% für die weibliche und m?nnliche Stichprobe. Die Unterteilung der gesamten Inzucht in laufende und nicht laufende Komponenten resultierte in Werten von 1.62, 1.25, 2.0, 2.0 für die weibliche und die m?nnliche Stichprobe. Langfristige Inzucht war die Hauptursache für Nicht-Rezente Inzucht mit Werten von 1.5 und 1.26. Inzucht aufgrund von Linienbildung war weniger wichtig (0.48% und 0.74%). Das durchschnittliche Generationsintervall war 8.02 Jahre. Die Rasse scheint noch nicht in Linien unterteilt zu sein, aber dieser Proze? k?nnte begonnen haben. Das durchschnittliche Generationsintervall ist mit 8.02 Jahren sehr hoch. Nichtverwendung alter Stiere k?nnte dieses Intervall verkürzen.  相似文献   

Biological features and life table parameters of the mealy plum aphidHyalopterus pruni on different apricot cultivars     

M. S. Özgökçe  R. Atlıhan 《Phytoparasitica》2005,33(1):7-14

Development, survival, reproduction rate, and population growth parameters of the mealy plum aphidHyalopterus pruni (Geoffroy) (Hom.: Aphididae) were evaluated on four different apricot cultivars (Tyrinte, Sakıt, Colomer, and Bebeco) under field conditions in the Van region of Turkey. Experiments were carried out on exterior leaves of trees, 1.5–2 m above the ground. Plexiglas clip-cells (25×6 mm) with the upper side covered by muslin were used in the experiments. The mealy plum aphid performed better on Tyrinte than on the other cultivars tested. The fastest development time (first instar to adult; 9.4 days), highest daily reproduction rate (2.6 offspring/aphid/day), and highest total fecundity (48.1 offspring/aphid) were obtained on Tyrinte. The intrinsic rate of increase — a good indicator of the growth potential of a population — of individuals fed on Tyrinte was significantly greater than that of individuals fed on cvs. Colomer and Bebeco. While mean generation times (T _o ) of populations on different cultivars were close to each other, the net reproductive rate was the highest (29.45 offspring/aphid/generation) on Tyrinte and the population doubling time on Tyrinte was 18.7%, 25.2% and 26.3% faster than those of individuals on other cultivars tested. The results obtained in this study indicated that Tyrinte appeared to be the most susceptible to the mealy plum aphid among the cultivars tested. http://www.phytoparasitica.org. posting Nov. 23, 2004.  相似文献   

Effect of the Pietrain breed used as terminal boar on Post-weaning Multisystemic Wasting Syndrome (PMWS) in the offspring in four PMWS-affected farms     

Nicolas Rose  Alain Abhervé-Guéguen  Gérald Le Diguerher  Eric Eveno  Jean-Pierre Jolly  Philippe Blanchard  Aurélie Oger  André Jestin  François Madec 《Livestock Production Science》2005,95(3):177-186

The aim of this study was to determine the potential risk factors for PMWS at the individual pig level and assess the effect of the Pietrain paternal genetic background of the animals in a cohort study. The survey was set up in four PMWS-affected farms with 2 repetitions (batches) per farm. A representative sample of 60 pigs per batch, stratified according to the paternal genetic background (Pietrain: yes vs. no), was randomly selected after farrowing. The representative cohort was divided into 8 batches and the pigs were individually monitored from birth to slaughter. Survival analysis was used to determine the factors related to the time to PMWS. The litter-cluster effect was taken into account using the marginal Cox model (robust estimation of the covariance matrix) and the gamma shared frailty model which were compared.No protective effect of the Pietrain breed on the time to PMWS and the proportion of affected pigs in the offspring was found in this study. Piglets showing low circovirus type 2 (PCV2) titres at 7 weeks-old with no subsequent seroconversion and piglets from PCV2 negative sows were most likely to be affected by PMWS (HR=7.0 and 2.8, respectively). Active infection of the pregnant dams with parvovirus was related to an increased risk of PMWS in the offspring (HR=2.3). Neck injuries due to poorly performed injections in the dams were associated with an increased risk of PMWS with the marginal model (HR=2.1). Oxytocin injection (dams) during farrowing was protective against PMWS in the offspring (HR=0.6).  相似文献   

The effects of agricultural fields and human settlements on the use of rivers by wildlife in the mid-Zambezi valley,Zimbabwe     

Fritz  Hervé  Saïd  Sonia  Renaud  Pierre-Cyril  Mutake  Snoden  Coid  Craig  Monicat  François 《Landscape Ecology》2003,18(3):293-302

After the eradication of the Tse-Tse fly in the Mid-Zambezi valley, human settlements and fields extended mainly along the main rivers. In order to investigate the consequences of this human development on wildlife diversity we monitored three rivers of the Mid-Zambezi valley in Zimbabwe: Angwa, Manyame and Kadzi. The rivers were divided in segments of 200 m which were checked for spoors in order to assess the number of species and the number of individuals that used the segments. Human settlements were also recorded. We used a GIS to define the spatial characteristics of the fields present along the rivers, and related them to the distribution and abundance of wild species spoors in the river beds and banks. Our results show that the number of species in one segment of the river decreased with the increasing size of the field area bordering the segment. For all the major ungulate species, the numbers of individuals recorded per segment decreased with increasing field area. A similar trend was observed for small and medium-sized carnivores, though they were in lower numbers when present. Our analyses thus confirm that the extension of human agriculture in wildlife areas has an impact on most wild species, but we also define some threshold value of field size above which there seem to be an acceleration of the decrease in wildlife density and diversity: 3.2 ha for medium and small herbivores and carnivores; only the elephant seem to tolerate larger field area with a threshold value of 32 ha.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   

Effects of surgical implantation of temperature dataloggers on reproduction of captive striped skunks (Mephitis mephitis).     

Yeen Ten Hwang  Marie-Line Gentes  Dennilyn L Parker  Serge Larivière  Fran?ois Messier 《Journal of zoo and wildlife medicine》2004,35(4):515-519

A total of 20 (14 females, six males) captive striped skunks (Mephitis mephitis) with miniature temperature dataloggers implanted free in the abdominal cavity were examined for reproductive performance and pathology because of implants. Eleven of 12 female skunks reproduced successfully 45.9+/-3.7 days after surgery to remove implanted dataloggers. The pregnancy rate of 91.7% (11/12) was much higher than other captive studies and was comparable with that of wild skunks. Eight striped skunks (six males, two females) that were euthanatized and necropsied after having implants in the abdominal cavity for 5 mo showed no apparent pathology associated with the implant. Implantation of the intraperitoneal devices did not lead to complications in abdominal tissues. Neither implant nor surgery affected reproduction. We conclude that implanted dataloggers can safely be used in physiologic studies of striped skunks or possibly other small carnivores in captive or field studies.  相似文献   

Identification of irisin immunoreactivity in porcupine (Hystrix cristata) adrenal glands and kidneys          下载免费PDF全文

Sema Timurkaan  Fatih M. Gür  Berrin Gençer Tarakçı  Mehmet H. Yalçın  Mustafa Girgin 《Anatomia, histologia, embryologia》2018,47(5):405-409

Irisin, a novel peptide, was initially been shown to be expressed explicitly in the muscle tissues. We studied the presence of irisin immunoreactivity in porcupine adrenal glands and kidneys. Immunocytochemistry showed that irisin was localised both in the adrenal cortex and adrenal medulla. In organs, irisin immunoreactivity was found in the tubular and collecting system of the nephron. The functional role of irisin in the adrenal gland and kidney has not been precisely yet. However, irisin might have a paracrine and autocrine function as do other locally produced peptides.  相似文献   

Surgical repair of propagating condylar fractures of the third metacarpal/metatarsal bones with cortical screws placed in lag fashion in 26 racehorses (2007–2015)          下载免费PDF全文

N. Moulin  I. François  N. Coté  C. Alford  O. Cleary  M. R. Desjardins 《Equine veterinary journal》2018,50(5):629-635

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