Troubleshooting early lactation problems

"Even though all fresh cows receive the same treatment, some of them produce less milk than expected. Why do some cows excel in early lactation, while others underperform?"

Many dairy farmers are confronted with production problems in early lactation. Those issues can usually be traced back to the transition period. But why does one particular cow develop downer cow syndrome after calving, while the other does not? What makes a cow more susceptible for mastitis or displaced abomasum? In this article, we delve into the importance of a good transition management.

Resilience

When we ask farmers to describe their ideal cow, the answers are often along the same line: "A healthy, productive cow without problems, one that is easy to manage." This can also be described as "resilience"; the ability to adapt to external changes, such as ration changes, temperature variations, bacteria or viruses, ... Resilient cows are less sensitive to external influences and recover faster if they do get sick [1]. 

The resilience or robustness of dairy cows is not only determined by their genetics, but also by the farm management. A recent study from Wageningen University [1] shows that resilience on herd level (expressed as the deviation from the expected milk yield) can vary from year to year, meaning it is more than just genetics. The researchers observed that the presence of rumen acidosis strongly undermines the herd's resilience. Of course, feed management, cow comfort and barn climate play an important role here.

Tip of the iceberg

Most health issues in dairy cattle can be traced back to the transition period, i.e. 60 days before to 30 days after calving [2]. Transition problems often stay beneath the radar: affected cows usually show no or subtle symptoms of disease, while the milk production is lower than expected. The clinically sick cows are just the tip of the iceberg. Blood analyses show that almost 50% of all fresh cows suffer from subclinical (invisible) ketosis in the first 2 weeks after calving [3] en te laag calciumgehalte heeft [4]. These animals have a higher risk to develop other health issues as well.

Two classic transition problems in early lactation are:

  • Ketosis (hyperketonemia):

    The dry matter intake starts to decline close to calving, yet the energy demand increases notably once the lactation begins. This mismatch between energy supply and demand results in a negative energy balance. To a limited extent, this is a normal, physiological event in fresh cows. The cows will make up for the energy deficit by breaking down their fat reserves and forming ketone bodies in the liver (acetoacetic acid, acetone and beta-hydroxybutyrate) as an alternative energy source.

    Serious energy deficits will lead to an abnormally high amount of ketone bodies (i.e. ketosis) and ultimately fatty liver disease. Milk production declines and the fat/protein ratio increases (>1.5). Cows with ketosis eat and ruminate less, become slower ("lazy cows") and lose weight. Cows with subclinical ketosis have a higher risk of developing other health issues, like displaced abomasum, endometritis and lameness [6].

picture-of-body-condition-score-system-for-cows

Cows that are fat at calving (body condition score > 3,5) are more likely to develop ketosis [5]. Image taken from [17].

  • Milk fever (hypocalcemia):

    Milk (and colostrum specifically) is packed with calcium, meaning it is very challenging for cows to maintain their blood calcium level after calving. Extreme calcium deficiencies lead to the typical "downer cow" demeanor: the cows become drowsy and slow in the first 3 days after calving, until they are no longer able to stand up. Their ears feel cold and their digestive system shuts down. If no action is taken, milk fever can have a fatal outcome. Milk fever typically occurs in older cows (+3 lactations) and the Jersey breed.

    Most cases of hypocalcemia (plasma Ca < 2.0 mmol/L) go by unnoticed. However, since calcium is needed for good muscle contraction. milk fever can lead to mastitis (because the teat sphincter cannot close properly), retained placenta (as the uterus fails to contract) and displaced abomasum. In herds with hypocalcemia, the dairy farmer is often confronted by a series of other health issues, seemingly unrelated to milk fever.

A new vision on transition management?

Historically, the transition cow management has been based on 2 important pillars: restricting the negative energy balance in early lactation and maintaining the mineral status in the dry period. Not only should the ration be formulated according to the dry cow's needs, but the cows should also be able to eat their actual (calculated) feed portions. Overstocking, insufficient feed bunk space, (heat)stress, etc. suppress the dry matter intake and increase the risk of health problems after calving.

However, some researchers now call into question the understanding that hyperketonemia and low calcium levels are the root cause of most fresh cow issues [7]. In fact, they propose that hyperketonemia and hypocalcemia are the result of a systemic immune activation. The immune response can originate from infections in the mammary gland or uterus, bacterial toxins, heat stress or the "leaky gut" syndrome (i.e. damaged gut lining allowing particles and bacteria to leak through). Since the immune responses consume a lot of glucose -the main building block of lactose, the synthesis of milk is suppressed in the udder. As the cow begin to feel sick, her feed intake drops and the energy and calcium deficits escalate.

If this hypothesis is correct, the transition cow management should focus more on preventing the immune system activation and stimulating gut health. Scientific studies on anti-inflammatory drugs after calving already show promising results [8].

Practical guidelines for transition cow health

eating cows

1. Maximize the feed intake in the dry period. Make sure dry cows have round-to-clock access to palatable, fresh (unspoiled) feed. Aim for an average dry matter intake of 12-14 kg per cow per day. Feeding the lactating herd's refusals to your dry cows is not a good option: the feed has become less palatable, the composition is not necessarily appropriate for dry cows and the risk of spoilage increases (especially during warm summer months). Straw is a popular fiber source to ensure sufficient rumen fill. However, the chop length of straw has an effect on the feed intake: short straw particles (< 4 cm) are better than long chopped straw (10 cm) [9]. Additionally, dry cows should have 80 cm of feed bunk space (i.e. one bunk space per cow).

2. Monitor the body condition. Ideally, cows have a body condition score between 3.0 and 3.5 at drying-off.10].

cow_feed

3. Voorzie een gebalanceerd rantsoen. Aan het begin van de droogstand zouden koeien een schraal rantsoen voorgeschoteld moeten krijgen (750-800 VEM/kg DS; 12-13% RE) dat eveneens laag is in calcium en kalium. Stro kan bijgegeven worden om toch voldoende pensvulling te krijgen (zie boven), naast een aangepaste mineralenkern. Luzerne of graskuil van bemeste percelen kunnen problematisch zijn door de hoge kaliumgehalten (> 30 g/kg DS) – hoewel die gehaltes nogal variëren [11]. Aan het eind van de droogstand stijgt de energie- en eiwitbehoefte, terwijl de koeien net minder kunnen eten door de groeispurt van het ongeboren kalf en de ruimte die de baarmoeder inneemt, evenals door de veranderende hormoonhuishouding. Enkele weken voor het afkalven krijgen ze daarom best een rantsoen dat energie- en eiwitrijker is (850-900 VEM/kg DS; 14-15% RE). Vanuit nutritioneel standpunt is het dus interessant om de droge koeien in 2 groepen te splitsen, de zgn. “far-off groep” (van 8 tot 3 weken voor afkalven) en de “close-up groep” (vanaf 3 weken voor tot moment van afkalven) [12]. In onze streken wordt deze voederstrategie niet zo vaak toegepast door de relatief beperkte bedrijfsgroottes (vergeleken met bv. de Verenigde Staten). Werken met één uniforme droogstaande groep heeft daarentegen het voordeel dat het minder stress veroorzaakt.

4. Vermijd bruuske rantsoenwissels. De close-up periode wordt ook gebruikt om de pens geleidelijk te laten wennen aan het lactatierantsoen. Door bijvoorbeeld krachtvoerbrok bij te geven in de laatste weken van de dracht, tracht men de lengte en de omvang van de penspapillen te doen toenemen – wat de vertering in de vroege lactatie ten goede zou komen. (Dat laatste kon echter nog niet wetenschappelijk bewezen worden [13]). Vaak wordt geadviseerd te starten met 1 kg krachtvoer in de droogstand en dit op te bouwen naar 2 kg op het moment van afkalven. Sommige veehouders kiezen ervoor om hun droge koeien en (hoog)drachtige pinken de laatste 2 à 3 weken bij de lacterende koeien te laten lopen.

5. Beperk stress. Stress kan grote gevolgen hebben voor de productiviteit en gezondheid van melkvee. Koeien zijn kuddedieren met een bepaalde sociale rang en ze hebben stabiele relaties met hun kuddegenoten. Op dagen dat ze van groep moeten wisselen of in een nieuwe kudde terecht komen, kan de melkproductie met 4L zakken [14]. Andere negatieve effecten, zoals het verminderen van de voeropname en herkauwactiviteit, houden zeker 3 dagen na groepswissel aan [15;16]. Vooral vaarzen zijn gevoelig voor sociale stress. Groepswissels en verplaatsingen naar een andere stalafdeling zijn natuurlijk nooit helemaal uit te sluiten, maar een lagere bezettingsgraad of het implementeren van een vaste vaarzengroep kan wel soelaas bieden. Verplaats de koeien ook op rustige momenten in de dag.

6. Ontwikkel je eigen transitieprotocol. Er zijn verschillende goede manieren om de droogstand en de opstart te managen, maar elk bedrijf moet zijn eigen, specifieke werkwijzen ontwikkelen. Hoe en wanneer ga je koeien droogzetten? Weet je wat de droge koeien effectief eten? Wat doe je met vette koeien aan het eind van de lactatie? Hoe controleer je of de pasgekalfde koeien goed opstarten? … Zeker als je met (extern) personeel werkt, kan het nuttig zijn om deze processen te documenteren in vaste protocollen in overleg met je (voer)adviseurs en dierenarts. Op die manier creëer je consistentie en kan je makkelijk nieuwe werkkrachten trainen en duidelijk maken wat er van hen verwacht wordt. Het transitiemanagement draait om het monitoren van kritieke prestatie-indicatoren en resultaten, zodat er op tijd bijgestuurd kan worden. De registratie en periodieke analyse van gegevens staan hierbij centraal.

Starten je koeien niet zo goed op als je zou willen? Zoek je een kritische, onafhankelijke sparringpartner om je transitieprotocol mee op punt te helpen zetten? 

References

[1] Poppe, M., Mulder, H.A., Kamphuis, C. and Veerkamp, R.F., 2021. Between-herd variation in resilience and relations to herd performance. Journal of dairy science104(1), pp.616-627.

[2] Managing and monitoring the health of transition dairy cows. 2019. University of Minnesota Extension. https://extension.umn.edu/dairy-milking-cows/transition-dairy-cows

[3] Vanholder, T., Papen, J., Bemers, R., Vertenten, G. and Berge, A.C.B., 2015. Risk factors for subclinical and clinical ketosis and association with production parameters in dairy cows in the Netherlands. Journal of dairy science98(2), pp.880-888

[4] Venjakob, P.L., Borchardt, S. and Heuwieser, W., 2017. Hypocalcemia—Cow-level prevalence and preventive strategies in German dairy herds. Journal of dairy science100(11), pp.9258-9266.

[5] Gillund, P., Reksen, O., Gröhn, Y.T. and Karlberg, K., 2001. Body condition related to ketosis and reproductive performance in Norwegian dairy cows. Journal of dairy science84(6), pp.1390-1396.

[6] Suthar, V.S., Canelas-Raposo, J., Deniz, A. and Heuwieser, W., 2013. Prevalence of subclinical ketosis and relationships with postpartum diseases in European dairy cows. Journal of dairy science96(5), pp.2925-2938.

[7] Horst, E.A., Kvidera, S.K. and Baumgard, L.H., 2021. Invited review: The influence of immune activation on transition cow health and performance—A critical evaluation of traditional dogmas. Journal of Dairy Science.

[8] Bradford, B.J. and Swartz, T.H., 2020. Following the smoke signals: inflammatory signaling in metabolic homeostasis and homeorhesis in dairy cattle. animal14(S1), pp.s144-s154.

[9] Havekes, C.D., Duffield, T.F., Carpenter, A.J. and DeVries, T.J., 2020. Effects of wheat straw chop length in high-straw dry cow diets on intake, health, and performance of dairy cows across the transition period. Journal of dairy science103(1), pp.254-271.

[10] Van den Top, A.M., Schonewille, J.T. and Beynen, A.C. 2000. CVB-documentatierapport nr 27: Voeding van drachtige koeien in de droogstand. https://edepot.wur.nl/332415

[11] Vakblad Elite. 2020. Droge koeien niet te veel kalium. https://www.vakbladelite.nl/2020/11/02/droge-koeien-niet-te-veel-kalium/

[12] Effects of Dry Cow Grouping Strategy and Prepartum Body Condition Score on Performance and Contreras, L.L., Ryan, C.M. and Overton, T.R., 2004. Effects of dry cow grouping strategy and prepartum body condition score on performance and health of transition dairy cows. Journal of dairy science87(2), pp.517-523

[13] Dieho, K., Dijkstra, J., Klop, G., Schonewille, J.T. and Bannink, A., 2017. The effect of supplemental concentrate fed during the dry period on morphological and functional aspects of rumen adaptation in dairy cattle during the dry period and early lactation. Journal of dairy science100(1), pp.343-356.

[14] Von Keyserlingk, M.A.G., Olenick, D. and Weary, D.M., 2008. Acute behavioral effects of regrouping dairy cows. Journal of Dairy Science91(3), pp.1011-1016.

[15]  Grant, R.J. and Albright, J.L., 2001. Effect of animal grouping on feeding behavior and intake of dairy cattle. Journal of dairy science84, pp.E156-E163.

[16] Schirmann, K., Chapinal, N., Weary, D.M., Heuwieser, W. and Von Keyserlingk, M.A.G., 2011. Short-term effects of regrouping on behavior of prepartum dairy cows. Journal of dairy science94(5), pp.2312-2319.

[17] Ferguson, J.D., Azzaro, G. and Licitra, G., 2006. Body condition assessment using digital images. Journal of dairy science89(10), pp.3833-3841.