Nutritional planning for Nellore heifers post-weaning to conception at 15 months of age: performance and nutritional, metabolic, and reproductive responses
The objective of this study was to evaluate the effects of strategic supplementation in the dry period and dry/rainy transition period on the performance and nutritional, metabolic, and reproductive responses of Nellore heifers grazing Urochloa decumbens. Forty-eight Nellore heifers with age and bod...
| Autores: | , , , , , , , , , , , |
|---|---|
| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2019 |
| País: | Brasil |
| Recursos: | Universidade Federal de Viçosa (UFV) |
| Repositório: | LOCUS Repositório Institucional da UFV |
| Idioma: | inglês |
| OAI Identifier: | oai:locus.ufv.br:123456789/23911 |
| Acesso em linha: | https://doi.org/10.1007/s11250-018-1662-z http://www.locus.ufv.br/handle/123456789/23911 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Animal nutrition Beef cattle Heifers Supplementation Tropical pastures |
| Resumo: | The objective of this study was to evaluate the effects of strategic supplementation in the dry period and dry/rainy transition period on the performance and nutritional, metabolic, and reproductive responses of Nellore heifers grazing Urochloa decumbens. Forty-eight Nellore heifers with age and body weight (BW) of eight months and 235 ± 3.3 kg, respectively, were used. The experimental design was a completely randomized design, with four treatments, all with 12 replications. The evaluated strategies were as follows: low supplementation (LOHI; 0.2% of BW/heifer/day) in the first 90 days and high supplementation (0.6% of BW/heifer/day) in the 90 days thereafter; average supplementation (AVER) with 0.4% of BW/heifer/day for 180 days; high supplementation (HILO; 0.6% of BW/heifer/day) in the first 90 days and low supplementation (0.2% of BW/heifer/day) in the 90 days thereafter; only mineral mix (MM) ad libitum during the 180 days. Data were evaluated using orthogonal contrasts. Supplementation improved the performance of the animals during of dry period (P < 0.05) and dry/rainy transition period (P < 0.05). Supplemented animals had higher longissimus muscle area (LMA) and subcutaneous fat thickness (SFT) at the end of the experiment (P < 0.05). Multiple supplementation increased intake of dry matter (DM), organic matter (OM), and crude protein (CP) in kg/day throughout the experiment. The supplementation increased the digestibility of DM, OM, CP, apNDF, and TDN (P < 0.05). Serum urea nitrogen (SUN), glucose (GLUC), insulin (INS), and progesterone (PROG) were higher in supplemented heifers (P < 0.05). Supplementation reduced the concentrations of non-esterified fatty acids (NEFA) (P < 0.05) and increased conception rate (P < 0.05). In summary, the supplementation strategies adopted in this study improve the performance, metabolic status, and carcass traits of heifers under grazing, allowing an improvement in the conception rate of 15-month-old Nellore heifers. |
|---|