Neelam Kumari
Assistant Professor at Mahatma Ghandhi Veterinary College Bharatpur, Rajasthan
The periparturient or transition period describes the change from a non-lactating cow to a lactating cow after parturition. Transition period usually considered to extend from about 3 weeks before calving to about 3 weeks post-calving (Drackley, 1999). The peripartum period is the most challenging time for the dairy cows considering the cascade of nutritional and physiological changes associated with the late pregnancy, parturition and onset of lactation. Thus, the transitional period needs to be carefully monitored regarding factors such as management, adequate feed composition, e.g. the balance between energy and protein, adequate micronutrient supplementation and feeding routines to make the transition from the dry to the lactating stage as smooth as possible.
Feeding management of periparturient cows
For prevention of periparturient disease and increase the potential for successful reproduction, there are five critical control points during the transition period that need to be addressed viz. (i) maximizing dry matter intake (ii) stimulating rumen papillae development (iii) minimizing negative energy and protein balance (iv) maintaining calcium homeostasis and (v) minimizing immune system dysfunction.
- Maximizing dry matter intake
Dry matter intake normally declines between 5 and 30% during the last 2-3 weeks of gestation Grummer et al., 2004). Maximizing prepartum intake may help in preventing periparturient disease, as well as also accelerate postpartum dry matter intake.
Maximizing DMI could be achieved by (i) recording of feed delivery amounts and dry cow numbers (ii) critical evaluation and monitoring of non-dietary factors such as environmental conditions, animal social interactions and stress levels (as potential issues impacting feed intake) (iii) properly balancing the diet and monitoring fibre content and quality (iv) ensuring 24h feed availability (v) monitoring and correcting for DM content of wet feeds and (vi) properly managing body condition score to minimize over conditioned dry cows.
- Stimulating rumen papillae development
Rumen papillae help to maintain acid-base balance in the rumen by absorbing volatile fatty acids, especially lactate, produced by microbial fermentation. An optimum rumen papillae development could be achieved by (i) providing some fermentable starch in dry cow diet and increasing grains to 1.5-3 kg/day in closeup dry diet (ii) formulating dry cow diets with same diet ingredients (forages, concentrates) as to be fed in the fresh cow diet and (iii) ensuring sufficient physically effective fibre in all diets.
- Minimize negative energy and protein balance
As a cow approach calving, it is essential that she continues to receive her entire daily allotment of required nutrients, especially energy and protein, to prevent perturbing metabolic adaptations and predisposing the cow to periparturient metabolic disease. The energy intake must not be compromised during the day before calving to prevent occurrence of ketosis.
For minimizing negative energy and protein balance approach therefore should be (i) increase dietary energy and protein density in the dry diet (ii) use a blend of carbohydrate and protein sources to ensure adequate amounts of rumen degradable and undegradable fractions (iii) monitor forage quality and dry matter content (iv) use good management practices to maximize dry matter intake and (v) include energy boosting feed additives (Ca propionate, propylene glycol) if necessary.
- Maintain calcium homeostasis
A periparturient disease most frequently associated with macro mineral nutrition is parturient hypocalcaemia. The approach, therefore, should be to (i) monitor calcium homeostasis via records of milk fever prevalence in the herd and by the number of cows that are treated for subclinical hypocalcaemia problems (ii) evaluate the responsiveness of the calcium homeostatic system from serum calcium concentrations in cows 1-2 weeks prior to and after calving (iii) routinely monitor forages and diet for changes in macro mineral content and subsequent alterations in DCAD and (iv) maintain moderate calcium and phosphorus intake and appropriate magnesium content relative to dietary potassium concentration for non-anionic salt diets, and (v) monitor urine pH if using anionic salts.
- Minimize immune dysfunction
The immune system of the dairy cow has been shown to decline in responsiveness during the transition period, possibly a result of increased cortisol secretion associated with calving. A compromised immune system may lead to increased incidence of metritis, mastitis or other infectious disease processes. Deficiencies of microminerals and fat-soluble vitamins have been related to retained placenta and compromised immune function problems. The pregnant cow must receive an adequate amount of all minerals to support both maternal maintenance and conceptus development throughout the duration of gestation to minimize deficiency disease problems of either the dam or neonate. Any approach to deal with the immunopotentiation should involve (i) increasing the trace minerals by 20-50% above NRC recommendations, (ii) force feeding rather than free choice mineral feeding, (iii) increasing vitamin E to 4,000 IU/d in close-up period and 2,000 IU/d in early fresh period and (iv) using more highly available mineral sources (chelates, proteinates).