Calcium and magnesium status of pregnant ewes grazing southern Australian pastures
Janelle E. Hocking Edwards A G , David G. Masters B , Emma Winslow A , Serina Hancock C , Andrew N. Thompson C , Gordon Refshauge D , Shawn R. McGrath E F , Susan M. Robertson E F , Marie S. Bhanugopan E F and Michael A. Friend E FA South Australian Research and Development Institute, Struan Research Centre, Penola Road, Naracoorte, SA 5271, Australia.
B School of Agriculture and Environment M085, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
C School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
D New South Wales Department of Primary Industries, Cowra Agricultural Research and Development Station, Binni Creek Road, Cowra, NSW 2794, Australia.
E School of Animal and Veterinary Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, NSW 2678, Australia.
F Graham Centre for Agricultural Innovation (Charles Sturt University and NSW Department of Primary Industries), Albert Pugsley Place, Wagga Wagga, NSW 2678, Australia.
G Corresponding author. Email: janelle.edwards@sa.gov.au
Animal Production Science 58(8) 1515-1521 https://doi.org/10.1071/AN17766
Submitted: 7 November 2017 Accepted: 19 March 2018 Published: 26 April 2018
Abstract
During pregnancy, ewes graze pastures that may be marginal in calcium (Ca) and magnesium (Mg), and may also be low in sodium (Na) and high in potassium (K), with a high dietary cation–anion difference. Such pastures may increase susceptibility to hypocalcaemia and hypomagnesaemia, leading to lamb losses. Clinical hypocalcaemia and hypomagnesaemia do occur in Australian sheep; however, it is unknown whether subclinical forms of these disorders compromise ewe or lamb health and survival. The present study monitored the Ca and Mg status of ewes in late pregnancy, so as to evaluate the risk of subclinical mineral disorders in ewes grazing typical southern Australian pastures. Calcium and Mg concentrations in pasture, ewe plasma and urine were monitored in 15 flocks in southern Australia. Mineral concentrations in pasture did not indicate a widespread risk of Ca or Mg deficiency; however, urinary pH and Ca and Mg concentrations in the plasma and urine of the pregnant ewes were not entirely consistent with the expectations from pasture analysis. Urine pH was above 7 on all properties and 87.5% of properties had a mean Ca in urine below the adequate concentration of 1 µmol/mosmol. The mean plasma Ca concentration was below adequate (<90 mg/L) on only one farm but five farms had more than 20% of ewes with below adequate Ca in plasma. In addition, although average farm concentrations of plasma and urine Mg indicated adequate Mg status of the ewes (>18 mg/L), more than 20% of ewes on six farms had below adequate concentrations of plasma Mg. Only one-third of the farms had 100% of ewes measured with adequate concentrations of plasma Ca (4/15) or Mg (5/15). The mineral concentrations in pre-lambing blood and urine samples suggested that a significant number of animals grazing southern Australian pastures during winter may be at risk of subclinical hypocalcaemia and hypomagnesaemia.
Additional keywords: grass tetany, hypocalcaemia, hypomagnesaemia.
References
Beede DK (1992) The DCAD concept: transisition rations for dry pregnant cows. Feedstuffs 64, 12–19.Benech A, Cal-Pereyra L, Da Silva S, Acosta-Dibarrat J, González-Montaña JR (2015) Transient apnoea in sheep: an alternative method for serial urine sample collection. Veterinarski Arhiv 85, 293–307.
Bhanugopan MS, Fulkerson WJ, Hyde M, Fraser DR (2015) Effect of dietary potassium supplementation on the calcium absorption capacity in the rumen and abomasum and fractional excretion of urinary minerals in sheep. Animal Production Science 55, 508–514.
| Effect of dietary potassium supplementation on the calcium absorption capacity in the rumen and abomasum and fractional excretion of urinary minerals in sheep.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXjvVOns70%3D&md5=559433aff2bc2044b59a5587b54c39ccCAS |
Block E (1984) Manipulating dietary anions and cations for prepartum dairy cows to reduce incidence of milk fever. Journal of Dairy Science 67, 2939–2948.
| Manipulating dietary anions and cations for prepartum dairy cows to reduce incidence of milk fever.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2MXhtFWqtrk%3D&md5=f76e553133c4db575d3358051df937a6CAS |
Caple I (1989) Nutritional problems affecting calcium and magnesium metabolism in grazing ruminants. Recent Advances in Animal Nutrition in Australia 7, 37–46.
Dove H, Kelman WM (2015) Responses of young sheep grazing dual-purpose wheat to supplementary sodium and magnesium supplied as direct supplement, or to magnesium supplied as fertiliser. Animal Production Science 55, 1217–1229.
| Responses of young sheep grazing dual-purpose wheat to supplementary sodium and magnesium supplied as direct supplement, or to magnesium supplied as fertiliser.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXhsVyqu7fK&md5=557bba50745193d562654616883b3b37CAS |
Dove H, Masters DG, Thompson AN (2016) New perspectives on the mineral nutrition of livestock grazing cereal and canola crops. Animal Production Science 56, 1350–1360.
| New perspectives on the mineral nutrition of livestock grazing cereal and canola crops.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC28XhtVCltLjM&md5=ad74e0db53e3c1ac8656531a5818a88dCAS |
Dwyer CM (2008) The welfare of the neonatal lamb. Small Ruminant Research 76, 31–41.
| The welfare of the neonatal lamb.Crossref | GoogleScholarGoogle Scholar |
English PB, Hogan AE (1979) A comparison of urine specific gravity and osmolality in sheep. Australian Veterinary Journal 55, 584–586.
| A comparison of urine specific gravity and osmolality in sheep.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL3c7ltlWhsQ%3D%3D&md5=1dec135140c1953655c7da4564e0e5e2CAS |
Freer M, Dove H, Nolan JV (Eds) (2007) ‘Nutrient requirements of domesticated livestock.’ (CSIRO Publishing: Melbourne)
Goubern M, Rayssiguier Y, Miroux B, Chapey M, Ricquier D, Durlach J (1993) Effect of acute magnesium deficiency on the masking and unmasking of the proton channel of the uncoupling protein in rat brown fat. Magnesium Research 6, 135–143.
Grant I, Foot J, Brockhus M, Bingham A, Caple I (1988) Factors affecting plasma calcium and phosphorus concentrations in grazing ewes in spring and autumn lambing flocks in Victoria. Proceedings of the Australian Society of Animal Production 17, 194–197.
Grant IM, Bingham AM, Caple IW (1992) Acid–base balance and susceptibiltiy of ewes to hypocalcaemia. Proceedings of the Australian Society of Animal Production 19, 412–415.
Herd RP (1965) The relationship between hypocalcaemia and hypomagnesaemia in sheep. Australian Veterinary Journal 41, 385–386.
| The relationship between hypocalcaemia and hypomagnesaemia in sheep.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaF28%2FotVagtQ%3D%3D&md5=39c2abe11af3bd0a2f81d5c8f2e3fc10CAS |
Hinch GN, Brien F (2014) Lamb survival in Australian flocks: a review. Animal Production Science 54, 656–666.
| Lamb survival in Australian flocks: a review.Crossref | GoogleScholarGoogle Scholar |
Hou W, Cheng S, Liu S, Shi B, Shan A (2014) Dietary supplementation of magnesium sulfate during late gestation and lactation affects the milk composition and immunoglobulin levels in sows. Asian-Australasian Journal of Animal Sciences 27, 1469–1477.
| Dietary supplementation of magnesium sulfate during late gestation and lactation affects the milk composition and immunoglobulin levels in sows.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXhsl2mtrfN&md5=693e995cf0053ee81f87ea9c8eebf0cbCAS |
Jonsson N, Daniel R (1997) Effects of hypocalcaemia on blood flow to the ovaries of the sheep. Journal of Veterinary Medicine Series A 44, 281–287.
| Effects of hypocalcaemia on blood flow to the ovaries of the sheep.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK2svhvFKnsw%3D%3D&md5=13985bbf49941fbc43c886cfe664f589CAS |
Judson GJ, McFarlane JD (1998) Mineral disorders in grazing livestock and the usefulness of soil and plant analysis in the assessment of these disorders. Australian Journal of Experimental Agriculture 38, 707–723.
Kempt A, ‘t Hart J (1957) Grass tetany in grazing milking cows. Netherlands Journal of Agricultural Science 5, 4–17.
Lane J, Jubb T, Shephard R, Webb-Ware J, Fordyce G (2015) ‘Priority list of endemic diseases for the red meat industries.’ (Meat and Livestock Australia: Sydney)
Marret S, Doyle L, Crowther C, Middleton P (2007) Antenatal magnesium sulphate neuroprotection in the preterm infant. Seminars in Fetal & Neonatal Medicine 12, 311–317.
Masters DG, Hancock SN, Refshauge G, Robertson SM, Bhanugopan MS, Friend MA, Thompson AN (2017) Mineral status of reproducing ewes grazing vegetative cereal crops. Animal Production Science
| Mineral status of reproducing ewes grazing vegetative cereal crops.Crossref | GoogleScholarGoogle Scholar |
National Research Council (2005) ‘Mineral tolerance of animals.’ (The National Academies Press: Washington, DC)
Paynter DI (1996) Diagnosis of mineral deficiencies. In ‘Detection and treatment of mineral disorders in grazing sheep’. (Eds DG Masters, CL White) pp. 45–56. (Australian Centre for International Agricultural Research: Canberra)
Refshauge G, Brien FD, Hinch GN, van de Ven R (2016) Neonatal lamb mortality: factors associated with the death of Australian lambs. Animal Production Science 56, 726–735.
| Neonatal lamb mortality: factors associated with the death of Australian lambs.Crossref | GoogleScholarGoogle Scholar |
Scott D, Loveridge N, Abu-Damir H, Buchan W, Milne J (1993) Effects of acute acid loading on parathyroid hormone secretion and on urinary calcium and cAMP excretion in the growing lamb. Experimental Physiology 78, 157–163.
| Effects of acute acid loading on parathyroid hormone secretion and on urinary calcium and cAMP excretion in the growing lamb.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXks1elsbk%3D&md5=c0384ad322a387f7c57c56fc831b3ccbCAS |
Suki WN, Massry SG (2012) ‘Therapy of renal diseases and related disorders.’ (Springer Science and Business Media: New York)
Suttle NF (2010) ‘Mineral nutrition of livestock.’ (CABI Publishing: Wallingford, UK)
Takagi H, Block E (1991) Effects of various dietary cation-anion balances on response to experimentally induced hypocalcemia in sheep. Journal of Dairy Science 74, 4215–4224.
| Effects of various dietary cation-anion balances on response to experimentally induced hypocalcemia in sheep.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38XhsFSnu7s%3D&md5=5cb3a594c7a3098fdf3bd443dcc5bb1eCAS |
Tucker KL, Hogue JF, Waterman DF, Swenson TS, Xin Z, Hemken RW, Jackson JA, Adams GD, Spicer LJ (1992) Sulfur should be included when calculating the dietary cation-anion balance of diets for lactating dairy cows. In ‘Animal Science research report’. pp. 141–150. (Oklahoma Agricultural Experiment Station: Stillwater, OK)
Wilkens MR, Praechter C, Breves G, Schröder B (2016) Stimulating effects of a diet negative in dietary cation-anion difference on calcium absorption from the rumen in sheep. Journal of Animal Physiology and Animal Nutrition 100, 156–166.
| Stimulating effects of a diet negative in dietary cation-anion difference on calcium absorption from the rumen in sheep.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC28XpsFCltg%3D%3D&md5=e43ade8620379c21296787eac20c0521CAS |
