Seasonal changes in digestibility, passage rate and rumen fermentation of alfalfa hay in sika deer (Cervus nippon) under restricted feeding     

Sanae ASANO  Shoshichi IKEDA  Yuzo KUROKAWA  Shuhei KANDA  Hisao ITABASHI 《Animal Science Journal》2007,78(1):28-33

To investigate seasonal variations in the digestive functions of sika deer, five female sika deer were provided with an amount of alfalfa hay cubes equivalent to voluntary food intake during winter. We measured the rate at which the food passed through the digestive tract, digestibility and rumen fermentation during the summer (August), autumn (November), winter (February) and spring (May). Total mean retention time in the digestive tract during summer and autumn was numerically longer than that in winter and spring, but the difference did not reach significance. Organic matter and fiber were less digestible in summer and autumn than in winter and spring (P < 0.05), whereas the digestibility of the dry matter tended to vary with the seasons (P < 0.1). Ruminal pH values seasonally changed (P < 0.01), and were the lowest in autumn. The concentration of ruminal ammonia‐nitrogen differed significantly among the seasons (P < 0.05), increasing in winter and decreasing during spring and summer. The numbers of protozoa changed significantly among the seasons (P < 0.05), being higher in autumn than in winter and spring, and intermediate in summer. The concentration of total volatile fatty acids was not seasonally affected, but the molar percentages of propionic acid and butyric acid significantly changed according to season (P < 0.05 and P < 0.01, respectively), and the ratio of acetic to propionic acid tended to change with the seasons (P < 0.1). The results of this study suggested that the digestive functions in sika deer, fed a commercial diet at a restricted level, differed notably among the seasons and these variations might partially be due to environmental effects.  相似文献   

Seasonality of Gyrodactylus brachymystacis Ergens on farmed rainbow trout,Oncorhynchus mykiss (Walbaum), in central China,with a report of an infection on wild Manchurian trout,Brachymystax lenok (Pallas)     

P You  Y Wang  X Sun  X Qiang  D Cone 《Journal of fish diseases》2008,31(12):941-945

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Blue light from individual light masks directed at a single eye advances the breeding season in mares     

B. A. Murphy  C. M. Walsh  E. M. Woodward  R. L. Prendergast  J. P. Ryle  L. H. Fallon  M. H. T. Troedsson 《Equine veterinary journal》2014,46(5):601-605

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桃蛀果蛾寄主间生活史与杂交研究     

花保祯  花蕾  宋金东 《西北农林科技大学学报(自然科学版)》1995,23(5):6-10

在２５℃恒温、１４．５～１５．０ｈ光照条件下，比较了杏、苹果、枣、桃、酸枣、山楂、海红、石榴等８种寄主上桃蛀果蛾越冬幼虫出土和成虫羽化的时间差异，并进行了杂交试验。结果表明，幼虫出土和成虫羽化时期在寄主间差异明显；不同寄主来源的成虫间容易杂交，并产生可育的Ｆ＿１代。Ｆ＿１代滞育率差异悬殊，表明不同寄主上的桃蛀果蛾临界光周期有差异。  相似文献   

Parthenogenesis, polyploidy and reproductive seasonality in the Taiwanese mountain earthworm Amynthas catenus (Oligochaeta, Megascolecidae)     

Huei-Ping Shen  Chu-Fa Tsai  Jiun-Hong Chen 《Pedobiologia》2011,54(2):133-139

Amynthas catenusTsai et al., 2001 is a terrestrial earthworm belonging to the Pheretima complex of the family Megascolecidae. It is endemic to Mt. Hohuan of central Taiwan at elevations of 2985-3004 m. Its reproductive organs showed various stages of degeneration in the present study. The spermathecae varied from being absent (athecal) to three pairs in VI-VIII (sexthecal), and the prostate glands from a large, symmetrical pair to complete absence. For the 44 specimens examined from May 2008 to May 2010, there were 47.7% athecals, 36.4% sexthecals and 15.9% intermediates. Results of a flow cytometric analysis showed that there were three DNA ploidy levels - diploid, triploid and tetraploid (2n, 3n, and 4n) - for the athecals but only diploid for the sexthecals. The intermediates consisted of diploids and triploids. The diploids had 2n = 112 and the triploids 3n = 168. The haploid chromosome number of A. catenus was 56. Spermatogenesis occurred throughout the year with the highest activity in summer for both athecals and sexthecals, but the number of mature ova peaked in summer for the athecals and in spring for the sexthecals. There was no significant difference in mean number of mature ova produced between the athecals and the sexthecals, but the sexthecals had significantly higher spermatogenetic activity than the athecals. For all specimens examined, sperm were present in testes and seminal vesicles but not in spermathecae, an indication of parthenogenesis in the species.  相似文献   

Reproductive seasonality in the mare: neuroendocrine basis and pharmacologic control     

Williams GL  Thorson JF  Prezotto LD  Velez IC  Cardoso RC  Amstalden M 《Domestic animal endocrinology》2012,43(2):103-115

Reproductive seasonality in the mare is characterized by a marked decline in adenohypophyseal synthesis and secretion of LH beginning near the autumnal equinox. Thus, ovarian cycles have ceased in most mares by the time of the winter solstice. Endogenous reproductive rhythms in seasonal species are entrained or synchronized as a result of periodic environmental cues. In the horse, this cue is primarily day length. Hence, supplemental lighting schemes have been used managerially for decades to modify the annual timing of reproduction in the mare. Although a full characterization of the cellular and molecular bases of seasonal rhythms has not been realized in any species, many of their synaptic and humoral signaling pathways have been defined. In the mare, neuroendocrine-related studies have focused primarily on the roles of GnRH and interneuronal signaling pathways that subserve the GnRH system in the regulatory cascade. Recent studies have considered the role of a newly discovered neuropeptide, RF-related peptide 3 that could function to inhibit GnRH secretion or gonadotrope responsiveness. Although results that used native peptide sequences have been negative in the mare and mixed in all mammalian females, new studies that used an RFRP3 antagonist (RF9) in sheep are encouraging. Importantly, despite continuing deficits in some fundamental areas, the knowledge required to control seasonal anovulation pharmacologically has been available for >20 yr. Specifically, the continuous infusion of native GnRH is both reliable and efficient for accelerating reproductive transition and is uniquely applicable to the horse. However, its practical exploitation continues to await the development of a commercially acceptable delivery vehicle.  相似文献   

Book Review     

G. Mitchell 《African Zoology》2013,48(3):99-100

Agricultural landscapes are typically associated with a decreased biodiversity, particularly when they extend across large spatial scales. Despite the fact that some African bat species seem to provide essential ecosystem services across landscapes, we only have a limited understanding of how intensive agricultural practices influence bat communities. This study investigated the effects of sugarcane monoculture on the composition of both bat species and functional groups across a conservation-agricultural matrix. Specifically, we wanted to understand changes in the bat communities within savannas and sugarcane plantations. We categorised bats into broad foraging (functional) groups based on their echolocation call structure: open-air; clutter-edge; and, clutter. To measure bat activity, we established twelve 25 ha grids randomly located in savanna and sugarcane vegetation. Within each grid we placed nine acoustic detectors, in 3 × 3 formation, 250 m apart; totalling 54 plots in each land use. We sampled each plot over four nights (two in the wet season and two in the dry season) during a one-year period. We did not observe a significant difference in species richness between savanna and sugarcane. However, there was a difference in functional group composition. Sugarcane negatively affected clutter foragers; this group was practically absent here despite occurring within neighbouring savannas. We observed distinct patterns of seasonality in bat activity, with activity of all functional groups being reduced in the dry season.  相似文献   

Field evidence for colony size and aseasonality of breeding and in Ansell’s mole-rat,Fukomys anselli (Rodentia: Bathyergidae)     

《African Zoology》2013,48(2):334-339

Ansell’s mole-rat, Fukomys anselli, is a cooperatively breeding bathyergid endemic to the Lusaka Province of Zambia. During a 12-month field study involving the capture of 33 colonies of mole-rats, the number of occupants, breeding females and sex ratio within colonies were recorded. While thirty of these social groups contained a single breeding queen, three were found to exhibit plural breeding among females, having two queens present simultaneously. Mean±S.E.M. colony size was 8.7±2.2 (range 6–16,n=33). The occurrence of plural breeding and small group size is consistent with the predictions of the aridity food distribution hypothesis for social species inhabiting mesic habitats. The sex ratio of the population was skewed towards females at 1.2:1. The mean mass of adult males was 63.0 ± 18.3 g (range 36.7–110.3, n=87) while that for adult females was 52.9±11.8 g (range 35.1–77.8, n=86). Pregnant and lactating females were found throughout the study period from February 2009 to February 2010, indicating an aseasonal pattern of breeding in this species. Autopsy of individuals (n=288) from the 33 colonies revealed a total of 19 pregnant females. Nine of these were in the latter stages of pregnancy and mean litter size was determined as 2.7 pups (range 1–4). Collectively, these new data reveal that Fukomys anselli share many similarities in life history and reproductive traits with the phylogentically closely related giant Zambian mole-rat, Fukomys mechowii.  相似文献   

A ram semen-collecting apparatus for mains or battery operation     

E.G. Upchurch 《New Zealand veterinary journal》2013,61(3):93-94

Extract

This stimulator has been designed to be used by veterinary surgeons who require an instrument that is portable and can be used, not only on the A.C. mains, but also in the field, where power is not available. The number of controls has been kept to a minimum and the overall size and weight reduced to enable the stimulator to be included easily in the veterinarian's equipment bag.  相似文献   

Foliar lifespan,phenology and seasonal dynamics of the invasive shrub Schinus terebinthifolia     

Brian N. Hogg  Keith Stokes  Min B. Rayamajhi  John Geiger  Paul D. Pratt 《Weed Research》2020,60(3):212-220

Schinus terebinthifolia is a dioecious tree native to South America that has become an invasive weed in Florida, southern California, southern Arizona, Texas and Hawaii and has been naturalised in over 20 countries. Biological control is considered a viable long-term control option for S. terebinthifolia because release from natural enemies appears to be at least partly responsible for its success in Florida. We examined leaf phenology of S. terebinthifolia over a period of 15 months at five sites in central and southern Florida to provide information that may help in predicting the impacts of potential biocontrol agents for this weed. We documented leaf lifespan, the seasonality of leaf development and abscission and the survivorship of leaves that emerged during either spring, summer or autumn. Average leaf lifespan was >4.5 months at all sites, and leaf phenology followed the seasons closely. Although S. terebinthifolia possesses leaves throughout the year, leaf production was greatest from April to September, and most leaves were abscised in February and March. Spring- and summer-emerging leaves were also longer-lived than leaves produced during autumn. These results suggest that leaves of S. terebinthifolia would be most vulnerable to herbivory during the spring and summer months when newly growing leaf tissue is most plentiful. Biocontrol agents capable of damaging these tissues during spring/summer might be an effective means of controlling this invasive weed.  相似文献