The Rumen Room Podcasts

50. Soil contamination of feeds – any issues for our ruminants?

Ingestion of soil during grazing of pastures and forage crops is a common and unavoidable event.   Soil contamination of silage and baleage is another challenge that we sometimes need to deal with. Our latest episode explores the whole topic of soil ending up where it doesn’t belong. How much mud and dirt do animals eat during grazing? What factors increase risk of animals eating too much soil? Are there any health or nutrition issues we need to think about when animals eat too much mud and dirt? What happens when we get soil contamination of silage? All this and more. We hope you enjoy our latest podcast.
2.25 Overview of content of our current podcast
4.00 How ruminants end up eating soil
4.30 Post-grazing residual management – it’s not only about soil ingestion
6.55 Soil type and structure
9.00 Plant pulling during grazing
11.00 Earthworms – wonderful things but how about those worm casts?
12.45 Hot, dry dusty conditions
13.15 Flood irrigation
13.55 Annual forage crops, including bulb crops (Fodder beet, swedes, turnips)
14.35 Different types of bulb crops and risk of soil ingestion
17.00 Sugar beet and soil tare
18.00 When soil contaminates conserved feeds. Risks for spoilage of silage
23.30 Listeriosis risk when soil-contaminated silage pH is high
25.05 What parts of a feed test reports could indicate the presence of soil in your silage sample?
27.20 Soil ingestion when animals have a depraved appetite and eat soil (pica)
29.20 How much soil do grazing ruminants eat during grazing?
34.45 Potentially good aspects of soil ingestion
39.00 Potentially not so good aspects of soil ingestion.
44.50 Risk of physical damage to the gastrointestinal tract when ruminants eat soil

49. Dry cow and transition cow management – it’s all about the COW. Featuring Dr Sue Macky

Well known New Zealand-based veterinarian, nutritionist and farmer Dr Sue Macky joins Charlotte Westwood in our latest podcast. Sue steps us through everything to do with the individual dairy cow during the dry and transition periods - from the cow's point of view. Too often we get overly focused on the detail of the diet and management dry and transition dairy cows - and forget about focusing specifically on the cow herself. Not in this latest episode, this is very much about the cow herself!
Sue discusses a cow-centric approach to managing dairy cows from dry off, during the far-off dry period and into the “springer” period (close-up dry period) and colostrum mob.  This is one episode you simply will not want to miss!
0.40 Introducing Dr Sue Macky, defining her lifetime of global experience in dairy cow feeding and management
3.35 The dairy cow is an elite athlete, and should be treated as such
4.35 The New Zealand dry (non-lactating) cow period - redefined
5.10 Managing cows heading into dry off including redrafting cows for the dry period. Impacts on an individual cow with changing herd social structure discussed
7.10 Cow body condition score at dry off through to calving
7.50 Gut fitness in dairy cows; Capacity and muscularity during the dry period
10.20 Feeding cows through dry off – “don’t confuse the cow”
10.50 Immune functionality through dry off
11.40 Stock water supply and access by cows during the dry period 
13.30 Late dry period through to the transition period – setting cows up well
14.00 “Calves are obligate parasites during late pregnancy”
14.40 The challenges of pasture-based diets in late pregnancy
15.30 Mob size for springer (close-up) dry cows, it’s all about compromise
16.05 How long should cows remain in the springer mob?
16.30 The calving cow – the importance of access by cows to feed and stock water
17.50 The cow-newborn calf bond
18.45 Feed, water and calcium for freshly calved cows
20.10 Cow behaviour after calving – the modern cow vs. the cow of ancient times
21.05 Milking out a cow after calving (“energy in, energy out”)
21.35 Once-a-day milking of cows after calving, it’s all about gut fill and rumination

48. Lignin – From pine trees to pastures – What do your grazing animals reckon?

All plants would be green slime growing sideways along the ground if it wasn’t for lignin– True!  Find out more in our latest podcast covering everything from the good, the bad and the ugly about lignin. Learn how lignin impacts overall quality of ruminant feeds, and how feed management decisions change how animals process and digest lignin in their day-to-day diets. Find out how the lignin content of feeds changes with feed type and feed management, and what you can do to reduce intake of lignin in the diet of your sheep, cattle, deer or goats to improve animal productivity.
Here’s where to find the key sections in this our latest podcast talking all things ruminant nutrition.
0.51 Defining lignin
2.00 Just what does lignin mean for sheep, beef, deer and goats?
4.55 Lignin and plant cell walls – holding hands
7.10 If it weren’t for lignin, where would plants be?
7.30 How lignin messes with feed quality for animals
9.50 Plant cell contents aren’t bothered by lignin – why not?
10.35 Lignin, feed digestibility and MJME
12.45 How high is high? Interpreting lignin results as part of feed test results
13.55 Lignin alongside NDF, NDFd, and ADF
15.10 “Book value” lignin results for common New Zealand feeds
17.00 Do zero lignin feeds exist?
17.30 Lignin content of some common “dry” byproduct feeds
20.25 Lignin and NZ pastures
23.30 Plant maturity influences lignin content
26.15 Weather, pasture and forage crops and lignin
31.20 Managing pastures for reduced lignin content
34.05 Plant breeding and lignin, including BMR forages

47. Kiwifruit as a feed for ruminants

Sliced on our morning cereal or perched on top of our iconic New Zealand dessert Pavlova, kiwifruit deliver a tasty powerpack of valuable nutrients for us humans. What about ruminants? Are reject kiwifruit from your local packhouse equally as good for our dairy cows and other animals on farm? Yes! A valuable source of energy delivered largely as water soluble carbohydrates, whole kiwifruit can be a very useful feed.  However… as for any byproduct feed, kiwifruit may not always meet our expectations as a stockfeed.
Join us for this latest podcast that explores the good, the bad and the (occasionally) ugly aspects of kiwifruit as a feed for ruminants, with a specific focus on kiwifruit feeding to lactating dairy cows.
Although this is a kiwifruit-focused topic, we include content that applies equally to the feeding of other byproduct fruit and vegetables. Enjoy!
Where to find the various topics within this podcast:
2.35 Overview of the episode
5.35 The nutritive value of kiwifruit – “so changeable as the fruit ripens”
6.45 Water soluble carbohydrates (WSC)
7.45 Neutral detergent fibre (NDF)
8.30 Crude protein (CP)
10.40 Ash and mineral content
13.10 Risk of rumen acidosis associated with kiwifruit feeding
19.00 Best practice approaches to minimise risk of rumen acidosis when feeding kiwifruit
20.30 The importance of knowing your kiwifruit on a dry matter (DM) basis - and not just a wet weight basis
21.35 Gradual adaptation by ruminants to a kiwifruit diet
22.40 The protective role of a rumen-full of long stem fibre in reducing risk of rumen acidosis
23.10 Day to day consistency when feeding kiwifruit is the key!
23.50 Maximum daily amounts of kiwifruit you can feed to dairy cows. The answer? “It depends”
25.05 Feed planning with kiwifruit – the “Three Versions” of a diet that contains kiwifruit
27.30 The role for Kiwi ingenuity and innovation when feeding kiwifruit
33.15 Handling kiwifruit storage on farm
34.00 What to do if kiwifruit is overripe?
35.00 Are rumen additives protective against kiwifruit-induced acidosis?
37.00 Risk of “choke” and rumen bloat with kiwifruit feeding
41.00 Know how much your kiwifruit are costing you. Converting $ per tonne wet weight to $ per tonne DM
44.15 The paperwork. Dairy Feed Declaration. Making sure your kiwifruit are fit to feed
45.45 Preventing birds from eating your stockpiled kiwifruit, helping out your local Regional Council.

46. Metabolisable Energy in Ruminant Nutrition - it’s an interesting topic, we promise!

A fundamental basic of ruminant nutrition – energy density of feeds – is covered in this latest Rumen Room Podcast.
Expressed as Megajoules of Metabolisable Energy per kilogram of dry matter (MJME/kgDM), energy density is an important driver of animal productivity and profitability.
In a down to earth, practical “gumboot level” manner, Dr Charlotte Westwood explores the basics of MJME as a concept and covers how feed testing laboratories measure MJME. How we use MJME values of a feed on farm on a day to day basis is explained. The strengths and possible limitations with the use of MJME in our day to day farm-level decisions is discussed.
Don’t be put off by what is often thought to be a rather "dry" topic of MJME - actually, it’s a straightforward concept - we’re sure you’ll learn a lot from this latest podcast!
Here’s where to find the various sections within the MJME podcast, below:
2.02 Outline of this MJME podcast
3.40 What is “energy”?
6.30 Defining Megajoules and Metabolisable Energy
7.50 Megajoules compared to Megacalories – what’s the difference?
10.25 What is gross energy and why might we be interested?
14.25 Why ruminants can’t use all of gross energy in feeds for useful things
15.10 Faecal energy – what a waste! (#1)
16.10 Digestible energy
17.25 Methane – what a waste! (#2)
18.10 Finally arriving at the MJME number…. How this is calculated
19.00 How different feeds change energy losses as methane
21.00 Measuring MJME – inside the sheep
23.00 Feed testing laboratories estimates of MJME
25.40 Using the digestibility value to calculate MJME
26.20 NIRS technology - digestibility and MJME
31.15 Strengths and weaknesses of MJME as a measure of feed quality – an overview
32.00 Typical MJME values of feed
34.40 Valuing our feeds on a cents per MJME basis – a simple task on farm! Valuing a bale of pasture baleage on an MJME basis as an example
38.00 Using MJME as part of your feed budgeting – MJME demand vs. MJME supply. A 30kg liveweight lamb as an example
40.30 Limitations of MJME as an indicator of suitability of a feed for animals
41.30 MJME is a calculated measure only!
42.00 MJME doesn’t tell us about all of the other interesting stuff in feeds
44.10 Summing up the MJME topic

45. Dietary Cationic Anionic Difference (DCAD) – One strategy for reducing challenges of low blood calcium in dairy cows

Our latest podcast explores DCAD - one specific aspect of the diet of “springer” (“close-up”) dairy cows.
The Rumen Room Podcast has briefly discussed DCAD previously (Episodes 10 and 34).  Changing the DCAD of a springer cow diet potentially reduces risk of hypocalcaemia (low blood calcium) in cows before, during and immediately after calving.
This latest episode takes a deeper dive into the detail of DCAD, explaining what DCAD is, what stock class stands to benefit the most from changing dietary DCAD, and how dietary DCAD influence risk of hypocalcaemia. Practical approaches to DCAD management for pasture-fed cows are covered and options for dietary DCAD additives are investigated.
Location of topics within our latest podcast.
1.00 DCAD as just one aspect of the springer dairy cow diet.
1.45 Introduction to the DCAD podcast
4.55 The definition of DCAD
5.45 Dietary cations and anions explained
6.45 The four dietary elements contributing to DCAD: Potassium, sodium, sulphur and chloride
7.50 The DCAD equations – there are a few out there, we like “equation 1” for calculating DCAD
9.10 How does changing DCAD work? DCAD simplified!
10.50 What’s the “ideal” DCAD for springer diets?
11.35 How long should springer dairy cows be exposed to low or negative DCAD diets before calving?
12.55 DCAD once a cow has calved
14.41 How slight changes to blood pH reduce risk of hypocalcaemia  
22.00 High potassium ryegrass (and other types of feeds) and DCAD in springer diets
23.40 Ryegrasses can accumulate lots of potassium!
24.42 Whey applied to pasture as a risk factor for high potassium and high DCAD pastures
25.45 Lucerne silage, baleage or hay and DCAD and calcium in springer diets
27.25 Sodium as a driver of DCAD for New Zealand pasture-fed springers
28.35 Lower DCAD feeds for springer diets – Maize (corn) silage
30.40 Additives that change the DCAD of springer cow diets
35.30 “Do no harm when trying to solve a milk fever problem” – the risk of reducing feed intake by springer cows when unpalatable / not very tasty anionic products are added to diets
37.45 Negative DCAD additives that also deliver calcium: Calcium chloride & calcium sulphate
40.35 Measuring DCAD of feeds – the role for feed testing and springer cow urine testing
43.20 Concluding / summing up the DCAD podcast

44. Hot and bothered lactating dairy cows - the how, the why and what we can do to help our cows

Our latest podcast carries on with our heat stress 'theme' from episode 43, where we explored the challenges of hot temperatures on pasture species.
We’ve moved the theme of heat stress across to how heat stress effects dairy cows. We discuss how heat stress bothers cows, and investigate strategies to reduce the effects of summer heat on lactating cows of hot summer temperatures.
Featuring expert heat stress guest podcaster, Lori Grinter, this episode covers a wide range of heat-related topics. Lori first explains how her heat stress studies as part of her Masters undertaken at the University of Kentucky uncovered different cow responses to heat stress, and gave industry new insights into how cows respond to hot weather.
The remainder of the podcast returns very much to a New Zealand-based discussion around how heat stress influences lactating cows, and farm-level strategies that reduce the heat load on our cows.  
If you’re short on time listening to our latest podcast, here’s where to find the various discussion sections:
1.46 Introducing guest heat stress podcaster, Lori Grinter
3.05 University of Kentucky heat stress research completed by Lori
4.12 Cows voluntarily taking a cool shower (we kid you not!)
9.10 The 5 hour time delay between exposure by cows to heat and cows seeking a cooling shower
12.45 “THI” the temperature humidity index defined – knowing when conditions are hotting up
15.15 Signs that our cows show us, when they’re getting hot and bothered
17.00 The rumen heat chamber – high fibre feeds and heat stress
17.20 Rumen acidosis risk, as worsened by heat stress
22.15 Shady dealings – The importance of shade for keeping cows cool
28.55 Exercise – hotting things up, the importance of walking and moving cows during cooler parts of the day
32.20 Cow nutrition – Concepts for keeping cows cooler during hot conditions
40.45 Cool clean stock water – a critical factor when managing hot cows
44.10 Cow wearable technologies – useful things to monitor for early signs of heat stress
47.00 Resources for learning more about hot and bothered cows
Below are the links for Lori Grinter’s publication in the highly esteemed Journal of Dairy Science
https://www.journalofdairyscience.org/article/S0022-0302(19)30151-1/fulltext
https://www.journalofdairyscience.org/article/S0022-0302(22)00677-4/fulltext
(Note that this heat stress study made editors choice!)

43. Hot and bothered summer pastures – less dry matter and poorer nutritive value for your grazing ruminants

With the New Zealand summer in full flight during early 2024, it’s timely to review how hot temperatures potentially alter the dry matter yields and nutritive value of our temperate pasture species.
Exploring first how hot temperatures impact dry matter yields (kilograms of dry matter grown per hectare per day), the podcast looks at effects of hot weather on New Zealand’s most common pasture species combination, perennial ryegrass (Lolium perenne) and white clover (Trifolium repens). Other species discussed include continental (summer active) tall fescue (Festuca arundinacea) and cocksfoot (Dactylis glomerata, otherwise known as orchard grass) and red clover (Trifolium pratense).
Nutritive value of temperate pasture species, as influenced by hot temperatures is covered, looking specifically at digestibility and MJME, as well as NDF, NDFd and non-structural carbohydrates as influenced by hot temperatures.
A note that we make within this podcast is that the selection of pasture species should never be made simply on the basis of heat tolerance, in isolation from other factors to consider. Multiple factors also requiring consideration include soil fertility, pH, rainfall/irrigation, and paddock aspect - to name but a few factors other than heat tolerance. Talk with your local PGG Wrightson Seeds agronomy expert for all the information you need around your regrassing requirements.
Various sections within the podcast can be found below. Hope that you find this topic a "cool little topic" to tune into (pun totally intended). Happy listening! 
 
0.55 Introduction
1.39 Overview of the content of our latest podcast
2.05 Scene set – Overview of New Zealand pastures (for the benefit of our non-New Zealand based listeners)
3.40 The wide range of pastures from the north to the south of New Zealand
6.35 Dry matter yield by pasture species when hot summer temperatures arrive (along with other factors including moisture deficit)
8.35 The “ideal” daytime temperatures that support optimum growth rates by our temperate C3 pasture species?
9.50 How hot is too hot for our temperate C3 pastures? Perennial ryegrass, continental tall fescues & cocksfoot
10.05 How hot does it need to be before perennial ryegrass gets hot and bothered?
10.40 Tolerance to temperature by tall fescue compared to perennial ryegrass
11.45 Adequate moisture allows C3 grasses to better tolerate hot temperatures.
14.10 Cocksfoot tolerance to hot temperatures and moisture stress/dry conditions compared to perennial ryegrass 
15.50 The role for endophytes in perennial ryegrass and tall fescue and tolerance of heat 
17.25 How frequent irrigation helps temperate grasses handle hot temperatures – “transpiration” and evaporative cooling
20.00 **Don’t select a temperate grass species ONLY on the basis of heat tolerance, there are so many other factors to consider when moving away from perennial ryegrass as you core grass species.**
22.30 Legume (clovers, lucerne) growth during hot weather
23.40 Chicory handling hot conditions – but only if adequate moisture is available
25.40 Nutritive value of temperate pasture during hot weather – changes to digestibility, MJME, NDF and NDFd
30.50 Digestibility and NDF changes by tall fescues and perennial ryegrass as summer temperatures increase
35.55 Legumes – changes in nutritive value with hot temperatures 
39.50 Legume quality changes over summer – not related to grazing management and temperature 
40.20 More clovers in pastures swards – the rumen bloat conundrum
42.35 Temperate grasses - Non-structural carbohydrates (water soluble carbohydrates and starch) changes with temperature
43.30 Temperate legumes - Non-structural carbohydrates changes with temperature
48.50 Recap / conclusion of topics covered

42. Thiamine deficiency in sheep and cattle – a nutritional challenge with an animal health twist

Thiamine (Vitamin B1) deficiency - a nutrition/diet-mediated animal health condition sometimes seen in ruminant species - features in this, our latest Rumen Room Podcast. Most often seen in young, spring-born ruminants during their first summer of life, thiamine deficiency is a sporadic animal health condition that most New Zealand dairy, sheep and beef farmers will be familiar with.Featuring five sections packed with information about thiamine, Dr Charlotte Westwood steps us through this podcast in a down to earth, practical manner. Thiamine as a vitamin is defined and clinical signs of thiamine deficiency are discussed – the “neurological” form of deficiency (Polioencephalomalacia, sometimes called "polio", "PE" or "PEM") and the “Ill-thrift” form of deficiency.  Why all ruminants are not equally at risk of thiamine deficiency is explored. How your vet will likely help you with dealing with thiamine deficiency is covered. Strategies that can reduce risk of thiamine deficiency in New Zealand ruminant species are suggested.
*Note* The information about thiamine contained in this podcast episode is NOT intended to replace the expert advice from your own veterinarian. If you have any concerns about animal wellbeing and/or underperformance by your ruminant animals, please contact your own veterinarian. 

41. Internal parasite management– the role for good nutrition (plus many other parasite topics!)

Our latest episode features guest speaker Dr Ginny Dodunski who joins Rumen Room host Dr Charlotte Westwood for a chat about all things internal parasites. As a New Zealand-based veterinarian and self proclaimed “gumboot parasitologist”, Ginny requires little introduction to most kiwis involved in farming. With a background in veterinary practice, farm consultancy and more recently, working part time with Wormwise, Ginny joins us to cover a range of topics relating to internal parasite management in sheep and cattle.
Given the concerning scale of resistance by internal parasites to our range of anthelmintic (drench) products, Ginny steps us through a range of down to earth, practical recommendations to managing internal parasites – including the important role for top quality nutrition for maternal and young stock.
Anyone who is involved in managing young stock should tune in - there will be some  practical tips and tricks for everyone.
Have a scroll (below) through the content for our latest episode featuring Ginny Dodunski. 
0.50 Ginny’s background and how her passion for all things animal health, and how her journey working with internal parasites began.
6.05 The timeline of New Zealand resistance since the days of effective anthelmintics
7.00 The cost of internal parasites (including resistance issues) to the New Zealand pastoral industries - and at the level of individual farms
8.40 The novel drenches, Zolvix™ Plus (monepantel and abamectin) and Startect® (derquantel and abamectin) help uncover the true cost of internal parasite resistance in lambs
9.50 Picking up sub-clinical internal parasite challenges (or not!) – especially when other autumn health challenges are occurring
12.10 Who to talk to if you suspect internal parasite resistance issues at your place
13.45 Is my drench working or not? Faecal egg counts
15.15 Starting the internal parasite journey – starting with the ewe/lamb(s) unit
16.25 Higher lambing percentages and internal parasite challenges (and opportunities)
18.40 Well fed ewes support good lamb weaning weights, reducing numbers of lambs on farm post-weaning
22.40 Anthelmintic treatments for ewes pre-lambing (or not)
24.10 Ewe nutrition and body condition– building tolerance to internal parasites
28.35 Hatching and development rates of larvae – differs for eggs from ewes and lambs
30.20 Ewe stocking rate combined with other stock classes – optimising ewe nutrition
32.50 Three Pillars of Parasite Management
33.30 First Pillar = well fed, healthy robust breeding stock
33.35 Second Pillar = young stock on clean feed (less worm larvae than average hill country pasture)
34.40 What’s the best crop for lambs? 
37.45 Feeding lambs the best quality feed that you can – the Third Pillar
38.10 Gross margin analyses on forage crops – understates the value of crops for young stock
39.00 Preparing pasture areas to finish lambs on – integrating cattle with sheep
40.00 100kg calves (dairy replacements, dairy beef) and internal parasites
43.00 Buying in 100kg calves – cautions around risk of parasite resistance
44.20 Holding young stock in yards to empty out after quarantine drenches
46.30 Faecal egg counting in young cattle – usefulness for different ages of cattle
48.40 Trace elements / trace minerals and internal parasites
52.05 Where to go to learn more about internal parasites