By SP Els, AFGRI Animal Feeds

Sound nutrition and management practices during the transition period will have a positive financial impact on dairy businesses.

Most farmers have specific, quantifiable goals regarding milk production, milk solids, feed and labour costs, and profitability in terms of profit per hectare or per cow. However, it seems that the opposite is true for reproduction and cow comfort.

Low dry matter intake (DMI), with subsequent negative energy balance (NEB) and metabolic disorders, as well as management and environmental factors occurring during the transition period, are responsible for reproductive failure and profit loss, and not high milk production as is commonly believed.

Pre- and postpartum feeding

 The transition period generally extends from three weeks before calving until three weeks after calving. During this phase, the cow undergoes dramatic physiological, immunological, metabolic and nutritional changes.

Formulating diets with a negative dietary cation-anion difference (DCAD) in the prepartum period in a bid to reduce subclinical and clinical hypocalcaemia and its associated diseases, is but one aspect of the nutritional strategy aimed at supporting metabolic adaption during the transition period.

Demand for amino acids, glucose and fatty acids at day 250 of gestation, increases approximately fivefold at day four postpartum for some of these nutrients. Furthermore, changes in the demand and supply of these nutrients, minerals and trace minerals postpartum directly impact immune function.

The question remains whether the feeding strategy is amended pre- and postpartum to help the liver function optimally and adapt the rumen, which is going through morphological, functional and microbiota changes, to achieve the   following:

• Higher DMI.
• Shortened duration of NEB.
• Higher glucose concentrations.
• Increased levels of circulating IGF-1.
• Lower non-esterified fatty acid (NEFA) concentrations.

Higher levels of NEFA in the blood is associated with lower reproduction and reduced oocyte quality and may lower the survival rate of the embryo after fertilisation. If the cow produced a calf from an inferior embryo, the gene expression of the calf may be negatively impacted, a process known as epigenetics. Epigenetics is a change in the genes’ core functionality and is impacted by something other than DNA; in this case, ‘poor’ nutrition pre- and postpartum.

Carbohydrates, amino acids, minerals 

Further nutritional strategies to consider are to feed a mix of carbohydrates and to finetune the amount of carbohydrates based on the dry, fresh and/or early lactation diets, as well as the total fermentable carbohydrates fed. The digestibility of starch as well as neutral detergent fibre (NDF) must also be measured.

The fibre in diets affects intake and rumen function. The amount of physically effective NDF (peNDF) needed in the fresh diet depends on intake, total starch and rumen degradable starch, forage digestibility and particle size. In addition, supplementing amino acids (the building blocks of enzymes and hormones), which is important in several biological functions during the transition period, has been shown to:

• Reduce oxidative stress.
• Increase DMI.
• Affect embryonic gene expression.
• Improve immune-metabolic status.

One should be aware of contradictory statements regarding ‘fats’ in transition diets and that only specific fatty acids may have positive effects, for instance decreasing the NEFAs in the liver. Special attention must be given to improving trace mineral availability that will positively impact immune function, and ultimately reproductive performance.

Improving feeding behaviour

Feeding behaviour associated with calving, stocking density, grouping and pen movement, may have a negative impact on rumen health. Key factors to remember when wanting to improve feeding behaviour in fresh cows, are:

• Reduction of heat stress.
• Maximising opportunities for cows to eat during the day.
• Keeping fresh cows separate.
• Avoiding overcrowding in fresh cow pens with a stocking density below or at 85%.

Remember, all dairy cows may experience low DMI, NEB and metabolic disorders to some extent. How these factors are minimised during the transition period through nutrition and sound management, as well as how environmental factors are managed, will positively affect profits.

SP Els, AFGRI Animal Feeds

When the grazing platform changes from ryegrass to kikuyu and/or the neutral detergent fibre (NDF) increases and the protein content decreases – historically the first nutrient nutritionist would increase is the crude protein (CP) concentration in the dairy meal. Making decisions based on CP concentrations as well as energy expressed as mega joules metabolizable energy per kg feed (MJME/kg) are based on old ideologies.

Formulating rations on CP, soluble protein (SP), rumen degraded protein (RDP), rumen undegraded protein (RUP) and non-protein nitrogen (NPN) which is the amount of nitrogen (N) analysed times 6.25 to give the CP value. This calculation assumes that all proteins in animals and plants have a 16% N content, which is not accurate. Furthermore, the CP value of a feed does not give any indication what the nutritional value of a protein source is, making it invaluable to use as a nutrient. Instead the profile of the amino acids (A/A) of the specific protein source and digestibility will determine the nutritional value. What is further important is that the total NPN and total or individual A/A available in the rumen and lower intestine are met for specific production targets. Frequently advise is given to increase the concentrations of CP in the diet before the profile of the A/A or limiting A/As has been looked at or are known. The profile of the A/A or limiting A/As cannot be overlooked or brushed aside when given advise to increase the concentrations of CP in the diet.

Lowering the CP of the cow’s diet offers an opportunity to improve the profitability as well as nitrogen utilization. Some dairy nutrition software has a dynamic rumen model wherein the passage rate of feeds determines the outflow of nutrients from the rumen. This passage rate of feeds is largely determined by feed intake but also adjusted by ration forage content and particle size. Nutrients that are not constant will vary according to feed consumption and ration ingredient such nutrients are metabolizable protein (MP), metabolizable energy (ME), amino acid content of MP, and rumen available protein (peptides and ammonia). Thus, linear programming can no longer be used and dynamic digestion models – nonlinear programming is required.

While the ryegrass pasture quality deteriorate and/or kikuyu comes in play consultants will more likely increase the CP content of the dairy meal, without considering that although CP of the pasture decreased, the higher lignin and NDF content and consequently lower NDF digestibility negatively impact dry matter intake (DMI). Generally, cows grazing on 24-hour rye or kikuyu pasture RDP is oversupplied in contrast with the energy especially fermentable carbohydrates which are deficient. On pasture farms energy is still the first limiting nutrient whereas rumen ammonia exceeds 200% of requirements and even on low quality pastures the rumen ammonia requirements are still above 150% – feeding a 10% CP meal. It is important to feed the correct energy and protein “package” instead of CP and ME content.

Non-protein nitrogen (NPN) consumed or ammonia derived from the degradation of true protein in the rumen is either used by rumen microbes – the amount used will be determined by the number of and how rapidly they are growing, in other words it will depend on the amount of energy available to the microbes. The rest of the ammonia is either recycled to the rumen via saliva or will be excreted in the urine or as milk urea nitrogen (MUN). The ammonia derived from NPN and from degraded true protein and not used by the microbes will not be of any value. The amount of A/A that is not supplied by the microbes needs to be supplied from bypass feed sources that is digestible in the lower intestine. Research showed from Figure 1 that diets with different CP percentage in lactating cows had no effect on milk nitrogen output – which is milk protein and should not be confused with MUN. Furthermore, as the CP percentage increased in the diets the oversupply of N was excreted as manure (faecal & urine).

Urea is then produced in the liver from the excess ammonia and this process uses energy, energy which could instead be used for other requirements. Dairy cows are particularly efficient in recycling urea when fed low-protein diets. It has been proven by some feed systems in the UK that the efficiency of using protein for milk protein synthesis is better for diets which are deficient or marginal in protein than those which are adequate.

When looking from a nutritional point of view, the standpoint would be not to apply CP any longer, but still CP are being used by nutritionist and/or consultants probably due to fear of the unknown. Ipharraguerre and Clark, 2005 found a significant curvilinear relationship between milk yield and the concentration of CP of the diet on 112 research trials. As indicated in figure 2 diets on the same CP concentration varied in 20kg milk yield per day. Which means that if there is a decline in milk production it’s less expected to be from a CP concentration and more probably a decrease in DMI and/or diet digestibility.

Tian Keet, Technical Advisor, AFGRI Animal Feeds.

Spring is an exciting time in the dairy industry especially for the farmer milking off pasture-based systems. This is your time for more profitable milking due to generally lower input costs and expected higher milk production. Spring however, seem to past far quicker than what we want, thus you need to get the most out of it while it lasts. To achieve this, you need to complement your pasture to get maximum milk production out of it and sustain that level of production for as long as possible. With issues related to our current economy, high costs of land and increasing production costs, pasture-based systems will require higher per animal production.

What does your pasture supply?

Crude Protein (CP) of pastures grazed in Spring typically range from 23 – 30 percent. This mainly consists of highly degradable protein which gets broken down in the rumen to ammonia.  The recommended dairy CP requirements for a lactating dairy cow range from 15 percent. With the high CP content of Spring pasture, you will easily exceed the CP requirements with a typical ration consisting of 70% pasture. Furthermore, the ammonia produced through pasture protein degradation in the rumen, will far outweigh that what can be used by the rumen microbes.

Neutral detergent fibre (NDF), primarily obtained from roughages, is extremely important in all ruminant diets.  Dairy cows, as in all ruminants, require enough fibre for optimal rumen function and to stimulate rumination. Through rumination cows mechanically break down fibre further and produce saliva which buffers the rumen. Fibre also forms a rumen mat and slows down the rate of passage which facilitate rumen microbes to break down fibre more efficiently. Neutral Detergent Fibre (NDF) typically range from 40 – 50 percent in pasture, thus can easily meet the dietary requirements of 28 – 35 percent NDF for lactating dairy cows. However, newly planted Spring ryegrass may have levels below 40 percent NDF at the first grazing.

What does your pasture need?

Energy is the first limiting nutrient for high producing cows grazing high quality pastures as the only feed (Kolver and Muller, 1998). Cows on pasture-based systems are often expected to walk great distances to paddocks to graze. Furthermore, dry matter intake (DMI) are significantly less for cows on pasture compared to cows on total mixed rations (TMR). Thus, losing a lot of energy through higher activity but also not getting enough energy in, due to lower DMI. Our African climate with higher temperatures adds to the issue. Cows willingly eat less in times of heat stress in an attempt to reduce metabolic heat. In addition, cows under heat stress have a higher energy cost to maintain body temperature.

It is essential to supply a good, well-balanced premix consisting of minerals and vitamins to meet the requirements of high producing cows. Soil profiles in and between farms vary significantly in mineral composition, hence the importance of a premix to supply the shortfalls. Certain vitamins (A, D and E) are recommended to be supplemented to cows housed in confinement. Cows on pasture, on the other hand, don’t need supplementary vitamin D as it is synthesized in the presence of sunlight.

Young Spring pasture, in difference to more mature pasture, have lower NDF. This causes a quicker rate of passage and sub-optimal rumen mat formation. By supplying a small amount of good quality hay or maize silage (1 – 2 kg DM) will stabilise rumen conditions and slow down the rate of passage.

Benefits of complementing your pasture with the right concentrate

Higher milk production can be expected with supplementing concentrate. Supplementary concentrate will supply the energy that falls short on pasture-based systems and allows cows to reach their genetic potential. It is important to supply highly available energy. Rumen microbes need energy to grow. With enough available energy, rumen microbes will grow and function more efficiently. Fresh in milk cows are in a negative energy balance, concentrate feeding can help them get out of that negative energy balance far quicker. Furthermore, cows will hold body condition better or recover body condition sooner.

Rumen ammonia will reduce with concentrate feeding. The rumen microbes now have the needed energy to utilise this free-flowing ammonia and convert it into microbial protein. Excess rumen ammonia is converted to urea in the liver which is an energy costly process. In utilizing rumen ammonia more efficiently, the cow conserve energy. Studies have shown that supplementing concentrate to cows on pasture, increase milk protein (Petch et al., 1997; Sayers, 1999; Reis and Combs, 2000).

To summarise

Milking off pasture-based systems are most profitable when pastures are utilised to the fullest. In this, you only need to supply where pasture falls short and not replace what it already supplies. Hence complimenting your pasture. By doing so you will meet all the requirements of a high producing dairy cow, milk those cows to their genetic potential and sustain milk production for longer.

– Bekamp Melkkoors vir Winsgewende Melkboerdery –

Inleiding

Die voeding en bestuur van suiwelkoeie tydens die oorgangsfase (21 dae voor tot 21 dae na kalf) het in die afgelope jare baie aandag geniet. Dit is met reg so omdat probleme tydens hierdie fase die wins van ‘n koei vir die spesifieke laktasie totaal kan erodeer. Die belangrikste abnormaliteite soos distokia, metritis, vassit van nageboorte, melkkoors, ketose, verplaasde abomasum en lamheid is interverwant en min melkkoeie kalf sonder gesondheidsprobleme. Die feit dat hierdie abnormaliteite interverwant is noop suiwelboere om te fokus op die totale bestuur en voeding van die oorgangsfase eerder as om op enkele probleme te konsentreer.

Melkkoeie se genetiese vordering is hoofsaaklik in melkproduksie gesetel en baie vinnig na kalwing word veelvoudig meer melk as die behoefte van die pasgebore kalf geproduseer. Daardeur ontstaan ‘n unieke fisiologiese toestand waar ‘n groot hoeveelheid kalsium (Ca) skielik uit die bloed opgeneem word en daarom ondervind meeste melkkoeie ‘n sekere graad van hipokalsemie en wat omgeskakel kan word in wat ons ken as kliniese melkkoors. Vleisbeeskoeie kan die toestand egter beter hanteer omdat die Ca behoefte veel laer is as by melkkoeie, weens ‘n veel laer melkproduksie.

Hipokalsemie en Melkkoors

Melkkoors is nie ‘n voedingkundige Ca tekort nie. Dit is ‘n toestand wat rondom kalwing ontstaan en nie in latere laktasie volhou word wanneer Ca verlies in melk selfs nog groter is as wat die dieet voorsien nie, soos byvoorbeeld tydens pieklaktasie. Melkkkoors is dus ‘n nie-voedingkundige, nie-degeneratiewe produksie siekte en word gekenmerk deur hipokalsemie tydens geboorte weens die skielike verhoogde Ca behoefte en ‘n vertraging in die aanpassing van ‘n vereiste verhoogde Ca metabolisme. Melkkoors word dus veroorsaak deur ‘n te stadige spoed in metaboliese aanpassing en nie deur ‘n tekort wat geskep word deur die behoefte van die koei en wat in die dieet voorsien word nie.

Serum Ca word hormonaal beheer deur onder andere parathormoon (PTH) en 1,25-dihidroksivitamien D (kalsitriol). Hierdie hormone is betrokke by renale Ca re-absorbsie, intestinale Ca transepiteleale vervoer en Ca omset in die skelet. PTH speel ‘n belangrike rol in korttermyn Ca balans deur opname en uitskeiding deur die niere te beheer. Renale Ca uitskeiding is egter klein (1g/dag) en kan nog kleiner wees of baie groter afhangende die Ca status en die PTH sein. Dit is dus net van waarde tydens hiperkalsemie en nie tydens hipokalsemie soos wat met kalwing ondervind word nie. Die proses waar kalsitriol intestinale Ca absorbsie beheer kan wel groot hoeveelhede Ca verskaf tydens tekorte, maar die proses kan tot 48 dae neem om effektief te wees. Been is egter ‘n groot bron van Ca (10kg) en kan dus ontgin word om ernstige Ca tekort periodes, soos tydens kalwing, op te hef. Die maklik beskikbare Ca in die skelet is egter klein, maar kalsitriol is die sneller om groot hoeveelhede Ca uit die been te mobiliseer indien die PTH sein nie verdwyn nie, m.a.w. die tekort sein moet aan wees. In die eerste paar maande van laktasie word tot 1kg Ca uit die beenmatriks gemobiliseer om in die Ca behoefte te voldoen.

Serum Ca vlakke onder 8mg/dl en 7.6mg/dl kan onderskeidelik as sub-klinies en kliniese melkkoors beskou word, maar is nie noodwendig altyd gekorrelleer met kliniese simptome nie. Verse is beslis minder vatbaar vir hipokalsemie en soos koeie ouer word, met meer laktasies, neem die vatbaarheid met ongeveer 9% per laktasie toe. Hierdie is nie noodwendig ‘n degeneratiewe toestand nie. Die verband tussen pariteit (laktasies) en melkkoors insidensie kan eerder verklaar word deur verhoogde melkproduksie, verlaagde DMI in die oorgangsfase (gewoonlik by oorvet koeie) en ander metabolise steurnisse.

Voorkoming van melkkoors

In die verlede is vele dinge en middels probeer om melkkoors te beheer onder andere verhoogde vitamien D vlakke, veranderinge op Ca:P verhouding, ‘n lae Ca dieet, orale toediening met Ca preparate en nog meer. Vandag is die voorkoming eerder multi faktoriaal en geïntegreer in ‘n oorgangsfase voeding- en bestuurstrategie om melkkoors EN ander metaboliese probleme te bekamp. Strategieë om melkkoors te bekamp fokus gewoonlik om Ca metabolisme aan te pas deur Ca balans weke voor kalwing “aan te wakker”. Dit kan gedoen word deur of die Ca voeding te verlaag of deur ‘n lae dieet katioon anioon balans om hiperkalsinurie (Ca uitskeiding deur die niere) te bewerkstellig. Orale toediening van Ca kan hier ook komplimenterend wees, terwyl binne-aarse toediening van Ca preparate nadelig kan wees. Dit is ook belangrik dat ander makrominerale, asook die energie en proteïen pakket in die dieet aandag moet kry om melkkoors effektief teen te werk.

Lae Ca dieet

Indien Ca inname verlaag kan word tot minder as 20g per dag is dit ‘n opsie om melkkoors te verhoed. Die probleem is dat dit nie altyd moontlik is nie en sal afhang van watter roumateriale gebruik word in die opstoomdieet. Konsentrate is gewoonlik laag in Ca terwyl ruvoere hoë waardes het en dit is nie heeltemal versoenbaar met ‘n opstoomdieet waar beperkende energie en hoër ruvoervlakke gevoer word nie. Sekere ruvoere soos mieliekuilvoer en strooie is laag in Ca, maar strooi beperk weer DMI. Groen grasse en lusern moet liewer vermy word, omdat dit betreklik hoog in Ca inhoud is.

Ca antagoniste

Zeoliet kleie is ook al ingespan om Ca beskikbaarheid voor kalwing te beperk, maar veroorsaak ook ‘n laer DMI en bloedvlakke van magnesium (Mg) en fosfor (P). Rumenbeskermde fitiensuur is egter effektief om Ca beskikbaarheid te beperk. Ryssemels is hoog in fitiensuur maar word in die rumen afgebreek en moet dus deur spesiale prosessering beskerm word om effektief te wees.

Negatiewe katioon anioon balans

Die mees algemene en effektiewe manier om melkkoors te verhoed is deur ‘n matige metaboliese asidose te skep deur die DKAB balans te modifiseer. Dit word gedoen deur minerale soos Cl- en S2- in verbindings te gebruik wat anioonsoute genoem word en so min moontlik Na+ en K+, genoem katione. Die balans word en milli-ekwivalente bereken deur die som van Na en K minus die som van Cl en S. ‘n Hoë DKAB is gewoonlik te wyte aan hoë K wat ook dan indirek verantwoordelik is vir melkkoors weens sy negatiewe impak op Mg opname. Anioonsoute is effektief wanneer ‘n DKAB van -50 tot -150 mEkw/kg DM bereik word, metaboliese asidose inskop, die uriene versuur en Ca uitskeiding in uriene verhoog. Dit verseker dat PTH en kalsitriol afgeskei word en Ca uit die been gemobiliseer word om sodoende melkkoors insidensie te verlaag. Uriene pH kan effektief as indikator van hipokasemie gebruik word en is hoogs gekorrelleerd met uriene Ca. Die proteien wat die tempo van aktiewe transport en dus opname van Ca in die niere bepaal is baie pH sensitief en aktiwiteit halveer teen lae fisiologiese pH, wat verhoogde utskeiding van Ca in die uriene tot gevolg het. Die mikpunt is uriene pH van 6-6.5 vir Holstein koeie en 5.8-6.2 vir Jersey koeie.

Anioonsoute kan egter ‘n negatiewe effek op DMI hê, maar gewoonlik net indien die konsentraat of meel wat die anioonsoute bevat,op sy eie gevoer word en nie wanner dit in ‘n volledige TGR gevoer word nie. ‘n Goeie alternatief is om soutsuur (HCl) in stede van anioonsoute te gebruik, wat geen negatiewe impak op DMI het nie, maar wat natuurlik ‘n uitdaging inhou t.o.v. veilige hantering en die erroderende effek op toerusting.

Magnesium (Mg), Kalium (K), Natrium (Na) en Ammoniak (NH3) as risiko faktore vir melkkoors

Mg absorpsie geskied hoofsaaklik in die rumen en word onderdruk deur ‘n hoë K konsentrasie in die dieet, veral teen lae Mg konsentrasies, ‘n lae Na konsentrasie asook ‘n skielike toename van NH3 in die rumen. Laasgenoemde se effek neem egter oor ‘n 2-3 dae periode af soos die rumenwand aanpas by hoër NH3 vlakke. Hipomagnesemia (lae bloedvlakke van Mg) wat hierop volg, onderdruk weer PTH afskeiding en die effek van PTH op die mobilisasie van Ca uit die been wat noodsaaklik is om melkkoors tydens kalwing teen te werk. Dit is dus belangrik, met in ag neming van dieet K inhoud en die biobeskikbaarheid van Mg, om dieet Mg vlakke te verhoog tot 0.4% van DM en selfs hoër om melkkoors risiko te beperk. Hierdie konsentrasie bereken deur die onderhoudsbehoefte, kolostrumbehoefte, biobeskikbaarheid en die daling in DMI rondom kalwing, in ag te neem.

Ander belangrike aspekte met betrekking tot die oorgangsfase

• Tekens van ‘n onvoldoende oorgangsprogram sluit in koeie wat trae en sikliese voerinname veral na kalwing toon, buitensporige metaboliese- en infeksieprobleme en erge verlies aan liggaamsmassa.

• Rondom kalwing verlaag rumenkapasiteit en dus inname, maar terselfdertyd styg die koeie se energiebehoeftes dramaties. Om te kompenseer verbruik die koeie liggaamsvet (NEFA) wat dikwels nie volledig na energie omgeskakel word nie. Een van die afbraakprodukte van die proses in die lewer, is asetaat. Indien propionaat beskikbaar is word die asetaat omgesit in energie. Indien propionaat nie beskikbaar is nie word ketone gevorm wat dikwels op die koei se asem geruik kan word. Vandaar die naam ketose en is basies ‘n gevolg van ‘n energietekort. Dit kom baie dikwels voor by vet koeie met ‘n kondisie van 4+.

• Skielike melkproduksie na kalwing veroorsaak ‘n geweldige behoefte vir kalsium (Ca) wat nie dadelik bevredig kan word nie. Bloed Ca vlakke daal dan sodanig dat melkkoors onstaan. Die verhoogde behoefte moet aanvanklik bevredig word deur Ca uit been te mobiliseer totdat die spysverteringskanaal se vermoë om Ca te absorbeer verhoog het.

• Subkliniese melkkoors kan ook aanleiding gee tot verplaasde abomasum en ketose omdat dit die gladdespierfunksie inhibeer wat krities is vir normale fuksionering van die spysverteringskanaal.

• Tydens die oorgangsfase word die immuunstelsel se funksionering onderdruk met die gevolglike verswakte vermoë om op infeksies te reageer. Dit verhoog dus die kanse vir infeksies soos mastitis en metritis.

Wenke en duimreëls vir die oorgangsfase

• Koeie moet in die regte kondisie kalf (kondiesiepunt 3.5).

• Stimuleer koeie se aptyt voor en na kalwing om te verseker dat DMI so hoog moontlik is en negatiewe energie balans (NEB) dus beperk word. Deur gebruik te maak van ‘n 21 dae voor kalf opstoomdieet en ‘n vars-in-melk dieet kan baie help om DMI maksimaal te hou, so min moontlik vet te mobiliseer (NEFA) en dus minder na-kalwing probleme te ondervind. Sulke diëte moet wetenskaplik saamgestel wees om aan al die besondere behoeftes van oorgangskoeie te voldoen en spesifieke aandag aan energie, aminosure, Ca, Mg, Na, K, spoorminerale en vitamiene is belangrik.

• Die rumen moet optimaal aangepas word vir die oorgang na hoë kragvoer diëte, met veral energiesamestelling in ag genome, sonder om asidose te veroorsaak of koeie vet te maak en insulien weerstandigheid te veroorsaak.
• Ruproteïen moet binne perke wees, met aandag aan die korrekte aminosure om lae, maar goeie kwaliteit kolostrumproduksie te verseker en om aanvanklike melkproduksie nie te veel te stimuleer nie.

• Handhaaf hoë bloedkalsiumvlakke rondom kalwing deur te verseker dat koeie Ca vinnig uit die been kan mobiliseer. Dit kan bewerkstellig word deur:

o Ca in die dieet sodanig te verlaag (< 20g/koei/dag) dat ‘n negatiewe Ca-balans ontstaan en sodoende mobilisasie van Ca uit die been stimuleer. Dit is egter baie moeilik om so ‘n dieet te formuleer.

o ‘n Metaboliese asidose te veroorsaak d.m.v ‘n negatiewe dieet-katioon-anioonbalans (DKAB), sodat die pH van die bloed daal en mobilisasie van Ca uit die been gestimuleer word. Negatiewe dieet-katioon-anioonbalans kan geskep word deur die gebruik van anioonsoute (soute van chloriedes- en sulfate) om ‘n negatiewe DKAB te verkry.

• Lae magnesium (Mg) vlakke in die bloed gee ook aanleiding tot melkkoors en dit is belangrik om 0.35-0.45% Mg in die opstoomdieet te voorsien.

• Die korrekte medikamente en spesifieke voedingstowwe moet ingesluit word vir die ondersteuning van die immuunfunksie, spesifieke organe en die endokriene stelsel wat krities is vir gesonde koeie met optimale metaboliese en fisiologiese funksies. Spesiale aandag moet ook gegee word aan medikamente om rumengesondheid te bevorder met ‘n fokus op positiewe energiebalans.

• Verskaf deurgaans voldoende skoon, vars en koel drinkwater.

• Moenie oorskiet of gemufde voer vir die koeie gee wat moontlik DMI kan onderdruk nie. Hou voerbanke vol vars voer. Verskaf voldoende koel maklik bereikbare drinkwater. Hou vesellengte dop en sluit ‘n bietjie ekstra lang vesel in die dieet in om rumensteurnisse te voorkom.

• Dra sorg dat koeie gemaklik is en beperk faktore wat tot “stress” aanleiding gee. Groepering van koeie kan belangrik wees deur oor-agressiewe koeie eenkant te hou omdat sulke koeie die inname van ander kan beïnvloed.

• Dit is uiters belangrik om spoorminerale en vitamiene gebalanseerd te voorsien vanweë die essesiële rol in soveel lewensfunksies en veral die handhawing van die immuunstelsel gedurende hierdie fase. Dit word sterk aanbeveel dat melkkoeie 3 weke voor kalwing ‘n dosis van ‘n inspuitbare vitamien-spoorminerale preparaat ontvang.

Vir meer inligting, skryf aan [email protected].