Sward structural characteristics and ingestive behaviour of beef heifers in a Pearl Millet pasture Características estruturais do pasto e comportamento ingestivo de novilhas de corte em pastagem de milheto
Ingestive behaviour of beef heifers and sward structural characteristics of Pearl Millet (Pennisetum americanum (L.) Leeke) were evaluated. The experiment was carried out in a randomized complete design following a repeated measure arrangement (three experimental periods) with three replications of...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Zootecnia
2009-09-01
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| Series: | Revista Brasileira de Zootecnia |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982009000900005 |
| Summary: | Ingestive behaviour of beef heifers and sward structural characteristics of Pearl Millet (Pennisetum americanum (L.) Leeke) were evaluated. The experiment was carried out in a randomized complete design following a repeated measure arrangement (three experimental periods) with three replications of two leaf blade masses (600 and 1,000 kg/ha DM), which were maintained using continuous grazing with variable stocking rate. The variables measured were sward height, herbage mass, leaf blade and stem bulk density in sward vertical strata (sward structural characteristics), grazing, idling, rumination time and bite rate of heifers (ingestive behaviour). Bite rate was modified by pasture management and was lower when the leaf blade mass was 1,000 kg/ha DM. The daily grazing, rumination and idling time of beef heifers were similar for both leaf blade masses. Structural variation of the sward, during the experimental period, altered the grazing, rumination and idling time of heifers, and affected the bite rate. In Southern Brazil, the beef heifers concentrate their grazing activities in the 12 p.m. to 6:00 p.m. period, decreasing the grazing between 12 a.m. and 6:00 a.m., even in the hottest season of the year.<br>Foi avaliado o comportamento ingestivo de novilhas de corte e as características estruturais do milheto (Pennisetum americanum (L.) Leeke). Utilizou-se o delineamento inteiramente casualizado com medidas repetidas no tempo (três períodos), duas massas de lâmina foliar (600 e 1.000 kg/ha de MS), mantidas por lotação contínua e com ajuste de carga, e três repetições. Avaliaram-se a altura do dossel, a massa de forragem, a densidade de lâminas foliares e colmos nos estratos verticais do pasto (características estruturais do dossel), os tempos de pastejo, ruminação e ócio e a taxa de bocados das novilhas (comportamento ingestivo). A taxa de bocados foi influenciada pelo manejo do pasto e foi menor quando a massa de lâmina foliar foi de 1.000 kg/ha de MS. Os tempos diários de pastejo, ruminação e ócio de novilhas de corte foram semelhantes entre as massas de lâmina foliar. As variações estruturais do pasto ao longo do tempo de utilização promoveram modificações nos tempos de pastejo, ruminação e ócio das novilhas e afetaram a taxa de bocados. Na Região Sul do Brasil, as novilhas concentram suas atividades de pastejo no período das 12 h às 18 h, diminuindo entre 24 h e 6 h, mesmo na estação mais quente do ano. |
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| ISSN: | 1516-3598 1806-9290 |