Owing to its contribution to the maintenance of carbon stocks, soil nitrogen and nutrient cycling for subsequent crops, the integrated systems become increasingly important for agricultural conservation. Thus, the objective of this study was to evaluate the biomass production of and total nutrient in Brachiaria spp. and Panicum maximum forage grasses used as mulch and soybean yields in an integrated crop–livestock system and second-crop maize succession system. The treatments consisted of the following cropping systems: Xaraes palisadegrass intercropped with soybean, Congo grass intercropped with soybean, Mombaça guinea grass intercropped with soybean, Tamani guinea grass intercropped with soybean and a soybean/maize succession system. The forage grasses were established during the soybean R6–R7 stage. Compared with Congo grass, Xaraes palisadegrass, Mombaça guinea grass and Tamani guinea grass produced more biomass and equivalent amounts of fertilizer returned to the soil and resulted in greater nutrient cycling, indicating the benefits of these grasses for use as mulch in integrated production systems. Maize had a greater C/N ratio, but the forage grasses also exhibited high potential by protecting the soil until the end of the soybean development cycle. The use of an integrated crop–livestock system combined with a forage cropping system provided greater soil nutrient cycling than the maize cropping system did, which resulted in increased soybean yields, thus contributing to the sustainability of agricultural systems.

Jiggs bermudagrass has presented competitive production potential over other forages. However, there is a lack of information about the nutritional value of this forage with important relevance in ruminant nutrition. This study aimed to evaluate the protein and carbohydrate fractionation of Jiggs bermudagrass in different seasons of the year under intermittent grazing by Holstein cows. The experiment was conducted during one year in a completely randomized design with nine replications and treatments consisted of the effect of four seasons: fall, winter, spring and summer. The results showed that there were seasonal variations in the fractions of proteins and carbohydrate, with the exception of the protein fraction B3. The better climatic conditions in spring and summer contributed to an increase in the protein fraction A and carbohydrate A+B1. The winter had a greater fraction C of protein and carbohydrate, reflecting the nutritive value of the forage. The use of irrigation during fall and winter had a positive effect on nitrogen fractions B1 and B2 and on non-fiber carbohydrates.

The objective of this study was to evaluate dry matter production, fermentative parameters, and nutritional value of the silage of corn intercropped with Paiaguas palisadegrass in different forage systems and maturity stages, in the off-season. The experiment was carried out in a randomized block design, with four replications, in a 5×3 factorial arrangement consisting of five forage systems: corn monocropped; Paiaguas palisadegrass monocropped; corn intercropped with Paiaguas palisadegrass in the row, inter-row, and oversown; and three corn maturity stages (milky, soft dough, and hard dough with 80, 90, and 110 days after sowing, respectively). The results showed that the silage of corn intercropped with Paiaguas palisadegrass in the row and inter-row at the hard dough stage presented greater productivity per area and better fermentative and nutritional characteristics. They can, therefore, be recommended as suitable sowing systems for silage production. Silages produced from intercropping systems proved to be an alternative feed supply technique, allowing the intensification of production systems, maximizing nutrient production per area, in a sustainable manner.

ABSTRACT. This study aimed to evaluate milk composition and metabolic profile of Holstein cows at different calving orders in the beginning, middle, and end of lactation. One hundred ten Holstein cows were housed in a free stall system receiving the same diet and were grouped according to calving order (first, second, third, and fourth calving) and days in milk (DIM): early (1-90 DIM), middle (91-180 DIM), and end of lactation (over 181 DIM) for comparing milk yield, milk composition, and blood metabolic profile between the calving orders within the same lactation period. These parameters were also evaluated between lactation periods of the cows in different calving orders. The calving order, in any lactation stage, had no influence on milk yield per day and blood biochemical profile of Holstein cows receiving the same diet. However, calving order in all stages of lactation influenced milk composition. The first, second, third, and fourth calving order had no effect on the blood biochemical profile of Holstein cows, in any lactation stage. On the other hand, the different stages of lactation influenced milk yield and milk composition of Holstein cows.Keywords: biochemical profile, lactation period, milk quality.Composição do leite e perfil metabólico sanguíneo de vacas holandesas em diferentes ordens de parto e estádios de lactação RESUMO. Objetivou-se avaliar a composição do leite e perfil metabólico de vacas da raça Holandesa em diferentes ordens de parto, no início, meio e fim de lactação. Foram utilizadas 110 vacas mantidas em sistema Free stal, recebendo a mesma dieta. Os animais foram agrupados de acordo com a ordem de parto em diferentes dias em lactação (DEL), início (1-90 DEL), meio (91-180 DEL) e fim de lactação (mais de 181 DEL), para a comparação da produção de leite, composição química do leite e perfil metabólico do sangue entre as ordens de parto dentro do mesmo período de lactação. Estes parâmetros também foram avaliados entre os períodos de lactação das vacas em diferentes ordens de parto. A ordem de parto, em nenhum estádio de lactação, influenciou a produção de leite por dia e o perfil bioquímico do sangue de vacas Holandesas que recebiam a mesma dieta. Entretanto, a ordem de parto em todos estádios de lactação influenciou a composição química do leite. A primeira, segunda, terceira e quarta ordem de parto em nenhum estádio de lactação influenciaram o perfil bioquímico do sangue de vacas Holandesas. Por outro lado, diferentes estádios de lactação influenciaram a produção e composição química do leite.Palavras-chave: perfil bioquímico, período de lactação, qualidade do leite.

Forages of the genus Brachiaria stand out among those used in integrated systems. Little is known about the potential value of new species and cultivars when intercropped with sorghum and planted in the second crop season. The objective of this study was to evaluate the performance (agronomic characteristics) of grain sorghum and the production and nutritional characteristics of forage plants of the genus Brachiaria in an integrated agricultural production system in the second season. The experiment had a randomized block design with four replicates. The treatments consisted of the intercropping of sorghum with forage plants of the genus Brachiaria (Ruziziensis grass, Marandu, Xaraes, Piata, Paiaguas palisadegrass and Ipypora grass), in addition to an extra treatment with sorghum in monoculture. The results showed that sorghum intercropping with Ruziziensis grass, Paiaguas palisadegrass, Piata, and Ipypora grass did not cause a reduction in grain yield. The Xaraes, Piata, and Paiaguas palisadegrass showed higher forage production. However, the Paiaguas, Piata palisadegrass, and Ipypora grass showed better nutritional value. The sorghum intercropping with forage plants of the genus Brachiaria were promising alternatives for grain and forage production in the off-season. The right forage grass combined with sorghum in an integrated system can intensify agricultural production, optimizing the use of the area and increasing sustainability.

With the adoption of integrated production systems, relative gains in soybean yield have been achieved due to the permanence of vegetal residues on the soil surface. These residues favour the soil microbiota responsible for the decomposition of organic matter and nutrient cycling, which makes integrated agrosystems sustainable. The objective of this study was to evaluate the agronomic characteristics of soybeans under the production and decomposition of sunflower and Paiaguas palisadegrass biomass in different integrated production systems. The experiment was conducted off season in a dystroferric Red Latosol soil in a randomized block experimental design with four replicates. The treatments consisted of the following forage systems: monocropped sunflowers; monocropped Paiaguas palisadegrass; row sunflowers x Paiaguas palisadegrass; inter-row sunflowers x Paiaguas palisadegrass; and oversown sunflowers x Paiaguas palisadegrass. The results showed that the monocropped sunflower and Paiaguas palisadegrass presented the highest biomass production throughout the soybean development cycle, with the slowest decomposition, representing a strategy to increase soil cover efficiency mainly in the period prior to summer planting. The soybean cultivated in the biomass of the monocropped Paiaguas palisadegrass and the Paiaguas palisadegrass intercropped in rows and in inter-rows presented better yields and was positively influenced by the production parameters compared with soybean cultivated otherwise. Therefore, sunflower intercropped with Paiaguas palisadegrass during the off season in the Central-West Region of Brazil was shown to be a promising and sustainable cultivation technique for the production of biomass for no-tillage systems.

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The use of silage has been an efficient alternative to feed supply during the shortage of roughage in dry periods, providing quality feed that is widely used in ruminant feeding. Thus, the objective of this study was to evaluate the fermentative characteristics and nutritive value of corn silage with Tamani guinea grass (Panicum maximum BRS cv. Tamani) through chemical composition, in vitro dry matter digestibility and protein fractionation. The experiment was conducted in a completely randomized design with four replications. The treatments consisted of five silages: corn; corn with 10% Tamani guinea grass; corn with 20% Tamani guinea grass; corn with 30% Tamani guinea grass; and corn with 40% Tamani guinea grass, totalling 20 experimental silos. The addition of tamani grass to silages was determined based on fresh matter. For ensiling, corn was harvested with 320 g kg-1 DM (dry matter) and Tamani guinea grass in a 30-day development cycle with 286 g kg-1 DM. After 50 days of silage, the silos were opened to analyse the fermentative characteristics, chemical composition and protein fractionation of the silage. The results showed that the addition of Tamani guinea grass in corn silage increased the pH and buffering capacity and reduced the dry matter and lactic acid concentration but did not compromise the fermentative characteristics of silages. The addition of 40% Tamani guinea grass in corn silage provided increased levels of crude protein, in vitro dry matter digestibility, protein A, B1 and C, and decreased the fractions B3 and C, which makes Tamani guinea grass an alternative to improve the quality of exclusive corn silage, resulting in better quality silage.