CAL: analysis of farm records Flashcards
Define % first recording SCC >200
The percentage of cows with a SCC over 200,000 cell/ml milk at the first recording in a new lactation
Define % chronic SCC >200
The percentage of all milk samples in the last 12 months originating from CHRONIC high SCC cows (cows that had a high SCC at the previous milk recording as well as the current)
Define % new SCC >200
The percentage of all milk samples in the last 12 months originating from NEW high SCC cows (cows that had a high SCC for the first time in the current lactation having only recorded low SCCs at earlier milk recordings in the current lactation)
Define Threshold index
new high / new low: Using the threshold value to distinguish between High and Low SCC, the threshold index is the number of cows passing from Low SCC one month to High SCC the next divided by the number of cows changing from High the previous month to Low this month.
Define % dry period cure (H-L):
The % of cows that ended their previous lactation with a (H)igh SCC (greater or equal to the threshold value – often set at 200,000 cells/ml) that started the new lactation with a (L)ow SCC (below the threshold value). This value gives some indication about how successful your dry cow protocols work at curing cows that are dried off with a high SCC
Define % dry period protection (L-L)
The % of cows that ended their previous lactation with a (L)ow SCC (below the threshold value) that started the new lactation with a (L)ow SCC (below the threshold value). This gives some indication about how well your dry period protocols protect the cow from infection during the dry period
Define Mastitis rate (cases / 100 cows / year)
Overall incidence rate of mastitis. This is calculated as All mastitis cow cases divided by the population of cows in milk
Define % cows calving with mastitis by Day 30
The percentage of cows that have recorded one or more mastitis cases by Day 30 of a lactation. This figure tells you if the early lactation period is a risk factor for picking up mastitis on the farm
Define Index mastitis rate after day 30
Incidence rate of index mastitis cases (the first mastitis case of a cow in a lactation) in cows that have not had an index mastitis case and are more than 30 days after calving
Define Recovery from new/first/repeat
The % of cows that followed a new/first/repeat high SCC recording with a SCC below the threshold value at the next milk recording
Define Milk / cow / Year (kg)
Total annual milk production per cow place: Definition: Total milk divided by the average population of cows (both dry and in-milk)
Define 305-day yield (kg)
Average milk yield (kg) by Day 305 of lactation. Definition: Average milk yield production by Day 305 of lactation (kg) of cows reaching Day 305. The 305 day figures effectively corrects for extended or short lactations and thus allows comparisons between cows and farms that are not affected by lactation length
