Silage Protein Research Articles

Potential of ensiling braquiaria grass with inclusion of rice meal: Review

Brazil is one of the countries with the highest potential for livestock production, mainly determined by its climatic conditions, vast territory and forage, that are the basis of the diet of ruminants in most production systems in the country. This assumption, an alternative to solve the lack of food during the year is the conservation of surplus grass as silage. However, the high moisture content at the ensilage predispose the growth of undesirable microorganisms, which result in loss of gases and effluents. However, one of the ways to reduce these losses is the addition of coproduct with high hygroscopic and increase the nutritional value and benefits during the fermentation process of preserving forage. Developed this study aiming to evaluate the fermentation characteristics, gas losses and effluent, nutrient recovery, nutritive value, the in situ degradability and fractionation of carbohydrates and protein in silages added hygroscopic additive, as rice meal.

Utilization of protein in red clover and alfalfa silages by lactating dairy cows and growing lambs

Feeding trials were conducted with lactating cows and growing lambs to quantify effects of replacing dietary alfalfa silage (AS) with red clover silage (RCS) on nutrient utilization. The lactation trial had a 2 × 4 arrangement of treatments: AS or RCS fed with no supplement, rumen-protected Met (RPM), rumen-protected Lys (RPL), or RPM plus RPL. Grass silage was fed at 13% of dry matter (DM) with AS to equalize dietary neutral detergent fiber (NDF) and crude protein contents. All diets contained (DM basis) 5% corn silage and 16% crude protein. Thirty-two multiparous (4 ruminally cannulated) plus 16 primiparous Holstein cows were blocked by parity and days in milk and fed diets as total mixed rations in an incomplete 8 × 8 Latin square trial with four 28-d periods. Production data (over the last 14 d of each period) and digestibility and excretion data (at the end of each period) were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). Although DM intake was 1.2 kg/d greater on AS than RCS, milk yield and body weight gain were not different. However, yields of fat and energy-corrected milk as well as milk content of fat, true protein, and solids-not-fat were greater on AS. Relative to AS, feeding RCS increased milk and energy-corrected milk yield per unit of DM intake, milk lactose content, and apparent N efficiency and reduced milk urea. Relative to AS, apparent digestibility of DM, organic matter, NDF, and acid detergent fiber were greater on RCS, whereas apparent and estimated true N digestibility were lower. Urinary N excretion and ruminal concentrations of ammonia, total AA, and branched-chain volatile fatty acids were reduced on RCS, indicating reduced ruminal protein degradation. Supplementation of RPM increased intake, milk true protein, and solids-not-fat content and tended to increase milk fat content. There were no silage × RPM interactions, suggesting that RPM was equally limiting on both AS and RCS. Supplementation of RPL did not influence any production trait; however, a significant silage × RPL interaction was detected for intake: RPL reduced intake of AS diets but increased intake of RCS diets. Duplicated metabolism trials were conducted with lambs confined to metabolism crates and fed only silage. After adaptation, collections of silage refusals and excreta were made during ad libitum feeding followed by feeding DM restricted to 2% of body weight. Intake of DM was not different when silages were fed ad libitum. Apparent digestibility of DM, organic matter, NDF, and hemicellulose was greater in lambs fed RCS on both ad libitum and restricted intake; however, acid detergent fiber digestibility was only greater at restricted intake. Apparent and estimated true N digestibility was substantially lower, and N retention was reduced, on RCS. Results confirmed greater DM and fiber digestibility in ruminants and N efficiency in cows fed RCS. Specific loss of Lys bioavailability on RCS was not observed. Based on milk composition, Met was the first-limiting AA on both silages; however, Met was not limiting based on production and nutrient efficiency. Depressed true N digestibility suggested impaired intestinal digestibility of rumen-undegraded protein from RCS.

Comparison of microalgae and rapeseed meal as supplementary protein in the grass silage based nutrition of dairy cows

Two experiments were conducted to evaluate microalgae as a protein supplement in the nutrition of lactating dairy cows in relation to unsupplemented and rapeseed meal supplemented diets. In both experiments multiparous Finnish Ayrshire cows were fed separately fixed amount of cereal-sugar beet pulp based concentrate (11kg/d in Exp. 1 and 12kg/d in Exp. 2), and grass silage ad libitum. In Exp. 1, six cows (212days in milk; DIM) were used in a replicated 3×3 Latin square. Diets were supplemented isonitrogenously with rapeseed meal (pelleted rapeseed supplement, RSS), mixture of Spirulina platensis and Chlorella vulgaris microalgae (1:1 on dry matter (DM) basis; ALG) or a mixture of RSS and ALG (1:1 on crude protein (CP) basis; RSS-ALG). In Exp. 2, four intact cows and four rumen cannulated cows (190 DIM) were used in a replicated 4×4 Latin square. Treatments consisted of basal diet without protein supplement (NEG) or supplemented similarly as in Exp. 1 with the exception of RSS-ALG and ALG containing only S. platensis. Protein supplementation increased fibre and N digestibility but did not affect dry matter intake (DMI) or milk yield. The substitution of rapeseed by microalgae did not affect total DMI or milk yield in neither of the experiments, but changed the quality of DMI in Exp.2 by linearly decreasing concentrate:forage ratio of the diet due to poorer palatability of microalgae. The efficiency of N utilisation (NUE) in milk production varied from moderate (Exp. 1) to high (Exp. 2), and in Exp. 2 was decreased by both protein supplementation and microalgae inclusion in the diet. Protein supplementation or microalgae inclusion in the diet did not affect ruminal pH or major volatile fatty acids in Exp. 2, but both increased ruminal NH3-N concentration. There was likely a shortage of N for rumen microbes on NEG in Exp. 2 as indicated by low milk urea N and increased microbial N flow on protein supplemented diets. In both experiments, only minor differences were observed in plasma metabolites when microalgae substituted rapeseed. Even though arterial histidine concentrations were high, arterial histidine and carnosine concentrations (Exp. 1 and 2) and milk protein yields (Exp. 2) decreased by microalgae inclusion suggesting that histidine supply may become suboptimal on microalgae supplemented diets. Experiments demonstrated the suitability of microalgae as protein supplement for dairy cows, however, the protein value of microalgae is likely slightly lower than that of rapeseed meal.

Can herbicides increase the content of crude protein in corn silage?

Can herbicides increase the content of crude protein in corn silage?

Conservation Characteristics and Nutritive Value of Sunflower Silages as Affected by The Maturity Stages and Fibrolytic Enzymes

Silage quality and nutritive value of sunflower silages ensiled with different level of fibrolytic enzymes at blooming, milk and dough stages were investigated. Fibrolytic enzyme complex (Viscozyme® L, V2010 Sigma Novozyme) was applied 0, 1, 1.5 and 2.5 ml/kgDM at ensiling. The dry matter (DM) yield increased with each increment of the maturity stage. Dry matter (DM), ether extract (EE) and crude cellulose (CC) contents of silages increased also in each delay in harvesting, while crude protein (CP), NDF and ADF contents of silages were the highest in blooming stage. The pH was higher in sunflower silage harvested at dough stage when compared to blooming stage, while acetic, propionic and butyric acid concentrations were all higher in blooming stage, although there were no differences in lactic acid concentrations among harvesting periods. Although silage structural carbohydrate composition was not significantly affected by any enzyme dose, Dose III enzyme treatment at the dough was associated with the highest concentration of lactic acid. Overall, there was no profound effect of enzyme supplementation on nutritive value and silage characteristics of sunflower silage.

Biological Silages from Tunisian Shrimp and Octopus By-Products

ABSTRACTBiological silages were prepared from shrimp head and octopus viscera by-products recuperated from the Tunisian seafood industry. Physical and biochemical changes and microbiological profiles were determined for raw materials during fermentation and on end-products. Results showed that biological silage significantly affected (p < 0.05) moisture, protein, and ash contents of shrimp head (CSHS) and octopus viscera silages (COVS). CSHS and COVS were stable, and their final pH values were 4.31 ± 0.01 and 3.71 ± 0.00, respectively. Proteolysis activity was confirmed by a significant increase (p < 0.05) of soluble nitrogen and low molecular weight of protein (<260 Da) found on the end-products for both silages. Lipid oxidation was delayed by addition of 150 ppm ethoxyquin to the raw material prior to fermentation. Biogenic amines detected in raw shrimp and octopus samples decreased significantly (p < 0.05) during the silage process. Histamine and tyramine, detected at high levels on octopus viscera, were absent in the end-products. Tyramine was produced in CSHS, indicating the possibility of the bacterial decarboxylation of tyrosine. Microbiological profiles showed that both silage products were free from pathogenic and spoilage bacteria. Therefore, biological silage can be used as a conservation procedure of shrimp and octopus by-products. The storage period could be shorter than 30 days, and further analysis should be carried out to ascertain safety and nutritional value of silage products.

Effects of essential oil compounds addition on ryegrass silage protein degradation

Five essential oil compounds in four doses (0, 50, 500, and 2000 mg kg−1of fresh forage) were sprayed on ryegrass forage before ensiling. Thymol, eugenol, and cinnamaldehyde at 2000 mg and carvacrol at 500 and 2000 mg inhibited deamination. Cinnamaldehyde at 2000 mg resulted in silages with 9.8% higher true protein.

Effect of Shrimp Head Silage Hydrolysate and Distiller's Dried Corn Grain on Digestibility and Growth of Red Tilapia (Oreochromis mossambicus)

We studied the effect of shrimp head silage protein hydrolysate (SHSP) and distillers dried corn grain (DDCG) as ingredients on the digestibility of diets for Oreochromis mossambicus. Three diets containing 30% protein, 10% lipid, and 4.9 kcal/g calorific value were prepared: a reference diet and two based on the inclusion of 84.0% of the reference diet, 15% of SHSP or DDCG, and 1% of chromic acid as a marker. Six fish (45.5±2.5g) were introduced in each culture unit (60 L). There were significant differences (P<0.05) for the apparent dry matter digestibility among the diets. The SHSP diet obtained the higher dry matter digestibility (86.33±0.8%). While, no differences (P<0.05) in the apparent protein digestibility were observed among the diets and ingredients. The mean final weight (58.77±3.8g) was similar for the three experimental treatments. It can be conclude concluded that the red tilapia is able to efficiently consume diets containing these animal and plant-derived ingredients.

Mixed silage of elephant-grass and leucaena: crude protein and minerals

This experiment was conducted to evaluate the effect of the addition of leucaena (Leucaena leucocephala) on the crude protein and minerals in silage of elephant-grass (Pennisetum purpureum Schum. cv. Napier). The experimental design was completely randomized design with three replications and three treatments: T1) 100% of elephant-grass var. Napier, T2) 80% of elephant-grass var. Napier + 20% leucaena var. BRA 1911 and T3) 60% of elephant-grass var. Napier + 40% leucaena var. BRA 1911. The addition of 20% and 40% of leucaena var. BRA 1911 increased significantly (P

Patterns of in vitro rumen fermentation of silage mixtures including sainfoin and red clover as bioactive legumes

In this study, we tested the effects of the inclusion in silages of bioactive legumes containing condensed tannins (CT) or polyphenol oxidase (PPO), ensiled alone or in mixture with one grass species, on in vitro rumen fermentations. Six mini-silos were prepared in triplicate as follows: pure sainfoin (SF), pure red clover (RC), pure timothy (T, control without bioactive compounds); binary mixtures T–SF and T–RC (in g/kg on a DM basis, 500:500); ternary mixture T–SF–RC (in g/kg on a DM basis, 500:250:250). Samples from each mini-silo were incubated under anaerobic conditions in culture bottles containing buffered rumen fluid from sheep. Rumen fermentation parameters, namely DM disappearance, volatile fatty acids (VFA), ammonia (NH3), gas production and methane (CH4) were determined. The presence of RC in mixtures with T or T–SF results in fermentation similar to pure T and a positive associative effect between T and RC on total VFA production was observed (P=0.029). The NH3: total N ratio was similar among the treatments, but lower values for NH3: insoluble N ratio in silages containing SF or RC (P<0.05, except for T–SF) indicates that the bioactive compounds can limit silage protein degradation in the rumen. The CH4 production per g of DM only tended to differ among treatments (P=0.096), being slightly lower for pure SF than for pure T and RC, probably due to differences in the fermentation pathways towards less acetate and butyrate productions. Overall, the benefits of including RC in forage mixtures previously observed on silage quality are also present on ruminal digestion efficiency.

Cinética de degradação in situ das silagens de capim Andropogon gayanus produzidas em três idades de corte

A idade ao corte é considerada o principal fator a afetar o valor nutritivo das forragens. Objetivou-se avaliar e comparar a cinética de degradação ruminal da matéria seca (MS), proteína bruta (PB) e fibra insolúvel em detergente neutro (FDN) das silagens de capim Andropogon gayanus obtidas em três diferentes idades de corte (56, 84 e 112 dias). As amostras das silagens secas e trituradas (5 mm) foram incubadas em sacos de nylon no rúmen por 0, 6, 12, 24, 48 e 72 h. Os parâmetros da cinética de degradação das silagens de cada tratamento (3 silagens) em cada animal (5 vacas) foram determinados pelo modelo: y = a + b(1 − e−c(t−L)). Os parâmetros gerados pela equação foram analisados como blocos inteiramente ao acaso, sendo que as idades de corte foram inseridas como efeito fixo e os animais como efeito aleatório (blocos). A silagem da planta aos 56 dias de rebrote apresentou maiores (P&lt;0,05) valores de degradabilidade efetiva da MS e da FDN calculada para a taxa de passagem de 2,0%/h. Todas as silagens apresentaram baixa fração solúvel (&lt;25,4%) e degradabilidade efetiva (&lt;40,1%) da proteína bruta com taxa de passagem de 2%. Foi observado maior (P&lt;0,05) tempo de colonização da FDN para as silagens realizadas com as plantas aos 84 e 112 dias de crescimento em comparação com a silagem produzida aos 56 dias. Os resultados da cinética de degradação ruminal das silagens de capim Andropogon gayanus indicam que a planta ensilada aos 56 dias de rebrote apresentou melhor valor nutricional.

Relationship between chemical composition and in situ rumen degradation characteristics of grass silages in dairy cows

The DVE/OEB2010 system in the Netherlands uses a large database of in situ rumen incubations with grass silage and grass hay samples to derive prediction formulas to estimate the rumen degradation characteristics of a number of feed value parameters. These in situ rumen incubations were not performed for this specific purpose and the data were generated at different research institutes over more than 40 years, using different grass management and fertilization practices and using different protocols. The objectives of this study were to 1) generate a new database on the rumen degradability of dry matter (DM), organic matter (OM), crude protein (CP) and neutral detergent fibre (NDF) of grass silages, 2) compare this new database with the old database used in the DVE/OEB2010 system, and 3) derive regression equations using the new database to investigate the relationships between chemical composition and in situ ruminal degradation characteristics of DM, OM, CP and NDF of the grass silages. Sixty nine grass silages, with a broad range in chemical composition and quality parameters, were selected and incubated using the nylon bag technique in the rumen of three lactating Holstein Friesian cows for 2, 4, 8, 16, 32, 72 and 336h. There was a large range in the rumen degradable fractions of DM, OM, CP and NDF of the grass silages at each rumen incubation period. The data on the rumen degradation characteristics of DM, OM, CP and NDF in the present study were determined using the same standard incubation protocol, the same cows, and the same chemical analysis procedures for all the grass silage samples. Regression analysis, using the new database, showed relationships between the washable (W) fraction, rumen undegradable (U) fraction, potentially rumen degradable (D) fraction and effective rumen degradation (ED) of DM, OM, CP and NDF, respectively, and the chemical composition of the grass silages.

Short communication. Effects of adding different protein and carbohydrates sources on chemical composition and in vitro gas production of corn stover silage

The use of protein-rich by-products based in swine manure (SM), poultry waste (PW) or chemicals compounds as urea (U), as well as energy products like molasses (M) and bakery by-product (BB), is a viable method to produce good quality silage. In addition, the use of a bacterial additive can improve the fermentation characteristics of silage. The objective of this study was to determine chemical composition, in vitro gas production (GP) and dry matter disappearance (DMd), using different sources of protein and energy in silage. The silages were made using SM, PW or U as protein sources and M or BB as energy source, with corn stover and with or without a bacterial additive. The organic matter (OM) content was higher (p &lt; 0.001) in silages with UBB, UM and SMBB compared with the rest of the treatments; meanwhile crude protein content was higher (p &lt; 0.001) in silages with U. The addition of a bacterial additive increased (p &lt; 0.05) OM content and decreased (p &lt; 0.05) fiber content. Total GP was higher (p &lt; 0.05) in silages containing BB, but DMd was higher (p &lt; 0.05) in silages with U and SMBB. The inclusion of a bacterial additive decreased (p &lt; 0.05) GP and DMd. The use of alternative sources of protein such as poultry and swine manure or urea, and of by-products of sugar industry and bakery is an alternative for silages based on corn stover. The results show that when properly formulated, the silages can provide more than 16% of crude protein and have DMd values above 60%.

잡초로 취급된 유채의 사일리지 제조에 관한 연구

본 연구에서는 관상용으로써 가치가 없어지면 잡초로 변해 버린 유채를 조사료원으로써 이용하기 위한 방법을 모색하기 위해서 천안에 위치한 국립축산과학원 자원개발부 초지사료포장에서 수행되었다. 유채는 생육시기별 3회(개화기, 유숙기, 호숙기)에 걸쳐 수확을 하여 사일리지를 제조한 후 사료가치 및 품질을 조사하였다. 수확시기가 늦어짐에 따라 수분함량은 감소하는 경향을 보였으며 예건에 의해서 사일리지 제조 적기 수분함량을 유지하였다. 그리고 호숙기는 거의 헤일리지 수준의 수분함량을 나타냈다. 유채의 원형곤포 사일리지는 수확시기가 늦어짐에 따라 조단백질 함량은 감소하는 경향을 보였으나(p<0.05) 섬유소인 ADF 및 NDF 함량은 증가하는 경향을 보였다(p<0.05). 그리고 유채 사일리지의 TDN 함량도 수확시기가 늦어짐에 따라 감소되었다(p<0.05). 수확시기에 따른 사일리지의 pH는 3.8~4.4을 유지하였으며, 호숙기의 pH는 개화기나 유숙기 보다 높았다(p<0.05) 그리고 수확시기가 늦어짐에 따라 젖산 함량은 증가하였으나(p<0.05) 초산 함량은 감소하였다(p<0.05). Flieg법에 의한 유채의 원형곤포 사일리지의 품질등급은 개화기(100), 유숙기(100) 및 호숙기(88) 모두 우수등급을 나타났다. This study was carried out to investigate the effect of harvest stage of rape on nutritive values and quality of round baled rape silage in field of forage crops of Department of Animal Resources Development, National Institute of Animal Science, RDA. Rape was harvested at three different growth stages (flowering, milk and dough stage) and ensiled at each harvest stages. The content of moisture of rape increased with delayed harvest maturity. However, the content of moisture of rape was controlled by pre-wilting (24 hr. and 48 hr). The content of moisture in dough stage was similar to that of haylage. The content of crude protein in round baled rape silage increased with delayed harvest maturity, but the contents of acid detergent fiber, neutral detergent fiber and total digestible nutrient decreased. The pH in all rape silage ranged from 3.8 to 4.4 at three different harvest stages, and pH in dough stage was higher than that of flowering and milk stages (p<0.05). The content of lactic acid of all rape silage increased with delayed harvest maturity (p<0.05), but the content of acetic acid decreased (p<0.05). And then, flieg's score revealed that there was an increase in order; flowering stage (100) = milk stage (100) > ripen stage (88).

Fracionamento de carboidratos e de proteína das silagens de diferentes forrageiras

Este experimento foi conduzido com os objetivos de caracterizar e quantificar as frações que compõem os carboidratos e a proteína de diferentes silagens. Foi utilizado delineamento inteiramente casualizado com quatro tratamentos e cinco repetições: silagem de milho (AG 5011), silagem de sorgo-sudão, silagem de sorgo-forrageiro (BR 601) e silagem de girassol (Rumbsol 91). A silagem de girassol apresentou menor valor de carboidratos totais (CT) e da fração B2 (fração potencialmente degradável da fibra). As silagens de milho, sorgo-sudão e sorgo-forrageiro não apresentaram diferença quanto aos teores de carboidratos totais. A fração C (fração indigestível da parede celular) foi encontrada em maior proporção nas silagens de sorgo-sudão e girassol. Não houve diferenças na fração A da proteína (nitrogênio não-proteico) entre as silagens. A silagem de girassol apresentou maior valor de proteína bruta e nitrogênio total. Não foi observada diferença nos resultados entre as silagens de milho e sorgo, e a fração C foi menor para silagem de milho e sorgo forrageiro. As silagens de sorgo-sudão e sorgo-forrageiro apresentam menor valor nutritivo, devido à maior quantidade de parede celular e ao menor conteúdo de energia em comparação às silagens de milho e girassol.

간척지에서 수확한 옥수수 AG-BAG 사일리지의 품질에 관한 연구

본 연구는 논에서 재배된 옥수수를 이용하여 AG-BAG 사일리지의 품질에 미치는 영향을 구명하기 위하여 충남 석문 간척지에서 수행되었다. 옥수수 AG-BAG 사일리지의 수분함량은 68~79% 범위를 유지하였고, pH는 3.49-3.65을 유지하였으며 수확기간에 따른 차이는 크지 않았다. 수확기가 늦어짐에 따라 AG-BAG 사일리지의 조단백질 함량은 감소하는 경향을 보였으나 섬유소인 NDF 및 ADF 함량은 증가하였다. 또한 수확기가 늦어짐에 따라 젖산 함량은 증가되었으나(P<0.05) 초산 함량은 감소되었다. 따라서 본 연구에서는 대단위 간척지 논에서 재배된 옥수수 사일리지 제조에 AG-BAG의 이용은 사일리지 발효가 양호하여 품질을 향상시켰을 뿐 만 아니라 옥수수 사일리지 제조에 경제적이며 효율적인 방법의 하나가 될 수 있다는 것을 보여주었다. This study was carried out to examine the nutritive values and quality of agricultural bag (AG-BAG) silage manufactured with corn grown in reclaimed paddy field of Sukmoon at Dangjin Province in Korea. The cultivars of silage corn used in this experiment 1 were both Kwangpyungok and P32B33. The fertilizer were applied with the amounts of customary applications (200 kg N/ha, 150 kg <TEX>$P_2O_5$</TEX>/ha and 150 kg <TEX>$K_2O$</TEX>/ha). The content of moisture in corn AG-BAG silage ranged from 68 to 79%. The pH in corn AG-BAG silage stages ranged from 3.49 to 3.65 and was not influenced by the harvest time. The contents of crude protein (CP) in corn AG-BAG silage decreased with delayed harvest time. However, the contents of ADF (acid detergent fiber) and NDF (neutral detergent fiber) increased. The content of lactic acid increased with delayed harvest time, but the content of acetic acid decreased. Therefore, we suggest that the system of AG-BAG silage can improve the quality of corn silage and be one of the economical and effective methods to manufacture corn silage.

Effects of ensiling of Bacillus thuringiensis (Bt) maize (MON810) on degradation of the crystal 1Ab (Cry1Ab) protein and compositional quality of silage

The study investigated the degradation of the Bt protein (Cry1Ab) in Bt maize during ensiling and chemical composition of the silage. Two laboratory studies were conducted at the University of Fort Hare. One Bacillus thuringiensis (Bt) maize cultivar (DKC80-12B) and its isoline (DKC80-10) in the 2008/2009 study and two Bt maize cultivar (DKC61-25B and PAN6Q-321B) and their isolines (DKC61-24 and PAN6777) in the 2009/2010 study, were ensiled for 42 days and analyzed for ash-free dry matter, Cry1Ab protein, neutral detergent fiber, acid detergent fiber, acid detergent lignin and crude protein. Silage from two of the Bt maize varieties had lower ash-free dry matter than their near-isolines, while variety DKC61-25B was similar to its near-isoline. At least, 60% of the initial Cry1Ab protein concentration remained in the silage. Bt maize had higher neutral and acid detergent fiber than its isolines before ensiling and remained constant after ensiling in 2008/2009, but was neither influenced by ensiling nor variety in 2009/2010. Crude protein and acid detergent lignin in Bt maize silages were similar to those in silages derived from their near-isolines. The findings suggested that Bt maize will result in silage with similar chemical composition to that of non-Bt maize but a large proportion of the Cry1Ab protein persists.

Free amino acid distribution in plasma and liver of juvenile cobia (Rachycentron canadum) fed increased levels of lizardfish silage

Juvenile cobia (Rachycentron canadum) (100 g) were fed four moist diets (447–476 g kg−1 dry wt) where 0, 130, 260 or 390 g kg−1 of concentrated lizardfish (Saurida undosquamis) silage replaced fresh lizardfish, respectively. Blood and livers were sampled at 0, 6, 12, 24 and 48 h postfeeding at the end of the 3-week experiment. At 6 h postfeeding in all groups, maximum concentrations of most plasma essential amino acids were observed, while significantly lower levels of most non-essential amino acid levels were recorded compared to the other sampled times. At 6 and 12 h after feeding, the concentration of most plasma free amino acid (FAA) increased with an increase in dietary fish silage levels. Most FAA in livers of all groups peaked at 12 and 24 h postfeeding. However, at 48 h postfeeding, concentrations of most plasma FAA were significantly higher in fish fed 0% silage-based diet than in fish fed the other diets (4999 versus 3390–4339 nmol AA mL−1 plasma). Growth rates and feed utilization were significantly lower in cobia fed 26% or 39% silage-based diets than in fish fed 0% or 13% silage-based diets. Different levels of silage protein thus seemed to have effects on growth and feed utilization efficiency of juvenile cobia. Results from this study support the premise that fish silage can be included until 130 g kg−1 in cobia diets.

Comparison between two methods for estimating the digestibility of starch and other nutrients in high moisture sorghum grain silage in horses

It was carried out two assays with the purpose of evaluating the mobile nylon bag technique and the method of total feces collection method in the estimative of the apparent digestibility of starch and other nutrients in high moisture sorghum grain silages in horses. Four adult horses of mixed origin at the age of 7 years and average body weight of 330 kg were used. In the first assay, the digestibility of the nutrients in the silage of high moisture sorghum grain with low level of tannin was evaluated by utilizing the total feces collection and the mobile nylon bag technique with silage samples ground in three particle sizes. In the second assay, the two methods were used for estimating the digestibility of the nutrients of the silage of high moisture sorghum grain with high level of tannin. A randomized block experimental design was used, considering each animal as a block. The disappearance of the nutrients, in the naylon bag, of the samples of the high moisture sorghum grain silages ground in three particle sizes of 1, 8 and 13 mm was also evaluated in laboratory. Daily dry matter intake was 2.0% of the body weight and test diets were made up of 30% of high moisture sorghum grain silages and 70% of coast-cross hay. The coefficients of dry matter digestibility, energy and protein of both silages were similar among the total feces collection method and the mobile nylon bag technique when 8-mm feed samples were used. The coefficient of starch digestibility was similar among the methods when sorghum samples were ground at 1 mm in the mobile nylon bag technique. Reduced particle size increased the nutrient losses of the nylon bags after washing in water. The mobile nylon bag technique allows to estimate the digestibility coefficient of nutrients, however, further studies for evaluation of particle size of the samples should be conducted.

Effect of the corn silage to grass silage ratio and feed particle size of diets for ruminants on the ruminal Bacteroides-Prevotella community in vitro

This study examined whether different corn silage to grass silage ratios in ruminant rations and different grinding levels of the feed affect the composition of the ruminal Bacteroides-Prevotella community in vitro. Three diets, composed of 10% soybean meal as well as of different corn silage and grass silage proportions, were ground through 1 mm or 4 mm screened sieves and incubated in a semi-continuous rumen simulation system. On day 14 of the incubation microbes were harvested by centrifugation from the liquid effluent of fermenter vessels. Microbial DNA was extracted for single strand conformation polymorphism (SSCP) analysis of 16S rRNA genes followed by sequencing of single SSCP bands. Fluorescence in situ hybridization (FISH) and real-time quantitative (q) PCR were used to quantify differences in the relative abundance of Bacteroides-Prevotella and Prevotella bryantii. SSCP profiles revealed a significant influence of the forage source as well as of the feed particle size on the community structure of the Bacteroides-Prevotella group. Different, phylogenetically distinct, so far uncultured Prevotella species were detected by sequence analysis of several treatment-dependent occurring SSCP bands indicating different nutritional requirements of these organisms for growth. No quantitative differences in the occurrence of Bacteroides-Prevotella-related species were detected between diets by FISH with probe BAC303. However, real-time qPCR data revealed a higher abundance of P. bryantii with increasing grass silage to corn silage ratio, thus again indicating changes within the community composition of the Bacteroides-Prevotella group. As P. bryantii possesses high proteolytic activity its higher abundance may have been caused by the higher contents of crude protein in the grass silage containing diets. To conclude, results of this study show an influence of the forage source on the ruminal community of Bacteroides-Prevotella. Furthermore, they suggest an effect of the feed particle size on this bacterial group.