Annual Variation of Body Composition, Reproductive Hormones, and Blood Constituents of Red Foxes

Lefebvre, Christine; Crête, Michel; Huot, Jean; Patenaude, Robert; Price, Christopher A.

doi:10.2307/1383167

Cited by 5 publications

(2 citation statements)

References 24 publications

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“…Lefebvre et al 1999). In this study, we predicted body components of HD-SW deer using new regression models, because Bois et al (1997) had developed models based only on relatively large animals from southern Québec.…”

Section: Discussionmentioning

confidence: 99%

Evidence for a trade-off between growth and body reserves in northern white-tailed deer

et al. 2001

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We contrasted patterns of growth and accumulation of body reserves in autumn between two high-density (HD) white-tailed deer populations facing winters of different severity and length. Both populations occurred in the absence of effective predators and suffered from some forage competition based on reduced body masses. A third population living at low density (LD) and confronting long and severe winters (SW) served to distinguish the influence of food competition and winter severity on growth and body reserves. We estimated body components (water, protein, fat and ash) of deer during the first half of November and compared growth patterns between sexes and regions. HD-SW males continuted growth to an older age than HD males facing short and mild winters (MW) but females of both regions reached adult body mass at the same age. LD-SW deer exhibited a growth pattern similar to that of HD-SW animals but were the heaviest and the largest, suggesting that growth patterns are related to winter harshness (or length of the growing season) and that final body size is related to forage competition in summer. Sexual dimorphism became evident at an older age in the HD-SW population than in the HD-MW population, demonstrating that winter harshness does not affect immature males and females in the same manner. Fawns from the HD-SW population had proportionally longer legs and a higher percentage of body fat. Adaptations of immature deer to long and severe winters suggest that survival during the first winter represents the most critical step in the life span of northern white-tailed deer.

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Section: Discussionmentioning

confidence: 99%

Evidence for a trade-off between growth and body reserves in northern white-tailed deer

et al. 2001

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“…Clear seasonal changes in semen quality are observed in undomesticated canids. Reproductive seasonality was noted in red fox, silver fox, coyote and gray wolf males (Mitsuzuka 1987, Smith et al 1987, Lefebvre et al 1999, Minter and DeLiberto 2008). In the above species, spermatogenesis and testosterone production peak during the breeding season (Lincoln 1989).…”

Section: Introductionmentioning

confidence: 99%

Semen characteristics and selected biochemical markers of canine seminal plasma in various seasons of the year

Strzeżek¹,

Szemplińska²,

Filipowicz³

et al. 2015

Polish Journal of Veterinary Sciences

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The aim of this study was to evaluate the influence of season on selected qualitative semen characteristics and biochemical markers of canine seminal plasma. Whole ejaculates were collected from 5 crossbred dogs aged 2-8 years. The study covered a period of one year divided into four seasons: spring (March, April, May), summer (June, July, August), autumn (September, October, November) and winter (December, January, February). Semen samples were subjected to macroscopic and microscopic analyses to determine semen volume, total sperm counts and sperm morphology parameters. The study also involved the determination of sperm motility parameters (CASA system), sperm plasma membrane integrity (SPMI, fluorescent staining SYBR-14/PI), sperm mitochondrial membrane potential (MMP, fluorescent staining JC-1/PI) and the ATP content of sperm cells. Total protein content (TPC) and the activity of alkaline phosphatase (AP) and acid phosphatase (AcP) were determined in biochemical analyses of seminal plasma. No significant differences in ejaculate volume, SMPI or ATP content of sperm cells were observed between seasons. The highest total sperm counts were reported in ejaculates acquired in summer and autumn. The lowest MMP values were determined in summer ejaculates. No significant differences in sperm motility (MOT) were observed throughout the experiment, but ejaculates collected in autumn and winter were characterized by the highest progressive motility (PMOT). AP activity and TPC were not significantly affected by season. However, AcP activity levels were significantly lower in autumn than in the remaining seasons. Seasonal variations in the analyzed macroscopic and microscopic parameters of ejaculates and biochemical markers of seminal plasma did not exert a clear negative effect on the quality of canine semen.

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The low performance of forest versus rural coyotes in northeastern North America: Inequality between presence and availability of prey

et al. 2002

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Annual Variation of Body Composition, Reproductive Hormones, and Blood Constituents of Red Foxes

Cited by 5 publications

References 24 publications

Evidence for a trade-off between growth and body reserves in northern white-tailed deer

Evidence for a trade-off between growth and body reserves in northern white-tailed deer

Semen characteristics and selected biochemical markers of canine seminal plasma in various seasons of the year

The low performance of forest versus rural coyotes in northeastern North America: Inequality between presence and availability of prey

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