Effects of phosphorus supplementation in high-grain diets on blood, chemical and physical parameters of bones of feedlot Nellore bulls

Author(s)

Souza, Vinicius C. ^[1] ; Malafaia, Pedro ^[2] ; Granja-Salcedo, Yury T. ^[1] ; Vieira, Bruno R. ^[1] ; Gomes, Raphael S. ^[3] ; Costa, Diogo F. A. ^[4] ; Negrao, Joao Alberto ^[5] ; Shimano, Antonio C. ^[6] ; Berchielli, Telma T. ^{[1, 7]}

Affiliation

^[1] Sao Paulo State Univ Unesp, Sch Agr & Veterinarian Sci, Dept Anim Sci, Rodovia Prof Paulo Donato Castellane, Km 5, BR-14884900 Jaboticabal, SP - Brazil

^[2] UFRRJ, Inst Anim Sci, Dept Anim Nutr & Pastures, BR-23853000 Seropedica, RJ - Brazil

^[3] UENF CCTA, Lab Anim Sci & Anim Nutr, BR-28013602 Campos Dos Goytacazes, RJ - Brazil

^[4] Kansas State Univ, Beef Cattle Res Ctr, Manhattan, KS 66506 - USA

^[5] Univ Sao Paulo, Fac Anim Sci & Food Engn, Dept Basic Sci, BR-13635900 Pirassununga, SP - Brazil

^[6] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Biomech Med & Rehabil Locomotor Syst, BR-14049900 Ribeirao Preto, SP - Brazil

^[7] INCT CA UFV, Dept Anim Sci, Ave Peter Henry Rolfs S-N, Campus Univ, BR-36570000 Vicosa, MG - Brazil

• Document type: Journal article
• Source: ANIMAL PRODUCTION SCIENCE; v. 58, n. 10, p. 1814-1821, 2018.
• Web of Science Citations: 1

Abstract

The study was conducted to evaluate the effects of phosphorus supplementation (PS) on blood, chemical and physical parameters from bones of feedlot Nellore bulls. Forty-two animals were distributed in a completely randomised design consisting of three treatments and 14 replicates. The treatments consisted of no supplementary phosphorus (P; T-1; 2.4 g P/kg DM), a commercial mineral supplement formulated according to recommendations from the main Brazilian industries of mineral supplements for feedlot beef cattle (T-2; 4.2 g P/kg DM) and dicalcium phosphate (T-3; 5.0 g P/kg DM) in high-grain diets. The animals submitted or not to PS had similar calcium (Ca) and P values, Ca : P ratio, specific gravity, cortical thickness and bone mineral density in the 12th rib. However, a decrease in magnesium (Mg) concentration was observed in the 12th rib in T-1 and T-3 treatments throughout the study (P < 0.05). The animals in T-1 had lower cortical thickness of the metacarpus (P < 0.05), without compromising its resistance and stiffness (P > 0.05). To evaluate the P status in the animals, we performed the needle test, which allowed an assessment of differences in bone strength on the basis of the resistance to needle penetration on the transverse process (TP) of the lumbar vertebrae. Throughout the trial period, no animals were positive for the needle test conducted in the transverse processes of the lumbar vertebrae. The PS significantly changed parathyroid hormone and alkaline phosphatase concentrations (P < 0.05) and the animals in T-1 had lower concentrations of these hormones. However, there was no effect of PS on the concentration of Ca and P in the serum of animals (P > 0.05). The inclusion of a mineral mix supplement in T-2 resulted in higher Mg concentrations in the serum of animals (P > 0.05). P supplementation for Nellore bulls, fed high proportions of concentrate during the feedlot period, resulted in no benefits in neither chemical nor physical properties of their bones and the level in the control diet appeared adequate in these circumstances. (AU)

• FAPESP's process: 14/08935-1 - Nutritional balance, performance, bone parameters, economics and meat quality of Nellore submitted or not to phosphorous supplementation during feedlot
• Grantee: Vinícius Carneiro de Souza
• Support Opportunities: Scholarships in Brazil - Master