Fachbereich Veterinärmedizin



    Effect of culling rates on profitability of dairy herds achieving the same pregnancy rate (2017)

    Schuenemann, Gustavo
    Galvao, Klibs
    Borchardt, Stefan (WE 19)
    Heuwieser, Wolfgang (WE 19)
    Federico, Paula
    American Dairy Science Association - Annual Meeting
    Pittsburgh, 23. – 29.06.2017
    Journal of Dairy Science; 100(Supplement 2) — S. 290
    ISSN: 0022-0302
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    Abstract / Zusammenfassung

    Objective was to assess the effect of each unit increment of culling
    (CULL; from 25 to 43%) on profitability of dairy herds achieving 20%
    pregnancy rate (PR) using a cow-based model. Same reproductive
    program was used, Presynch-Ovsynch with estrus detection (ED) and
    timed-artificial insemination (TAI) with a voluntary waiting period of
    60 d in milk (DIM). Probability of involuntary CULL was set at 0.1%
    per d for the first 60 DIM, and 0.03% per d for the remaining of the
    lactation and dry period. Probability of death was set at 0.05% per d for
    the first 60 DIM, and 0.0076% per d for the remaining of the lactation
    and dry period. Herd size was set to 1,000 cows and each unit of CULL
    was modeled using the same TAI-ED to achieve 20% PR. Four factors
    affecting the economic benefits of dairy herds remain unchanged for the
    simulation: (1) milk price ($0.37 per kg), (2) feed prices for lactating
    ($0.25 per kg of dry matter [DM]) and dry cows ($0.15 per kg of DM),
    (3) cull cow price ($1.00/kg of live weight), and (4) replacement price
    ($1,600 per heifer). Conception to first service was set at 32% and then
    decreased by 2.6% for every subsequent service. Abortion was set at
    9.3% for the first 90 DIM and at 1.7% for the remaining of gestation.
    Cows were not bred after 366 DIM and open cows were culled after
    450 DIM. Simulation was performed until steady state was reached
    (3,000 d), and then average daily values for the subsequent 2,000 d were
    used to calculate profit/cow per yr. Net daily value was calculated by
    subtracting the costs (replacement, feeding, breeding, and other costs)
    from the daily income (milk sales, cow sales, and calf sales). Higher
    CULL reduced (P < 0.05) the proportion of cows with lactations ≥
    3, increased replacement costs, and reduced profit by $186 per cow/
    yr. For each unit increment of CULL, the proportion of first lactation
    cows increased by 0.66 percentage points and the proportion of net
    profit decreased by 1.09 percentage points. On average, it took 53 mo
    to reach the breakeven point considering the heifer replacement cost
    to first calving and the subsequent milk revenues over 3 consecutive
    lactations. Excessive CULL increased the proportion of first lactation
    cows and replacement costs; thus, reducing profitability.