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Evaluation of dietary cation-anion difference (DCAD) for lactating buffalo

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Author(s):
Thaysa dos Santos Silva
Total Authors: 1
Document type: Doctoral Thesis
Press: Pirassununga.
Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
Defense date:
Examining board members:
Raul Franzolin Neto; André Mendes Jorge; Arlindo Saran Netto; Humberto Tonhati; Marcus Antonio Zanetti
Advisor: Raul Franzolin Neto
Abstract

This study aimed to evaluate the effects of feeding diets with different dietary cation-anion difference (DCAD) in the production and quality of buffalo milk, in the fermentation characteristics by in vitro gas production technique, and in addition to showing nutritional profile lactating buffalo on farms located in the central region of São Paulo state, Brazil. Thus, this thesis is presented in the form of eleven sections, where the Chapters 1, 2 and 11 describe the introduction, literature review, and final considerations, respectively. The others describe different experiments performed under the general theme from 2012 to 2014. The Chapter 3 contains the evaluation of four cationic diets with high DCAD (+362, +370, +379 and +390 mEq / kg / MS) formulated as mozzarella cheese yield basis in 350 buffaloes, divided into two groups (buffaloes less and above 100 days of lactation at beginning of the experiment) during the experimental period of 120 days. Ten treatments were assigned adopting different ways feeding system throughout the experiment. The covariate age did not influence the production and quality of milk, except in somatic cell counting (SCC) and electrical conductivity in buffaloes ≤100 days of lactation. Significant differences were observed between treatments for daily milk production in both groups buffaloes. Only lactose has differed between treatments in buffaloes in early lactation. The feeding system with changing diets containing different DCAD every 30 days has no effect on production and quality of milk in buffalo in the early stage of lactation, but it increases milk production in buffalo over 100 days of lactation. In chapter 4, the daily production and milk quality were evaluated in 297 buffaloes, divided into two groups, one with less than 100 and another 100-220 days of lactation receiving two cationic diets with low DCAD: D121 (+121 mEq / kg / DM) and D164 (+164 meq / Kg / MS) to two feeding systems, defining four treatments. DCAD has influenced the milk production of buffaloes. Lower DCAD has produced higher milk production. The highest DCAD has promoted increases in protein, total solids (TS), solid no fat (SNF) and SCC in buffaloes with 100-200 days of lactation. In Chapter 5, four anionic diets with DCAD of -61, -67, -73 and -100 mEq / kg / DM were evaluated in 259 buffaloes, divided into two groups: between 100 - 200 days and over 200 days of lactation. The negative DCAD has not interfered in daily milk production and milk quality in buffaloes, however, has influenced the fat and lactose contents of milk in buffalo in both groups of lactation and also in protein levels, and total solid and SCC of buffalo over 200 days of lactation. In Chapter 6, were evaluated three increasing levels of DCAD: +40, +120 and +190 mEq / kg / DM in production, quality and minerals in buffalo milk. No significant differences were observed in production, quality and minerals in buffalo milk except in electrical conductivity, acidity and levels of Na and Cl. In Chapter 7, the characterization of production, quality and minerals of milk along the lactation curve were evaluated in buffaloes on cationic diets with low DCAD. The data showed that the lactation curve started rising, peaking on the 2nd. and 3rd. month and subsequent decline with higher milk production in the first 90 days of lactation (40%). The calved buffaloes in the second half of the year had higher average daily milk production along the lactation than that calved in the first half with the quality of milk similar in both groups. The fat, protein, TS and SNF increased in milk throughout the lactation and, then remained constant, while lactose decreased and the SCC did not change. The buffalo milk macrominerals have maintained the same levels along lactation, except chlorine that dropped. Ca and K showed up in higher concentration. In Chapter 8 describes the characterization of accumulated and daily production of buffalo milk during lactation curve as a function of lactation period, number of lactation and age of the animals fed diet with medium DCAD of +83 mEq/kg/DM. The lactation curve in buffaloes characterized by the growth of milk production until the first 90 days, followed by a gradual decline until the end of lactation, with no influence of lactation period, lactation number and age of the animals. Four phases have been identified with different monthly decline levels of production compared to the previous month (increase; slight, medium and, strong declines). Older buffaloes above 11 years of age had steeper decline than younger buffaloes. In early lactation up to 90 days, buffaloes with more lactations and age have produced more milk than younger. In Chapter 9, three diets of DCAD +110, +220 and +440 mEq/kg DM were evaluated by ruminal fermentation kinetics, involving total production and methane gases, degradability of dry matter and organic matter and fatty acids of short chain and ammonia nitrogen productions in 24 and 96 hours of inoculation, by using in vitro gas production technique with inoculum of rumen contents of buffalo. No differences were observed between treatments. No observed effects suggest other actions of DCAD on animal metabolism than on ruminal metabolism in producing productive performance of the animals. Completing these studies, Chapter 10 describes the evaluation of buffalo milk operating system of four rural properties, comprising a total of 794 buffaloes, with characterization of the composition of 11 types of diets and chemical composition of the diet ingredients used. The buffaloes had dry matter intake daily average of 17.8 kg per animal (2.6% of body weight and 91 g DM / kg0.75) and average milk production of 8.1 kg / animal / day with feed conversion 2.2 kg of dry matter per kg of produced milk / animal / day. (AU)

FAPESP's process: 11/19562-3 - Assessment of diet cation-anion balance (DCAB) the production and quality of buffalo milk
Grantee:Thaysa dos Santos Silva
Support Opportunities: Scholarships in Brazil - Doctorate