Níveis de suplementação com sal mineral proteinado para novilhos Nelore terminados em pastagem no período de baixa produção forrageira

Abstract

RESUMO -Foram avaliados dois níveis de suplementação com sal mineral proteinado (290 e 400 g.an -1 .dia -1 ), em comparação ao sal mineral, em 90 novilhos Nelore, mantidos em pastagem de grama estrela roxa (Cynodon plectostachyus Pilger) no inverno. O consumo do suplemento foi ajustado pelo teor de cloreto de sódio adicionado à mistura. Quando considerado o período de adaptação (28 dias) na análise estatística, não foi observada diferença no ganho médio diário (GMD) entre os tratamentos, ao passo que, quando desconsiderado, a suplementação com 400 g.an. -1 .dia -1 resultou em maior GMD (0,15 kg.dia -1 ), em comparação aos demais tratamentos (0,06 e 0,05 kg.dia -1 para o sal proteinado, com consumo de 290 g.an. -1 .dia -1 , e sal mineral, respectivamente). A qualidade e disponibilidade da forragem foram semelhantes entre os tratamentos, com médias de 4366 kg de matéria seca.ha -1 , 2145 kg de matéria verde seca.ha -1 e 353 kg de folhas.ha -1 . Houve redução na proporção de folhas e colmos e aumento na proporção de material morto, em função dos períodos experimentais. Os valores médios para composição química da pastagem foram de 3,5% de PB, 1,6% de PB digestível, 48,1% de FDA e 48,4% de DIVMS. A pastagem de grama estrela roxa apresentou baixo valor n utritivo entre os meses de maio e outubro, sendo necessária a suplementação protéica para que os animais pudessem manter ou ganhar peso neste período.Palavras-chave: bovinos de corte, cynodon, grama estrela, inverno, proteína bruta, uréia Levels of Protein and Mineral Salt Supplements for Nelore Steers Finished in PastureDuring the Low Grass Production Season ABSTRACT -Two levels of protein and mineral supplements (290 and 400 g.an. -1 .day -1 ) were evaluated and compared with the mineral supplement in 90 Nelore steers on star grass pasture (Cynodon plectostachyus Pilger) during the winter. The supplement intake was ajusted by the concentration of sodium clore into the mixture. Considering the first 28 days (adaptation period) in the statistical analysis, there was no difference in average daily gain (ADG). Taking out this period of adaptation, the ADG was better for the protein and mineral supplement with intake of 400 g.an. -1 .day -1 (0.15 kg per animal a day), when compared with the other supplements (0.06 and 0.05 kg per animal a day, respectively for intake of 290 g.an. -1 .day -1 of protein mineral supplements and mineral salt). The forage quality and availability were similar for the different treatments, with average levels of 4366 kg dry matter.ha -1 , 2145 kg green dry matter.ha -1 , and 353 kg of leaves.ha -1 . The proportion of leaves and stems were reduced and the dead material proportion rose during the experimental periods. The chemical composition of forage had values of 3.5% of CP, 1.6% of digestible CP, 48.1% of ADF, and 48.4% of IVDMD. The sta grass pasture presented poor nutritional quality during beetwen the months of may and october, so the protein supplement is necessary to the animals mantain or gain weight during this period. IntroduçãoA p...

Urea levels in multiple supplement for lambs grazing on buffelgrass

“…In this case, the use of protein or multiple supplements may increase the productive performance of animals. In this research study, results showed lower productive performance than that found by Ruas et al (2000), Zanetti et al (2000), Moreira et al (2004), Moraes et al (2006), who reported higher productive performance for beef cattle receiving protein or multiple supplementation. Higher total dry matter intake found in studies carried out by Ruas et al (2000) and Zanetti et al (2000) may justify those results.…”

“…Higher total dry matter intake found in studies carried out by Ruas et al (2000) and Zanetti et al (2000) may justify those results. However, a study by Moreira et al (2004) found higher dry matter intake of supplement. Probably, supplement dry matter intake (58 to 142 g day -1…”

“…However, this activity is characterized as extensive or ultra-extensive, showing low stocking rate of native pastures, low meat and milk yields, low reproductive efficiency and high mortality rate of herds, resulting in low economic performance for farmers (MOREIRA et al, 2008).…”

“…For beef cattle, the use of protein or multiple supplementations for animals grazing on dormant grass during the dry season has resulted in higher productive performance (MOREIRA et al, 2004(MOREIRA et al, , 2006RUAS et al, 2000;ZANETTI et al, 2000). However, information about the use of protein supplementation for lambs grazing on dormant buffelgrass is scarce in domestic and international literature about this topic.…”

Concentrate levels for lambs grazing on buffel grass

“…In this study, concentrate supplementation containing high levels of protein may be an important tool to increase dry matter intake and digestibility of fibrous fractions of forage, also to improve the productive performance of lambs in the rainy-dry transition period and in dry period of year (MORAES et al, 2006;MOREIRA et al, 2004;RUAS et al, 2000;ZANETTI et al, 2000). In the present trial, the CP level used in concentrate was 20.0% of DM.…”