Effect of dietary phosphorus deprivation on leukocyte function in transition cows

Abstract

Phosphorus depletion and hypophosphatemia have been described to hamper immune function in different species, an effect barely studied in dairy cows commonly developing hypophosphatemia in early lactation. Dietary P deprivation in mid lactating dairy cows was associated with a decline of the number of granulocytes and impaired granulocyte survival, whereas the phagocytic activity remained unaffected. The objective of the study reported here was to determine the effect of P deprivation on the leukocyte function of periparturient dairy cows. Eighteen multiparous and late pregnant dairy cows were randomly assigned to either a treatment group that was offered a markedly P-deficient diet or a control group receiving the same ration with adequate P content. The study consisted of a 2-wk acclimation period that was followed by a P deprivation period extending from 4 wk before to 4 wk after parturition and a P repletion period of 2 wk thereafter. Blood samples for leukocyte counts and leukocyte function analysis were obtained at the end of the acclimation period, after 2 wk of P deprivation, within the first week of lactation, at the end of the P depletion period and after 2 wk of dietary P supplementation. Blood samples for biochemical analysis were obtained weekly. Immune function was assessed by means of a phagocytosis assay and a lymphocyte stimulation test. Dietary P deprivation resulted in pronounced and sustained hypophosphatemia. Time effects were observed on the counts of different leukocyte fractions, the relative number of phagocytic granulocytes, the degree of phagocytosis, and the lymphocyte proliferation. Differences between P-deprived and control cows were only identified for the degree of phagocytosis that was lower in P-deprived cows compared with control cows. The correlation and regression analyses, however, revealed positive associations of the plasma phosphate concentration and the granulocyte count, the relative number of phagocytic granulocytes, and the degree of phagocytosis at the end of the dietary P deprivation when P depletion was most severe. The results of the study reported here indicate a mild negative effect of pronounced and sustained hypophosphatemia on the granulocyte count and the phagocytic activity of granulocytes in transition dairy cows. The clinical relevance of this effect for health and productivity of dairy cows remains to be determined.

Feeding synthetic zeolite to transition dairy cows alters neutrophil gene expression

“…The positive effect of zeolite on blood calcium concentrations at calving is at least partially dependent upon lower plasma concentrations of phosphorus prepartum as additional prepartum supplementation with phosphorus interferes with the calcium response (Pallesen et al, 2008). Recent research also indicates that hypophosphatemia has a mild negative effect on granulocyte phagocytosis ability in transition dairy cows (Eisenberg et al, 2019). The clinical effects of short-term suppression of plasma phosphate remain unclear.…”

Acidified diet is not effective in preventing hypocalcemia in dairy cows on French commercial farms

“…The consequences of SHC on health and reproduction have been widely studied worldwide, but those of SHP remain uncertain. Its detrimental effects on immunity have been demonstrated (Mullarky et al, 2009;Eisenberg et al, 2014;Eisenberg et al, 2019), but epidemiological studies quantifying the consequences regarding disease incidence and reproductive performance are lacking. Such studies are sorely needed to assess the need to take hypophosphatemia into consideration when implementing hypocalcemia prevention programs.…”

The Association between Selected Dietary Minerals and Mastitis in Dairy Cows—A Review

“…Phosphorus deficiency, especially around calving and in early lactation, has been associated with hampered productivity, feed intake depression and an increased risk of morbidity in fresh cows [ 27 ]. When investigating the immune system and resistance to infection, Eisenberg et al [ 28 ] stated that hypophosphatemia negatively affects both phagocytic activity and granulocyte count in transition Holstein dairy cows. However, in research conducted earlier by the same authors [ 29 ], granulocytes derived from cows fed a phosphorus-deficient diet were less viable, but phagocytic activity was not affected.…”

“…Reports on other animal species such as rats suggest that ATP content of leukocytes tends to be lower in hypophosphatemic individuals and that explains their decreased phagocytic activity and proliferation [ 31 ]. It is important to note that there are concerns regarding environmental pollution with P of fecal origin, thus it has been suggested that the P content of manure should be limited, thereby enforcing a more restrictive use of P in bovine nutrition [ 28 ].…”