Selection for hybrids with greater starch and NDF digestibility may be beneficial for dairy producers. The objective of this study was to determine the effect of feeding a TMR containing a floury-leafy corn silage hybrid (LFY) compared with a brown midrib corn silage hybrid (BMR) for intake, lactation performance, and total-tract nutrient digestibility in dairy cows. Ninety-six multiparous Holstein cows, 105±31d in milk at trial initiation, were stratified by DIM and randomly assigned to 12 pens of 8 cows each. Pens were randomly assigned to 1 of 2 treatments, BMR or LFY, in a completely randomized design; a 2-wk covariate period with cows fed a common diet followed by a 14-wk treatment period with cows fed their assigned treatment diet. Starch digestibilities, in situ, in vitro, and in vivo, were greater for LFY compared with BMR; the opposite was observed for NDF digestibility. Cows fed BMR consumed 1.7kg/d more dry matter than LFY. Although, actual-, energy-, and solids-corrected milk yields were greater for BMR than LFY, feed conversions (kg of milk or component-corrected milk per kg of DMI) did not differ. Fat-corrected milk and milk fat yield were similar, as milk fat content was greater for cows fed LFY (4.05%) than BMR (3.83%). Cows fed BMR had lower milk urea nitrogen concentration, but greater milk protein and lactose yields compared with LFY. Body weight change and condition score were unaffected by treatment. Total-tract starch digestibility was greater for cows fed the LFY corn silage; however, dry matter intake and milk and protein yields were greater for cows fed the BMR corn silage. Although total-tract starch digestibility was greater for cows fed the LFY corn silage, feed efficiency was not affected by hybrid type due to greater dry matter intake and milk and protein yields by cows fed the BMR corn silage.

Microbial protein represents the majority of metabolizable protein absorbed by ruminant animals. Enhanced understanding of the AA digestibility of rumen microbes will improve estimates of metabolizable protein. The objective of this experiment was to determine the digestibility of AA in fluid- (FAB) and particle-associated bacteria (PAB) using the precision-fed cecectomized rooster bioassay. Bacteria were isolated from 4 ruminally cannulated lactating Holstein cows by differential centrifugation, including particle suspension in 0.1% Tween-80 for increased removal of PAB from ruminal digesta. Samples of FAB and PAB were fed to 9 cecectomized roosters to determine standardized digestibility of AA. Total AA digestibility was 76.8 and 75.5% for FAB and PAB, respectively, but did not differ. Differences existed in AA digestibilities within bacterial type when compared with the mean essential AA digestibility value. Compared with previous literature estimates of AA digestibility in microbes (mean = 76%; range = 57-87%) and relative to National Research Council estimates of total AA from rumen bacteria (80%), the precision-fed cecectomized rooster assay is an acceptable in vivo model to determine AA digestibility of rumen bacteria.

The success of maize+soybean intercrop depends on the correct synchronism between species phenological stages at the silage point. Due to it, the experiment was carried out to evaluate maize+soybean intercrop forage yield and silage quality using crops with different maturity cycle combination. The experiment used a randomized complete block design with a 2 × 3 factorial scheme. Treatments consisted of two maize hybrids (1: P1630YHR-early cycle and 2: middle cycle P30F53VYHR) and two soybean cultivars (P95R51-maturity cycle of 5.1; TMG7062-maturity cycle of 6.2) and one control represented by maize monocrop. Silage harvesting was performed when maize had reached 2/3 milk line stage. Intercropping soybean into maize did not affect its biomass yield. Both soybean cultivars present compatible cycles for ensiling together with maize hybrids, since they were in phenological stages from R5.3 to R7 by the time maize was at its optimum stage for ensiling. There was interaction between species for the soybean biomass yield. Maize hybrid P30F53 produced higher biomass yield than P1630 what also resulted in higher amount of total crude protein yield. Intercrop P1630-P95R51 produced 458 Kg ha-1 of crude protein more than maize monocrop. Maize+soybean intercropping system results in higher silage crude protein percentage and yield per area (Kg of CP ha-1).

O trigo é a espécie com maior potencial de uso no período de inverno e estudos sobre a produtividade dos genótipos e forma de utilização do nitrogênio (N) na cultura, demonstram elevada importância. O estudo tem o objetivo de avaliar os componentes de rendimento e a produtividade de diferentes cultivares de trigo, submetidas a aplicação de N parcelado ou em dose única. O experimento foi conduzido no município de Realeza – Paraná, em delineamento de blocos ao acaso, com três repetições. Avaliou-se diferentes cultivares (Toruk, Sonic, Sossego e Sintonia) e duas formas de aplicação de N (parcelado e dose única). Mensurou-se o número de espiguetas e grãos por espiga, comprimento da espiga, produtividade e pH dos tratamentos. O comprimento da espiga é maior para a cultivar Sossego (8,87 cm) e menor para a cultivar Sintonia (7,63 cm). Sonic, juntamente com Sossego e Sintonia exibiram maior número de espiguetas por espiga e Sossego e Sonic maior número de grãos por espiga, quando o N foi aplicado parcelado. O pH do trigo é maior na cultivar Toruk (81) em relação as demais cultivares, quando o N é aplicado parcelado. Sonic apresenta menor pH entre as cultivares quando a adubação é realizada em dose única. Sintonia e Toruk apresentam aumento de produtividade de 243 e 665 kg ha-1, quando o N é aplicado em dose única. Entre as cultivares, Sossego, seguida de Toruk, Sintonia e Sonic proporcionaram maior produtividade respectivamente, independente da forma de aplicação de N. De modo geral, ocorreu uma variabilidade na resposta da produtividade e qualidade dos grãos de trigo em relação a cultivar e o modo de suprimento de N, devido às diferenças de demanda nutricional das cultivares, no entanto, fica evidente que o fornecimento de N é essencial na triticultura, principalmente em períodos que antecedem a maior demanda nutricional, levando os materiais genéticos mais próximos a atingir o máximo potencial produtivo.

Maize silage is the main conserved roughage used in animal feed in Brazil and improving its quality has great relevance. The aim of this experiment was to evaluate the characteristics of maize silage, containing different percentages of soybean biomass. In this way, different percentages of soybean green biomass added to maize ensilage (0, 10, 20, 30 and 40%-experiment 1 and 0, 10, 20, 30, 40 and 50% in experiment 2) were evaluated. Experiments were laid out as a completely randomized. Variables were submitted to analysis of variance and when it present significance was applied regression analysis. Silage ashes increased as soybean biomass increased. Regarding to the neutral and acid detergent fiber and the amount of total digestible nutrients, there was no effect of the treatments. At experiment 1, silage crude protein increased from 7.5 to 12.6% from sole maize silage to the silage with 39.2% of soybean dry biomass, which represent an increase of 67.24%. At experiment 2, it increased from 6.77 to 12.09%, which represent 78.58% more protein at the treatment with 50% of soybean green biomass (41% dry matter of soybean) in relation to the sole maize silage. At experiment 2, for every 1% increase in soybean dry matter biomass addition, there was an increase of 0.1% of maize silage crude protein. The addition of soybean biomass to corn silage increases the ashes and crude protein content of silage.