Freestall bedding materials for dairy cows and colostrum replacer for beef calves
Authors:   , Gomes João Paulo Ferreira 
Published: August 2024

The aim of the first study was to evaluate sand or sawdust materials for freestall system. Sixteen Holstein cows were used in this trial, with an average production of 38 ± 9.0 L/d. Eight cows were allocated in sand beddings and 8 cows were allocated in sawdust beddings, receiving three dailies’ meals, and milked three times a day. The experimental period lasted 30 d, preceded by a 7 d adaptation period. Animal behaviour, milk yield, somatic cell count, and the hygiene score of the thigh, legs, and udder were evaluated. Samples of sand and sawdust were collected for microbiological evaluation and the surface temperature of the beds was also measured. The type of bed did not affect milk production and the lying behaviour of the cows. The sawdust bed had a greater count of enterobacteria. For staphylococcus count, sand had a greater value at d2; however, for sawdust at d28 the staphylococcus count was greater than in sand beddings. The cows kept in the sawdust bed showed greater somatic cell count, but no case of clinical mastitis for both materials was observed. The sand bed warmed up more than the sawdust, but there was a loss of temperature more quickly at night. The results obtained in this study demonstrate that sawdust may be used to replace sand, but care with handling bed replacement must be considered to ensure the quality of the material for longer periods. The second study aimed to evaluate the influence of colostrum replacer on health and performance of beef calves. Two experiments were carried out. In the first one, 206 ¾ Angus × Nellore calves, offspring of ½ Angus × Nellore primiparous cows were used. Calves were divided into 3 groups: NRG (no replacer group) (n = 68), 50I (50 g of IgG supply) (n = 68), and 100I (100 g of IgG supply (n = 70). The serum protein level was assessed using three methodologies: optical brix refractometer, digital brix refractometer, and serum total protein refractometer (STP-REF). In the second, 247 Nellore calves, offspring of Nellore cows were used. Calves were divided into three groups: NRG (n = 85), 50I (n = 81) and 100I (n = 81). The serum protein level was assessed as the experiment 1. The animals were weighed using weighing tapes at calving and weaning at 80 days of age. For the first experiment, there was no difference (P>0,05) for colostrum efficiency regardless of the method used and gender. In the second experiment, an effect was observed (P = 0.02) on STP concentrations measured by the STP-REF and through the digital brix refractometer in the 50I group. Serum total protein evaluated through the optical brix refractometer did not vary among treatments as well as ADG. The effect of colostrum replacer was different from Nellore pure calves and ¾ Angus × Nellore calves, with greater passive transfer efficiency for Nellore calves. However, for dams well fed like in these experiments, no effect on morbidity, mortality and animal performance were observed for calves. Keywords: Animal welfare. Immunoglobulin G. Milk quality. Passive Immunity. Sand. Sawdust