From the Director's Desk
Dr. Tilahun Sahlu
Mr. Erick Loetz
Mr. Erick Loetz can be reached at (405)466-3160 or at eloetz@luresext.edu.
Mastitis Workshop
by G. Tomita
The 1st annual Mastitis Workshop is scheduled to be held on Saturday, May 25, 2002, at the E (Kika) de la Garza Institute for Goat Research dairy facility. The workshop will consist of a comprehensive lecture on mastitis in the morning session and a hands-on laboratory course in the afternoon session.
In the morning session, Dr. Grant M. Tomita, a mastitis researcher at the Institute, will start off the program with a seminar on the cause, prevention, and management of mastitis in dairy goats. The pathogenesis of the disease as well as management strategies to prevent mastitis and treatment options in the event of intramammary infection will be covered in the presentation. Dr. Tomita's seminar will be followed by a presentation given by Dr. Max J. Paape of the United States Department of Agriculture, Immunology and Disease Resistance Laboratory, located in Beltsville, Maryland. Dr. Paape is a nationally and internationally recognized expert in the area of milk somatic cell function and mastitis. The role of milk somatic cells during mastitis and the effect of increased somatic cell count on milk quality will be discussed by Dr. Paape. This session will provide participants a basic knowledge of mastitis and an understanding of how to prevent and treat this disease.
In the afternoon session of the workshop, Drs. Tomita and Paape will conduct a laboratory course on the detection and diagnosis of mastitis. Participants in this session will be instructed on various techniques that are utilized to collect milk samples for the observation of mastitis and the identification of mastitis pathogens. Live dairy goats will be utilized for all demonstrations and by workshop attendees. This session will provide the participant hands-on experience in determining the udder health of lactating goats.
The registration deadline is April 27, 2002.
Please use the enclosed form to register for the Mastitis Workshop.
Abortion Diseases by Lionel Dawson, D.V.M.
Abortions can account for significant economic losses to the goat producer, however, the impact is often unrecognized unless a severe outbreak occurs. Most abortions in goats, especially those of an infectious nature, occur in the last 50 days of the gestation period. Common infectious causes of abortion are Toxoplasmosis, Chlamydiosis, Salmonellosis, Brucellosis, Listeriosis, Leptospirosis and Q-Fever. Proper samples should be submitted to get a definitive diagnosis in an abortion outbreak caused by an infectious agent.
Abortion Diagnosis
A reliable rapid laboratory diagnosis of abortion depends on the correct selection, processing, storage and shipment of specimens. In addition, a comprehensive herd history and history of the abortion outbreak should be submitted with the specimens.
1.Placenta - Include cotyledon and intercotyledonary areas: Select areas of placenta that appear to be abnormal. Both fresh and formalin fixed samples should be submitted.
2.Fresh whole fetus chilled but not frozen is first choice when rapid delivery (within 48 hours) is possible, to the laboratory.
3.When a whole fetus cannot be submitted fresh and formalin fixed.
4.Fetal liver
5.Fetal lung
6.Fetal abomasums and contents (fresh only)
7.Fetal heart blood
8.Fetal pleural and peritoneal fluid
9.Fetal brain
10.Serum separated from the clot and frozen (collected from the doe).
11.Frozen tissue is usually suitable for virus and most bacteriological examinations but not for histopathology examination.
12.Fresh tissue for bacteriological examinations should be packaged individually in sterile sealed containers and chilled.
13.Blood for virus isolation should be in Na-Heparin tubes and chilled ASAP
The following table discusses the infectious causes of abortions: (This is a partial table; other abortion diseases will be tabulated in the next newsletter.)
This is caused by a Chlamydial agent
that affects sheep, goats, occasionally
cattle and rarely man. Abortion-producing strains differ antigenically
from strains producing polyarthritis
(sheep and cattle) and conjunctivitis
in sheep and goats (pinkeye). The
disease appears to be of greatest
importance in Britain, Europe and the
western United States. For more information regarding goat diseases, contact Dr. Lionel Dawson at (405) 744-8580 or at dlionel@okstate.edu Research Spotlight Abstracted by A. Goetsch Feeding Programs for Dairy Goats. Optimal feeding programs for dairy goats in late lactation and when dry are not well established. Dietary characteristics influence milk yield and body
condition of dairy goats, as well as growth of primiparous goats. Objectives of this experiment were to determine effects of dietary concentrate and energy
levels in late lactation and the dry phase on performance of Alpine yearling doelings and mature does in late lactation and the subsequent early lactation phase.
The experiment consisted of 16 weeks in late lactation, 8 to 13 weeks dry, and 12 weeks in the subsequent lactation. Diets of 20, 35, 50, or 65% concentrate
(2.18, 2.34, 2.49 and 2.62 Mcal/kg metabolizable energy [ME], respectively) were consumed free-choice in late lactation, with a 35% concentrate diet (2.18
Mcal/kg ME) in the first 4 weeks of the dry phase and 50% concentrate (2.65 Mcal/kg ME) until kidding. All goats consumed a 50% concentrate diet (2.42
Mcal/kg ME) in the subsequent early lactation. Yearling doelings and mature does differed in milk yield response to dietary concentrate and energy levels in
late lactation, with no effect for doelings and increased milk yield for does as the concentrate level increased to 50% (2.49 Mcal/kg ME). Conversely, a 65%
concentrate diet depressed milk yield in late lactation by does compared with 50% concentrate. Dietary concentrate level may have little effect on subsequent
lactational performance with adequate nutritional planes in subsequent dry and early lactation phases, for both mature does and yearling doelings incurring
significant growth. A. L. Goetsch, G. Detweiler, T. Sahlu, R. Puchala, and L. J. Dawson. 2001. Dairy goat performance with different dietary concentrate levels in late lactation. Small Ruminant Research
41:117-235. Dairy Replacement Management. A concern of many goat producers is feeding management in the first few months of life for kids removed from does soon after birth. A number of factors may
influence performance of kids artificially reared on milk or milk replacer. To study these factors, two sets of 40 Alpine kids (3 to 9 days of age) were used to
determine effects of group versus individual pens, preweaning access to forage, and different milk feeding restriction regimens on preweaning and early
postweaning growth. Treatments in the first experiment were: individual pens, 91 × 91 cm; two kids (one in the experiment and another older) per pen, 182 ×
91 cm; group pen (with at least two older kids present), 2.43 × 1.22 m; and group pen plus free access to alfalfa hay. Treatments in the second experiment
were: ad libitum milk intake with two meals in weeks 3-8, then 50% of intake on the preceding few days with one meal in week 9 to 10; 75% of intake on the
last few days of week 2 with two meals in weeks 3-8, then 50% intake (67% of intake in weeks 3-8) with one meal in weeks 9-10; 75% intake with one meal in
week 3-8, then 50% intake with one meal in weeks 9-10; and 75% intake with two meals in weeks 3-6, then 37.5% intake with one meal in weeks 7-10. In the
first experiment, neither group pens nor providing access to forage preweaning enhanced growth of Alpine kids. Results of the second experiment indicate that
milk consumption can be moderately restricted without impairment of growth in preweaning and early postweaning periods compared with ad libitum milk
consumption. Furthermore, there appears potential for effective employment of regimens with only one daily meal of milk, although most appropriate
restriction levels deserve further study. Lastly, a second step reduction in milk intake in the latter few weeks of the preweaning phase may be useful in further
stimulating dry feed consumption. A. L. Goetsch, G. Detweiler, T. Sahlu, and L. J. Dawson. 2001. Effects of different management practices on preweaning and early postweaning growth of Alpine kids. Small Ruminant Research 41:109-116. GIGR Establishes Computer Laboratory for Awassa College of
Agriculture in Ethiopia by R. Merkel The establishment of an internal computer network
incorporating a student computer laboratory will vastly
improve computer facilities at ACA for use in research,
teaching and extension activities. The student computer
laboratory allows ACA students better access to computers
and increases their opportunities to obtain computer skills.
Presently, there are future plans to train senior students in basic computer skills. This training will be lead by Mr. Wondimagegn Mekuria, who will also be the
administrator of the computer laboratory. The computer project also funded the procurement of multimedia equipment, i.e. digital camera, scanner, LCD projector and screen, etc. and called for the
proper training to allow ACA faculty to use computers in the classroom. Dr. Gipson was the first to demonstrate the multimedia equipment when he gave a
follow-up presentation on statistical analyses using Statistical Analysis System (SAS®) software. For the preliminary SAS presentation, Dr. Gipson used an
overhead projector, technology already in use at ACA. For the follow-up SAS session, Dr. Gipson used the newly acquired laptop and LCD projector. With the multimedia equipment, class presentations, homework assignments, pictures, and other class materials can be put into digital format and stored on a
computer. Students could then have access to class material outside of normal class hours through using the student computer laboratory. Another aspect of the use of multimedia is in the realm of extension activities. Extension personnel at
Langston University regularly use a laptop computer and LCD projector at producer meetings. The use of this
technology by scientists at Awassa represents a giant leap in the technology used in extension presentations.
Through using digital technology, pictures of various production settings, training materials, etc. could be presented to villagers. A digital camera could be used to capture pertinent training materials such as disease
symptoms, types of forages and plants best suited for animal production, medicines used in treating diseases,
vaccination methods, etc. for presentation. Combined with hands-on practice this would be a very strong and
effective teaching tool. Two portable generators were also part of the computer project in order to supply
power to villages where there is no electricity. The computer project was funded through a Technology Enhancement Grant from the United States Agency
for International Development's (USAID) Leland Initiative and through a sustainability grant from the
Association Liaison Office for University Cooperation in Development. The USAID Mission in Addis
Ababa, Ethiopia provided essential assistance and support. In addition to establishing the computer laboratory, Drs. Merkel and Gipson were able to travel to several
villages south of ACA and discuss the goat project with women participants. During the past year, ACA has increased the number of women participants in the
goat extension project to 80, doubling the original number of cooperators. Each woman initially received two does and production training. In a little over two
years, one woman now has a herd of 11 goats and has goat milk to feed her infant son. Because of the importance of milk to families in the region, ACA is now
providing Toggenburg crossbred bucks to villagers to upgrade the milk production potential of village goats. Prior to arriving in Awassa, Drs. Merkel and Gipson traveled to Alemaya University (AU) in eastern Ethiopia, where Langston and AU have a similar women's
goat project and met with several participants in that goat project. AU has plans to add 50 new women participants to their goat extension project, raising the
total number of women to receive goats to 150. This project is very popular among village women and goats are used for milk production and for sale as meat
animals, particularly during holiday and festival periods. Funding for the AU/Langston collaborative project is through the United Negro College Fund's
Institutional Development Partnerships Activity and USAID. For more information on the Ethiopia projects, see the Spring 2001 and the Summer 2000
newsletters. For a detailed description of the women's goat projects at ACA and AU, visit our website at http://www2.luresext.edu/goats/other/international.htm. Noteworthy News Langston University has been awarded a USDA Initiative for Future Agriculture and Food Systems grant. The project will develop a computer simulation
model to evaluate resources and conditions for goat production systems. Dr. Terry Gipson will lead this project. Drs. Tilahun Sahlu and Art Goetsch traveled to Cyprus to meet with collaborators of the MERC project. Drs. Roger Merkel and Terry Gipson traveled to Ethiopia to visit our collaborators at two Ethiopian universities and to establish a computer laboratory for
faculty and students at one of the universities. Dr. Ignacio Luna, visiting scholar from Chapingo University in Mexico, arrived to assist with an ongoing project of determining energy requirements for goats. Dr. Bill Pomroy returned to Massey University in New Zealand following his short-term sabbatical research on internal parasites in goats. Dr. Tumen Wuliji completed his research stay and will be returning to New Zealand. Drs. Terry Gipson, Steve Hart, and Grant Tomita traveled to Portland, OR to attend the 97th Annual American Dairy Goat Association convention. Dr.
Tomita presented a paper entitled "Dairy Goats and Mastitis". Dr. Hart presented two papers entitled "Nutrition for the High Producing Doe" and "The
Effects of Concentrates and Forage and Milk Production and Quality - Preliminary Results". Dr. Gipson assisted with the Dairy Herd Improvement Training. Dr. Steve Hart spoke on the principles of goat nutrition and how they differ from feeding cattle at the Commonwealth Goat Seminar in Lexington, Kentucky.
Disease
Transmission
Clinical Features
Diagnosis
Diagnostic Aids
Control 1. Toxoplasmosis: Toxoplasma
gondii affects a wide range of animals
as well as man. It is widespread and
has been reported in Australia, New
Zealand, Britain, Turkey, USSR, and
North America. Cats and other
Felidae are considered the primary
host and excrete oocysts; species such
as goats and man are regarded as
secondary hosts.
Oocysts excreted in cat feces are
thought to provide the major source of
infection. Congenital transmission
from does to kids is also established.
Further epidemiologic knowledge is
required to establish how the disease
spreads during an epidemic.
Does infected in the earlier stages of
pregnancy either resorb the embryo, or
fetal death and under go
mummification (often only one of a
twin pair) may occur. Infection in late
pregnancy leads to abortion and
perinatal losses of kids. Many
congenitally affected kids survive.
Disease in the adult is generally
asymptomatic, occasionally CNS
signs develop.
Gross lesions of the cotyledons
(numerous grey-white foci 1 to 3 mm
in diameter) are indicative of the
disease. Not all cotyledons are equally
affected, and such lesions should be
differentiated from nonspecific
calcification. Focal
leukoencephalomalacia in the CNS of
stillborn kids, or kids dying shortly
after birth is a common finding.
Histology of cotyledon to demonstrate
local areas of necrosis and the
organisms. Histology of fetal brain to
demonstrate foci of glial cells and
leukoencephalomalacia. A range of
serologic tests has been developed by
different laboratories to assist with
diagnosis of this disease.
Prevent exposure to barn cats. Don't
allow cats to consume aborted fetuses
in a Toxoplasma abortion. 2. Enzootic Abortion (EAE,
Chlamydial Abortion):
Ingestion by does during the kidding
period following contamination of
food and surroundings by aborted
fetuses, placentae and vaginal
discharge are the routes of
transmission. Spread is more rapid
when does are confined. Many
carriers are seen in endemic herds.
Infection at birth in kids kept as
replacement does may be carriers
through to their first pregnancy.
Late abortions, stillbirths and birth of
weak infected progeny are the main
features. Fetal mummification is
occasionally seen. Kids with
congenital infections usually abort
during their first pregnancy; does
infected in the last month of
pregnancy may not abort until the next
gestation period. Does seldom abort
more than once.
A chorionitis with chlorionic
epithelial cells packed with elementary
bodies appears to be the essential
lesion.
Placental smears and smears of
vaginal discharge (but not fetal
stomach) stained by the modified
Ziehl-Nielsen or Gimenez stain
techinique should be done.
Organisms can be cultured in yolk sac
of embryonating chicken eggs. CF
tests may also be used.
Vaccine available; must be given to
males and females 4-6 weeks prior to
breeding, or use 150 mg of
tetracyclines per head per day in the
feed for 2-3 weeks prior to breeding:
may continue this in their feed
through the first half of gestation. 3. Salmonellosis (Paratyphoid
Abortion): Salmonella abortus ovis, S.
typhimurium and S. dublin has been
associated with abortion in does.
Ingestion of contaminated food and
water usually from carrier animals.
Does in later pregnancy appear more
susceptible. Overcrowding and other
forms of stress favor an outbreak.
Unless the infecting dose is large or
the strain exceptionally virulent,
infection seldom causes clinical
disease in the absence of some other
predisposing factors resulting in
stress.
Abortions, stillbirths, births of weak
infected progeny that usually die
within 7 days of birth. Does may
show high fever before aborting; most
recover, but some die from metritis
and/or septicemia. Some does and
newborn kids show diarrhea; in the
kids this is usually fatal. When
infection is endemic, abortions tend to
be confined to the younger does.
No specific placental lesions have
been reported. Aborted fetuses show
usual signs of intrauterine death.
Septicemia lesions may be seen in
those kids dying during or shortly
after birth.
Culture of organisms from fetus,
placenta and uterine discharge.
Antibiotic treatment on flock basis not
effective and is very expensive. Avoid
overcrowding or stressing of does. Do
not feed on the ground unless a new
area can be used each day. For
valuable individuals, supportive
therapy (fluids) and antibiotics are
recommended.
Skill in using computers and the Internet are essential tools
for faculty and students around the world. In November,
Drs. Roger Merkel and Terry Gipson traveled to Ethiopia to
assist the Awassa College of Agriculture (ACA) of Debub
University in establishing a computer laboratory for the
development of much-needed computer skills.
This latter enhancement of delivery of the extension program
will support the already existing project of women's goat groups.
For more information regarding the Ethiopian project, contact Dr. Roger Merkel at (405) 466-3826 or at
rmerkel@luresext.edu