Summary of St. Croix Dairies Work
 A milk production two year comparison was done for the four
herds on DHIA records between the years 1981-82 and 1982-83
(Table 3). The total cows, average cows/herd, and percent cows
in milk remained the same, but the rolling herd average (average
milk/cow/year) increased by 772 lbs. The net dollars over feed
cost was estimated to be $86,730 based on a $21.00/100 milk
market price.

 TABLE 3. Milk production summary.

 March 1981- March 1982-
 March 1982 March 1983
 4 herds total cows 533 537
 average no.
 cows/herd 133.4 134.5
 % cows in milk 69.8% 70.5%
 total milk diff.
 1981-83 413,002 lbs
 Net $ over feed cost $86,730



 The reproduction comparison between 1981-82 and 1982-83 is
shown in Table 4. The total number of cows remained the same
over the 2 years of the comparison, but the calving interval (CI)
was reduced by an average of 1.13 months or 32 days. A
13-month calving interval is considered to be a reasonable goal
for dairy cows with production records of under 20,000 lbs of
milk/year. A $3.00/day loss for every day over 13 months CI is
considered by economists to be appropriate. The total dollar sav-
ings is estimated to be approximately $62,145 for the four herds
on DHIA records. The CI for these herds on St. Croix is con-
siderably longer than the optimal 13 months. There are several
reasons for this problem which is depressing the milk production
of the cows in these herds. The culling rate for infertility is low
because of the high incidence of infertile cows and the delay in
achieving pregnancy. Cows are kept in the milking herd after
they are not profitable in order to maintain cow numbers since
native replacement heifers numbers are not sufficient to replace
the low production cows. Imported replacement heifers are ex-
pensive and are not adapted to the environment if imported from
the U.S. Therefore, the native replacement heifer supply is a
limiting factor in the culling process. Improved fertility rates by
disease control, good nutrition, and improved management
techniques will allow a more aggressive and realistic culling rate.
Culling of low production and infertile cows and widespread use
of artificial insemination to introduce new genetics will have im-
mediate positive impact on milk production and reproduction.


TABLE 4. Production summary.


 4 herds 1981-83
 Total Calving Days Dift S/cow/year Total $*
 Herd# Cows Interval Open (Days)
 81-82 81-82 81-82 81-82 81-82 81-82
 1 109 104 15.1 14.6 178 163 15 $ 45 $ 4,680
 2 221 22 17.7 15.6 257 196 61 $183 $41,175
 3 69 68 16.4 15.2 32 $108 $ 7,344
 4 134 142 17 16.3 236 215 21 $ 63 $ 8,946

 Average change 1.13 29 $62,145
 The dollar value is based on $3/day over 13 months calving interval.




Future Plans
 A five year research proposal, if funded, will employ the
multiphased research/demonstration approach to the complex
problem of inadequate dairy production in the Caribbean. It will
utilize five dairy units on St. Croix to model actual field produc-
tion conditions, but under a controlled test situation. The use of
this model will validate the usefulness and reproducibility of the
results obtained. Demonstration herds will be established
throughout the Caribbean region to provide application and im-
plementation of new techniques and knowledge gained from the
controlled study on St. Croix.
 The overall objective of this project is to develop and test
management and technology alternatives to increase dairy pro-
duction in the Caribbean in a cost-effective, sustainable manner.




Objectives:
 1. Test the production potential of existing dairy stock
 through managed energy feeding and challenge feeding
 trials.
 2. Identify genetically superior alternatives for cost-effective
 tropical dairy production animals through artificial in-
 semination, crossbreeding, and embryo transfer tech-
 niques. Explore long-term feasibility of above techniques
 with existing management and infrastructure conditions in
 the Caribbean region.
 3. Minimize reliance on imported feedstuffs by identifying
 forage varieties as alternatives to improve the grasses and
 legumes available for dairy nutrition.
 4. Explore water catchment, storage and irrigation methods
 to stabilize water supplies for crop forage production.


References
 1. Cates, W.F., L. Ball andJ.N.Wiltbank. 1976. A Compilation of Current In-
formation on Breeding Soundness Evaluation, and Current Subjects. The Society for
Theriology 7.
 2. Craig, T. 1983. The Milk Mess: Jamaica attempts to develop its dairy in-
dustry, Extension Newsletter, Dept. of Ag. Extension 15:16-20.
 3. Everson, Everett, J. Beausolei, R.J. Deans, R. Freed, D. Gait. 1982. An
Evaluation of the CARDI/USDA Small Farm Multiple Cropping Systems Research
Project No. 538-001 MUCIA/Caribbean TSM-9 1-67.
 4. Hanson, L.E. 1980. Effects of Leptospirosis on Bovine Reproduction, in:
Current Therapy in Theriogenology (Ed. Morrow, D.A.), Philadelphia: W.B.
Saunders Co. 488-492w.


 5. Hillman, D., J.T. Huber, R.S. Emery, J.W. Thomas, R.M. Cook. 1975.
Basic Dairy Cattle Nutrition Ext. Bul. E-702, Coop. Ext. Ser., Michigan State
University 15-19.
 6. IICA/IBA. 1981. Consultation Meeting on International Cooperation in
Animal Health, Proceedings 4-7.
 7. Morrow, D.A. 1969. Phosphorus Deficiency and Infertility in Dairy Heifers,
Jour. AVMA 154(7):761-768.
 8. Morrow, D.A. 1980. Nutrition and Fertility in Dairy Cattle, Modern
Veterinary Practice. June 499-502.


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