WisGraph 7. Interpretive Manual Ken Nordlund, DVM and Tom Bennett UW School of Veterinary Medicine Introduction to the Graphs The graphs are generated from herd DHI data from Wisconsin AgSource and downloaded through the DairyNet system. Line graphs over time Most of these graphs show a herd summary trend over the past 24 DHI test dates and usually summarize a period of two years. However, in cases where the dairy does not test on a monthly basis, the time span of the graph can exceed the expected time period. Check the dates on the graphs routinely. Checking the current herd performance against performance at the same month a year ago is often a useful test to measure progress. It removes the effect of season from the interpretation of the graph. Occasionally, data errors appear after downloading from DairyNet. If values are received that are clearly out of the normal range, we recommend that you repeat the DairyNet request and download process. If the values remain abnormal, call AgSource and ask them to investigate the herd data file. Scatterplots The scatter plots are generated from individual cow data. Each dot usually represents one single cow. These graphs make it possible to look at variation within the herd. Scatterplots may be useful in looking for outlier data points. Outliers would represent cows that have produced an extreme value that might have a substantial effect on a calculated average. Several of the scatterplots show a performance value plotted against the current days in milk of the cow. Special attention should be paid to the graphs that plot peak milk and ME35 against days in milk. We have developed these graphs to try to assess current performance of the early lactation cows, as the herd-level graphs of these items include the average of the entire lactating herds and respond relatively slowly to changes in fresh cow performance. These plots require careful and cautious interpretation as there may be effects of season, stage of lactation, and management at play simultaneously and may be confounded by small populations of animals of different productive capability. Food Animal Production Medicine - UW School of Veterinary Medicine 1
It is usually very difficult to evaluate a scatterplot in any quantitative way. Because of this, a regression line and formula is generated automatically in some of the graphs. With a large number of data points, the regression usually helps describe the central tendency of the data. However, individual points that lie far outside the general cluster can skew the regression, so take care in the interpretation. The regression formula explains the relationship between the two variables on X and Y. The r 2 value indicates how much of the variation in y is explained by variation in x. For example, if the r 2 of Sire PTA milk on ME35 milk of individual cows is.25, it means that the sire PTA milk explains about 25% of the variation in the cow s ME35 milk production. The regression formula is based upon the standard Y = ax + b, where b is the intercept of the Y axis and a is the constant. For example, if the regression formula in the Sires PTA milk versus Cow ME35 milk appears as y = 1.1 x + 25,, this indicates that for each pound of Sire PTA milk the daughters produce 1.1 lbs of ME35 milk. Histograms Several of the graphs are displayed as histograms where each bar represents the number of animals that are characterized by some range of values. Some histograms will display a normal bell shaped curve and these populations are well described numerically by a mean (average) and standard deviation. Other histograms such as days to first breeding are skewed to the right and the central tendency is best described by a median. Food Animal Production Medicine - UW School of Veterinary Medicine 2
1-TOC Table of Contents Section Page # Title Tab 1 Table of Contents TOC I. Populations 2 Adult Cow Numbers Size II. Culling 3 Turnover Summary (Last 12 months) Cull 4 Days in Milk Distribution of Culled Cows DimCull 5 Calving and Culling Fresh 6 DIM at Culling vs. Relative Value of Culled Cow Relv II. Production 7 Rolling Herd Average, Heifer and Cow ME's RHA 8 Current ME35 vs. Days In Milk MEDIM 9 Milk Production (Lbs/Cow/Day) Milk 1 "Rolling" Peak Milk Production-All Lactating Cows Peak-h 11 Current Peak Milk (2+ Lactating Cows) vs. Days In Milk Peak-c 12 Milk Fat and Protein Tests %Fat 13 DIM and Current Test Day Percent Fat DIM%F 14 Bulk Tank Milk and DHI Milk Tank III. Reproduction 15 Age at First Calving distribution Age 16 Days in Milk DIM 17 Days Dry Distribution Dry 18 Days Open, Pregnant Cows ADO 19 Days in Milk at First Breeding, All cows bred DIB 2 Reported Services per Pregnancy, Pregnant Cows S-C 21 Reported Services per Pregnancy, All Cows S-C all IV. Genetics 22 Net Merit Trends NM$-h 23 Previous ME35 vs. Sire PTA PTAM V. Mastitis 24 Subclinical Mastitis Data Mast 25 Prevalence and New Infections Rates 26 Dry Cow and Heifer Summary DryCow 27 Bulk Tank Contribution Bulk Tank 28 Individual SCC SCC Food Animal Production Medicine - UW School of Veterinary Medicine 3
Graph: 2-Size Adult Cow Numbers Purpose: To monitor size trends of total herd numbers, dry and lactating cows, and first and second and greater parity groups. Interpretive Comments: In a stable herd with year-around calving, approximately 15% of the herd is expected to be dry. With average turnover rates in an established herd, 35% of the herd is expected to be first lactation. Questions: 1. Note absolute herd size. Is the herd size stable, increasing or decreasing? 2. What is the approximate % of the herd that is first lactation cows? 3. If herd has expanded, was the expansion done with first lactation or older cows? 4. What is the approximate % of the herd that are dry cows? Is the % relatively constant or highly variable in this herd? Food Animal Production Medicine - UW School of Veterinary Medicine 4
2-Size Example Herds: Big Year (2/17/1) Herd Adult Cow Numbers Grazier (5/28/1) Herd Adult Cow Numbers 16 14 14 12 12 1 Number of Cows 1 8 6 4 83 27 8 6 4 71 32 2 2 3/2/1999 4/19/1999 5/24/1999 6/21/1999 7/19/1999 8/23/1999 9/2/1999 1/17/1999 11/22/1999 12/19/1999 1/16/2 2/21/2 3/2/2 4/16/2 5/21/2 6/18/2 7/16/2 8/2/2 9/17/2 1/21/2 11/2/2 12/18/2 1/2/21 2/17/21 6/29/1999 7/28/1999 8/26/1999 9/28/1999 1/28/1999 11/29/1999 12/28/1999 1/24/2 2/24/2 3/22/2 4/18/2 5/16/2 6/26/2 7/21/2 8/24/2 9/26/2 1/24/2 Number of Cows 11/29/2 12/27/2 1/26/21 2/28/21 3/22/21 4/17/21 5/28/21 Test Date Test Date Total Number of Cows in Herd Total Number of Lactating Cows Total Number of Cows in Herd Total Number of Lactating Cows Number of 1st Lactation Milking Cows Number of 2+ Lactation Milking Cows Number of 1st Lactation Milking Cows Number of 2+ Lactation Milking Cows Percent 1st Lactation Cows in milking herd on last test = 24 Percent 1st Lactation Cows in milking herd on last test = 31 Percent Dry Cows on last test = 19 Percent Dry Cows on last test = 7 Number of tests in last 12 months = 13 Number of tests in last 12 months = 12 Big Year Dairy has increased herd size from about 1 cows to around 14 in the last 12 months. The expansion was completed in a single month with mature cows resulting in a very small proportion of first lactation cows in the herd. The proportion of dry cows at 19% of the herd is currently greater than on a typical dairy. It might reflect the fact that so many lactating cows were purchased at one time approximately a year previously. Grazier Dairy tries to establish a seasonal dairy to match the grass growth curve. Many cows that do not fit the calving window of mid-march to May are sold from the herd as replacement cows to other farms. The proportion of dry cows is highly variable from month to month because of the seasonal calving. Food Animal Production Medicine - UW School of Veterinary Medicine 5
Graph: 3-Cull Turnover Summary (Last 12 Months) Purpose: To summarize the numbers and parity groups of cows entering and leaving the herd, as well as the reported reasons for their removal. The box in the lower right contrasts the number of cows culled for each reason in your herd compared to the industry average number of culls in an equivalent sized herd. If the cull codes are used, it is a convenient way to identify herd success and problem areas. Interpretive Comments: Turnover rate equals number of cows leaving the herd divided by the rolling average number of cows in the herd. Average annual turnover rate equals 37%, while goal annual turnover rate equals 25%. For first lactation animals entering the herd, the goal is that less than 25% are culled in the first year. The stated reason for culling is reported by dairy operator and is very subjective. For example, a cow may have several problems such as a high SCC and 2 days open before becoming pregnant. While each reason contributes to her removal, the operator has to choose one answer. Some dairy operators report a default reason such as low production for all cows and do not complete reasons on an individual cow basis. In an average herd, reproduction is the most common reason for culling, followed by mastitis. Questions: 1. Review the in/out numbers. Did the herd expand or contract in the period of the last 12 tests? 2. What proportion of culls were first lactation cows? Of the first lactation cows that entered, approximately what proportion left the herd in the last 12 tests? 3. Did any mature cows enter the herd in the last year? 4. The stated reason for culling is sometimes very subjective. Does the distribution of reasons appear to be rational? 5. Are there any categories where culling is much lower or higher than industry averages? Food Animal Production Medicine - UW School of Veterinary Medicine 6
3-Cull Example Herds: Sand Stall Dairy (11/4/2) Herd Mattress Dairy (12/28/2) Herd Turnover Summary (Last 12 Months) Turnover Summary (Last 12 Months) 9 14 8 12 Number of Cows 7 6 5 4 3 2 Number of Cows 1 8 6 4 1 2 In Out Feet/Legs Dairy Production Reproduction Disease/Injury Died Mastitis In Out Feet/Legs Dairy Production Reproduction Disease/Injury Died Mastitis Reasons for culling Reasons for culling 1st lactation 2nd lactation 3+ lactation 1st lactation 2nd lactation 3+ lactation Average Number of Animals in herd (last 12 months) = 237 Turnover Rate (last 12 months) = 26 Number of tests in last 12 months = 12 Culling Reason Total, # cows culled Industry Ave 88 Your Herd Turnover rate 37% 26% 62 Average Number of Animals in herd (last 12 months) = 39 Turnover Rate (last 12 months) = 4 Number of tests in last 12 months = 1 Culling Reason Total, # cows culled Industry Ave 114 Your Herd Turnover rate 37% 4% 123 Feet/Legs, # cows 7 5 Feet/Legs, # cows 9 Dairy 5 Dairy 6 122 Production 11 8 Production 15 Reproduction 17 11 Reproduction 22 Disease/Injury 24 17 Disease/Injury 31 1 Died 12 6 Died 16 Mastitis 13 14 Mastitis 17 Sand Stall Dairy has a turnover rate of 26%, very close to optimal. The distribution of stated reasons for removal appear to be rational and lower than industry averages in all categories except mastitis, which might be the next bottleneck to investigate as a herd health manager. All cows entered the herd as first lactation cows. Mattress Dairy reports a slightly higher turnover rate than the industry average, and more cows left than entered in the past year. All cows entering were first lactation cows. The stated reason for removal is dairy, suggesting that the cows were sold as milk cows to other dairy farms. However, that is not the case. The current software interface between onfarm DairyComp records and DHI converts various reasons to a default Dairy reason for removal. Food Animal Production Medicine - UW School of Veterinary Medicine 7
Graph: 4-DimCull Days in Milk Distribution of Culled Cows Purpose: To monitor the stage of lactation when cows are removed from the herd. Interpretive Comments: Questions: The histogram represents all cows that were sold or died in the past year. The y-scale indicates the percent of the herd, not the % of culled cows, that are removed during each 3-day interval. Please note that the range of the y-scale varies from graph to graph. Cows removed from the herd in the first 3 days-in-milk usually represent fresh cow disease problems. These are also very costly because the cow will have been housed and fed through the dry period or through the heifer raising years, only to produce milk for a few weeks. Our data suggests that the average herd removes about 4% of all cows in the herd within 3 days of calving, with a range from about 2-12%. High removal rates in this period usually reflect problems with dry cow management. Cows removed from the herd at greater than 45 days-in-milk usually represent good producing cows that are sold because of reproductive problems. Our data suggests that the industry removes about 4% of all cows after 45 DIM, with a range from about 2-7%. 1. Is the removal rate during the first 3 days after calving higher or lower than the industry average? 2. What factors could be influencing the rate? 3. What is the rate of removal from the herd at 45 days in milk or greater? 4. If higher than average, does the herd also have poorer overall reproductive performance than average? If lower, does the herd have better overall reproductive performance? Food Animal Production Medicine - UW School of Veterinary Medicine 8
4-DimCull Example Herds: 4.5% 4.% 3.5% 8 Sand Stall Dairy (11/4/2) Cow Herd Distribution of DIM at Culling 1 12.% 1.% 33 Mattress Dairy (12/28/2) Cow Herd Distribution of DIM at Culling 3.% 7 8.% 2.5% 2.% 1.5% 1.%.5% 6 4 3 1 6 4 3 4 3 6 3 2 3 Percent of Herd 6.% 4.% 2.% 12 13 7 11 12 7 11 1 8 12 1 7 1 3 13.%.% 1-3 31-6 61-9 91-12 121-15 151-18 181-21 211-24 241-27 271-3 31-33 331-36 361-39 391-42 421-45 >45 1-3 31-6 61-9 91-12 121-15 151-18 181-21 211-24 241-27 271-3 31-33 331-36 361-39 391-42 421-45 >45 Percent of Herd DIM at Culling DIM at Culling % of Herd % of Herd Number of cows culled between 7/13/1 and 1/25/2 = 73 Average Number of Animals in herd (last 12 months) = 237 Number of cows culled between 9/12/1 and 12/1/2 = 161 Average Number of Animals in herd (last 12 months) = 39 Average DIM at Removal = 236 Median DIM at Removal = 219 Average DIM at Removal = 193 Median DIM at Removal = 161 Sand Stall Dairy removed 3.4% of their cows within the first 3 DIM, a slightly lower removal rate than average. The dairy has excellent dry cow management and fresh cow health. The 4.2% removal rate at greater than 45 DIM is approximately industry average. Mattress Dairy removed almost 11% of all calving cows within the first 3 days after calving, many of which died. The manager should work with advisors to identify the reasons for sick and injured fresh cows and take corrective actions. The 4.2% removal rate after 45 DIM is about average for the industry. Food Animal Production Medicine - UW School of Veterinary Medicine 9
Graph: 5-Fresh Calving and Culling Purpose: To monitor the number of calvings and subsequent culling on a monthly basis. Interpretive Comments: Questions: The wide shaded bars represent the total number of calvings that occurred during the month, with gray representing the first lactation cows and the checked area representing the older cows. The narrow interior bars indicate the number of cows that were removed from the herd at less than 31 days-in-milk during the month, with black representing first lactation cows and white representing older cows. The reported % represents the percentage of all calvings during the month that resulted in culling within 3 days. As before, the industry average is about 4%. The 6-month average removal within 3 DIM is reported in the text below. It may vary with the <3 day cull rate from the prior graph, as this represents the most recent 6 months whereas the prior graph summarizes the past year. The superimposed line represents the total number of cows removed, regardless of stage of lactation, during the month. 1. Is the number of calvings per month very stable, moderate, or highly variable? 2. Is the loss of cows <3 DIM during the past 6 months higher or lower than the rate of the past year? 3. Were there any individual months that presented unusual problems? 4. Were there any individual months where an unusual number of cows were removed, regardless of stage of lactation? Food Animal Production Medicine - UW School of Veterinary Medicine 1
5-Fresh Example Herds: 35 Sand Stall Dairy (11/4/2) Cow Calvings and Fresh Cow Culls or Deaths by Month Mattress Dairy (12/28/2) Cow Calvings and Fresh Cow Culls or Deaths by Month 5 3 45 25 4 Number of Cows 2 15 1 Number of Cows 35 3 25 2 15 5 1 % May-2 % Jun-2 4% Jul-2 6% Aug-2 7% Sep-2 % Oct-2 5 % 13% 3% 9% 1% 3% Month Jun-2 Jul-2 Aug-2 Sep-2 Oct-2 Nov-2 Total Lact 2+ Calvings Month Total Lact 1 Calvings Total Lact 2+ Calvings Lact 2+ Cows sold/died <31 DIM Total Lact 1 Calvings Lact 1 Cows sold/died <31 DIM Lact 2+ Cows sold/died <31 DIM Total Sold and Died Lact 1 Cows sold/died <31 DIM Total Sold and Died Percent Reported = Cows Sold or Died <31 Days in Milk as a Percent of Calvings Percent of Fresh Cows Leaving within 3 days, 6 Month Weighted Average = 4% Percent Reported = Cows Sold or Died <31 Days in Milk as a Percent of Calvings Percent of Fresh Cows Leaving within 3 days, 6 Month Weighted Average = 6% Sand Stall Dairy had almost 3 times as many cows calve during August as in May. Almost 7% of the herd was culled in September, perhaps because of crowding after the August calvings. The loss of fresh cows reached 6 and 7% during August and September, compared to almost none in the other months represented. Mattress Dairy has a steadier calving pattern and removal rate over the past 6 months, but the number of calvings does almost double. Virtually all of the cows removed within the first 3 DIM were older cows (white bar). Food Animal Production Medicine - UW School of Veterinary Medicine 11
Graph: 6-Relv DIM at Culling vs. Relative Value (ME35) of Culled Cow Purpose: To visualize the relative quality of the individual culled cows and the approximate time into the lactation at which they were culled. Interpretive Comments: Relative value is calculated by taking the ME35 of the individual cow and dividing it by the herd average ME35. In this chart, the ME35 represents the relative value of the current lactation for the individual cow. Generally, herds with excellent herd health can cull cows on the basis of low production and will have an average cull cow relative value of about 85%. An average relative value of culled cows that is equal to 1 means that the culled cows were as good as the cows remaining in the herd. A cow with a relative value of 75% removed at 3 days in milk could be a very low producer, or it could be an excellent cow that had severe disease problems that prevented her from getting a good start on her lactation. A cow with a relative value of 11% culled at 1 days in milk is a cow that started her lactation very well, but was removed too early, probably because of disease problems. A cow with a relative value of 11% culled at 4 days in milk is likely a reproductive failure. A regression line and formula are calculated. Generally, the greater the r 2 value, the more orderly and controlled are the reasons for culling. In plain language, an r 2 value of.25 indicates that relative value explains 25% of the basis for time of removal, whereas an r 2 value of.1 means that production explains on 1% of the time of removal. Questions: 1. What is the herd average relative value of culled cows? Were the culled cows poorer producers than the herd average? 2. Is there any sign of common fresh cow health disasters? 3. Is there evidence of high rates of reproductive failure culls? 4. Does the r 2 value suggest order or lack of control? Food Animal Production Medicine - UW School of Veterinary Medicine 12
6-Relv Example Herds: Sand Stall Dairy (11/4/2) Cow Mattress Dairy (12/28/2) Cow DIM at Culling vs. Relative Value of Culled Cow DIM at Culling vs. Relative Value of Culled Cow 15 15 Relative Value of Current Lactation 13 11 9 7 5 Relative Value of Current Lactation 13 11 9 7 5 3 1 2 3 4 5 6 DIM at Culling 3 1 2 3 4 5 6 DIM at Culling Relative Value (ME) Linear (Relative Value (ME)) Relative Value (ME) Linear (Relative Value (ME)) Average Relative Value of Culled Cows = 83% Average Relative Value of Culled Cows = 88% Median Relative Value of Culled Cows = 82% Median Relative Value of Culled Cows = 88% Note: Some cows are removed before they have a ME35 or relative value and are therefore not represented on the graph Note: Some cows are removed before they have a ME35 or relative value and are therefore not represented on the graph y =.64x + 67.847 R 2 =.244 y =.644x + 74.25 R 2 =.167 Relative Value = ME35 at Removal Current Herd Average ME35 x 1 Relative Value = ME35 at Removal Current Herd Average ME35 x 1 Selection Criteria: Selection Criteria: Cull Code=21-28 Cull Code=21-28 Sand Stall Dairy had no cows culled within the first 18 days with RV greater than 9%. The r 2 value of.24 indicates that production level explained about 24% of the variation in days-inmilk at removal. Mattress Dairy had many above average cows removed before 2 days in milk, suggesting health problems with relatively fresh cows. The r 2 value of.17 suggests less control over stage of removal than the example dairy to the left. Food Animal Production Medicine - UW School of Veterinary Medicine 13
Graph: 7-RHA Rolling Herd Average, Heifer and Cow ME s Purpose: To monitor rolling herd average milk (RHA), as well as mature equivalent 35 day milk (ME35) of first lactation and mature cow groups. Interpretive Comments: There is more momentum in RHA than ME35, meaning that RHA resists changes in direction more than ME35. ME35 is independent of herd calving intervals, whereas RHA is not. Long calving intervals will lower RHA and spread the difference between RHA and ME35. ME35 includes a conversion to 2X milking, so RHA and ME35 tend to be closer in absolute value in herds milked 3 times a day. In typical herds, first lactation ME35 milk is an average of 3-5 pounds greater than the ME35 of second and greater lactation cows. Questions: 1. Based upon ME35, is herd production going up or down? 2. Relative to ME production, is there a difference between first lactation and mature cow ME s? 3. Does either subgroup appear to be performing differently, better or worse, than the other? Food Animal Production Medicine - UW School of Veterinary Medicine 14
7-RHA Example Herds: Guru (2/19/1) Herd Diverging (5/23/1) Herd 335 Rolling Herd Average, Heifer and Cow ME's 245 Rolling Herd Average, Heifer and Cow ME's 33 325 32656 24 23869 32 315 235 Milk Production, lbs 31 35 3 295 29 285 28 275 3486 28744 Milk Production, lbs 23 225 22 215 21 21344 27 25 265 26 2 19729 255 25 195 245 19 2/18/1999 3/22/1999 4/26/1999 5/25/1999 6/28/1999 8/11/1999 9/15/1999 1/13/1999 11/15/1999 12/13/1999 1/1/2 2/17/2 3/23/2 4/24/2 Test Date 5/31/2 7/3/2 7/31/2 8/28/2 9/25/2 1/23/2 11/27/2 12/21/2 1/18/21 2/19/21 6/23/1999 8/2/1999 8/31/1999 9/28/1999 1/26/1999 11/24/1999 12/22/1999 1/21/2 2/23/2 3/22/2 4/26/2 5/25/2 6/22/2 7/27/2 Test Date 8/3/2 9/27/2 1/26/2 11/3/2 12/21/2 1/18/21 2/21/21 3/27/21 4/26/21 5/23/21 RHA MILK LBS 1ST 35 ME MILK LBS GT1 35 ME MILK LBS RHA MILK LBS 1ST 35 ME MILK LBS GT1 35 ME MILK LBS Guru Dairy shows a very strong rise in average ME35 values and Rolling Herd Average Milk. The first lactation cows are performing tremendously and slightly better than expected relative to the older cows. The changes in ME35 precede the directional changes in RHA by a month or two. Diverging Dairy shows declining RHA milk starting in September of 2. The ME35 graph shows that the production problem lies exclusively with the mature cows in the 2 nd or greater lactations, and that the first lactation cows are doing wonderfully. An investigation of herd production problems on the dairy would focus almost exclusively on problems with the mature cows. Food Animal Production Medicine - UW School of Veterinary Medicine 15
Graph: 8-MEDIM Current ME35 vs. Days in Milk Purpose: To monitor peak milk of mature cows and obtain more current information than is available from the standard reported herd average ME35. Interpretive Comments: Each dot represents a single cow and is positioned over her days in milk on the current test and at the ME35 milk that she has achieved at her current stage of lactation. The month abbreviations below the x-axis suggest the approximate time of year that the cow calved. ME35 milk standardizes individual animal production for age, lactation, 2x milking, and season. ME35 will respond to production changes that occur until 35 days in milk, after which it is fixed. ME35 is more sensitive to change in early lactation than late lactation. The ME35 of a cow who is more persistent than average will increase as the cow progresses through the lactation, while the ME35 of a cow who is less persistent than average will fall slightly as the lactation progresses. Low production cows tend to be culled earlier in lactation than high producers, resulting in a selected group of higher producers on the right side of the graph. The regression line and formula can give an indication of change between early and late lactation. The slope A (y = Ax + constant) indicates how much ME35 changes for each increasing day in milk. From a moderate number of farms, the typical value of A ranges from about 5-15. In general, values approaching 2 or more are found in herds with relatively disappointing early lactation performance and good late lactation production. Questions: 1. Should we expect to see a seasonal effect on the ME35 values of cows that calve in July? 2. How would you expect the use of BST in the herd affect this graph? Food Animal Production Medicine - UW School of Veterinary Medicine 16
8-MEDIM Example Herds: Steady (2/28/1) Cow Ketone (2/7/1) Cow 5 Current ME35 vs Days in Milk 4 Current ME35 vs Days in Milk 45 35 4 35 3 Current ME35, lbs 3 25 2 15 1 Current ME35, lbs 25 2 15 1 5 5 3 6 9 12 15 18 21 24 27 3 33 36 DIM Feb Jan Dec Nov Oct Oct Sep Aug Jul Jun May Apr Mar Month of Calving 3 6 9 12 15 18 21 24 27 3 33 36 DIM Feb Jan Dec Nov Oct Sep Aug Jul Jun May Apr Mar Feb Month of Calving CURRENT ME35 MILK LBS Linear (CURRENT ME35 MILK LBS) CURRENT ME35 MILK LBS Linear (CURRENT ME35 MILK LBS) Average ME35 = 27196 Standard Deviation = 3957 Coefficient of Variation = 14.6% DIM 1-1 Average ME35 # cows Ave 128 2584 Average ME35 = 25865 Standard Deviation = 474 Coefficient of Variation = 18.3% DIM 1-1 Average ME35 # cows Ave 42 22537 y = 11.263x + 2511 R 2 =.1431 11-2 21-35 193 132 26526 2923 y = 26.55x + 2195 R 2 =.3415 11-2 21-35 42 17 26613 28826 Selection Criteria: Dim>=1, Test Day Milk>=1 To view cows over 36 days in milk adjust the x-axis scale Selection Criteria: Dim>=1, Test Day Milk>=1 To view cows over 36 days in milk adjust the x-axis scale Steady Dairy shows a herd with stable, consistent performance of cows over the past year. The average ME35 goes up 11.26 lbs per day of lactation and the difference between the early and late groups is about 4, lbs. Culling has removed lower producers that are greater than 2 days in milk. Ketone Dairy has a long-term problem of fresh cow health problems of ketosis and hepatic lipidosis in many cows, but most cows produce milk quite well after they have gotten through the early lactation period. BST is also used in the herd. The ME35 increases 26 lbs. Per day of lactation and the difference between the early and late group is about 6, lbs. Food Animal Production Medicine - UW School of Veterinary Medicine 17
Graph: 9-Milk Milk Production (Lbs/Cow/Day) Purpose: To monitor daily milk production per cow over time. Interpretive Comments: Milk per cow reflects productivity, but is confounded by days in milk and other factors such as age and parity of the herd. Management level milk adjusts actual milk to standard 15 days in milk, constant fat %, protein %, and parity. Questions: 1. Is the herd doing better at the current test than the previous test? Which monitor is best to make comparisons over time? 2. Is the herd doing better at the current test than a year ago? Food Animal Production Medicine - UW School of Veterinary Medicine 18
9-Milk Example Herds: Steady (2/28/1) Herd Grazier (5/28/1) Herd Milk Production (Lbs/Cow/Day) Milk Production (Lbs/Cow/Day) 95 75 7 9 65 85 6 Milk/Cow/Day, lbs 8 Milk/Cow/Day, lbs 55 5 75 45 4 7 35 65 9/15/1998 1/19/1998 12/11/1998 1/27/1999 3/1/1999 4/14/1999 5/18/1999 6/23/1999 7/28/1999 9/1/1999 1/6/1999 11/9/1999 12/15/1999 1/2/2 Test Date 2/23/2 3/3/2 5/4/2 6/13/2 7/2/2 8/29/2 1/4/2 12/1/2 1/16/21 2/28/21 3 6/29/1999 7/28/1999 8/26/1999 9/28/1999 1/28/1999 11/29/1999 12/28/1999 1/24/2 2/24/2 3/22/2 4/18/2 5/16/2 6/26/2 7/21/2 Test Date 8/24/2 9/26/2 1/24/2 11/29/2 12/27/2 1/26/21 2/28/21 3/22/21 4/17/21 5/28/21 Average Milk/cow/day Average Mgmt Level Milk Average Milk/cow/day Average Mgmt Level Milk 12 Month Average Milk/Cow/Day = 79 12 Month Average Milk/Cow/Day = 48 12 Month Average Mgmt Level Milk = 78 12 Month Average Mgmt Level Milk = 5 Steady Dairy shows an increase in actual milk and MLM since the last test, and while actual milk is slightly increased from one year ago, MLM is down. Both indexes indicate a decline from the period in the spring of 1999. Actual milk at Grazier Dairy shows the variation possible due to extreme ranges of days in milk. In the period from March through December, the average herd production looks like a lactation curve. Conversely, the MLM index remains relatively flat. The MLM index suggests that the cows are doing better than expected in December or January. Food Animal Production Medicine - UW School of Veterinary Medicine 19
Graph: 1-Peak-h Rolling Peak Milk Production Purpose: To monitor average peak performance of separate parity groups over time. Interpretive Comments: Each dot represents the average peak of all animals currently lactating. There is much momentum in this index. The numbers printed represent first lactation peaks divided by later lactation peaks. Peak milks are strongly dependent on early lactation nutritional management. Peaks typically associated with various rolling herd averages are as follows: Herd Lactation Avg, Lbs Peak, 1 st Lactation Peak, 2+ Lactation 27, 87 116 26, 85 112 25, 82 19 24, 8 15 23, 77 12 22, 75 98 21, 72 94 2, 7 91 19, 67 87 18, 65 84 17, 62 8 16, 6 77 The normal ratio of first lactation peaks to second and greater lactation peaks is 74 to 78%. If the peak ratio is <74%, the first lactation cows are performing poorly relative to older cows. Conversely, if the peak ratio is >78%, the older cows are performing poorly relative to first lactation cows. Questions: 1. Is there a trend in peak milks? 2. Does the calculated peak ratio suggest any problems? 3. Is any subgroup doing better or worse than expected? Food Animal Production Medicine - UW School of Veterinary Medicine 2
1-Peak-h Example Herds: Diverging (5/23/1) Herd Red Pencil (3/13/1) Herd "Rolling" Peak Milk Production - All Lactating Cows "Rolling" Peak Milk Production - All Lactating Cows 12 12 14 1 1 87 8 73 8 8 6 Milk/Cow/Day, lbs 6 4 2 75 73 69 7 7 7 68 7 7 69 71 73 81 78 74 7 79 79 8 81 86 85 84 82 4 2 78 79 8283 82 79 8 82 84 8 77 76 85 82 8 79 85 83 79 78 79 78 78 77 6/23/1999 8/2/1999 8/31/1999 9/28/1999 1/26/1999 11/24/1999 12/22/1999 1/21/2 2/23/2 3/22/2 4/26/2 5/25/2 6/22/2 7/27/2 8/3/2 9/27/2 5/18/1996 6/21/1996 7/2/1996 8/23/1996 9/21/1996 1/19/1996 1/1/1997 3/25/1997 6/2/1997 8/28/1997 2/14/1998 4/24/1998 9/25/1998 12/29/1998 4/23/1999 9/7/1999 11/19/1999 1/2/2 3/29/2 5/23/2 8/1/2 1/24/2 12/19/2 3/13/21 Milk/Cow/Day, lbs 1/26/2 11/3/2 12/21/2 1/18/21 2/21/21 3/27/21 4/26/21 5/23/21 Test Date Test Date 1st Peak milk lbs 2+ Peak Milk lbs PEAK MILK RATIO (1st/older) 1st Peak milk lbs 2+ Peak Milk lbs PEAK MILK RATIO (1st/older) Target Peak Ratio = 73-78% Target Peak Ratio = 73-78% Diverging Dairy has an emerging problem with mature cows that began in early 2. The average peak of the older cows has declined, whereas the first lactation cows have increased. In the short term, both groups have increased slightly in the last test interval. The peak ratio is now 84%. Similar trends are shown in the ME35 graph. Red Pencil Dairy has improved average peaks for both groups over the past year compared to two years ago. Currently, there is a very small decline in both first lactation and older cow groups starting to appear at the last test. Food Animal Production Medicine - UW School of Veterinary Medicine 21
Graph: 11-Peak-c Current Peak Milk (2+ Lactating Cows) vs. Days in Milk Purpose: To monitor peak milk of mature cows and obtain more current information than is available from the standard reported average peak milk. Interpretive Comments: Peaks of 2 nd and greater lactation cows are shown as solid circles, while peaks of first lactation cows are shown as open triangles. A single dot represents a single cow and is positioned over her days in milk at the current test and at the level of the peak milk that she achieved at some undescribed point in her lactation. In general, the peak milk value is established by 6 days in milk, but the cow carries that value with her to the end of her lactation. The month abbreviations below the x-axis suggest the approximate time of year that the cow calved. Cows that calve in June through September are expected to peak at lower levels than if they had calved during cooler months of the year. Because low producers tend to be culled earlier in lactation than high producers, culling tends to remove cows disproportionately from the lower right portion of the graph. Questions: 1. Does season of year appear to affect peak milk in this herd? 1. How do the most recently fresh cows appear to be performing relative to herdmates who calved in past months? 2. How does the culling of low producers at mid-lactation affect the appearance of this graph? Food Animal Production Medicine - UW School of Veterinary Medicine 22
11-Peak-c Example Herds: Birdwatcher Dairy (12/23/2) Cow Hot August Dairy (1/19/2) Cow 17 Current Peak Milk (Mature Cows) vs. Days In Milk 15 Current Peak Milk (Mature Cows) vs. Days In Milk 15 13 13 11 Peak Milk, lbs 11 9 7 5 Peak Milk, lbs 9 7 5 3 3 1 3 6 9 12 15 18 21 24 27 3 33 36 39 Days In Milk 1 3 6 9 12 15 18 21 24 27 3 33 36 39 Days In Milk Dec Nov Oct Sep Aug Jul Jun May Apr Mar Feb Jan Dec Oct Sep Aug Jul Jun May Apr Mar Feb Jan Dec Nov Oct Month of Calving Month of Calving Lactation 1 Peak Milk Lactation 2+ Peak Milk Lactation 1 Peak Milk Lactation 2+ Peak Milk Lactation 1 Peak Milk Lactation 2+ Peak Milk Lactation 1 Peak Milk Lactation 2+ Peak Milk Average Peak Milk = 82 Average Peak Milk = 17 Average Peak Milk = 82 Average Peak Milk = 97 Standard Deviation = 9 Standard Deviation = 14 Standard Deviation = 13 Standard Deviation = 19 Coefficient of Variation = 9.3% Coefficient of Variation = 7.5% Coefficient of Variation = 6.2% Coefficient of Variation = 5.2% Selection Criteria: DIM>5, DIM<365 Selection Criteria: DIM>5, DIM<365 Birdwatcher Dairy peaks appear to be quite steady over the past year. There is some suggestion that new high peaks in the 15 lb range have started to show since September calvings, but not before. Overall, this is a very steady and excellent record. Hot August Dairy peak milks appear to have been lower on cows that calved in July and August. There are more mature cows below 7 lbs. than in the earlier months, and fewer appear to be exceeding 12 lbs. The decline has occurred in cows that calved in July and August, so it may reflect a seasonal problem. However, this is a more dramatic decline than typical. Food Animal Production Medicine - UW School of Veterinary Medicine 23
Graph: 12-%Fat Milk Fat and Protein Tests Purpose: To monitor milk fat % and protein % over time. Interpretive Comments: Fat % and protein % vary with breed. 1998 Wisconsin DHI shows the following breed average milk components: Breed Ayrshire Brown Swiss Guernsey Holstein Jersey Milking Shorthorn Fat % 4. 4.1 4.6 3.7 4.8 4. Protein % 3.3 3.6 3.5 3.2 3.8 3.3 Fat % that is.3% higher than breed average suggests that the rations may be short on energy and that the herd would respond with increased milk if corrected. Fat % that is.3% lower than breed average suggests that the herd may be short on fiber and may be experiencing rumen acidosis. There are lactation fat % and protein % curves that are almost mirror images of the milk curve. If the herd is seasonal, expect wide variation in component % as the herd changes from short days in milk to long days in milk. Questions: 1. Are there any months where fat % is abnormally low or high? 2. Are these seasonal problems or not? 3. Are there any months where protein % is too low or too high? Food Animal Production Medicine - UW School of Veterinary Medicine 24
12-%Fat Example Herds: Guru (2/19/1) Herd Milk Fat and Protein Tests Ketone (2/7/1) Herd Milk Fat and Protein Tests 4.1 4.3 3.9 4.1 3.7 3.9 Milk Fat and Protein Test, % 3.5 3.3 3.1 Milk Fat and Protein Test, % 3.7 3.5 3.3 3.1 2.9 2.9 2.7 2.7 2.5 2.5 2/18/1999 3/22/1999 4/26/1999 5/25/1999 6/28/1999 8/11/1999 9/15/1999 1/13/1999 11/15/1999 12/13/1999 1/1/2 2/17/2 3/23/2 4/24/2 Test Date 5/31/2 7/3/2 7/31/2 8/28/2 9/25/2 1/23/2 11/27/2 12/21/2 1/18/21 2/19/21 2/19/1999 3/19/1999 4/15/1999 5/14/1999 6/22/1999 8/3/1999 9/3/1999 1/5/1999 11/5/1999 12/5/1999 1/7/2 2/9/2 3/14/2 4/1/2 Test Date 5/11/2 6/11/2 7/13/2 8/7/2 9/11/2 1/6/2 11/6/2 12/6/2 1/6/21 2/7/21 TEST DAY AVERAGE FAT PERCENT TEST DAY AVERAGE PRO PERCENT TEST DAY AVERAGE FAT PERCENT TEST DAY AVERAGE PRO PERCENT 12 Month Average Percent Fat = 3.5 12 Month Average Percent Fat = 3.8 12 Month Average Percent Protein = 3.1 12 Month Average Percent Protein = 3.1 Guru Dairy shows large fluctuations in fat % over the past 8 months, ranging from 3.2% to 3.9%. While the 3.2% test in July 2 is alarming, the most recent test at 3.35% in February is even more alarming because of the season. The protein % shows the expected drop in May 2 when testing methods changed. Ketone Dairy shows an unusually high milk fat % for Holsteins, particularly over the past 3 months. The high fat % is suggestive of rations that are moderately low in energy. Usually ration manipulations to reduce fiber and increase energy in this situation will increase milk and reduce fat% to more typical ranges. Food Animal Production Medicine - UW School of Veterinary Medicine 25
Graph: 13-DIM%Fat DIM and Current Test Day Percent Fat Purpose: To display the individual cow fat % values by stage of lactation. Interpretive Comments: The fat % curve is almost opposite a lactation curve. Milk fat % is expected to be high in early lactation, decline to a low near 6 days in milk, and then gradually increase as the lactation progresses. The variation above and below is expected to be about 1% of the lactation average fat %. Abnormal low fat % is suggestive of dietary fiber deficiency or dietary fat excess. Abnormal high fat % is suggestive of excess dietary fiber, inadequate ration energy, and sometimes ketosis. Questions: 1. Does the herd scatterplot resemble the expected fat % curve? 2. Estimate the overall average fat %. 3. Are there any cows that are either alarmingly low or high? Food Animal Production Medicine - UW School of Veterinary Medicine 26
13-DIM%F Example Herds: Guru (2/19/1) Cow Ketone (2/7/1) Cow 6 DIM and Current Test Day Percent Fat 6 DIM and Current Test Day Percent Fat 5.5 5.5 5 5 Current Test Day Fat, % 4.5 4 3.5 3 Current Test Day Fat, % 4.5 4 3.5 3 2.5 2.5 2 2 1.5 3 6 9 12 15 18 21 24 27 3 33 36 DIM 1.5 3 6 9 12 15 18 21 24 27 3 33 36 DIM Average Percent Fat = 3.4 Standard Deviation =.78 Coefficient of Variation = 4.4% TEST DAY FAT PCT Average Percent Fat = 4. Standard Deviation =.78 Coefficient of Variation = 5.1% TEST DAY FAT PCT Cows >= 5.% Fat and < 7 DIM= 5 of 42 (12%) Cows < 2.5% Fat = 33 of 37 (11%) Cows >= 5.% Fat and < 7 DIM= 6 of 26 (23%) Cows < 2.5% Fat = 6 of 114 (5%) Selection Criteria: Dim>=1, Test Day Milk>=1 To view cows over 36 days in milk adjust the x-axis scale Selection Criteria: Dim>=1, Test Day Milk>=1 To view cows over 36 days in milk adjust the x-axis scale The overall average % fat at Guru Dairy is 3.4%. There are many cows with abnormal fat %, both high and low, spread across all stages of lactation. The herd percentages of unusual fat % exceeds out guidelines on both high fat % in the fresh cows, as well as low tests across lactation. If there are metabolic health problems in this herd, diagnostice testing for both ketosis and ruminal acidosis should be performed. At Ketone Dairy, 23% of the cows less than 7 days in milk showed milk fat % greater than 5%. This is very suggestive of a fresh cow ketosis problem. Testing for ketones should be performed on both closeup dry cows and fresh cows to identify if either group is affected. Food Animal Production Medicine - UW School of Veterinary Medicine 27
Graph: 14-Tank Bulk Tank Milk and DHI Milk Purpose: To monitor total milk sales from dairy and reconcile DHI and milk plant weights. Interpretive Comments: Bulk tank milk is reported by the milk truck driver who records the amount before emptying the tank and hauling it away. DHI milk pounds are expected to be equal or up to 3% higher than bulk tank weight. DHI measures milk from all cows, but some of that milk is discarded because of antibiotics, fed to calves, or used for other purposes. Therefore, bulk tank milk is expected to be slightly less than DHI. DHI milk meters can malfunction resulting in variation. Bulk tanks can shift resulting in errors in dipstick calibration. Bulk tank pickup may not be synchronized with the completion of milking, resulting in variance. Unequal milking intervals paired with am/p.m. testing can produce variance Questions: 1. Review the absolute pounds over the past year. Estimate the high and low gross milk income per day in the last year. 2. Is there a difference between bulk tank and DHI milk? What would be some reasons for a difference in this herd? Food Animal Production Medicine - UW School of Veterinary Medicine 28
14-Tank Example Herds: Painted (3/7/1) Herd Grazier (5/28/1) Herd 19 Bulk Tank Milk and DHI Milk 8 Bulk Tank Milk and DHI Milk 7 18 6 Daily Milk from Herd, lbs 17 16 15 5 4 3 2 14 1 13 4/6/1999 5/6/1999 6/3/1999 7/9/1999 8/6/1999 9/3/1999 1/7/1999 11/4/1999 12/8/1999 1/17/2 2/9/2 3/9/2 4/6/2 5/4/2 6/7/2 7/7/2 8/11/2 9/14/2 1/6/2 11/6/2 12/8/2 1/1/21 2/9/21 3/7/21 6/29/1999 7/28/1999 8/26/1999 9/28/1999 1/28/1999 11/29/1999 12/28/1999 1/24/2 2/24/2 3/22/2 4/18/2 5/16/2 6/26/2 7/21/2 8/24/2 9/26/2 Daily Milk from Herd, lbs 1/24/2 11/29/2 12/27/2 1/26/21 2/28/21 3/22/21 4/17/21 5/28/21 DHI Total Pounds Test Date Bulk Tank Pounds DHI Total Pounds Bulk Tank Pounds Test Date Current Month Percent Shipped = 99 Current Month Percent Shipped = 9 12 Month Average Percent Shipped = 13 12 Month Average Percent Shipped = 93 Painted Dairy has sold more milk over the past year than DHI testing has measured. This usually reflects a problem with either the meters used for testing, or it may reflect a milking system inadequacy when the meters are introduced for testing. Grazier Dairy shows less milk sold than found on DHI testing. This may reflect milk used for calves, milk withheld because of antibiotic withdrawal, or other uses. The disparity between bulk tank an DHI weights is greatest when the herd is milking the most and when calves would be consuming milk. In this seasonally calving herd, there is tremendous difference in milk income per month between the high and low production months. Food Animal Production Medicine - UW School of Veterinary Medicine 29
Graph: 15-Age Age at First Calving Distribution Purpose: To evaluate the distribution of calving ages of first lactation cows in the herd. Interpretive Comments: The average age at first calving for all Wisconsin DHI herds is 27 months, while the standard industry goal is 24 months. Questions: Very successful replacement rearing programs are capable of calving 8% of their replacements in a 2 month window. A wide distribution of calving age can suggest inconsistent heifer growth rates, reproductive problems in the replacement herd, or inconsistent replacement management goals. A small number of very old animals will have a greater effect on the average age than on the median age at calving. 1. What is the average and median age at first calving? 2. Is the distribution pattern desirable? 3. What does the distribution histogram of calving age tell you about the replacement program? Food Animal Production Medicine - UW School of Veterinary Medicine 3
15-Age Example Herds: Steady (2/28/1) Cow Relaxed (3/12/1) Cow 9 8 Age at First Calving Distribution 2% 5% 93% 25 Age at First Calving Distribution % 6% 4% Number of 1st Lactation Cows 7 6 5 4 3 2 2 15 1 5 1 2 mo 21 mo 22 mo 23 mo 24 mo 25 mo 26 mo 27 mo 28 mo 29 mo 3 mo 31 mo 32 mo 33 mo 34 mo 35 mo 36 mo 2 mo 21 mo 22 mo 23 mo 24 mo 25 mo 26 mo 27 mo 28 mo Number of 1st Lactation Cows 29 mo 3 mo 31 mo 32 mo 33 mo 34 mo 35 mo 36 mo Age in Months Age in Months Average Calving Age in Months = 24 Median Calving Age in Months = 23 Target = 24 Average Calving Age in Months = 27 Median Calving Age in Months = 27 Target = 24 % < 22 months = 2 % > 26 months = 5 % < 22 months = % > 26 months = 6 Selection Criteria: Lactation=1 Selection Criteria: Lactation=1 Steady Dairy achieves 93% of heifers calving between 22 and 27 months of age. The rather tight distribution of ages reflects excellent breeding, and probably feeding, management of the heifers. While the average heifer on Relaxed Dairy has a calf at 27 months, age is extremely varied with animals calving at a similar frequency from 22 to 36 months of age. There would be substantial economic benefits to this dairy in improving the management of the replacement herd. Food Animal Production Medicine - UW School of Veterinary Medicine 31
Graph: 16-DIM Days in Milk Purpose: To monitor herd average days in milk. Interpretive Comments: Herd average DIM can be very stable if similar numbers of cows freshen and are dried off each month. The 12 month rolling average DIM is quite dependent upon herd reproductive performance. Industry goal for rolling average DIM is about 16 days. Cows milk less with increasing DIM, and are expected to decline.12 to.17 pounds per cow per day for each day over 16. Questions: 1. What is the rolling average DIM? 2. What factors cause the average day-in-milk to go down? 3. Do you view the 12-month rolling average days in milk for this herd as a problem? Food Animal Production Medicine - UW School of Veterinary Medicine 32
16-DIM Example Herds: Guru (2/19/1) Herd Grazier (5/28/1) Herd 25 Days In Milk 35 Days In Milk 2 3 25 15 2 Days 1 15 1 5 5 2/18/1999 3/22/1999 4/26/1999 5/25/1999 6/28/1999 8/11/1999 9/15/1999 1/13/1999 11/15/1999 12/13/1999 1/1/2 2/17/2 3/23/2 4/24/2 5/31/2 7/3/2 7/31/2 8/28/2 9/25/2 1/23/2 11/27/2 12/21/2 1/18/21 2/19/21 6/29/1999 7/28/1999 8/26/1999 9/28/1999 1/28/1999 11/29/1999 12/28/1999 1/24/2 2/24/2 3/22/2 4/18/2 5/16/2 6/26/2 7/21/2 8/24/2 9/26/2 Days 1/24/2 11/29/2 12/27/2 1/26/21 2/28/21 3/22/21 4/17/21 5/28/21 Test Date Test Date TEST DAY LACT DIM AVG TEST DAY LACT DIM AVG Rolling Average DIM* (last 12 months) = 189 Target Average Days in milk = 16 Rolling Average DIM* (last 12 months) = 182 Target Average Days in milk = 16 Estimated lost milk sales in past 12 months due to long days in milk = $59,835 (assumes $12. cwt milk price) Estimated lost milk sales in past 12 months due to long days in milk = $15,316 (assumes $12. cwt milk price) * The rolling average DIM value is valid only if the herd tests at regular intervals * The rolling average DIM value is valid only if the herd tests at regular intervals Average DIM at Guru Dairy has increased dramatically over the past year. The herd reached a low average DIM of 15 days, but has climbed steadily to the current 22. There does not appear to be any seasonality to the trend, as the low point in January 2 has not reappeared. The current situation probably reflects herd reproductive problems starting in early in year 2. Grazier Dairy is a seasonal calving dairy that shows a similar repeating pattern each year. With a rolling average DIM of 182, the herd has ranged from 7 to 31 days in milk in the past year. Food Animal Production Medicine - UW School of Veterinary Medicine 33
Graph: 17-Dry Days Dry Distribution Purpose: To monitor distribution of dry day periods over time. Interpretive Comments: The average days dry for Wisconsin dairy herds is 64 days. Industry goal is 55 to 6 days dry. The average Wisconsin herd has about 13% of cows <4 days dry and about 26%> than 7 days dry. Dry periods less than 4 days result in lowered milk production in the next lactation and are estimated to cost $2. for each day below 4. Dry periods greater than 7 days result in feed wasted in maintaining unproductive dry cows and in reduced milk sales from the farm. Losses are estimated in the range of $3. per dry day over 7 days. Questions: 1. Is the distribution of dry periods normal? 2. Is there a trend and is it desirable or undesirable? 3. What management factors can create long dry periods? Food Animal Production Medicine - UW School of Veterinary Medicine 34
17-Dry Example Herds: Guru (2/19/1) Herd Days Dry Distribution Calendar (3/14/1) Herd Days Dry Distribution Percent of Dry Periods 1 9 8 7 6 5 4 3 2 GT7 DAYS DRY PCT 4 to 7 DAYS DRY PCT Percent of Dry Periods 1 9 8 7 6 5 4 3 2 GT7 DAYS DRY PCT 4 to 7 DAYS DRY PCT LS4 DAYS DRY PCT 1 2/18/1999 3/22/1999 4/26/1999 5/25/1999 6/28/1999 8/11/1999 9/15/1999 1/13/1999 11/15/1999 12/13/1999 1/1/2 LS4 DAYS DRY PCT 2/17/2 3/23/2 Test Date 4/24/2 5/31/2 7/3/2 7/31/2 8/28/2 9/25/2 1/23/2 11/27/2 12/21/2 1/18/21 2/19/21 1 4/6/1999 5/11/1999 6/8/1999 7/9/1999 8/12/1999 9/14/1999 1/14/1999 11/9/1999 12/3/1999 1/6/2 2/2/2 3/8/2 4/5/2 Test Date 5/3/2 6/5/2 7/4/2 8/11/2 9/12/2 1/24/2 11/17/2 12/12/2 1/1/21 2/12/21 3/14/21 LS4 DAYS DRY PCT 4 to 7 DAYS DRY PCT GT7 DAYS DRY PCT LS4 DAYS DRY PCT 4 to 7 DAYS DRY PCT GT7 DAYS DRY PCT Average Days Dry (Current Test) = 58 Average Days Dry (Current Test) = 42 Average Days Dry (last 12 months) = 59 Average Days Dry (last 12 months) = 4 Target Days Dry = 56 Target Days Dry = 56 Guru Dairy is doing an exemplary job of minimizing short dry periods, and average with long dry periods. Calendar Dairy is making good progress since December 2 in correcting a substantial problem with short dry periods. In contrast, the herd has always shown good control of long dry periods. Food Animal Production Medicine - UW School of Veterinary Medicine 35