Data/hora: 01/06/2024 17:04:26

Biblioteca(s): | Embrapa Cerrados.
Data corrente: | 04/09/2002
Data da última atualização: | 04/09/2002
Autoria: | ANDERSON, D. M.
Título: | Standing crop, diets, travel and weight changes under short-duration and continuous grazing.
Ano de publicação: | 1977
Fonte/Imprenta: | [S. l.]: Texas A&M University, 1977.
Páginas: | 181 p.
Idioma: | Inglês
Notas: | Doctor of Philosophy Dissertation.
Conteúdo: | The influence of stocking pressure at a fixed sticking rate (5.6 há/ A. U) was investigated by comparing continuos grazing with a short-duration grazing (SDG) system from March through December 1975. The SDG system consisted of five paddocks grazed sequntially by one herd o a 28-day rotation sechedule. Each treatment was stocked with four non-fistulated and two esophageally-fistulated Hereford heifers which remained in the same treatment thoughout the study. Vegetation was evaluated in the continuous-grazed paddock on 28-day intervals ans immediately before amd after grazing  in each SDG padock. Foliar cover of each species was estimated; then a measured ampunt of cover representaive of the species and/or species group was clipped and weighed. Standing crop was composed of cool and warm season species with Texas wintergrass (Stipa leocotricha) dominating. Cool season forbs were abundant during the spring and Texas broomweed (Xanthocephlum texalum), a warm season annual, was abundent during  summer and fall. There was more grass stading crop on day 1 and day 28 in teh SDG system then under continuous grazing. Forb estanding crop was significantly lower after grazing in the SDG system compared to continuous grazing. Stocking pressures (kg of forage available per animal-unit) were approximately one fifth as great under SDG as compared to continuos grazing. Maximum stocking pressure values corresponded to  peak periods of stading crop. Botanical and chemical components of the diets followed trends for standing crop. Diets were sampled on days 1, 7, 14, 21 and 28 withing each of the tem 28-day periods under both grazing treatments. Grasses were major component of the diets. Forbs and prockly-pear (Opuntia macrorhiza) fruit were selected in  greates amounts when their availability was highest. In the SDG system forb consumption declined most rapidly during the first 7 days of the  28-.days. Crude protein also followed  this trend, while  digestible anergy showed a more linear decline over the 28 days. Crude protein  were highest in early spring diets and thereafter declined linearly reflecting standing crop maturity. A digital pedometer, housed in a foam-ribber-padded metal case attached to a leather band  bucked around the heifer's foreleg, was used to motor travel of four heifers between july 31 and December 31. Heifers under traveled less than those on continuous grazing with a significant linear decrease for both treatments from July to December. Travel for esophageally-firstulated animals under continuous grazing appeared to be related most to botanical and chemical components of the diet, while under SDG animal travel was also related to several westher parameters. Non-fistulated animals on continuous ans SDG did differ significantly with respect to actual weight, average daily gain or percent change in weught during the 28-day grazing periods. There was a significantly lincar increase in actual weight for both treatments between March and December. The largest average dialy gain and percent change in weight corresponded to teh time of spring forage growth with lowest gains in teh fall when starding crop was mature. Over the tem 28-day periods,,mean actual weight, average daily gain and percent change in weight for the esophageally-fistulated heifers on continuous grazing.
Thesagro: | Animal; Dieta; Pastejo Continuo.
Thesaurus Nal: | animal feeding; diet; grazing.
Categoria do assunto: | --
Registro original: | Embrapa Cerrados (CPAC)
Exemplares: | CPAC - (21713-1) - ADD - TS - -- - T066/77 - AND - T066/77 - DIS