Comparisons between intake values observed and predicted by nutritional systems for confined nellore cattle

This study compared the dry matter intake (DMI) of Nellore heifers and bulls in the feedlot, predicted by the BR-Corte (2010 and 2016) and NRC (2000) nutritional systems. Hence, two experiments were conducted in a completely randomized design. The first one used 47 Nellore bulls, not castrated, with an average initial weight of 413 kg, and 19 months of age. The second experiment used 24 Nellore heifers with an average initial weight of 300 kg and 23 months of age. The accuracy and approximation of the DMI estimates by the nutritional systems were adjusted with the simple linear regression model and the root mean square error of prediction (RMSEP). The DMI was 8.06 kg day-1 for Nellore heifers and 11.54 kg day-1 for bulls, which are higher than the values ​​ predicted by the nutritional systems. The NRC (2000) and BR-Corte (2010 and 2016) underestimated DMI in 20.84, 20.09, and 19.35% for heifers and 28.07, 16.20, and 11.78% for bulls, respectively. It was concluded that the BR-Corte 2010 and 2016 were the most suitable models to estimate the DMI of Nellore heifers and bulls for higher precision and accuracy.

Consumption of dry matter observed and predicted by the nutritional systems in senepol bulls kept in confinement / Consumo de matéria seca observado e previsto pelos sistemas nutricionais em touros senepol mantidos em confinamento

The objective was to compare the dry matter consumption (CMS) observed, through the use of the GrowSafe® electronic system, with that predicted by the BR-Corte (2010 and 2016) and NRC (2000) nutritional systems in confined Senepol bulls. To this end, 24 Senepol Bulls were used in a completely randomized design, uncastrated with an average initial weight of 368 kg and 16 months of age. The evaluation of the accuracy and approximation of the CMS estimates by the nutritional systems was adjusted by the simple linear regression model and the decomposition of the mean square of the prediction error (QMEP). The mean CMS observed was 10.33 kg.day-1, higher than the values predicted by the nutritional systems, in which the values predicted by the NRC (2000) and BR-Corte 2010 and 2016 underestimated the CMS by 29.62, 6.19 and 2.03%, respectively. The verification of QMEP and its decomposition made it possible to infer the proximity of the values predicted by the BR-Corte 2010 and 2016 models and the values observed, which presented a better adjustment in relation to the NRC. Surprisingly the values predicted by the NRC, created from a database with Bos taurus animals, showed greater distance from the values predicted and observed, and it was expected greater accuracy of the NRC models for this category and animal breed. It is concluded that the BR-Corte 2016 was the most appropriate model to estimate the CMS of confined Senepol bulls.

Objetivou-se comparar o consumo de matéria seca (CMS) observado, por meio do uso do sistema eletrônico GrowSafe®, com o predito pelos sistemas nutricionais BR-Corte (2010 e 2016) e NRC (2000) em touros da raça Senepol em confinamento. Para isso, foram utilizados 24 Touros da raça Senepol em delineamento inteiramente casualizado, não castrados com peso inicial médio 368 kg e 16 meses de idade. A avaliação da exatidão e aproximação das estimativas do CMS pelos sistemas nutricionais foi ajustada pelo modelo de regressão linear simples e decomposição do quadrado médio do erro de predição (QMEP). O CMS médio observado foi de 10,33 kg.dia-1, valor superior aos valores preditos pelos sistemas nutricionais, no qual os valores preditos pelo NRC (2000) e BR-Corte 2010 e 2016 subestimaram o CMS em 29,62, 6,19 e 2,03%, respectivamente. A verificação do QMEP e sua decomposição possibilitou inferir sobre a proximidade dos valores preditos pelos modelos BR-Corte 2010 e 2016 e os valores observados, os quais apresentaram melhor ajuste em relação ao NRC. Surpreendentemente os valores preditos pelo NRC, criado a partir de banco de dados com animais Bos taurus, apresentou maior distanciamento dos valores preditos e observados, sendo que era esperada maior precisão dos modelos NRC para esta categoria e raça animal. Conclui-se que o BR-Corte 2016 foi o modelo mais adequado para estimar o CMS de touros da raça Senepol em confinamento.

Productive performance of Holstein calves finished in feedlot or pasture

ABSTRACT The use of animals from dairy farms is an alternative to meat production since it provides an increment of total income for farmers. This study aims to evaluate the performance of Holstein calves finished in two feeding systems (feedlot or pasture). Forty-three animals with 58 days old and 57 kg were divided in two treatments: 23 animals finished in feedlot with corn silage plus concentrate based on corn and soybean meal (40:60); 20 animals kept in cultivated pastures according to the period of the year: Italian ryegrass (Lolium multiflorum) and pearl millet (Pennisetum americanum) with supplementation with the same feedlot-concentrate at 1% body weight. Animals were slaughtered with 200 kg. Dry matter and nutrient intake were determined, with the use of chromium oxide for estimating pasture intake. Feedlot animals had greater total intake and total digestible nutrients, resulting in higher average daily gain (0.949 vs 0.694 kg day-1). Crude protein intake, neutral detergent fiber and feed conversion did not show significant differences. Holstein calves have improved performance when finished in feedlot.

Avaliação de sistemas alimentares para terneiros desmamados aos três meses de idade / Evaluation of feeding systems for calves weaned at three months old

Objetivando avaliar o desempenho de torneiros desmamados aos 3 meses de idade em quatro diferentes sistemas alimentares: S1 - Campo Nativo + Silagem de Sorgo (Sorghum bicolor), S2 - Campo Nativo + Pastagem cultivada de inverno (Avena strigosa + Lolium multiflorum); S3 - Pensacola (Paspalum notatum var. Saurae) + silagem de sorgo; e S4 - Pensacola + pastagem cultivada de inverno, bem como a qualidade destes sistemas expresso em proteína bruta e digestibilidade in vitro da matéria orgânica, foi realizado um experimento nas dependências da Pulquéria Agropecuária, em São Sepé, Depressão Central do RS, em solo da unidade de mapeamento Cerrito, classificado como Laterítico Bruno Avermelhado distrófico. O delineamento experimental foi o inteiramente casualisado, tendo os animais como repetições. Utilizaram-se 30 torneiros cruza Nelore x Charolés, em pastejo contínuo com lotação variável. O período experimental foi de 244 dias (verão/outono e inverno/primavera). Os animais foram pesados com intervalos médios de 28 dias. O sistema S4, apresentou um Ganho Médio Diário de peso (545g) superior aos demais (P<0,05), não diferindo significativamente do sistema S2 (475g), no total do período experimental. Quando analisados os períodos em separados, verifica-se que no verão/outono, não houve diferença significativa entre campo nativo e pensacola, porém no inverno/primavera verifica-se que os animais submetidos à pastagem cultivada apresentaram desempenho superior aqueles submetidos à silagem de sorgo acrescida de um suplemento.

A trial was conducted to evaluate lhe performance of calves weaned of three months old in four systems: S1 - Natural pasture + Sorghum bicolor silage; S2 - Natural pasture + Winter pasture (Avena strigosa + Lolium multiflorum); S3 - Bahiagrass (Paspalurn notatum var. Saurae) + Sorghum silage and S4 - Bahiagrass + Winter pasture. The experiment was installed in Pulquéria Agropecuária, São Sepé, RS, in a Ridish-Brown Latheritic Soil. It was evaluated the crude protein and in vitro organic matter digestibility of the forage. Thirty calves, Nelore x Charolais Breed, were used as replications, in a completely randomized design. with continuous grazing and variable stocking rate in the pastures. The experimental period was of 244 days (summer/autumn and winter/spring ). The calves were weighted at a 28 day intervals. S4 system presented a daily live weight gain (545g) higher than lhe others (P<0.05), except for the S2 system (475g), in the total experimental period.