Term
| the ability of a dairy herd to achieve optimum productivity depends on the interaction of? |
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Definition
genetic potential
diet
environment
digestion
metabolism
management |
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Term
| parametres used to assess adequacy of the diet |
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Definition
1. DMI
2. feed quality
3. feacal consistency
4. observing cows
5. milk production- peak and persistency ( peak x 200= lactation yield)
6. BCS
7. milk quality- butterfat and protein reflect roughage and energy status of the diet.
8. disease |
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Term
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Definition
Timing is important
May or June: when grass is of optimum quality, provides valuable baseline for comparison with results obtained later in the year under less favourable conditions.
July or August: valuable to test in summer calving herds.
Autumn grazing period: Id's potential problems resulting from an over estimation of the nutritional contribution from autumn grass, especially for recently calved cows.
Winter feeding period: atleast 2-3 wks after cows have been exposed to feeding regime will give a good indication of energy requirements being met
After management changes |
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Term
| correct timing of blood test |
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Definition
essential to allow 2-3 hours to elapse after the cow has had a major intake of concentrate feed.
- also wait atleast 2 weeks after a major dietary changes. the microflora in the rumen take 7-10 days to adjust to a new substrate |
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Term
| Cow selection for sampling |
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Definition
1. early lactation group- MOST IMPORTANT: 10-20 days post calving, if cows are sampled too long after calving, they may respond to underfeeding by dropping milk yield and quality and have normal biochemical parameters.
2. Mid lactation group: normally would be over 100 days calved, they will have full potential dry matter intake and should be pregnant again.
3. Dry cows: 2 weeks prior to calving, sample 5-12 cows |
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