. Additional Nutritional Factors Water Quality Action and Reaction Water Quality Management and Biofilter Maintenance Post larval fitness parameters YOU ARE IN HEALTH MANAGEMENT Risk Management, Bio-security and HACCP Implementation System Disinfection Procedures Record Keeping and Report Templates
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. Variables to be used in health evaluation Survival Rates The survival rate is an estimate of the change in number of shrimp in a tank over a period of time. The validity of a survival rate value depends on the accuracy of the data. Mistakes may result from inappropriate counting techniques,human error or inexperience and variability in the counting method. Often the shrimp are miscounted when they are first added to the tank. Mortality Rates Mortality rate is the number of dead shrimp that are counted over a period of time. Daily, weekly and monthly counts of dead shrimp are used to show the trends in disease progression, transmission, response to treatment or other management manipulations. Survival rates are normally the opposite of mortality rates unless there is escapement, miscounting or theft. Growth Rates Growth rates are a good indicator of the health of the shrimp in the system. Growth rates are influenced by environmental, genetic,biological and nutritional factors. For the first month of grow-out percentage increase in body weight are used to measure growth rates. By the sixth week weekly weight gains are estimated to determine the growth rates. From here on in growth rates can vary from 0 - 2.5 grams per week.At this stage growth rates of less than 0.5 grams per week are considered to be poor rates of growth and indicative of some sort of culture problem. Size Variation Some diseases or health problems can be identified by looking at the size distribution of shrimp in the tank.This does not need to be determined unless you see there is a problem with growth rates or mortality. Feed Conversion Ratio The feed conversion ratio (FCR) is a measure of the efficiency of feed utilization by shrimp. FCR values, together with other information, can be used to understand a problem with a production run. In general, the lower the FCR, the more efficient the feed utilization. Poor feed quality can reduce growth and increase FCR. Shrimp should be visually examined on a daily basis for changes in behaviour and colour (Form 1) . In order to identify problems, you must first be able to recognize normal appearance and behaviour of cultured L. vannamei. Unusual behaviour (i.e., lethargy, disorientation) can be indications of a disease problem. Changes in appearance, texture and colour of organs (i.e., gills,appendages,cuticle,abdominal muscle) should also be noted. Stomach fullness should be evaluated. |
. HEALTH MANAGEMENT & DISEASE CONTROL INDEX Health evaluation tests Shrimp Diseases Disease control . |
