Volume 22 • Issue 03 • 2018
Input-metabolism-output relationships for Calcium , Magnesium , Sodium and Potassium
INPUT THROUGHPUT OUTPUT
Mineral |
Dietary intake ( g / day ) |
Absorbed intake ( g / day ) |
Total reserves ( g ) |
Available reserves ( g ) |
Endogenous loss ( g / day ) |
Milk loss ( g / day ) |
Ca |
100.0 |
34.0 |
6000 |
3.0 |
8.0 |
26.0 |
Mg |
20.0 |
4.0 |
175 |
0.75 |
1.5 |
2.5 |
Na |
19.5 |
19.5 |
700 |
35.0 |
6.5 |
13.0 |
K |
50.5 |
50.5 |
820 |
185.0 |
22.5 |
28.0 |
From : Metabolic and Nutritional Diseases of Cattle , J . M . Payne
The high risk period The definitions of terms are indicated in the following diagramme :
Dry-off Calving
End previous lactation → 305 days
Dry period ( 60 days )
Steam-up 21 d
Start of new lactation
Negative Energy Balance 75-90 d Transition period 42 d
Production vs Health and Reproduction
Over the last approximately 50 years , genetic selection has led to markedly increased milk production ability of dairy cows . At the same time , despite advancements in technology and knowledge to prevent production diseases , the incidence of these diseases has stayed more or less unchanged . The same applies for reproduction parameters , except in the case of reproduction the situation has deteriorated and not just stayed the same . There is now some physiological evidence that the mismatch between milk production ability ( genetic ) and management ( including nutrition ) leads to deterioration in oocyte quality and embryo survival . In other words , reproduction ( or production diseases for that matter ) acts as a barometer for the mismatch between advances in genetics for production , and improvement in management practices to sustain such high production in the cows . The following diagramme illustrates this principle :
MILK PRODUCTION
MANAGE- MENT
FERTILITY IS THE BAROMETER
Leroy JLMR 2009 Nutrient prioritisation in dairy cows early post partum : Mismatch between metabolism and fertility ? Annual conference of the Livestock Health and Production Group of the SAVA , 21 - 23 July 2009 , Mossel Bay , South Africa
It is important to consider production diseases on a herd basis , in order to predict occurrence and set up preventative measures . This can be a very challenging , but also extremely rewarding task to the practising veterinarian .
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