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61.
Previously, the structure of the adult goat parotid salivary glands (PGs) was studied. However, little information was elucidated of the juvenile ones. This study aimed to clarify the correlations between the structure of goats' PGs and the nature of food intake among milk‐suckling kids (MSKs) and diet‐fed goats (DFGs). The secretory endpieces of the goats' PGs are of the pure serous type. The serous cells in MSKs showed apical accumulation of numerous secretory granules (SGs) of smaller size and of more intense positive periodic acid‐Schiff reaction. Ultrastructurally, most of the SGs in the DFGs contained peripherally located inclusions that showed dense reaction products for acid phosphatase. In MSKs, the PGs showed less‐developed basal infoldings, sparseness of the inter‐cellular inter‐digitations, fewer inter‐cellular canaliculi and microvilli and also less‐developed myoepithelial cells with fewer and shorter cytoplasmic processes. In conclusion, the less‐developed membrane specializations and myoepithelial cells, as well as the accumulated SGs in the PGs of MSKs, suggest that it secretes less saliva with a little secretory activity than that of DFGs, which may be correlated with the reduced masticatory activity.  相似文献   
62.
A survey of aldicarb poisoning in companion animals was conducted by posting questionnaires to all private practitioners in Gauteng Province, South Africa. The survey was designed to determine the percentage of aldicarb cases seen, treatment regimen, clinical signs observed, proposals for preventative actions and more effective treatments. Other questions included duration of treatment, survival rate, cost to clients, post mortem findings and reasons for poisonings.  相似文献   
63.
Global climate change is expected to influence the distribution of global biodiversity. C4 and C3 perennial grasses co-occur in the fire-prone KwaZulu-Natal uKhahlamba-Drakensberg grasslands, with C3 grass species occurring at cooler locations in the mountain range and C4 grass species at warmer locations. If a warming climate is expected to cause a contraction in the ranges of C3 grasses, evidence of temperature controlling current distributions is required. This study modelled the distribution of five C3 grass species, namely Tenaxia stricta, Tenaxia disticha, Festuca costata, Merxmuellera drakensbergensis and Merxmuellera stereophylla, to temperature-related surrogate variables using presence–absence data collected across the environmental heterogeneity of the mountain range. Distributions of each species, and of all species combined, were modelled using generalised additive models. These temperature-related variables accounted for the distribution of all five species, least so for F. costata. Four species could therefore contract in range in response to climate change, whereas F. costata is least likely to have a range contraction directly related to a warming climate and could experience a range expansion owing to the fertilising effect of increased [CO2].  相似文献   
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The purpose of this study was to compare the sexual performance of rams that differed in age (maturation) and sexual experience. Twenty-four ram lambs (8 mo of age) and 21 rams (20 mo of age) were individually exposed to four females in hormonally induced estrus for 30 min on five occasions, 7 d apart. Half (12) the ram lambs and nine of the yearlings were sexually naive at the start of testing (had been denied access to females since weaning); the remaining males were sexually experienced. The sexual performance of the virgin rams was poorer during the initial exposure to females than in subsequent tests, whereas the sexual behavior of the sexually experienced males did not change over the days of testing. Sexually naive ram lambs and rams exhibited an improvement in sexual performance between Tests 1 and 2; during Test 3 to 5 the sexual performance (ejaculations per test) of sexually naive and experienced rams was similar. The only effects of age (maturation) on sexual performance during the last three test days were a higher frequency of mounts without ejaculation plus mount attempts (P less than .03) and a greater number of mount interactions per ejaculation (P less than .02) by ram lambs. In conclusion, one or two relatively brief exposures to estrous females can bring the sexual performance of virgin rams up to levels comparable to that of experienced males. Also, ram lambs in good condition exhibit acceptable levels of sexual performance.  相似文献   
67.
Development of sexual and aggressive behaviors in Hereford bulls   总被引:1,自引:0,他引:1  
The purpose of this study was to describe maturation-related changes in the sexual and aggressive behaviors of Hereford bulls. Two groups of 13 and 14 bulls, respectively, were tested for sexual and aggressive behaviors every 3 mo from 3 to 24 mo of age. At 3 and 6 mo of age, the bulls were exposed, as groups, to two estrous females, whereas at 9, 12, 15, 18, 21, and 24 mo these bulls were tested under each of the following several treatment conditions: 1) individual tests (single males were exposed to single females), 2) small-group tests (three or four bulls:three females), 3) large-group tests (13 or 14 bulls:3 females), and 4) male-only tests (13 or 14 bulls were placed in the test arena in the absence of females). Most bulls consistently mounted females by 9 mo of age. Twenty-one of the 27 bulls (78%) attained their first ejaculation at either 12 or 15 mo of age. The frequency of mounting without ejaculation was greatest in large-group tests at 12 mo of age, and ejaculation frequency peaked at 18 mo. The incidence of male-male mounting in large-group tests (with females) did not appreciably change from 3 to 24 mo, whereas male-male mounting in male-only tests was greatest at 9 and 24 mo. We conclude that sexual performance data obtained in serving capacity tests administered to yearling bulls before 18 mo of age may underestimate the mating potential of certain individuals.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
68.
The incidence of dermatitis and otitis resulting from overgrowth of M. pachydermatis is great enough that cytological sampling techniques should be considered a routine part of the dermatological examination. Because most cases of MD and Malassezia otitis cannot be grossly distinguished from bacterial pyoderma and otitis, respectively, efficiency in performing cytology testing of skin and ear canal exudate is essential to the successful diagnosis and management of pruritic skin diseases and otitis. Although Malassezia infections are rarely primary, therapy can be instituted to remove the yeast as a confounding factor while a differential diagnosis is pursued in evaluating the underlying disease process.  相似文献   
69.
The aim of this research was to observe the effects of cyclophosphamide and its uroprotective agents, mesna and hyperbaric oxygen (HBO), on the motility of urinary bladder muscle in guinea pigs. In the experimental groups, mesna and cyclophosphamide were intraperitoneally injected at a dose of 21.5 mg/kg and 68.1 mg/kg, respectively. For the combination of mesna and cyclophosphamide, one dose of mesna was injected 20 min before cyclophosphamide administration and three additional injections of mesna were repeated every three hours. A total of 8 HBO exposures were performed at 2.8 ATA for 90 min twice daily for another experimental group. In the HBO and cyclophosphamide combined group 5 HBO exposures were given prophylactically before cyclophosphamide. The combination of mesna, HBO and cyclophosphamide was administered by the same procedure. The contractions obtained in response to acetylcholine (ACh, 10(-4) M) in the control group were reduced using cyclophosphamide and HBO individually, but not by mesna. However, the contractions belonging to the various combinations of these three agents were not different from those seen in the control group. On the other hand, the combinations of cyclophosphamide, mesna and HBO showed higher responses to ACh than the groups in which cyclophosphamide and HBO were used individually, while the responses elicited by the cyclophosphamide and HBO combination were greater than those seen in the group treated with HBO only.  相似文献   
70.
Cells infected by Newcastle Disease Virus were observed to contain both intracytoplasmic and intranuclear inclusion bodies. Ultrastructurally, they consisted of twisted strands of about 18–20 nm diameter resembling nucleocapsids. The presence of these inclusions was detected irrespective of host cell or pathogenicity of the virus. In immunofluorescence and immunogold labelling experiments, these structures were tagged by an anti-P protein monoclonal antibody. In summary, we show that intracytoplasmic and intranuclear inclusion bodies, hitherto used as a taxonomic characteristic for the genus Morbillivirus of the Paramyxoviridae, also occur in a member of the genus Rubulavirus.  相似文献   
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