Full text
| |
| Author(s): |
Ariany Faria de Toledo
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2020-05-25 |
| Examining board members: |
Carla Maris Machado Bittar;
Danilo Domingues Millen;
Alexandre Mendonça Pedroso
|
| Advisor: | Carla Maris Machado Bittar |
| Abstract | |
Tropical hay may result in ruminal health, however, may be decrease energy intake while the whole corn grain may be an alternative fiber source in the diet of young dairy calves. Forty- two Holstein calves were used in a randomized block design, considering sex, birth date and weight at 21 days of age, when the supplementation started. Three solid diets were compared: 1) Control: starter concentrate; 2) Hay: starter concentrate, supplemented with free choice chopped Tifton hay; and 3) Whole corn: starter concentrate supplemented with free choice whole corn grain. The experimental period was 84 days, but calves were equally managed during the first 21 days when they were fed with 6L/d of whole milk and commercial concentrate ad libitum. After that, milk feeding was reduced to 4L/d of whole milk until gradual weaning at 56 days of age. At d56, four animals were randomly chosen per treatment to be slaughtered to collect tissue for histological analysis of the rumen, duodenum and cecum, the other thirty animals were weaned and evaluated for a further 28d when control animals received hay ad libitum. Feed intake was measured daily. Weight gain and metabolic indicators of intermediate metabolism were evaluated weekly. Ruminal fluid was collected at week 6, 8, 10 and 12 of age. Free access to hay promoted an increased in the total DMI and concentrate DMI, consequently, calves supplemented with hay presented higher average daily gain and higher body weight at d56. Free access to whole corn grain promoted an increase in propionate and decreased acetate-to-propionate ratio. Morphometrics parameters were affected by free access to hay. The performance in the postweaning period were unaffected by solid diets, however, supplementation with whole corn grain decreased rumen pH and fecal pH. Tifton hay, since 21 day of life, can stimulate an early solid diet intake, promoting better performance, ensuring ruminal and intestinal health after weaning. (AU) | |
| FAPESP's process: | 18/01248-0 - Whole corn grain as fiber source for dairy calves: effects on performance, ruminal development and metabolism |
| Grantee: | Ariany Faria De Toledo |
| Support Opportunities: | Scholarships in Brazil - Master |