The effect of T. vivax infection in West African Dwarf goats on energy and nitrogen metabolism

Summary

To investigate how T. vivax affects metabolism in dwarf goats, nine wethers (infection group) given alfalfa pellets ad libitum were infected intravenously and food intake was recorded up to 49 days after infection in the infection group and in the control group (n=9). Controls received the same diet, ad libitum before infection and in restricted amounts after infection in order to obtain similar intakes in the two groups. Digestible organic matter intake (DOMI) and nitrogen balance (NB) were determined during four balance trials. All animals were bled regularly to measure parasitaemia, packed cell volume (PCV) and a number of serum metabolites.

All infected animals showed symptoms typical for T. vivax infection as judged by parasitaemia, PCV and rectal temperature. Infection had a non‐uniform negative effect on food intake. Compared with controls at equal DOMI, NB was lower in infected animals, the difference being significant 4 weeks after infection. This was caused by a gradual increase in NB at equal DOMI of the control group. The NB of the ad libitum fed infected animals 2 and 4 weeks after infection was comparable to values normally found in healthy ad libitum fed dwarf goats with an equal DOMI.

NEFA values in serum were significantly elevated after infection. Except for two infected animals with an extremely low food intake towards the end of the experiment, no rise in serum ketone bodies was evident. After infection, serum protein increased, differences with controls being significant 4 and 7 weeks after infection.

It is concluded that T. vivax infection results in a decrease in energy intake and a decrease in NB up to at least 4 weeks after infection. At equal DOMI, NB of infected animals was not lower than expected for ad libitum fed healthy animals but was lower than in healthy controls on a restricted diet, probably as a result of a decrease in maintenance requirements of the latter. The data on NB and serum NEFA concentrations suggest that non‐protein energy sources are used to supply the increased energy demand as a result of infection.     

Blood Polymorphism in West African Breeds of Sheep

This paper reports the blood groups and blood protein distribution in West African sheep breeds. About 100 animals of the Djallonke, Fulani and Touabire breeds were sampled for blood polymorphism analysis. Their blood groups were typed by haemolytic and agglutination reactions, and their blood proteins by starch gel electrophoresis. Almost all the loci analysed showed variability in the three breeds, with the Touabire and Fulani being closer to each other than to the Djallonke.     

Milk production of West African Dwarf goats in The Gambia

Goats are important in the low-input systems of West Africa and their main importance lies in their role for income and saving. In addition, it is known that milk offtake for home consumption is also important. In order to obtain information about the real importance of milk offtake, a recording scheme was operated in 27 villages in the Central River Division of The Gambia from July 1998 until January 2000. Detailed information was obtained from about 1500 kiddings. In the recording scheme, any sheep being milked as well as the goats of the International Trypanotolerance Centre nucleus flock were also recorded. In the villages, 36% of all lactations were used for milk offtake, but the fraction milked was lower for the first two lactations. The average length of lactation was 127 days and the average daily milk offtake was 0.18 L. Goats are milked once a day and the residual milk is left for the kids. Milking starts about one week after parturition and stops when the goat becomes pregnant or the kid(s) die or the goat is drying off. The repeatability of the 90-day milk offtake was 0.24 ± 0.09. Sixty-five percent of goat owner were women and a large fraction of goat owners also owned cattle. Goat milk was used exclusively for home consumption. It is concluded that in breeding and extension work more attention should be given to aspects of milk production.     

Village production of West African Dwarf goats and sheep in Nigeria

Results from a 41 month study of West African Dwarf goats and sheep under village conditions in south-west Nigeria are reported. Even at a very low level of management these trypanosomiasis-tolerant animals produced 2.01 kids or 1.51 lambs per dam per year. Mortality of young particularly kids and low growth rates limit production. Of these mortality is probably the first constraint to increased productivity and profitability. Control of peste des petits ruminants appears to significantly reduce mortality and should stimulate the further development of this production system.     

Radiographic Study of Postnatal Development of the Tarsus in West African Dwarf Goats

Seven goats of the West African dwarf breeds, three females and four males, from the same farm were studied by serial radiography from the first week of life and at 3, 6, 9, 16, 23, 28, 37 and 46 weeks of age. The radiological appearance of the developing tarsus as Avaluated from radiographs is described. During the first week postnatally, eight loci were observed to be partially ossified. The talus, tarsi centrale (Tc), first (T1), second (T2), third (T3) and fourth (T4) tarsal bones had each a single loci. The calcaneus bone had two loci, one for the tuber calcanei and another for the calcaneus himself. Fusion of the locus for T2 and T3 was evident in radiographs taken at three weeks. The fused T2 + T3 also appeared fused with die Tc in one of the goats at 23 weeks. The Tc and T4 were observed to fuse in only three of the goats at 23 weeks while in others the bones remained separate throughout the study period. In those goats where the Tc and T4 tarsal bones were not fused, the three tarsal joints were linked by a radiolucent line between these bones. While in the goat where Tc and T2 + T3 bone fusion has occurred the distal intertarsal joint was blocked and the proximal intertarsal was communicating with the tarso metatarsal joint between the separate Tc and T4. The tarsus of the goat is variable and differs from that of sheep and cattle.     

Comparison of assays for the detection of West Nile virus antibodies in chicken serum

Six tests for the detection of West Nile virus (WNV) antibodies in the serum of experimentally infected chickens were compared. The tests included the hemagglutination-inhibition test (HIT), immunoglobulin M (IgM)-capture enzyme-linked immunosorbent assay (ELISA) with WNV-infected mouse brain antigen, immunoglobulin G (IgG) indirect ELISA with tickborne encephalitis viral antigen, the microtitre virus neutralization test, the standard plaque reduction neutralization test (PRNT), and the microtitre PRNT (micro-PRNT). Thirty adult chickens, intravenously and intramuscularly inoculated with 10⁷ plaque-forming units (PFU) of WNV strain Egypt 101, were bled and given a booster of 10⁷ PFU at 7, 15, and 21 d postinoculation; the final blood collection was on day 28. Although the micro-PRNT is capable of detecting the highest antibody titres during both early and late infection, because of the technical complexity and time requirements of this test a combination of IgM and IgG ELISAs is recommended for serologic screening. Serum samples that give positive results in the ELISAs can then be tested by the micro-PRNT to determine the specificity of antibodies to WNV.     

Seasonal changes and hypobiosis in Haemonchus contortus infection in the West African Dwarf sheep and goats in the Nigerian derived savanna

A survey was conducted in the Nigerian derived savanna (from August 1987 to July 1988) on the seasonal fluctuations in the composition of Haemonchus contortus burden of naturally infected West African Dwarf sheep and goats. During this period 117 abomasa collected from locally slaughtered animals were processed. Male, female as well as immature worms were enumerated. The incidence of Haemonchus infection was high (77.8-100%) with no definite seasonal distinction. There was however, a clear seasonal trend in the worm burden of animals; higher burdens were evident during the rainy rather than the dry season. There was no significant hypobiosis; Haemonchus contortus survived in the host during the unfavourable dry season (November to March) as adults.     

Prevalence of feline leukemia virus infection and serum antibodies against feline immunodeficiency virus in unowned free-roaming cats

OBJECTIVE: To determine prevalence of FeLV infection and serum antibodies against feline immunodeficiency virus (FIV) in unowned free-roaming cats. DESIGN: Cross-sectional serologic survey. ANIMALS: 733 unowned free-roaming cats in Raleigh, NC, and 1,143 unowned free-roaming cats in Gainesville, Fla. RESULTS: In Raleigh, overall prevalence of FeLV infection was 5.3%, and overall seroprevalence for FIV was 2.3%. In Gainesville, overall prevalence of FeLV infection was 3.7%, and overall seroprevalence for FIV was 4.3%. Overall, FeLV prevalence was 4.3%, and seroprevalence for FIV was 3.5%. Prevalence of FeLV infection was not significantly different between males (4.9%) and females (3.8%), although seroprevalence for FIV was significantly higher in male cats (6.3%) than in female cats (1.5%). CONCLUSIONS AND CLINICAL RELEVANCE: Prevalence of FeLV infection and seroprevalence for FIV in unowned free-roaming cats in Raleigh and Gainesville are similar to prevalence rates reported for owned cats in the United States. Male cats are at increased risk for exposure to FIV, compared with female cats.     

Comparative Structure and Morphology of the Goat Sternum in West African Dwarf and Danish Landrace Breeds

The structure and morphology of the sternum from 33 West African dwarf (WAD) and sixteen Danish Landrace breed goats were studied radiographically. In young kids of the Danish Landrace breed (DL), the number of sternal elements (Sternebrae) was six or seven with the fifth or the last but one being double in some animals due to bilateral bodies. All the sternal elements in the WAD breed appeared to have each a single locus of ossification and the number of sternal elements varied between 5, 6 or 7 at birth. In those goats with 5 or 6 sternal segments, bilateral indentations were observed on the left and right side on either the last or the last two segments. These indentations were considered to indicate a prenatal cranial coalescence of the last segments leading to the reduced number of sternebra. The structure and morphology of the sternum in neonatal kids for the two breeds appears to be basically different. 8 sternal and 5 asternal ribs were observed in animals of both breeds. The cartilaginous attachments of the ribs on the sternal segments were variable. A floating rib was also observed in one of the WAD goats. The comparative structure and morphology of other ruminant sternum is also discussed.     

Wesselsbron disease: a cause of congenital porencephaly and cerebellar hypoplasia in calves

Fifteen pregnant cows were inoculated subcutaneously and intravenously between 101-147 days of gestation with the wild-type Wesselsbron disease virus. In addition, 2 foetuses were injected directly through the uterine wall after surgical exposure of the pregnant horn. The clinical symptoms, viraemia and serology in the cows are reported, as also the gross- and histopathology and the virological and serological results of the calves and foetuses. Abortion was not an important manifestation of experimental Wesselsbron disease in cows, as it occurred in 3 animals only. Apart from a short temperature reaction in some cows no other clinical symptoms were recorded. A viraemia was not always present in these cows and, when detected, was of low magnitude and short duration. One cow, in which the foetus was ioculated at 115 days of gestation, aborted at 231 days. The foetus showed marked porencephaly and cerebellar hypoplasia.     

Situation of serum antibodies against Newcastle disease virus in slaughter-age ostriches after vaccination campaign in Japan

A total of 516 slaughter-age ostrich sera were collected in Japan during 2006-2009. Sixty-one of five hundred and sixteen were positive by virus neutralization (VN) test and the titer of most positive samples was low level. Within the 61 positive sera, 35 sera were collected from unvaccinated ostriches. This result implies that these ostriches might have been infected naturally with low-virulent Newcastle disease virus (NDV). Within the 455 negative samples, 125 samples were from vaccinated ostriches. Since ostrich farmers use live attenuated vaccines, it is reasonable that the titer decreased to below detection level by 1 or 1.5 year-old. The above data indicate that NDV has infiltrated into ostrich farms in Japan, and that the efficacy of ostrich ND vaccination is often time-limited.     

鸡传染性法氏囊病毒感染对B淋巴细胞线粒体能量代谢的影响

为研究鸡传染性法氏囊病毒(IBDV)感染对宿主免疫细胞线粒体代谢的影响和从代谢方面揭示致病机制,本试验以IBDV毒株感染DT40细胞,分别于病毒感染后24,48,72和96h取样,细胞计数并分离细胞线粒体,通过线粒体染色,检测线粒体蛋白含量,线粒体膜电位,线粒体ATP水平,肉碱脂酰转移酶和NADH-CoQ还原酶活性,线粒体脂酰-CoA和NADH、NAD+的含量及NADH/NAD+比值,初步评估IBDV感染对宿主细胞线粒体生物氧化的影响。结果表明,IBDV感染DT40细胞48h后,线粒体蛋白含量显著降低(P0.01),肉碱脂酰转移酶和NADH-CoQ还原酶活性在感染后24h开始下降(P0.05),48h后显著被抑制(P0.01);脂酰-CoA和ATP含量在感染后48h显著降低(P0.01),NADH/NAD+比值显著增高(P0.01)。说明IBDV感染DT40细胞后不但对线粒体造成了损伤,而且脂酰CoA的转运和NADH呼吸链受到抑制,导致线粒体能量代谢障碍。本研究从代谢角度为进一步探索IBDV感染对鸡细胞的致病机理提供依据。     

Effect of diffferent levels of maternally derived antibodies on protection against infectious bursal disease virus

Fertile eggs were obtained from three different broiler breeder flocks with different levels of virus neutralizing antibodies to infectious bursal disease virus. Egg yolk from these flocks was tested for antibody titers by the virus neutralization test. Flock I eggs had no antibodies, flock II had medium level antibodies (1:200-1600; geometric mean = 1:975), and flock III had a high level of antibodies (1:1600-6400; geometric mean = 1:3365). Chicks from the above flocks were challenged each with 10(2) 50% embryo infective dose of the IN serotype 1 variant virus at 1, 2, and 4 wk of age and examined at 5 and 11 days postchallenge. The average organ/body weight ratios were calculated and statistically analyzed. Chicks with no maternal antibodies were not protected at any age. Chicks with medium levels of maternal antibodies were protected when challenged at 1 and 2 wk of age. Chicks with high levels of maternally derived antibodies were protected when challenged at all the ages tested. The above results were statistically significant (P < 0.05).