Technical Report 13-01
Dynalac Again Proved As Effective As Ca-Soap Product
Introduction
Several farm-based trials have confirmed that DYNALAC is effective in supplying
energy to high-performing dairy cows. In comparison with familiar calcium-soap
products (CSP) such as Megalac, DYNALAC proves time and again to provide
similar levels of digestible energy in spite of lower oil content. The trial reported here
continues these observations.
Site and Protocol
The farm is a specialist dairy unit of approximately 300 cows in north Somerset.
Rolling Annual Yield (RAY) is 10,500 litres. The herd has used CSP for a
considerable period, fed at 300 g / h / d. The trial was conducted during September
to November 2012. Data was collected on specific cows, initially fed on CSP then
switched to DYNALAC, fed at the same rate ie 300 g / h / d. After approximately one
month the herd was then switched back to CSP. Milk yield, milk quality and body
condition score data were then compared for the three periods. Three separate
groups of cows were chosen to enable changes in body condition to be monitored.
Results; Milk Production
Yield
Butterfat
Protein
Initial CSP
36.1litres
3.9 %
3.0 %
DYNALAC
41.3 litres
4.4 %
3.1 %
Final CSP
34.1litres
3.8 %
3.3 %
Table 1; Milk Production and Quality Comparison
Obviously to correctly compare the results the appropriate lactation curve needs to
be considered. A curve was derived specifically for the herd in question and the data
points plotted. This is shown in Figure 1.
From the graph it is clear that DYNALAC maintained milk yield at a level above that
expected; once removed, milk production dropped back to a level at or just below
expectation. This confirms previous trials that on a kg per kg basis DYNALAC can
effectively replace calcium soap products such as Megalac.
45
Daily Milk Yield / litres
40
35
30
25
- Calcium Soap Product
- DYNALAC
20
15
1
11
21
31
41
51
61
71
81
91 101 111 121 131 141 151
Days In Milk
Figure 1; Lactation Curve and Product Performance
Milk quality was also maintained throughout the trial, with a clear suggestion that
butterfat was actually enhanced during the DYNALAC period. Again, this confirms
previous on-farm trials, and demonstrates that DYNALAC is effective at supporting
butterfat production in dairy cows.
Results; Body Condition
BCS Change
Estimated Daily Weight Loss
Days of Milk
Initial CSP
-0.22
490 g
20
DYNALAC
-0.30
240 g
57
Final CSP
-0.50
660 g
33
Table 2; Body Condition and Weight Changes
Whilst in negative-energy balance in early lactation, cows utilise body fat reserves to
maintain milk production. It is widely accepted that minimising this weight loss avoids
metabolic problems such as ketosis and fatty liver, and improves fertility.
Considering body condition score, it is also accepted that condition will decline for
the period 5 days prior to calving and day 50 of lactation. Using groups of cows in
this interval, we can estimate weight changes based on the assumption that each
body condition score is about 50kg. The corresponding dry-cow group were
assessed, and the days to calving noted. The change in body condition was then
assessed, the weight change estimated, and daily change calculated using days in
milk + days to calving.
Clearly all cows lost condition, as was expected. However, the rate of loss was much
lower in the group fed DYNALAC than either of the CSP-fed groups. The rate of loss
was between 50% and 65% lower in the DYNALAC-fed group. The clear implication
here is that DYNALAC provided more energy to the cows at this crucial point.
The consequence of excessive weight loss has been widely studied; body condition
loss was associated with prolonged calving intervals (Garnsworthy and Topps 1982;
Ruegg et al 1992; Gillund et al 2001; Pryce et al 2001). The impact of excessive
weight loss is mainly on delayed first service and lower conception rates. With costs
associated with extended calving interval exceeding £5.50 / day (Veterinary Times),
this is a seriously important point.
Conclusions
This on-farm trial confirms previous reports;
•
•
•
•
•
•
DYNALAC can replace calcium-soap product directly on a kg for kg basis
DYNALAC supports performance and supplies energy in a readily digestible
form in spite of a lower total oil content
Production levels and milk quality are maintained
Body condition loss is reduced using DYNALAC compared to CSP
There is a strong likelihood that reproductive performance will be improved
and some metabolic diseases will be reduced using DYNALAC
Farmers can save money as DYNALAC costs less on farm. In this trial the
likely cost implications were;
Feed Rate
300g / h / d
Total Fed
90kg / d
Cost Differential
£ 80 / tonne
Saving / day
Annual Saving
£
7.20
£2630.00
References
Garnsworthy PC and Topps JH (1982) The effect of body condition of dairy cows at calving on their
food intake and performance when given complete diets. Animal Production 35: 113-119
Ruegg PL, Goodger WJ, Holmberg CA, Weaver LD and Huffman EM (1992) Relation among body
condition score, serum urea nitrogen and cholesterol concentrations, and reproductive performance in
high-producing Holstein dairy cows in early lactation. American Journal of Veterinary Research 53:
10-14
Gillund P, Reksen O, Grohn YT and Karlberg K (2001) Body condition related to ketosis and
reproductive performance in Norwegian dairy cows. Journal of Dairy Science 84: 1390-1396
Pryce JE, Coffey MP and Simm G (2001) The relationship between body condition score and
reproductive performance. Journal of Dairy Science 84: 1508-1515
Veterinary Times 23/01/09
MC + MPS 12/12
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