2018/19 Season HUB Weekly Farm Update as at 20th December 2018

Have a wonderful festive season everyone and thank you for your interest in SDH during 2018. We look forward to sharing our ongoing farm and science journey in 2019.

MERRY CHRISTMAS

Over the Christmas break we will be posting the farmlet summary from each week on Facebook but the next full set of notes won’t be until the 11th January

 

Table 1: Farmlet feed wedges and general information

*If you are struggling to view the tables and wedges you can download the pdf here

General Farm Information

Table 2: Key Numbers 20th December 2018

Kale Fodder beet
Soil temp (C) 17.7
Rainfall (mm) 1
Milker Intake Target (kg DM/cow)
Av. Kg MS/cow/day (##incl staph cows) 1.7 1.6
Average milk fat (%) 4.63 4.63
Average milk prot (%) 3.83 3.87
Average SCC (cells/ml) 126 107
Animal Summary Std Kale LI Kale Std FB LI FB
Pink Blue Green Yellow
Milkers – TAD 174 164 171 151
Milkers – OAD 15 4 16 7
Other/Penos 0 4 2 3
  • This week we noticed a drop in the milk fat % for both systems – kale: 4.63 vs. 4.81, FB 4.63 vs. 4.88. Milk fat content is linked to fibre intake, so the drop may reflect a change in pasture composition as we are now grazing regrowth from topped or conserved paddocks and have been on a shorter rotation.
  • For a full update on the Hub mastitis and milking efficiency plan scroll to the last section of this document.

 

Key Decisions: this week

  • This week the decision was made to push the rotation length out for all farmlets to 25 days; once at 25 days we will push the rotation of the LI farmlets closer to 30 days as growth allows. This decision was made to maximise pasture growth and leaf emergence stage and as an insurance policy if conditions go dry. The target is to graze at a 2.5-3 leaf stage, however at a faster rotation length this has meant grazing earlier than this, forgoing extra pasture growth. You can read more about leaf emergence and the 3-leaf principle at: https://www.dairynz.co.nz/feed/pasture-management/assessing-and-allocating-pasture/leaf-stage/
  • We have been asked for clarification about our area allocation of 2.5 ha/day when our paddocks are 2.9 ha. The 2.5 ha/day is the average target area allocation for the 7 days. In practice what this means is that some paddocks are grazed in 24 hours and others over 36 hours depending on pre-graze pasture mass. Because of the range in cultivars across the farm (8 in total) paddocks come back from grazing at different rates. When determining the grazing rotation for each farmlet we consider pre-graze cover, days since grazing, feed quality and post graze cover from the previous grazing (the ‘+’ on the feed wedges indicate paddocks that need attention).
  • We will be applying 25kg N to all LI farmlet paddocks this week (except the silage regrowth ones that were done last week) to maximise growth should conditions go dry post-Christmas.
  • The Std. farmlet paddocks will receive another round of 25 kg N over the next 3 weeks taking into consideration when their last application occurred.
  • The additional N will help with build cover in front of the cows as the round length is extended.
  • No supplement will be cut off the farmlets this week, but we are watching residuals in the LI Kale farmlet as they have more pdks at or above the target line.

General Notes:

  • X7 paddocks were blanket sprayed for thistles this week. Spot spraying is continuing along fencelines and in paddocks with low plant numbers
  • Versatill will be sprayed on x3 second year FB crop paddocks due to the first spray having little impact on the mass of weeds that are present.
  • We have noted a significant difference in the weed burden between crop paddocks with the first year FB paddocks being much cleaner than the 2nd year FB crops. The main difference between these paddocks was a much finer seedbed in the grass to crop paddocks compared with the crop to crop paddocks, reiterating the importance in seedbed preparation prior to crop establishment.
  • As posted on Facebook this week, a white pigmentation has been noticed in the kale leaves. The crop was sprayed with pre-emergent spray Ombare, which can cause this discolouring, however it is of no concern to plant performance or yield.

 

Diagram 1: White pigmentation in kale leaves caused by pre-emergent spray

 

  • New grass paddocks are also experiencing high weed levels including willow weed and dock. The strategy will be graze, top, then reassess the need for spraying after a week.
  • The cows were BCS this week. For this time of year, we are comfortable with where the BCS is sitting. Cows <BCS 4 are being milked once a day.

Table 3: Body condition score of cows 20th December 2018

Std Kale LI Kale Std FB LI FB
Pink Blue Green Yellow
BCS 4.3 4.4 4.2 4.2
% whole herd less than BCS 4 4 3 9 5
  • This week marked the end of 6 weeks Al.
    • From the table below, you can see that the farm exceeded the industry targets; a huge thanks to the SDH farm and tech team for these fantastic results and their commitment and motivation over this period.
    • No intervention was used, and the % submitted is calculated using all cows on farm at mating start date. Cows not submitted for mating because they are already on the cull list have not been excluded from the calculation.
    • The Hereford bulls are now out with the cows (2 bulls per herd). At this stage the bulls will run with the cows until the 8th January at which point we are planning to complete the 10-week mating period with AI using short gestation semen (9th – 16th Jan).

Table 4: Reproduction results

Std Kale LI Kale Std FB LI FB
Pink Blue Green Yellow
6-week SR (%) 97 97 97 97
1st return (%) 36 35 37 36
2nd return (%) 3 4 4 4

Animal Health

  • X4 Cull cows left this week (x3 std. kale and x1 LI FB). Reason for culling included: low production and bad temperament. There are another 5 animals identified for culling, but we are waiting on space at the abattoir.
  • At calf weighing last week it was noticed that some of the calves were coughing. After a visit from the vet, they were diagnosed with lung worm; x18 calves were treated with engemycin to prevent and/or treat pneumonia that could result from the lung worm.

People Management

  • We said goodbye to Shane this week as he takes on his new management opportunity on the West Coast. Again, a big thanks for all his hard work and best wishes for his new challenge! The farm team is in the capable hands of Charlie McGregor as stand in manager whilst we advertise for a replacement research farm manager. This is also just a chance to say a big thankyou to the farm and research tech team for all your hard work and effort for the 1st half of the season. Enjoy the time off you are having between Christmas and New Year and we will see you back refreshed and ready to go again!

Research on-farm

  • The tech team will be taking a well-deserved break over much of the holiday period but will be in to update all the data and complete a farm walk on the 27th December and 3rd January. Detailed farm notes will recommence on Friday 11th December.

SDH Milking efficiency and mastitis management update

Over the last 5 months SDH has embarked on a monitoring program to better understand the mastitis risk of the herd and how this can be managed to minimize the impact on the research being conducted on the farm. This journey started in spring 2017 when the farm was concerned about the BMSCC and had a high incidence of clinical mastitis (16% of herd treated by 1st Dec 2017). Milk cultures identified staph aureus in the herd and the decision was made at that time to run these animals in a separate herd to minimize the risk of cross infection. With the farm already running four milking herds this added considerably to the workload and complexity for the farm team especially around feed management. At the end of the season incidence of mastitis, herd test SCC data and infection status were used to discretionary guide culling decisions. In addition, the fortnightly herd test information was used to inform the dry cow therapy options for individual animals as per SMART SAMM.

On reflection the likely causes for the elevated BMSCC and high clinical rates in 2017 include:

  1. A new herd being put together and comprising animals from 5 different sources with pre-exposure to different pathogens
  2. 60% of the herd adjusting to a new region and exposure to new strains of pathogens
  3. A new farm team getting their head around the complexities of the farm and the operation of the dairy

Fast forward to spring 2018.

An observation by the farm team that some cows were not clearing post calving RMT’s within the expected timeframes raised concerns that we were heading for another spring like 2017. The farm then embarked on a monitoring program to identify the level and type of pathogen infection in the herd. Cows above 200 000 SCC/ml from the fortnightly herd test had aseptic milk samples collected for bacteriology analysis. Between 22 August and 5 December 220 cows have had samples collected and their bacto results are summarized in Table 1.

% quarters % cows sampled % of the total herd
CNS 10 29 9
Staph Aureus 5.5 19 6
Strep Uberis 3.5 11 3
Yeast Species 1 5 1
Not infected 80 36 81

Table 1: Proportion of the SDH herd with major mastitis pathogens present.

 

In December we contracted Josh Wheeler (QCONZ) to undertake a milking assessment where over 2 milkings he observed current milking practices, assessed teat end damage and teat condition, rated the effectiveness of teat spraying, identified risks for mastitis management and control and looked opportunities to simplify the herd management and milk processes.

Armed with the data and Josh’s assessment we convened a meeting with Josh Wheeler (QCONZ) Milk smart expert); Jane Lacy-Hulbert and John Williamson (DairyNZ mastitis experts); Paul Edwards (DairyNZ Milk smart expert); Sunita McGrath (Vet South) and the farm management team to develop a plan for the rest of the season to simplify the herd structure while ensuring we had good control over mastitis prevention and management.

So what have we found? 

  1. BMSCC has fluctuated between 80 and 150 000 for most of this season (compared with 150 to 200, 000 for the same period last season
  2. Only 3% of cows treated for clinical mastitis compared with 16 % last year 
  3. CNS is by far the biggest contributor to subclinical intramammary infections
  4. The percentage of new Staph infections is decreasing but the % of Strep Uberis and CNS infections are increasing slightly
  5. Staph infections are reasonably uniform across quarters but in Strep infected cows double the percentage of back quarters are infected compared with front quarters which is not surprising for an environmental pathogen
  6. Strep infected cows have a higher SCC than Staph infected cows
  7. New infection and self-cure rates for all pathogens in the herd are steady and “average” – 3.5 to 5.3% new infections per month; 3.6 to 8.5% are self-curing; based on SCC data.

What does it tell us?

  1. The herd is showing more resilience to pathogen challenges this season than last as evidenced by the significant reduction in the % of clinical cases treated and the lower BMSCC
  2. While we have Staph in the herd it appears to be a relatively benign strain as evidenced by only 4.5% of Staph infected animals developing clinical mastitis
  3. The level of new infections across all pathogens is within industry norms

What are we doing now to simplify management, reduce milking time and manage mastitis and SCC:

  1. The in-bail teat sprayer was found to be operating very well and to ensure this continues will be checked weekly.
  2. All quarters of all cows will be stripped once per week to identify clinical mastitis quicker
  3. Fortnightly SCC data will continue to be used to identify at risk animals for checking
  4. We will complete a second sample on all cows identified with Staph to confirm their infection status and will continue to track cows over 200 000 SCC
  5. All cows, including those with an identified Staph infection, will be run in their farmlet herds unless they are under treatment for clinical mastitis or are lame and the process of getting cows back into their herds following treatment will be tightened up
  6. The farm team will undergo cupping technique training to improve their cupping speed
  7. An efficient milking routine poster will be developed with the farm team, implemented and displayed at cups on.
  8. We are investigating the use of MaxT to further reduced time spent on the milking process

This is an approach that suits SDH and has been taken using advice from multiple sources. We would recommend strongly that anyone else looking at a similar approach use the advice of your own vet before mixing positive Staph cows with the herd.

We will monitor and report any resulting changes to herd health and SCC as a result of these decisions.

General Farm Systems information

The project farm systems comparison has been designed to better understand crop-based wintering in relation to consequences for environmental impact and profit

  • The four herds are split evenly on age, BW / PW, calving date and breed to ensure the herds are as even as possible.
  • Each herd allocated a farmlet corresponding to their herd tag colour Green, Blue, Yellow and Pink.
  • Farmlets have paddocks allocated so each herd has equal walking distance from the shed and the same proportion of each soil type and equal proportions of pastures in the FVI trial (forage value trial – refer web site section on research).

Research Proposals

The SDH welcome research proposals for any sampling or research on the SDH, these are assessed by the Research Advisory Committee (RAC). Just send your request or ask for information via guy.michaels@southerndairyhub.co.nz

For more information check out the DairyNZ link:

https://www.dairynz.co.nz/about-us/research/research-farms/southern-dairy-hub/