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1.
South African Angora goats (Capra aegagrus) are susceptible to stress conditions, possibly due to adrenal cortex malfunction. Selection for mohair production may reduce adrenal function and decrease cortisol production. Secretion of cortisol by the adrenal cortex is essential for the induction of several gluconeogenic enzymes that enable animals to survive stressful conditions, and adrenocortical insufficiency, therefore, precipitates a vulnerability to stress. In this study, Angora goats were compared with two breeds generally accepted as hardy, Boer goats (Capra hircus) and Merino sheep (Ovis aries). Adrenal steroidogenesis was studied using subcellular fractions prepared from the adrenal glands of freshly slaughtered animals. Adrenal microsomes and mitochondria were incubated with the relevant steroid substrates, and products were analyzed and quantified with TLC, HPLC, or RIA. Subsequently, the activity of individual enzymes involved in this pathway were further investigated. The cytochrome P450 content in the preparations was also compared. The results from these studies indicated that the activity of the cytochrome P450c17 enzyme in Angora goats differed (P < .01) from that of the other species investigated. This difference may contribute to the cause of the observed hypoadrenocorticism in Angora goats.  相似文献   

2.
Merino sheep in Thornveld, Dorper sheep and Angora goats in inland Valley Bushveld, Angora goats and Boer goats in Valley Bushveld on the coastal plateau, and springbok, Antidorcas marsupialis, and black wildebeest, Connochaetes gnou, in Karroid Mountainveld, all in the Eastern Cape Province, were examined for the larvae of nasal bot flies. The sheep and goats were infested with the larvae of Oestrus ovis, and Dorper sheep and Boer goats harboured more larvae than Angora goats on the same farms. Most infestation was present from November to May in Merino sheep in Thornveld, from February to June in Dorper sheep in inland Valley Bushveld, and from May to September in Angora and Boer goats in Valley Bushveld on the coastal plateau. These patterns of seasonality appeared to be regulated by the severity of the summer temperatures at the various localities. The springbok were infested with the larvae of Rhinoestrus antidorcitis, most of which seemed to mature from June to August. All larval sages of Oestrus variolosus and Gedoelstia h?ssleri were present in the black wildebeest, and large numbers of 1st instar larvae of G. h?ssleri appeared to accumulate on the dura of the wildebeest from June to August.  相似文献   

3.
Sheep scab mites, Psoroptes ovis, collected from a Merino donor sheep, were used to infest Merino and Dorper sheep, and Angora and Boer goats. Mites were placed on the sheep on 1 or 2 occasions and on 5 occasions on the goats. All the animals were examined at regular intervals for the presence of scab lesions and living mites. Both sheep breeds developed lesions, but those on the Merino sheep were always larger than those on the Dorper sheep at the same intervals after infestation. None of the goats developed lesions or showed signs of irritation, or harboured any mites.  相似文献   

4.
Angora goats do not cope well with stress compared with goats of other breeds. Our hypothesis that this involves subclinical primary hypoadrenocorticism associated with low cortisol release in response to ACTH stimulation was tested by measuring adrenocortical response (plasma cortisol) in six Spanish (37 +/- 2 kg BW) and six Angora wethers (39 +/- 3 kg BW) under simulated acute and chronic ACTH challenges. In Exp. 1 (acute ACTH challenge), wethers were dosed i.v. with high (2.5 IU/kg BW) or low (.4 IU/kg BW) quantities of ACTH. In Exp. 2 (chronic ACTH challenge), ACTH at the rate of .015 IU/(kg BW x min) or saline (.15 M NaCl) was infused i.v. at 15 mL/h for 6 h. The mean baseline plasma cortisol concentration before ACTH stimulation was similar (P > .05) between Angora and Spanish goats in Exp. 1 (averaged over days) and in Exp. 2. The cortisol concentration response area (ng/ (mL x min) x 10(-3)) above the baseline was similar (P > .05) between Angora and Spanish goats during low (7.6 +/- .5 and 9.0 +/- 1.7, respectively) and high (12.8 +/- 1.0 and 16.0 +/- 1.8, respectively) levels of acute ACTH challenge (Exp. 1) and during chronic ACTH challenge (45.1 +/- 5.9 and 41.8 +/- 7.3, respectively; Exp. 2). In conclusion, these data indicate that, under the conditions of this study, adrenocortical responsiveness to ACTH stimulation is not different between Angora and Spanish goat wethers and, thus, may not contribute to stress susceptibility in Angora goats.  相似文献   

5.
In a previous study, it was found that there are sex differences in goats with respect to the levels of cortisol secretion induced by transportation stress. We also found that treatment of castrated male goats with dihydrotestosterone (DHT) suppressed the increase in plasma cortisol concentration following transportation, but did not suppress the secretion of adrenocorticotropic hormone (ACTH). This suggests that androgen might block ACTH ‐ induced cortisol secretion. In order to examine this hypothesis, the effects of androgen on ACTH‐induced cortisol secretion in goats were investigated. First, castrated male goats were treated with testosterone (T), DHT or cholesterol (cho) for 21–25 days. Cho was used as a control for T and DHT treatment. Then, plasma cortisol concentrations were compared among the hormonal treatments after ACTH injection. Subsequently, the distribution of androgen receptors in the caprine adrenal gland was investigated. There were no differences in the basal cortisol concentrations among the hormonal treatments. However, plasma cortisol concentrations after ACTH injection were significantly lower in T ‐ and DHT ‐ treated goats than in cho ‐ treated goats. Androgen receptors were present in 60% of the cells in the zonae fasciculata and reticularis of the adrenal cortex, the regions that secrete glucocorticoids. These results suggest that androgen may act directly on the adrenal cortex to suppress cortisol secretion induced by ACTH.  相似文献   

6.
Inactivated vaccines for heartwater prepared with the commercially acceptable Montanide ISA 50 (ISA 50) adjuvant were field tested in Boer goats in Botswana, Angora goats in South Africa, and Merino sheep in Zambia and Zimbabwe. Two vaccines, one made using the Zimbabwean Mbizi isolate and the other using the respective local field isolate (Sunnyside in Botswana; Bathurst in South Africa; Lutale in Zambia), were tested at each site, except in Zimbabwe where only the Mbizi vaccine was tested. Compared with unvaccinated animals, the Mbizi vaccine significantly protected goats and sheep against field Amblyomma tick challenge in Botswana, Zambia and Zimbabwe (P = 0.018, 0.002 and 0.017, respectively), but failed to protect Angora goats in South Africa. However, in South Africa the vaccine prepared using the local field isolate Bathurst, induced significant protection (P=0.008). The vaccines containing the local isolates at all other sites were less protective than the Mbizi vaccine. The Mbizi inactivated vaccine also significantly protected 17 of 21 cattle (P = 0.05) against heartwater challenge from field ticks in Zimbabwe. Against the same challenge only 7 of 21 unvaccinated control cattle survived.This study demonstrates that heartwater is a major constraint to upgrading livestock in endemic areas, and caused an overall mortality of 77.6% in naive sheep and goats (97 of 125 died) and 67% in cattle (14 of 21 died). In contrast, the vaccine had a protective effect by reducing the overall mortality in sheep and goats to 54.3% (113 of 208 died) and to 19% in cattle (4 of 21 died).  相似文献   

7.
The development of veld research in the semi‐arid Karoo areas since 1934 is outlined. It entailed key experiments on different types of veld, and the synthesis of grazing systems and their testing in experimental camps and co‐operatively on a practical farming scale. The experiments were primarily conducted with Merino sheep but Angora goats, Boer goats, cattle and Persian sheep were also employed. A large number of rotational grazing systems, special treatments and methods have been set out for the entire Karoo Region. The group camp approach serves as a basis for complete veld management planning in the Karoo Region.

Supporting research covered plant physiological, phenological and ecological studies; the determination of selective grazing habits of livestock; production of karoo bushes; and the development of research techniques especially in connection with quantitative and qualitative vegetation surveys.  相似文献   

8.
The adrenal cortex is believed to be implicated in the high incidence of abortion in the Angora goat. Stimulation testing with adrenocorticotrophic hormone (ACTH) was used to assess the adrenal cortical function in 5 Angora does from herds with a history of abortion and 5 non-Angora does. An acute test involving a single intramuscular (i.m.) injection of 0.25 mg of synthetic ACTH was given during anoestrus, at mid-oestrus, on day 90 and on day 120 of gestation. Blood samples were collected from the jugular vein at 30 min intervals for 1 h before and 5 h after injection. Cortisol concentrations rose within 30 min and returned to baseline values within 3.5 h. Cortisol production was lower (p<0.01) in the pregnant state compared to the non-pregnant state in both groups. Production of cortisol was consistently lower (p<0.05) in the Angora does compared to the non-Angora does during anoestrus and pregnancy and marginally so at mid-oestrus. A chronic stimulation test involving once daily injections of 0.5 mg of a depot form of ACTH i.m. for 7 days commencing on day 90 of pregnancy was also conducted. Cortisol concentrations rose to reach a peak on the third day of treatment in both groups. The values then declined in the Angora does despite continued ACTH treatment, while those for the non-Angora does exhibited a second peak. During and following this treatment, two non-Angora does delivered live kids (day 95, day 120). Out of 7 Angora pregnancies, one Angora doe aborted two dead fetuses at day 116. No significant difference in the cortisol response in the acute test was detected between the animals that aborted and their respective cohorts, but the two non-Angora does that aborted had significantly lower cortisol concentrations during depot ACTH administration. Progesterone and oestradiol levels did not differ between Angora and non-Angora animals during pregnancy or on the test days. The results suggest that the steroidogenic response of the adrenal cortex to ACTH stimulation is significantly less in Angora does with a history of abortion than it is in non-Angora does and support the view that the Angora goat would make a more limited adrenal cortical response to a stressful occurrence during pregnancy.  相似文献   

9.
Body condition scoring is widely used for sheep and cattle but the practice is included in only one Code of Practice for the welfare of goats in Australia. There is no published scientific evidence to support or defend its use in the assessment of welfare risks to farmed goats. PROCEDURE: The significance of stocking rate, grazing system, body condition score (CS) and live weight were investigated in explaining the risk of mortality of individual and flocks of grazing Angora goats from hypothermia following a severe weather event in April. This event occurred 5 weeks after shearing the goats. Angora goats and Saxon Merino sheep were grazed alone, or mixed together in equal numbers at each of three stocking rates. RESULTS: There was no mortality amongst Angora goats provided they grazed at the lowest stocking rate even when their CS was < or = 2.0. Mortality in flocks of Angora goats was most related to the CS reached during the preceding 2 months. For flocks of Angora goats there was no mortality at CS > or = 2.5 and mortality increased sharply at mean CS < 2.0. For individual Angora goats, mortality increased as CS declined and stocking rate and grazing combinations were additive in effect on mortality. Grazing with sheep increased mortality of Angora goats at higher stocking rates. The individual goat mortality rate was not dependent on individual plot effects suggesting that these results are applicable widely. Live weight loss was not related to mortality rates of goats once CS had been accounted for. CONCLUSION: It was concluded that CS and stocking rate were highly significant determinants of welfare risk in Angora goats.  相似文献   

10.
The number of Boer crossbred meat goats has been increasing rapidly, although how their growth and slaughter traits compare with those of Spanish goats and influences of maternal genotype have not been thoroughly evaluated. This information would be useful to achieve optimal meat goat production systems and yield of goat products desired by consumers. Therefore, postweaning growth (9 to 24 wk of age) and slaughter traits (212 +/- 5.0 d of age) of Boer x Spanish, Spanish, and Boer x Angora wethers (n = 16, 18, and 18 for growth measures, respectively, and n = 6 per genotype for slaughter traits) consuming a concentrate-based diet were compared. Over the 16-wk performance period, ADG, DMI, and ADG:DMI were greater (P < 0.05) for Boer crossbreds than for Spanish goats (ADG: 154, 117, and 161 g; DMI: 646, 522, and 683 g/d; ADG:DMI: 263, 235, and 261 g/kg for Boer x Spanish, Spanish, and Boer x Angora, respectively). Dressing percentage (46.3, 47.3, and 47.0% of BW; SE = 1.21) and quality grade score (11.17, 9.67, and 11.17 for Boer x Spanish, Spanish, and Boer x Angora, respectively; SE = 0.66 [12 = Choice+; 11 = Choice; 10 = Choice-; 9 = Good+]) were similar among genotypes. Weights of some noncarcass components were greater for Boer crossbreds than for Spanish goats, but relative to empty BW, noncarcass component weights were similar among genotypes. Concentrations of moisture, ash, fat, and protein in carcass and noncarcass components did not differ among genotypes. Contributions to the carcass of different primal cuts were similar among genotypes, and there were few differences in concentrations of separated lean, bone, and fat in primal cuts. In conclusion, when consuming a concentrate-based diet, early postweaning growth rate was similar between Boer x Spanish and Boer x Angora wethers and greater for Boer crossbreds than for Spanish wethers. Slaughter traits were primarily related to differences in final BW.  相似文献   

11.
Angora goat, Spanish goat, and Suffolk x Rambouillet sheep wethers (20 of each type; 30.4+/-.57, 31.3+/-.93, and 32.4+/-1.08 kg BW for Angora goats, Spanish goats, and sheep, respectively) were used to investigate influences of animal type and two grass-based pasture treatments on heat energy during summer grazing (mid-August through September in Oklahoma). The improved pasture treatment consisted of .7-ha paddocks primarily of Old World bluestem and johnsongrass, whereas the native pasture treatment entailed 10.8-ha paddocks dominated by big and little bluestems and indiangrass. Grasses were 95 to 100% of diets for the improved pasture treatment and 71 to 95% for the native pasture treatment; forbs were 2 to 25%, and shrubs were less than 4% of diets for the native pasture treatment. Metabolizable energy intake was similar (P > . 10) between pasture treatments but differed (P <.01) among animal types: 79, 99, and 113 kcal/(kg(.75) BW.d) for Angora goats, Spanish goats, and sheep, respectively; SE 7.1. Heat energy estimated via CO2 entry rate was affected by pasture treatment ( P = .08) and animal type (P < .001): improved pasture treatment 109, 132, and 151 kcal/(kg(.75) BW.d); native pasture treatment 126, 138, and 163 kcal/(kg(.75) BW.d) for Angora goats, Spanish goats, and sheep, respectively. Likewise, daylight grazing time was greater (P = .04) for the native than for the improved pasture treatment and differed (P < .01) among animal types: improved pasture treatment 5.3, 4.7, and 6.7 h; native pasture treatment 6.0, 5.7, and 8.1 h for Angora goats, Spanish goats, and sheep, respectively. In conclusion, heat energy during summer grazing of grass-based paddocks was less for goats than for sheep, and animal type can affect the increase in heat energy as energy intake and grazing time increase.  相似文献   

12.
Helminth parasites were collected from 13 grysbok, Raphicerus melanotis, 12 common duikers, Sylvicapra grimmia, 24 Angora goats and 24 Boer goats killed on a farm in Valley Bushveld in the eastern Cape Province. Nematodes belonging to 9 species and a further 2 genera and cestodes belonging to 1 species and a further genus were recovered from the grysbok. Of these, worms of the genus Skrjabinema, Trichostrongylus rugatus, Trichostrongylus pietersei and Nematodirus spathiger were the most prevalent and the most numerous. An amended list of the helminths of grysbok is included. Seven nematodes, identified to species and 1 identified to genus were recovered from the common duikers. N. spathiger and Setaria scalprum were the most prevalent, while N. spathiger and Trichostrongylus axei were the most abundant. The Angora goats were infested with at least 10 nematode species and 2 cestodes and the Boer goats with at least 14 nematode species. With the exception of Trichostrongylus pietersei, the Boer goats harboured more nematodes of each species than did the Angora goats. Nematodirus spp. and worms of the genus Skrjabinema were most numerous in Angora goats, and Nematodirus spp. and Teladorsagia circumcincta in the Boer goats. No clear pattern of seasonal abundance was evident for any of the helmith species in the various hosts.  相似文献   

13.
OBJECTIVE: To determine whether basal serum or plasma cortisol concentration can be used as a screening test to rule out hypoadrenocorticism in dogs. DESIGN: Retrospective case-control study. ANIMALS: 110 dogs with nonadrenal gland illnesses and 13 dogs with hypoadrenocorticism. PROCEDURES: Sensitivity and specificity of basal serum or plasma cortisol concentrations of either 2 microg/dL that are not receiving corticosteroids, mitotane, or ketoconazole are highly unlikely to have hypoadrenocorticism. However, if the basal cortisol concentration is 相似文献   

14.
Four groups of goats, Boer x Spanish, straightbred Spanish, Spanish x Angora, and straightbred Angora were slaughtered at a constant age according to accepted industry procedures. At 24 h postmortem, various carcass yield and quality measurements were taken. At 48 h postmortem, one side from each carcass was fabricated into major wholesale cuts for dissection into percentage lean, bone, and fat. Rib chops from the opposite side were fabricated, packaged, and displayed in a retail case. Trained panelists evaluated the rib chops over 4 d of retail display for lean color, surface discoloration, and overall appearance; packages were opened and analyzed for off-odor on d 4. When slaughtered at constant ages, Angora goats had lighter (P < .05) live and hot carcass weights than all other breed types, and Boer x Spanish goats had heavier (P < .05) live and carcass weights than Spanish goats. Live and carcass weights for Boer x Spanish and Spanish x Angora goats did not differ (P > .05). Carcasses from Angora goats had considerably smaller (P < .05) longissimus muscle areas than all other breed types. Carcasses from Spanish goats had lower (P < .05) carcass conformation scores than carcasses from Boer x Spanish goats but did not differ (P > .05) from carcasses of the other two breed types. Carcasses from Angora goats had smaller (P < .05) leg circumferences than the carcasses from Boer x Spanish and Spanish x Angora breed types. In general, carcasses from Boer x Spanish and Spanish goats possessed higher (P < .05) percentages of lean and lower (P < .05) percentages of fat for the side than did carcasses from Spanish x Angora and Angora goats. When the Spanish x Angora carcasses were compared to the Angora carcasses, it seemed that the addition of the Spanish breeding tended to increase lean and decrease fatness for most side or primal comparisons. There were no (P > .05) breed type or breed type x day effects for lean color, surface discoloration, overall appearance or off-odor; however, day of display did influence (P < .05) these traits. Crossing Spanish with Angora goats may be an option to improve carcass characteristics over that of straightbred Angora.  相似文献   

15.
Worm egg counts of yearling Angora or Merino wethers grazing in mixed flocks at either 4/ha or 8/ha were observed over a 5 month period. Based on faecal egg counts infection levels in the sheep increased for the first 3 months and then decreased as the animals developed resistance. Egg counts in the goats did not decrease during the experiment. Post mortem worm counts indicated that there was a significant host species--stocking rate interaction on worm burdens of Haemonchus contortus adults and Ostertagia circumcincta adults and larvae. Goats had more H. contortus and O. circumcincta adults than sheep at the 8/ha stocking rate. At 4/ha goats had fewer O. circumcincta fourth stage larvae than sheep. There was no stocking rate effect on the numbers of Trichostrongylus axei or T. colubriformis. Sheep had more T. axei and fewer T. colubriformis than goats.  相似文献   

16.
Ten male, juvenile pigmy goats of similar age and weight were allocated randomly to two groups. Goats in one group were each inoculated with 20,000 infective larvae of Haemonchus contortus. The other group served as uninfected controls. Goats were housed together, and precautions were taken to avoid the creation of differential, between group, stressogenic circumstances. Body weights, nematode egg production, hematocrits, and clinical signs were monitored over a 61-day period following inoculation of larvae. On Days 59 and 61, adrenal response tests (ART) were conducted by measuring the levels of plasma cortisol before and 2 h after administration of porcine ACTH at the rate of 0.35 I.U. kg-1 body weight on Day 59 and 2.2 I.U. kg-1 on Day 61. Although the infections did not reduce body weights, they were 'heavy' on the basis of egg production, and led to significant reductions in packed erythrocyte volumes. There was no significant difference between the groups of goats in the responses to ART, indicating that the infections did not produce sufficient stress to reduce the ability of the adrenal cortex to respond to exogenous ACTH.  相似文献   

17.
Anatolia has been an important region for civilizations and agricultural revolution as a major domestication centre for livestock species. Goats (Capra hircus) were among the earliest domesticated animals in this region. In this study, genetic diversity of Anatolian goat breeds was characterized by comparison of mitochondrial DNA hypervariable region 1. A total of 295 individuals, including 99 Anatolian Black goats, 96 Angora goats and 100 Kilis goats, were used. Haplogroup A was found to be the dominant haplogroup in all three breeds. The highest haplogroup diversity, including haplogroups A, B2, C and G, was observed in the Anatolian Black breed. Haplogroup D was only observed in Kilis and Angora goats. Haplogroup G was found in Angora and Anatolian Black breeds. The Anatolian goat breeds had high genetic diversity values and a weak phylogeographical structure. The nucleotide diversity values were found to be higher than those in previously studied goat breeds. The fact that Anatolia is a domestication centre and its geographical position as a junction of trade routes may have caused the higher genetic diversity of Anatolian goat breeds.  相似文献   

18.
4个引进山羊品种mtDNA控制区序列变异和系统发生关系研究   总被引：5，自引：2，他引：5  
本研究测定了四川4个引进山羊品种24个个体的线粒体控制区全序列,并从GenBank获得山羊属2个野山羊种的2每控制区序列。利用MEGA2．0软件构建分子系统发育无根树。序列分析表明:山羊控制区线粒体控制全序列长度为1 212bp或1 213 bp,A+T含量占59．9％,其中64个核苷酸位点存在变异(约占5．28％),核苷酸多样度为 1．731％,这些差异共定义了16种单倍型,单倍型多样性为0．913±0．048。安哥拉山羊、波尔山羊都有自己独特的单倍型,与其他品种间都没有共享类型。使用NJ法构建了系统发育树,结果表明:2个野山羊种中,角(?)羊与家养山羊的关系相对较近,4个家养山羊品种有2个母系来源,在4个家养山羊品种内部,安哥拉山羊的分化要比其他3个品种早。  相似文献   

19.
设计4对引物,采用PCR-SSCP技术检测骨形态发生蛋白2（bone morphogenetic protein 2,BMP2）基因外显子2、3在济宁青山羊、安哥拉、波尔、内蒙古绒山羊4个品种共191个个体中的单核苷酸多态性,分析该基因对济宁青山羊高繁殖力的影响,并对济宁青山羊BMP2基因2个外显子进行克隆测序。结果表明,4对引物的扩增片段在4个山羊品种中均无多态性;山羊扩增片段核苷酸和氨基酸序列与人、黑猩猩、牛、犬、大鼠、小鼠6个物种的同源性分别为86.5%～91.3%和88.8%～99%;与其他物种相比,山羊BMP2扩增片段推导氨基酸序列存在3处特有突变,分别是位于第131、353、365位的脯氨酸、缬氨酸、亮氨酸变为苏氨酸(P131T)、天冬氨酸(V353D)、脯氨酸(L365P)。可见,哺乳动物BMP2基因外显子2、3序列保守性强,该区域可能不是影响山羊高繁殖力的功能结构域。  相似文献   

20.
山羊BMP15基因FecX-L突变的检测   总被引：2，自引：0，他引：2  
采用PCR-SSCP方法在高繁殖力山羊品种（济宁青山羊、波尔山羊和文登奶山羊）和低繁殖力山羊品种（内蒙古绒山羊、安哥拉山羊和辽宁绒山羊）中检测骨形态发生蛋白15(bone morphogenetic protein 15,BMP15)基因的FecX-L突变,同时研究该基因突变对济宁青山羊高繁殖力的影响。结果表明这6个山羊品种都没有发生与Lacaune绵羊相同的FecX-L突变（C53Y）。可见BMP15基因中影响Lacaune 绵羊高繁殖力的突变位点对济宁青山羊的高繁殖力没有显著影响。  相似文献   

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