The Revista Brasileira de Zootecnia (RBZ) is a publication dedicated to the broad field of Animal Science. We publish high-quality, original scientific research that spans across diverse areas within the discipline. The scope of RBZ encompasses a wide range of topics, including aquaculture, biometeorology and animal welfare, forage crops and grasslands, animal and forage plants breeding and genetics, animal reproduction, ruminant and non-ruminant nutrition, meat science and muscle biology, precision livestock, and animal production systems and agribusiness.
The Revista Brasileira de Zootecnia (RBZ) is a publication dedicated to the broad field of Animal Science. We publish high-quality, original scientific research that spans across diverse areas within the discipline. The scope of RBZ encompasses a wide range of topics, including aquaculture, biometeorology and animal welfare, forage crops and grasslands, animal and forage plants breeding and genetics, animal reproduction, ruminant and non-ruminant nutrition, meat science and muscle biology, precision livestock, and animal production systems and agribusiness.
The Revista Brasileira de Zootecnia (RBZ) is a publication dedicated to the broad field of Animal Science. We publish high-quality, original scientific research that spans across diverse areas within the discipline. The scope of RBZ encompasses a wide range of topics, including aquaculture, biometeorology and animal welfare, forage crops and grasslands, animal and forage plants breeding and genetics, animal reproduction, ruminant and non-ruminant nutrition, meat science and muscle biology, precision livestock, and animal production systems and agribusiness.
Five Holstein cows were allotted to a 5 × 5 Latin square design with the objective of evaluating the microbial protein production, using the total excretion of purine derivatives (PD), obtained from spot urine collection, plasma and milk urea and nitrogen (N)-urea. The five treatments contained different forage sources: sugar cane bagasse (CB), tifton hay (TH), elephant grass hay (EH), sorghum silage (SS) and a mixture of sugar cane bagasse + sorghum silage (CBSS). The milk urea (10.98 mg/dL) and N-urea (5.11 mg/dL) concentrations were not influenced by the forage sources, such as plasma urea (28.10 mg/dL) and N-urea (13.09 mg/dL) concentrations. The urinary urea, N-urea, allantoin and PD excretions, the absorbed purine, N-microbial synthesis and milk allantoin concentration remained unchanged. The different forage sources in association with forage cactus did not change the microbial protein production.
Microbial protein synthesis and urea nitrogen concentrations in lactating dairy cows fed spineless cactus and different forages based diets
Ferreira,Marcelo de Andrade and Silva,Renata Rodrigues da and Ramos,Alenice Ozino and Véras,Antonia Sherlânea Chaves and Melo,Airon Aparecido Silva de and Guimarães,Amanda Vasconcelos. Microbial protein synthesis and urea nitrogen concentrations in lactating dairy cows fed spineless cactus and different forages based diets. R. Bras. Zootec. [online]. 2009, vol.38, 1, [cited 2026-06-05], pp.159-165. Available from: <https://rbz.org.br/article/microbial-protein-synthesis-and-urea-nitrogen-concentrations-in-lactating-dairy-cows-fed-spineless-cactus-and-different-forages-based-diets/>. ISSN 1516-3598. https://doi.org/10.1590/S1516-35982009000100020.
Ferreira,Marcelo de Andrade; Silva,Renata Rodrigues da; Ramos,Alenice Ozino; Véras,Antonia Sherlânea Chaves; Melo,Airon Aparecido Silva de; Guimarães,Amanda Vasconcelos. Microbial protein synthesis and urea nitrogen concentrations in lactating dairy cows fed spineless cactus and different forages based diets. R. Bras. Zootec., v.38, 1, p. 159-165. Jan. 2009. Available from: <https://rbz.org.br/article/microbial-protein-synthesis-and-urea-nitrogen-concentrations-in-lactating-dairy-cows-fed-spineless-cactus-and-different-forages-based-diets/>. acess on 05 Jun. 2026. https://doi.org/10.1590/S1516-35982009000100020.
Ferreira,Marcelo de Andrade, & Silva,Renata Rodrigues da, & Ramos,Alenice Ozino, & Véras,Antonia Sherlânea Chaves, & Melo,Airon Aparecido Silva de, & Guimarães,Amanda Vasconcelos. (2009). Microbial protein synthesis and urea nitrogen concentrations in lactating dairy cows fed spineless cactus and different forages based diets. R. Bras. Zootec., 38(1) , 159-165. https://doi.org/10.1590/S1516-35982009000100020.
FerreiraMarcelo de Andrade, SilvaRenata Rodrigues da, RamosAlenice Ozino, VérasAntonia Sherlânea Chaves, MeloAiron Aparecido Silva de, GuimarãesAmanda Vasconcelos. Microbial protein synthesis and urea nitrogen concentrations in lactating dairy cows fed spineless cactus and different forages based diets. R. Bras. Zootec. [Internet]. 2009 Jan [cited 2026 Jun 05]; 38(1): 159-165. Available from: https://rbz.org.br/article/microbial-protein-synthesis-and-urea-nitrogen-concentrations-in-lactating-dairy-cows-fed-spineless-cactus-and-different-forages-based-diets/. https://doi.org/10.1590/S1516-35982009000100020.
Figure 2
Evolution of cow weight according to the genetic group of calves, from farrowing to weaning.
PCH - calves from predominantly Charolais cows; PNE - calves from predominantly Nellore cows; AACH - calves from breed bulls Aberdeen Angus and predominantly Charolais cow; AANE - calves from breed bulls Aberdeen Angus and predominantly Nellore cow.
