Milk fever in dairy cows: A review of pathophysiology and control principles
Introduction
The periparturient or transition period of 4 weeks before and 4 weeks after calving is characterised by greatly increased risk of disease (Shank et al., 1981, Curtis et al., 1985, Stevenson and Lean, 1998). The period is dominated by a series of adaptations to the demands of lactation, a process described as homeorhetic (Bauman and Currie, 1980). Homeorhetic processes are the long term physiological adaptations to changes in state, such as from non-lactating to lactating or non-ruminant to ruminant, and involve an orchestrated series of changes in metabolism that allow an animal to adapt to the challenges of the altered state. The problems that result from disordered homeorhetic change reflect disorders in homeostasis and include hypocalcaemia, the downer cow syndrome, hypomagnesaemia, ketosis, udder oedema, abomasal displacement, metritis and poor fertility.
These conditions are often inter-related (Curtis et al., 1983, Curtis et al., 1985, Curtis and Lean, 1998) and this, combined with the dramatic changes in endocrine function and metabolism associated with calving and the initiation of lactation, makes transition an inherently difficult period to study. Notwithstanding these challenges, the potential to increase subsequent production, improve health and improve reproduction has made nutritional manipulation of the periparturient cow a focus for research.
It can be broadly stated that the transition cow should be adapted to provide minimal risk of metabolic disorders of macro-mineral metabolism including absolute or conditioned calcium (Ca), magnesium (Mg) or phosphorus (P) deficiencies, or excesses of sodium (Na) and potassium (K); disorders of lipid metabolism arising from inadequate energy intake in the dry period and early lactation; disrupted rumen function associated with dietary change and impaired immune response.
The aims of this paper are to review some of the changes that occur around calving related to hypocalcaemia and to examine the potential to modify the risk of disease, reproductive failure and milk production through better nutritional management.
Section snippets
Incidence and background
While the focus on nutritional management of hypocalcaemia is appropriate, not all of the risks for periparturient hypocalcaemia results from ration formulation. Recumbency is often caused by hypocalcaemia, but other significant causes include hypomagnesaemia, musculo-skeletal injury predisposed by calving and hypocalcaemia, ketosis associated with twinning, hypophosphataemia and a number of less frequent problems such as peracute mastitis and other infections. Dystocia is a major cause of
The pathophysiology of hypocalcaemia
Changes in Ca metabolism induced by lactation are more significant than parturition per se to the pathogenesis of parturient paresis, as the loss of blood Ca to milk may exceed 50 g per day. Before calving, the approximate daily requirement for Ca is only 30 g, comprising 15 g in faecal and urinary loss and 15 g to fetal growth. This demand for Ca may only be satisfied by increasing absorption from the rumen or intestines, and increasing mobilisation from tissue, especially bone reserves of Ca, as
Milk fever prevention: Dietary Ca, Mg and P
One of the areas of continuing contention is the role of pre-calving dietary Ca intake as a risk factor for milk fever. Beede et al. (1992) stated that high Ca intake pre-calving is not the primary cause of subclinical hypocalcaemia and milk fever. However, it is important to note that the improved understanding of the role of the monovalent cations in hypocalcaemia does not refute the research on Ca and vitamin D metabolism over the previous 40 years (Ramberg et al., 1996).
Early studies (Boda
Milk fever prevention: Dietary cation anion difference (DCAD)
Early studies by Norwegian workers found that diets high in Na and K and low in chlorine (Cl) and sulfur (S) tended to increase the incidence of milk fever, while those high in Cl and S and low in Na and K or containing added anionic salts (AS), decreased the occurrence of milk fever (Ender et al., 1962, Dishington, 1975, Dishington and Bjornstad, 1982). Block (1984) found a significant increase in the incidence of milk fever for cattle fed on diets that differed only in their quantities of Cl,
Integrating milk fever prevention: A meta-analysis
Meta-analysis is a systematic and rigorous method of pooling data from previous studies and re-analysing them. It is a particularly powerful tool for examining rare events such as disease studies conducted in relatively small populations, such as is evident in the milk fever data. Two significant meta-analyses of milk fever risk were conducted by Oetzel, 1991, Enevoldsen, 1993 who both used fixed effects models for predicting outcomes, although it is now widely accepted that these models are
Effects of exposure to pre-calving diet: Production, reproduction and health
Grummer (1995) stated that: “If transition feeding is important, then perturbations in nutrition during this period should affect lactation, health and reproductive performance.” While physiological research on the impact of manipulating various fractions of the pre-calving diet is substantial, studies on the effects of integrating dietary strategies and providing an ‘optimal’ pre-calving diet are rare. A prospective cohort study was used to examine the effect of increasing days of exposure to
Conclusions
While further studies are required on a number of aspects of milk fever, particularly in relation to the length of exposure to diets and Ca concentrations, many tools are now present to control the risk of milk fever. The exposure studies conducted by DeGaris et al., 2004a, DeGaris et al., 2004b, DeGaris et al., 2004c suggest that positive dietary changes in the pre-calving diet will result in substantial production, reproduction and health benefits.
Conflict of interest statement
The two authors of the paper entitled Milk fever in dairy cows: A review of pathophysiology and control principles are Peter Degaris and Ian Lean. Peter Degaris advises on feeds that control milk fever risk and sells products to treat and prevent milk fever. Ian Lean has conducted research and consulted to companies producing products to control milk fever; he is involved with importation to Australia and sale of products that control milk fever risk.
References (92)
- et al.
Use of 1 alpha-hydroxyvitamin D3 in prevention of bovine parturient paresis. 8. Maternal and neonatal plasma calcium, parathyroid hormone and vitamin D metabolite concentrations
Journal of Dairy Science
(1988) - et al.
24,25-Dihydroxyvitamin D3 administration increases incidence of parturient paresis
Journal of Dairy Science
(1984) - et al.
Impact of prepartum dietary phosphorus intake on calcium homeostasis at parturition
Journal of Dairy Science
(1987) - et al.
Partitioning of nutrients during pregnancy and lactation: a review of mechanism involving homeostasis and homeorhesis
Journal of Dairy Science
(1980) Manipulating dietary anions and cations for prepartum dairy cows to reduce incidence of milk fever
Journal of Dairy Science
(1984)Further studies on the influence of dietary calcium and phosphorus on the incidence of milk fever
Journal of Dairy Science
(1956)- et al.
The influence of dietary calcium and phosphorus on the incidence of milk fever
Journal of Dairy Science
(1954) - et al.
Impact of lowering dietary cation–anion difference in nonlactating dairy cows: a meta-analysis
Journal of Dairy Science
(2006) Clinical assessment of acid–base status: strong ion difference theory
The Veterinary Clinics of North America: Food Animal Practice
(1999)- et al.
Calcium homeostasis in hypomagnesaemic cattle
Research in Veterinary Science
(1982)
Path analysis of dry period nutrition, postpartum metabolic and reproductive disorders, and mastitis in Holstein cows
Journal of Dairy Science
Disease, production and culling in Holstein-Friesian cows: Part ii, Age, season and sire effects
Preventative Veterinary Medicine
Path model of reproductive disorders and performance, milk fever, mastitis, milk yield and culling in Holstein cows
Journal of Dairy Science
Potential use of 1,25-dihydroxycholecalciferol for prevention of parturient paresis
Journal of Dairy Science
Parturient hypocalcemia in Jersey cows fed alfalfa haylage-based diets with different cation to anion ratios
Journal of Dairy Science
Treatment of calcium, phosphorus and magnesium balance disorders
The Veterinary Clinics of North America: Food Animal Practice
Pathophysiology of calcium and phosphorus disorders
The Veterinary Clinics of North America: Food Animal Practice
Use of 24-F-1, 25-dihydroxyvitamin D3 to prevent parturient paresis in dairy cows
Journal of Dairy Science
Addition of chloride to a prepartal diet high in cations increases 1,25-dihydroxyvitamin D response to hypocalcemia preventing milk fever
Journal of Dairy Science
Relative acidifying activity of anionic salts commonly used to prevent milk fever
Journal of Dairy Science
Prevention of parturient paresis by a prepartum calcium deficient diet
Journal of Dairy Science
Vitamin D metabolites in plasma of cows fed a prepartum low-calcium diet for prevention of parturient hypocalcemia
Journal of Dairy Science
Postpartum body condition score and results from the first test day milk as predictors of disease, fertility, yield and culling in commercial dairy herds
Journal of Dairy Science
The effect of age on calcium absorption and accumulation of 1,25-dihydroxyvitamin D3 in intestinal mucosa of rats
Metabolic Bone Disease and Related Research
Strategies for preventing milk fever in dairy cattle
Journal of Dairy Science
Plasma concentrations of 1,25-dihydroxyvitamin D, 1,24R,25-trihydroxyvitamin D3 and 1,25,26-trihydroxyvitamin D3 after administration to dairy cows
Journal of Dairy Science
Milk fever in dairy cows. viii. Effect of injected vitamin D3 and calcium and phosphorus intake on incidence
Journal of Dairy Science
Relationships between prepartal dietary calcium and phosphorus, vitamin D metabolism, and parturient paresis in dairy cows
Journal of Nutrition
Hypocalcemia in dairy cows: meta analysis and dietary cation anion difference theory revisited
Journal of Dairy Science
Vitamin D3 toxicity in dairy cows
Journal of Dairy Science
Some aspects of calcium metabolism in the dairy cow
Research in Veterinary Science
Type appraisal: Part ii. variation in type traits due to sires, herds and years
Journal of Dairy Science
Meta-analysis of nutritional risk factors for milk fever in dairy cattle
Journal of Dairy Science
Management of dry cows for the prevention of milk fever and other mineral disorders
The Veterinary Clinics of North America: Food Animal Practice
Screening of anionic salts for palatability, effects on acid–base status, and urinary calcium excretion in dairy cows
Journal of Dairy Science
Ammonium chloride and ammonium sulphate for prevention of parturient paresis in dairy cows
Journal of Dairy Science
Effects of milk fever, ketosis and lameness on milk yield in dairy cows
Journal of Dairy Science
Dietary calcium, calcium kinetics and plasma parathyroid hormone concentration in cows
Journal of Nutrition
Sulphur fertilization of cool season grasses and effect on utilization of minerals, nitrogen and fibre by steers
Journal of Dairy Science
Reproductive disorders in the periparturient dairy cow
Journal of Dairy Science
Effects of dietary cation–anion difference on the acid–base status of dry cows
Journal of Dairy Science
Influence of a deficient supply of magnesium during the dry period on the rate of calcium mobilization by dairy cows at parturition
Research in Veterinary Science
Effects of reducing dietary [(Na+ + K+) - ] on the rate of calcium mobilisation by dairy cows at parturition
Research in Veterinary Science
Effects of diet magnesium on acid–base status and calcium metabolism of dry cows fed acidogenic salts
Journal of Dairy Science
Prevention of parturient paresis by a low-calcium diet prepartum: a field study
Journal of Dairy Science
Effect of pH and Ca2+ on retention of Ca2+ by rat liver mitochondria
Archive of Biochemistry and Biophysiology
Cited by (229)
Considerations in the Diagnosis and Treatment of Early Lactation Calcium Disturbances
2023, Veterinary Clinics of North America - Food Animal PracticeMetabolic Profiling in Ruminant Diagnostics
2023, Veterinary Clinics of North America - Food Animal PracticeNanoscale calcium oxide and its biomedical applications: A comprehensive review
2023, Biocatalysis and Agricultural BiotechnologyDevelopment of a blood calcium test for hypocalcemia diagnosis in dairy cows
2022, Research in Veterinary Science