The use of agroindustrial byproducts in cattle diets, such as castor-bean (Ricinus communis L.) meal, is a more sustainable practice because it does not compete with human food and reduces the volume ...of organic waste deposited in the environment. The aim of this study was to examine the effect of replacing soybean {Glycine max (L.) Merr.) meal with castor-bean meal on the intake, digestibility, feeding behavior and performance of crossbred steers supplemented while on Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster 'Marandu' pasture. The experiment was laid out in a randomized complete design with 40 animals, which started the experiment weighing 227.1 kg, at 10 mo of age, and were divided into four treatment groups. Castor-bean meal was added to replace soybean meal at the levels of 0, 90, 180, and 280 g kg.sup.1 in the supplement, which was supplied at the rate of 0.4% of body weight. Total DM, pasture DM and neutral detergent fiber intakes did not change (P > 0.05) with the castor-bean levels added to the supplement. Ether extract intake and digestibility decreased linearly (P < 0.05). The animals showed no differences (P > 0.05) in production performance (average daily gain), which averaged 0.65 kg d.sup.1 Grazing, idle, and rumination times were not influenced (P > 0.05) by the treatments. Castor-bean meal can be included up to 280 g kg.sup.1 in the total diet without changing the performance of crossbred steers finished on tropical pasture. Key words: Beef cattle, biodiesel by-product, steers performance, Ricinus communis, Urochloa brizantha.
This trial aimed to analyze the effects of including three byproducts from the biodiesel industry on the intake, digestibility, milk yield and composition, and feeding behavior of lactating cows. ...Eight crossbred Holstein-Zebu lactating cows with average body weight 525 ± 18.5 kg and average milk yield of 8 ± 1.45 kg day
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were assigned to four treatments (diets) in a double-Latin square design, as follows: a diet based on corn- and soybean meal-based concentrate and three diets with 20% inclusion of byproducts from the biodiesel industry (cottonseed cake, sunflower meal, and castor bean cake) on a total dry matter basis. The cows were housed in individual covered stalls with concrete floor equipped with individual concrete troughs for feeding and automatic drinkers, and fed diets containing 60% sugarcane and 40% concentrate. The inclusion of the byproducts in the diet changed the intake, digestibility of some nutritional components, milk yield and composition, and feeding behavior of lactating cows. The use of cottonseed cake and sunflower meal in the diet increased milk yield, and fat-corrected milk yield; while the use of castor bean cake reduced the intake, digestibility of dry matter and total digestible nutrients, milk yield, and fat-corrected milk yield. The inclusion of byproducts from the biodiesel industry in the diets did not change the fat, lactose, total solids, and solids-not-fat of milk. Therefore, the cottonseed cake and sunflower meal can be included at up to 20% of the total diet.
Our hypothesis is that the total replacement of ground corn grain (GCG) by cactus pear (CP) in association with 70% of leucaena hay (LH) increases dry matter (DM) intake and digestibility and ...nitrogen metabolism and maintains the feeding behavior of cattle. The objective was to evaluate the effects of inclusion of these feeds on the nutritional parameters and nitrogen metabolism of cattle. Eight steers, average age of 12 months, weight of 267.5 ± 15 kg, were distributed into two simultaneous 4 × 4 Latin squares according to a 2 × 2 factorial scheme, in which the first factor evaluated was different proportions of inclusion of LH (50 or 70% DM basis), and the second factor was the total replacement of GCG with CP. There was lower DM intake in animals fed with 70% LH. There was an interaction between the factors for DM digestibility, in which the animals fed CP did not differ regardless of the inclusion of LH, but for animals without CP, the greater inclusion of LH decreases DM digestibility. The inclusion of CP decreased free water intake. There was an interaction for total water intake (WI), in which the animals fed without CP presented similarity for this, while in the inclusion of CP, the animals fed 70% of LH presented higher WI. Also, lower values of chewing were observed for animals fed with CP. The replacement of GCG with CP improves the efficiency of nitrogen utilization in the rumen. The inclusion of 70% LH depresses intake.
The purpose of this study was to examine the growth and senescence dynamics of Digitaria eriantha cv. Survenola as a response to several canopy heights (25, 35, 45, and 55 cm) of harvests in two ...seasons of the year (rainy and dry). The experiment was established at the Federal University of Sergipe, in São Cristóvão - SE, Brazil, from 03/26/2015 to 03/28/2016, under a randomized-complete-block design with four replicates. Plots were irrigated, and upon reaching the pre-established canopy heights, they were cut to a 10 cm-residual height. Increasing canopy heights in the dry season led to lower tiller density, for basal and aerial tillers. However, irrespective of tiller type and season, this variable increased after the rest period. Light interception rose with canopy heights (P<0.05) in the dry period and it showed a quadratic response in the rainy season. Greater canopy heights led to a higher (P<0.05) daily leaf senescence rates and daily stem growth rates. Regardless of the season, the total accumulation and net herbage accumulation rates of basal tillers increased as canopy heights did. The greatest canopy height promoted the daily stem production, whereas the lowest height did not allow the grass to express its production potential. The defoliation-height range of 35 to 45 cm is the most recommended, as it favors the control of stem growth and leaf senescence.
The objective of this study was to evaluate the activity of invertases and amylases in Brachiaria brizantha cv. Marandu under various shade and nitrogen fertilization conditions. The experiment was ...carried out in a greenhouse using a 4 x 2 factorial scheme (shading levels of 0, 30, 50, and 80% and fertilization with 0 and 100 kg N ha-1). The activity of the enzymes, cytosol-neutral invertase (Inv-N), vacuole acid (Inv-V) and cell-acidic acid (Inv-CW), reducing sugars (RS), and α and β-amylases were evaluated (α = 0.05). The interaction was significant for Inv-N within the leaf. In the first cycle, the highest activity was in fertilized plants with 30, 50, and 80% shading. For Inv-CW in the 1st cycle, the highest activity occurred with 0, 30, and 50% shading. However, the interaction for Inv-V leaf activity was not significant in the 1st and 2nd cycles. The highest activity observed for Inv-V was in the fertilized plants, suggesting that fertilization increased the enzymatic activity. The activity of the invertases increased both under 30-50% shaded conditions and in full sun. Furthermore, invertase activity was directly linked to the osmoregulatory system. The reduction in RS was related to a low photosynthetic rate, and an increase α and β-amylase was associated with the use of reserve energy sources to meet energetic needs.
Abstract This study aimed to evaluate the effect of the first and last stocking strategies combined with a partial substitution of the protein from the supplement for urea nitrogen on nutrient intake ...and digestibility, milk composition, and nitrogen balance of primiparous Girolando cows. The cows were allocated to a double 4 × 4 Latin square composed of four animals and four treatments in a 2 × 2 factorial arrangement. Supplements were formulated to provide an intake of 0.6% body weight, with and without the inclusion of 21% urea nitrogen in their composition. The first stocking management method improved nutrient intake and digestibility. Supplementation with urea led to a 47% higher excretion of urine N (g/day) than the urea treatment. The combination of the supplement without urea and the first stocking provided higher intake and retention of nitrogen and higher retained-N levels (%digested N). The combination of a supplement containing 21% urea nitrogen and the first stocking can be used without compromising the nutritional and productive parameters of the cows.
Resumo Objetivou-se avaliar os efeitos dos manejos do pastejo ponta e repasse combinados a substituição parcial da proteína do suplemento por nitrogênio ureico sobre o consumo e digestibilidade dos nutrientes, composição do leite e balanço de nitrogênio de vacas primíparas da raça Girolanda. As vacas foram alocadas em dois quadrados latinos 4 x 4 compostos de quatro animais cada e quatro tratamentos em um esquema fatorial 2 x 2. Os suplementos foram formulados para um consumo de 0,6% do peso corporal: sem utilização de nitrogênio ureico; ou com 21% de nitrogênio ureico em sua composição. O manejo do pastejo de ponta melhorou o consumo e a digestibilidade dos nutrientes. O suplemento contendo ureia excretou 47% a mais de N urina (g/dia) em comparação ao suplemento sem ureia. A combinação entre o suplemento sem ureia e o manejo de pastejo ponta apresentou maior ingestão e retenção de nitrogênio e maior N retido (%N digerido). A combinação entre o suplemento contendo 21% de nitrogênio ureico e o pastejo de ponta pode ser utilizada sem prejuízos aos parâmetros nutricionais e produtivos das vacas.
The aim was to evaluate the fermentative dynamics and nutritional characteristics of mixed maize silages with and without commercially viable cobs associated with butterfly pea hay. A completely ...randomized experimental design was used in a 2 × 2 factorial scheme, with 4 replications, which corresponded to the maize cobs factor and the butterfly pea hay factor (inclusion of 30% of butterfly pea hay during the ensiling process and without the inclusion of butterfly pea hay). The inclusion of butterfly pea hay increased the dry matter contents, reduced the silage density and its interaction with the absence of viable cobs promoted less losses and greater dry matter recovery (P < 0.05). The lowest value of butyric acid was found in the interaction of silage without viable cobs and butterfly pea hay (P < 0.05). The inclusion of butterfly pea hay reduced fiber contents and increased protein contents (P < 0.05). The inclusion of 30% butterfly pea hay promotes better values of organic acids, nutritional components and lower fermentation losses when the maize is ensiled without cobs that are viable for commerce.
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