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.     

The effect of dietary protein supplementation on the pathophysiology of Haemonchus contortus infection in West African Dwarf goats

The effect of dietary protein on the pathophysiology of Haemonchus contortus infection in reproducing first pregnancy West African Dwarf (WAD) goats was studied. Eighteen 10-12-month-old pubertal female WAD goats divided into two equal groups were used and confined separately. One group was maintained on high-protein diet (HPD) while the other was maintained on low-protein diet (LPD) from day 1 of pregnancy up to week 6 post-partum. Each animal was infected with 600 infective larvae of H. contortus weekly for 4 weeks and blood collected by jugular venipuncture for the determination of packed cell volume and serum proteins. The results of the study showed that improved protein nutrition significantly enhanced the level of serum albumin (p<0.05). It also significantly lowered the level of serum globulin (p<0.05) that otherwise would be high in haemonchosis. However, improvement in the dietary protein level appeared not to have any effect on the packed cell volume and total serum protein level.     

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.     

Haematological and serum biochemical parameters of West African Dwarf goats fed dried cassava leaves-based concentrate diets

The study was conducted to investigate the effects of feeding different levels of dried cassava leaves at 0%, 20%, 40% and 60%, respectively, using guinea grass as basal feed, on the haematological and serum biochemical parameters of West African Dwarf (WAD) goats. The study lasted for 116 days during which haematological and serum biochemical parameters were monitored in 40 male goats before and after, using a completely randomized design. At the start of the experiment, packed cell volume (PCV) ranged from 21.5% to 25.5% while haemoglobin concentration (Hb) and RBC significantly (P < 0.01) ranged from 7.3 to 8.6 g/dl and 10.4 to 13.2 × 10¹²/l, respectively. White blood cells reduced significantly (P < 0.05)) from 16.4 to 11.7 × 10⁹/l) as dried cassava leaves increased in the diets. At the end of the trial, there was a slight increase in the values of PCV and Hb in the diets (P > 0.05). Lymphocyte reduced significantly (P < 0.05) from 50.0% to 63.5% in the diets. Neutrophils, however, increased (P > 0.05) at the 0% to 40% levels and reduced at the 60% level of dried cassava leaves inclusion. At the start of the experiment, values for glucose significantly (P < 0.05) ranged from 40.1 to 56.0 mg/dl. Total protein and albumin values ranged significantly (P < 0.05) from 56.0 to 68.5 g/dl and 30.6 to 38.4 g/dl, respectively. At the end of the experiment, serum creatinine increased significantly (P < 0.05) as the level of dried cassava leaves increased from 0% to 60% in the diets. The study revealed that inclusion of dried cassava leaves in the diets of West African Dwarf goats had no deleterious effects on the haematological and serum biochemical parameters of WAD goats and could therefore be included in ruminant diets up to 60%.     

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.     

Susceptibility of West African Dwarf goats and WAD x Saanen crosses to experimental infection with Trypanosoma congolense

West African Dwarf goats (WADs) and their Saanen crosses were experimentally infected with Trypanosoma congolense. No significant differences were found between trypanosome parasitaemia and antibody response of the crossbred and WAD goats. Neither the WAD goats nor the Saanen crosses were able to control the drop in PCV following trypanosome infection. The level of anaemia caused by the trypanosome infection was similar in the two breeds during the trial. Based on these findings, no difference in tolerance or susceptibility to T. congolense could be demonstrated between the WAD goats and their Saanen crosses. Although the weight of all goats increased during the trial, the crosses gained significantly more weight than the WAD goats. The trypanosome infection reduced the growth rate of both breeds, but this reduction was not statistically significant. Crossbreeding trypanotolerant WADs with trypanosusceptible Saanen goats might, therefore, be an effective means of increasing productivity.     

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.     

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.     

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.     

Immune response to avian leukosis virus infection in chickens: Sequential expression of serum immunoglobulins and viral antibodies

Chickens of a 15I₅ × 7₂ cross that produces endogenous Rous associated virus (RAV-0) were infected with subgroup A lymphoid leukosis virus (RAV-1). Within 3 weeks, before RAV-1 neutralizing antibodies were detected, significantly higher levels of serum immunoglobulin G (IgG) were found in infected birds than in uninoculated hatchmates. Immunoglobulin M was significantly elevated only during the late leukotic state. Although most of the inoculated birds tested had RAV-1 neutralizing antibodies, no correlation was found between IgG levels and antibody titers. Tolerance to endogenous virus (RAV-0) and viral group-specific antigen was apparently abrogated by RAV-1 inoculation because significantly higher percentages of iodinated envelope glycoprotein (gpE) of RAV-0 and a viral structural antigen of mol. wt 19,000 daltons (p 19) were precipitated by sera from inoculated birds than from control birds.     

Spreading of West Nile virus infection in Croatia

West Nile virus (WNV) is an emerging zoonotic pathogen with rapid global expansion. The virus circulation is confirmed in many countries of Mediterranean Basin and Southern and Central Europe. In our study detection of specific WNV antibodies was performed in horses and cattle sera samples collected from October 2010 to April 2011. Serum samples were randomly taken from different parts of Croatia and tested by IgG and IgM ELISA. Positive serological results were confirmed by virus neutralization assay (VN-assay) and plaque reduction neutralization test (PRNT). Results showed that WNV antibodies were present in 72 out of 2098 horse sera (3.43%) and 3 of 2695 cattle sera (0.11%). The highest seroprevalence was found in Eastern Croatia in counties next to Hungarian, Serbian and Bosnia and Herzegovinian state borders. In Adriatic part of Croatia positive animals were found only in the westernmost county, near Slovenian and Italian borders. Geographic distribution and number of positive horses indicated that WNV is highly present in Croatia and spreading from East to West. However, positive horses in westernmost part of country indicate possible second origin of spreading. Location of serological positive cattle supports the hypothesis that seropositive cattle could be indicators of high WNV activity in the respective geographic regions.     

Leucaena and dried poultry waste improve the performance of West African Dwarf sheep on a grass diet

This study investigated the effects on digestibility and growth when West African Dwarf (WAD) sheep were fed a basal diet of Tripsacum laxum with Leucaena leucocephala or dried poultry waste as supplement. Fifteen WAD sheep (12 rams and 3 ewes) were randomly allocated to three dietary treatments of 5 animals each, namely T1—basal diet of chopped T. laxum (control), T2—basal diet plus dried poultry waste, and T3—basal diet plus L. leucocephala. Animals had access to drinking water and a mineral mix ad libitum. They were weighed weekly after a 2-week adaptation period, for a duration of 12 weeks. At the end of the feeding trial, three rams randomly selected from each treatment group were used for the digestibility study. Results revealed that average daily intake of L. leucocephala (350.0?±?0.3 g/animal) was higher than that of dried poultry waste (260.0?±?0.1 g/animal). The supplemented groups, T2 and T3, gained 21.4 and 31.0 g daily respectively, while animals of the control group (T1) lost 6.0 g daily. There was a significant difference (P?<?0.01) in dry matter intake between the control and supplemented groups, with T2 recording the highest intake. Organic matter intake of treatment 3 was significantly (P?<?0.01) higher than that of T1 and T2. The differences in crude fibre (CF) ingestion between T2 and T1 as well as T3 and T1 were significant (P?<?0.01), with the highest ingestion of CF occurring in T1. The dry matter digestibility of the supplemented groups was significantly higher (P?<?0.05) than that of the control. The organic matter digestibility of T2 and T3, as well as T1 and T3 were significantly different (P?<?0.05), being highest in T3 (77.0?±?2.1 %) and lowest in T2 (58.1?±?1.0 %) It was concluded from the study that T. laxum can be better utilized in West African Dwarf sheep when supplemented with dried poultry waste or L. leucocephala.