Effects of exogenous amylase on the in vitro digestion kinetics of whole-crop maize silages made from flint or dent grain type at different phenological stages grown in tropical condition     

Abias Santos Silva  Luiz Gustavo Ribeiro Pereira  Márcio dos Santos Pedreira  Fernanda Samarini Machado  Mariana Magalhães Campos  Cristina Simões Cortinhas  Tiago Sabella Acedo  Rafael Dantas dos Santos  João Paulo Pacheco Rodrigues  Rogério Martins Maurício  Thierry Ribeiro Tomich 《Journal of animal physiology and animal nutrition》2020,104(1):76-87

The effect of exogenous amylase on the in vitro rumen digestion kinetics of whole-crop maize silage made from dent (RB9004) or flint grain type (RB9308) was evaluated at different phenological stages: soft dough (SOD), early dent (EAD), ½ milkline (½M) and ¾ milkline (¾M). Forage was harvested from 70 to 110 days after sowing. Two rumen-cannulated cows receiving or not exogenous amylase (0.7 g/kg dry matter—DM, provided to achieve 396 kilo Novo units of amylase activity/kg of TMR DM) were used as donor of ruminal fluid. The in vitro gas production kinetics was evaluated according to a dual-pool logistic model. The chemical composition and gas production kinetics were affected by the hybrid and phenological stages. The flint hybrid had lower range for chemical analysis among physiological stages. Harvesting at ½M and ¾M improved DM content, bromatological composition and silage quality parameters compared to dent or flint types. Amylase (i) increased methane (CH₄) production and in vitro dry matter digestibility (IVDMD) in ½M stage, (ii) improved digestion kinetics by reducing lag time and increasing total gas production and fermentation rates of non-fibrous carbohydrates (NFC) and fibrous carbohydrates (FC), and (iii) increased extent and fermentation rate of NFC and increased fermentation rate of FC fraction in whole-crop maize silages produced from dent or flint types in all phenological stages. Harvesting between ½M and ¾M is the best phenological stage to improve chemical composition and silage quality parameters. Exogenous amylase showed improvements on fibre digestion of silages at ½M and ¾M phenological stages in both grain types of corn.  相似文献   

Herd characteristics and management practices associated with bulk tank milk quality of dairy herds in southeastern Brazil     

Cortinhas  Cristina Simões  Botaro  Bruno Garcia  de Macedo  Susana Nori  dos Santos  Marcos Veiga 《Tropical animal health and production》2018,50(7):1605-1610

Tropical Animal Health and Production - This study identified the association of management practices and herd characteristics with milk quality of bulk tanks in southeastern, Brazil. Milk samples...  相似文献   

<Emphasis Type="Italic">Staphylococcus aureus</Emphasis> intramammary infection affects milk yield and SCC of dairy cows     

Bruno Garcia Botaro  Cristina Simões Cortinhas  Aline Gerato Dibbern  Luis Felipe Prada e Silva  Nilson Roberti Benites  Marcos Veiga dos Santos 《Tropical animal health and production》2015,47(1):61-66

Staphylococcus aureus (S. aureus) is the most prevalent infectious microorganism affecting dairy cattle worldwide, and its pathogenic characteristics facilitate its spread in dairy herds. S. aureus intramammary infections (IMI) are mainly subclinical, and associated losses can exceed average herd losses where the pathogen is not isolated. However, the extent it affects milk composition at udder and quarter levels is still unknown, and cow composite milk losses may be underestimated due to the dilution effect. The aim of this study was to investigate the effects of S. aureus subclinical mastitis on mammary quarter milk yield and composition. In order to determine the effects of the pathogen on milk yield and composition at quarter level, a pairwise comparison of infected and non-infected mammary quarters (n?=?28) from two dairy herds was carried out. Quarters were individually milked, and milk production and composition were assessed. S. aureus has increased somatic cell counts at quarter level; however, no effect of S. aureus IMI on milk lactose, fat, and protein contents was observed. Fat yield from infected quarters decreased, but losses due to the infection caused by S. aureus were not associated with quarter positioning in cows.  相似文献   

Antioxidant enzymes and somatic cell count in dairy cows fed with organic source of zinc,copper and selenium     

C.S. Cortinhas  B.G. Botaro  M.C.A. Sucupira  F.P. Renno  M.V. Santos 《Livestock Science》2010,127(1):84-87

The objectives of this study were to evaluate the effects of dietary organic sources of zinc (Zn), copper (Cu) and selenium (Se) for dairy cows on somatic cell count (SCC), occurrence of subclinical mastitis, number of clinical mastitis cases and concentration of superoxide dismutase (CuZnSOD), glutathione peroxidase (GSH-Px) and ceruloplasmin (CP). Nineteen dairy cows, with confirmed pregnancy, were selected by body weight, body condition score (BCS), number of lactation, and milk yield in previous lactation, and randomly distributed among two groups, one to receive organic (n = 9) and the other the inorganic (n = 10) source of Zn, Cu and Se. Diets were formulated to meet the nutritional requirements of animals from 60 days before the expected date of calving up to 80 days of lactation. Blood samples were collected at − 60, − 21, 1, 21, 40 and 80 days in relation to the expected date of calving for analysis of CuZnSOD, GSH-Px and CP concentration. Milk samples for SCC determination were collected weekly after 15 days of lactation, also at day 1 and 7 and when a clinical case was diagnosed for microbiological culture. The number of new and total cases of subclinical mastitis was lower for the group of cows fed with organic sources of Zn, Cu and Se compared to animals receiving inorganic sources. Average SCC during the first 80 days of lactation tended to be lower for the group fed with organic Zn, Cu and Se. Feeding organic Zn, Cu and Se did not alter the concentration of CuZnSOD, GSH-Px and CP.  相似文献