Banca de DEFESA: JOSÉ DIÓGENES PEREIRA NETO
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.DISCENTE : JOSÉ DIÓGENES PEREIRA NETO
DATA : 10/01/2023
HORA: 13:00
LOCAL: on line
TÍTULO:
SUSTAINABLE FEEDING STRATEGIES IN BEEF CATTLE SYSTEMS
PALAVRAS-CHAVES:
feed, suplementação, pastagem
PÁGINAS: 97
RESUMO:
SUSTAINABLE FEEDING STRATEGIES IN BEEF CATTLE SYSTEMS
The Southeast United States livestock systems rely on pastures, and the warm season forages are mostly used in the south pastures. The use of legumes in grass pasture mixtures are positive to reduce the N applications and enhance pasture quality, in warm and cool seasons. However, there is a forage scarcity period between the warm and cool transition, which is a challenge faced by farmers in this region. Limpograss (NC) is a warm season present in Florida, that has the potential to overcome this scenario as a new alternative and used as a silage associated with protein supplement may improve animal performance. The aimed of this study is divided in two. First was access the herbage, nutritive value, and animal performance of steers in grass-legume grazing system in North Florida. Second was evaluated the effect of protein supplementation in intake, digestibility and animal performance of heifers fed on limpograss silage-based diet. Eighteen steers were used as tester in a grazing trial experiment. The pastures were considered experimental unit. The treatments were three grazing systems replicated three times in a randomized block design. The treatment was grass+N that consisted of N-fertilized bahiagrass (Paspalum notatum Flugge in the warm season and overseed with a N-fertilized mixture of ryegrass (Lolium multiflorum Lam.) and oat (Avena sativa L.) in the cool season. The treatment cool-season mixture is unfertilized bahiagrass in warm season, overseed by a mixture of ryegrass+oat+clover (Trifolium sp.) fertilized with 34 kg N ha-1in cool season. The treatment year-round mixture is consisted as the mixture of N fertilizer bahiagrass with ‘Ecoturf’ rhizoma peanut (Arachis glabrata Benth.) during warm season, and overseed with ryegrass+oat+clover mixture plus 34 kg N ha-1in cool season. The ryegrass + clovers had the same performance of ryegrass + N animal performance in cool season. Including rhizoma peanut increased cattle average daily gain (ADG) in 0.1 and 0.2 kg d-1 during summer. The ADG in Grass+Clover+RP was 0.38 kg d −1 compared with 0.28 kg d−1 and 0.18 kg d−1 on Grass+N and Grass+Clover. The GPA in cool season was the same in all treatments and warm the legume mixture was the superior. This result can indicate that inclusion of legumes is efficient in N fertilizer inputs since that animal production was similar and superior in cool and warm season. The inclusion of clover and rhizome peanut in grass pastures systems in cool and warm season may reduce the N utilization in Southeast U. S. Twenty-four heifers Angus crossbred (330 ± 16 kg live weight) were blocked by initial weight and then housed mixed in a pen and submitted to four different treatment such as: 1) control, no supplementation and ad libitum access to silage of limpograss; 2) 1.4 kg of protein supplementation and ad libitum access to silage of limpograss; 3) 2.8 kg of protein supplementation and ad libitum access to silage of limpograss; 4) 4.2 kg of protein supplementation and ad libitum access to silage of limpograss. The silage intake reduced with the inclusion of 2.8 kg of supplement but increased the total intake. The supplements improved the organic matter digestibility which was 574 g kg-1 in no-supplemented to 638 g kg-1 supplemented with 4.2 kg. The neutral detergent fiber digestibility was affected by the treatment and reduced from 620 g kg-1 to 604 g kg-1 in the greater supplement level. The supplement promoted an increasement in the passage rate and increased the intake, which reduced the fiber digestibility. The inclusion of supplement improved the ADG of growing heifer, that increased 0.6 kg d-1with the inclusion of 4.2 kg of protein supplement.The use of protein supplementation increases the animal performance of animals fed by limpograss silage.
MEMBROS DA BANCA:
Presidente - ***.517.214-** - JOSE CARLOS BATISTA DUBEUX JUNIOR - UFRPE
Interno - VALDSON JOSE DA SILVA
Externa à Instituição - ERICK RODRIGO DA SILVA SANTOS
Externa à Instituição - GLEISE MEDEIROS DA SILVA
Externo à Instituição - NICOLAS DILORENZO