Crude Protein Degradability Research Articles

Feeding Polyunsaturated Supplements to Grazing Dairy Cows Improve the Healthy Value of Milk Fatty Acids

The objective of the experiment was to improve the healthy value of milk fatty acids (FA) by feeding sunflower oil (SO) or sunflower seed (SS) combined or not with fish oil (FO) to grazing dairy cows. Four Holstein cows (515 ± 80 kg liveweight) in late lactation (230 days postpartum) fitted with ruminal cannulae were allotted to a 4 × 4 Latin square design with factorial arrangement of treatments: SS = 1.9 kg dry matter (DM)/cow/d of SS; SO = 0.8 kg/cow/d of SO; SS-FO = SS + 0.24 kg/cow/d FO and SO-FO = SO + 0.24 kg/FO. Cows grazed a high quality pasture offered at 11 kg DM/cow/day. After the afternoon milking cows also received 5.6 kg DM/cow of corn silage and during each milking time cracked corn grain (1.3 kg DM/cow) mixed with a mineral-vitamin premix was fed. Oils and SS were introduced via ruminal cannulae and SS was fed roughly grounded. Milk yield tended (p 12:0, 51% for C14:0 and 29% for C16:0. Atherogenicity index (AI) of milk was reduced particularly in SS-FO. Basal concentration of cis-9, trans-11 C18:2 (CLA) in milk was 1.39 g/100g FA and increased (p < 0.05) by 144% across treatments without differences between SS or SO. Feeding FO increased (p < 0.05) milk contents of CLA (2.86 to 3.92 g/100g FA) and linolenic acid. Comparing SO or SS with or without FO showed no changes for neutral detergent fiber (NDF) and crude protein (CP) degradation of pasture. Polyunsaturated fatty acid (PUFA) fed to grazing dairy cows had a marked effect on milk FA profile putatively enhancing its healthy value.

Does microbial nitrogen contamination affect the estimation of crude protein degradability of concentrate feeds?

The effects of microbial contamination (MC) on CP degradability of concentrate feeds are still controversial. Therefore, the aim of this study was to use N to estimate the impact of MC on estimations of CP fractions (the soluble fraction of CP [a], the insoluble but potentially degradable fraction of CP [b], and the rate of digestion of fraction b [kd]) of concentrate feeds. Twelve types of feed were evaluated: 6 energy concentrates-wheat bran ( L.), rice meal ( L.), ground corn ( L.), ground sorghum ( Pers.), ground corn cob ( L.), and soybean hulls [ (L.) Merr.]-and 6 protein concentrates-cottonseed meal ( L.), soybean meal [ (L.) Merr.], ground bean ( L.), peanut meal ( L.), sunflower meal ( L.), and corn gluten meal ( L.). The feeds were divided into 4 groups and were incubated in the rumen of 4 crossbred bulls. The samples were incubated for 0, 2, 4, 8, 16, 24, 48, and 72 h. To estimate the MC of the incubated residues, the ruminal bacteria were labeled with N via continuous intraruminal infusion of (NH)SO. There was no difference ( = 0.738) between corrected and uncorrected parameters a, b, and kd for all feeds that were evaluated. All of the feed tests followed an exponential model of degradation, and the model fitted well to the data, except for corn gluten meal, probably because the maximum incubation time that was used (72 h) was not long enough to allow for an accurate estimation of the degradation profile. Therefore, correction of ruminal protein degradation to MC is irrelevant with regards to the concentrates that were studied.

Productivity, chemical composition and ruminal degradability of irrigated Napier grass leaves harvested at three stages of maturity

The effect of the stage of maturity on the productivity, chemical composition, and ruminal degradability of Napier grass ( Pennisetum purpureum ) leaves under irrigation was studied. Samples were collected at three stages of maturity, at intervals of four weeks starting from the fourth week until the twelfth week (April–July) after sprouting and then harvested to determine biomass. The stages of maturity had significant effects on longest leaf length per plant and plant height, but had no effect on number of leaves per plant and number of tillers. Dry matter (DM) increased significantly with maturity, while crude protein (CP) and fat content decreased significantly, with no significant effect on acid detergent lignin (ADL), ash, acid detergent fibre (ADF) and neutral detergent fibre (NDF). Maturity significantly decreased potassium, copper and sodium, while calcium and zinc increased significantly up to the intermediate stage, then declined toward the late stage of maturity. Maturity did not affect the magnesium, phosphorus, manganese and iron contents of the forage. Ruminal degradability of CP at 48, 72, 96 and 120 incubation hour decreased significantly with maturity, with no effect on all other incubation times for DM and CP. Maturity significantly decreased the soluble fraction (a) of DM, with no significant effect on other fractions of DM and CP. Effective degradability (%) of DM and CP decreased with maturity when the rate of passage increased from 2% to 8%. Napier forage should be harvested before maturity to retain its high nutrient content, and the degradability of DM and CP. Keywords: mineral composition, in sacco, dry matter, crude protein disappearance

Chemical Composition and Nutritive Value of Agro-Industrial By-Products in Ruminant Nutrition

This study was carried out to determine the chemical composition and in situ degradability of agro-industrial by-products found in Eritrea. Three categories of by-products were evaluated and were the milling industry (wheat bran; WB, short; WS, and middling; WM), brewery (brewers’ dry grain; BDG, hops; BDH, and yeast; BDY) and sesame cakes (sesame cake machine extracted; SCM and manually extracted; SCT). The dry matter (DM) varied between 88.46% in BDY to 92.39% in SCT. The lowest (P The metabolisable energy (ME) value of the agro-industrial by-products ranged from 8.72 to 11.18 MJ per kg DM with the BDH recording the lowest value (P The sesame cakes (SCM and SCT) recorded higher values of 11.17 and 11.18 MJ per kg DM respectively. The SCT recorded the highest ash content at 10.93% followed by BDY at 10.16% with the least being obtained from WM at 2.48%. The ether extract and acid detergent lignin contents were generally low in all cases for all the by-products. Generally, the results indicated that there was no clear pattern in terms of nutrients content amongst the by-products. The in situ DM, organic matter (OM) and CP degradability differed amongst and within the sesame cakes, milling and brewery by-products. The wide variation in chemical composition, DM, OM, CP degradability, and ME obtained from this study offer farmers huge flexibility in formulating rations according to the productive performance of target animals.

Effect of quantity and source of rumen nitrogen on the efficiency of microbial protein synthesis in steers consuming tropical forage

Low values for the efficiency of microbial protein synthesis (EMPS) in cattle consuming tropical forages are related to low rumen degradable crude protein (RDP) intakes. This study examined the effect on the EMPS of the quantity and source of nitrogen (N) supplied to the rumen of eight entire and four rumen-fistulated Brahman steers consuming mature tropical grass hay (57.3 g crude protein/kg DM). Four treatment diets were fed in a Latin square design and included a basal diet of mature pangola grass (Digitaria eriantha) hay (control) and hay plus supplements estimated to provide 150 g RDP/kg digestible organic matter intake (DOMI), as urea or casein, or 300 g RDP/kg DOMI as casein. The EMPS was only increased (P &lt; 0.05) above that for the control diet (167 vs 123 g microbial crude protein (MCP)/kg DOMI) when RDP was provided at the highest rate of 293 g/kg DOMI. This increase was also associated with an ~4-fold increase in the concentration of NH3-N (277 vs 73 mg/L) and of branched-chain volatile fatty acids (44 vs 10 mmol/mol of total volatile fatty acids) in rumen fluid of the steers. However, the source of rumen degradable N (urea or casein) had no effect on the EMPS (109–115 g MCP/kg DOMI) when supplied at ~150 g RDP/kg DOMI. There was no effect of treatment on in vivo neutral detergent fibre digestibility (599 g/kg DM) or the rate (0.037/h) or extent (potential degradable fraction: 636 g/kg OM) of in sacco disappearance of pangola grass hay. In addition, rumen particle dilution rate was unaffected by treatment (0.022/h) and rumen fluid dilution rate, although showing some treatment differences (0.048–0.062/h), was poorly correlated with EMPS. It was concluded that only high amounts of RDP supply to the rumen, in the form of true protein, resulted in increased EMPS whereas at the lower intakes of RDP formulated to achieve EMPS in the range suggested in the feeding standards (130–170 g MCP/kg DOMI) there was no difference in providing the RDP as non-protein N or degradable-protein.

Effect of lactic acid bacteria inoculants on alfalfa (Medicago sativa L.) silage quality: assessment of degradation (in situ) and gas production (in vitro)

Alfalfa (Medicago sativa) is difficult to ensile successfully because of the low content of moisture and water-soluble carbohydrates (WSC) in fresh alfalfa and the high buffering capacity in fresh alfalfa. Here, we conducted a study to evaluate the effects of three lactic acid bacteria (LAB) inoculants (Lactobacillus casei, Lactobacillus plantarum, and Pediococcus pentosaceus) on silage quality, in situ ruminal degradability, and in vitro fermentation of alfalfa silage. The first cut of alfalfa was wilted, chopped, and randomly divided into four groups: the control (CON) and control mixed with three separate LAB inoculants (106 cfu g−1). Simmental steers with a body weight of (452±18) kg and with installed rumen fistulas were prepared for in situ degradation and for in vitro gas production. LAB inoculants had a lower (P<0.05) content of butyric acid than the CON group. Among them, the L. casei inoculated silage had a higher (P<0.05) content of water-soluble carbohydrate (WSC) and a lower (P<0.05) NH3-H content. The effective degradation (ED) of crude protein in LAB inoculation decreased (P<0.05), while the ED of acid detergent fiber increased (P<0.05) in situ fermentation. The alfalfa silage with LAB inoculants produced more carbon dioxide (P<0.05). The NH3-H content of mixed incubation fluid in L. casei inoculated silage was lower (P<0.05) compared with other groups. Therefore, this study showed that LAB inoculants could improve both ensiling quality and degradation. In particular, the L. casei inoculations exhibited better performance by limiting proteolysis during ensiling.

Degradabilidade ruminal e digestibilidade intestinal dos grãos de soja crus e tostados em bovinos leiteiros

RESUMO Objetivou-se estudar o efeito de diferentes tratamentos térmicos, tempos e procedimentos na degradação ruminal de grãos de soja crus e tostados e sua ação na digestão intestinal da proteína não degradada no rúmen (PNDR) pelo método dos três estágios. Para a degradação ruminal in situ foram pesados cinco gramas de matéria natural em sacos de náilon incubados durante 2; 4; 8; 16; 24 e 48 horas. No tempo zero foi efetuado o mesmo procedimento, excetuando a incubação ruminal. Os resíduos de cada tratamento formaram uma amostra composta para determinar a matéria seca (MS) e proteína bruta (PB). Para a digestibilidade intestinal realizou-se a incubação in situ por 16 horas, usando a técnica dos três estágios. A degradabilidade efetiva da MS com taxa de passagem de 5%/hora para a soja crua (SC) foi de 71,94% e tostada entre 52,23% a 68,78%. Após 16 horas de incubação a PNDR variou de 32,12 a 67,72% e a digestibilidade intestinal de 73,21% a 86,02%. A menor degradação da MS e PB foi da soja tostada a 145°C durante um minuto com steeping (STC1). A digestibilidade intestinal in vitro dos grãos crus foi superior e diferiu dos tostados, exceto a soja tostada a 115°C durante quatro minutos com steeping. A menor degradação proteica foi obtida da STC1de 67,72% da PNDR,52,33% a mais do que à SC. A tostagem dos grãos de soja a 145°C(STC1)contribuiu para uma menor degradabilidade ruminal da proteína bruta.

Effect of dietary Quebracho tannin extract on feed intake, digestibility, excretion of urinary purine derivatives and milk production in dairy cows

ABSTRACTThe aim of this study was to evaluate the effects of dietary Quebracho tannin extract (QTE) on feed intake, apparent total tract digestibility (ATTD), excretion of urinary purine derivatives (PD) and milk composition and yield in dairy cows. Fifty Holstein cows were divided into two groups. To reach a similar performance of both groups, cows were divided according to their milk yield, body weight, days in milk and number of lactations at the start of the experiment averaging 33.2 ± 8.2 kg/d, 637 ± 58 kg, 114 ± 73 d and 2.3 ± 1.6 lactations, respectively. The cows were fed a basal diet as total mixed ration containing on dry matter (DM) basis 34% grass silage, 32% maize silage and 34% concentrate feeds. Three dietary treatments were tested, the control (CON, basal diet without QTE), QTE15 (basal diet with QTE at 15 g/kg DM) and QTE30 (basal diet with QTE at 30 g/kg DM). Two treatments were arranged along six periods each 21 d (13 d adaptation phase and 8 d sampling phase). The ATTD of DM and organic matter were reduced only in Diet QTE30, whereas both QTE treatments reduced ATTD of fibre and nitrogen (N), indicating that QTE impaired rumen fermentation. Nevertheless, feed intake was unaffected by QTE. In Diet CON, urinary N excretion accounted for 29.8% of N intake and decreased in treatments QTE15 and QTE30 to 27.5% and 17.9%, respectively. Daily faecal N excretion increased in treatments CON, QTE15 and QTE30 from 211 to 237 and 273 g/d, respectively, which amounted to 39.0%, 42.4% and 51.7% of the N intake, respectively. Hence, QTE shifted N excretion from urine to faeces, whereas the proportion of ingested N appearing in milk was not affected by QTE (average 30.7% of N intake). Daily PD excretion as indicator for microbial crude protein (CP) flow at the duodenum decreased in treatment QTE30 compared with Diet CON from 413 to 280 mmol/d. The ratios of total PD to creatinine suggest that urinary PD excretion was already lower when feeding Diet QTE15. While there was no effect of Diet QTE15, treatment QTE30 reduced milk yield, milk fat and protein. Both QTE treatments reduced milk urea concentration, which suggest that ruminal degradation of dietary CP was reduced. In summary, adding QTE at dosages of 15 and 30 g/kg DM to diets of lactating dairy cows to improve feed and protein use efficiency is not recommended.

Effects of corn treated with foliar fungicide on in situ corn silage degradability in Holstein cows

With increasing feed prices and decreasing profit margins livestock producers are constantly searching for ways to increase nutritive value of the feed in order to get more production per unit of feedstuff. The objective of this study was to assess the digestibility of corn silage made of corn plants treated with various foliar fungicide applications. Treatments were: control (CON), corn received no foliar fungicide application; 1X, corn received one application of pyraclostrobin foliar fungicide (PYR; Headline; BASF Corp.) at vegetative stage 5 (V5); 2X, corn received 2 applications of foliar fungicides, PYR at stage V5, and a mixture of pyraclostrobin and metconazole (PYR+MET; Headline AMP; BASF Corp.) at reproductive stage 1 (R1); and 3X, corn received 3 applications of foliar fungicides, PYR at stage V5, PYR+MET at stage R1, and PYR+MET at reproductive stage 3. Corn was harvested at the same time and ensiled for 7 months. Dried unground corn silage was put into 288 (3 per time points/treatment/cow) 10×20cm bags and incubated for 8 different time points (0, 2, 4, 8, 12, 48, 72, and 96h). A sample of unground dried corn silage was also placed into 20×40cm bag and incubated for 48h. Digestibility of corn silages was estimated using in situ procedure with 3 rumen-cannulated lactating multiparous Holstein cows. The degradable fraction of dry matter (DM) tended to be greater (P=0.08) for corn silages treated with fungicide when compared with CON. There was no treatment effect (P>0.05) on neutral detergent fiber (aNDF), acid detergent fiber (ADF), starch, and crude protein (CP). However, the soluble fraction of DM, aNDF, and ADF decreased (P<0.05) as fungicide applications increased. Effective degradability (ED) was greater (P<0.05) in CON than corn silages treated with fungicide mainly due to decreased ED in 3X compared with 1X and 2X. In situ digestibility for bigger and smaller bags was different. Degradability of DM, aNDF, and ADF was higher (P<0.05), while starch and CP degradability was lower (P<0.01) in the larger bags. Fungicide application to corn for silage lead to higher DM degradable fraction which seems to be the result of increased sugar and starch along with decreased aNDF and ADF.

1519 Does microbial contamination affect in situ estimation of crude protein degradability of concentrate feedstuffs?

1519 Does microbial contamination affect in situ estimation of crude protein degradability of concentrate feedstuffs?

Rumen degradability in situ forage diet for Ruminants Formed by Hays Tifton 85 and Leucena

We evaluated the nutritional value, as the chemical composition and in situ degradation of dry matter, crude protein and neutral detergent fiber. We adopted a completely randomized design (CRD), a 2 x 2 (hay Tifton 28 days 85 + 20% hay leucaena [FT28d +20 L], hay Tifton 28 days 85 + 40% hay Leucaena [FT28d +40 L], hay Tifton 42 days 85 + 20% hay leucaena [FT42d +20 L], hay Tifton 42 days 85 + 40% Leucaena hay [FT42d +40 L]) in split plot at 6, 24, 72 h. Hay Tifton 85 with two levels of regrowth x leucaena hay (20 and 40% of DM) resulted in degradation rate of DM c exceeding 3.0% / h, the soluble fraction of NDF increased level with 40% Leucaena hay, with the participation of fraction b, with the rate of degradation (c) exceeding 2.0% / h. The DM of Leucaena hay, were much soluble fraction (a = 33.59%) and little in situ degradable fraction (b = 32.59%), however, estimates of potential degradation rates of passage 2, 5 and 8% h-1 for the levels of food consumption low, medium and high of 60.07, 54.25 and 50.53% respectively. The Leucaena hay promotes an increase in protein content, increasing the CP content, the in situ and the kinetics of degradation of DM, CP, and 40% Leucaena hay.

Evaluation of grape pomace from red wine by-product as feed for sheep.

This work aimed to study the chemical composition and in vitro digestibility of seeds and pulp from grape pomace. In sacco degradability, ruminal fermentation of grape pomace fractions and plasma lipid peroxidation were also studied in sheep fed with or without grape pomace. Seed and pulp fractions of grape pomace had different values for cell walls (523 vs 243 g kg-1 dry matter (DM)), crude protein (CP, 104 vs 138 g kg-1 DM), ether extract (EE, 99.0 vs 31.7 g kg-1 DM), polyunsaturated fatty acids (PUFA, 69.6 vs 53.3%) and extractable polyphenols (55.0 vs 32.1 g kg-1 DM). The in vitro true digestibility, DM in sacco degradability and CP degradability of seeds and pulp were also different (0.51 vs 0.82, 0.30 vs 0.45 and 0.66 vs 0.39 respectively). The ammonia-N concentration and total volatile fatty acids (VFA) in ruminal liquid were significantly lower and plasma lipid peroxidation was also numerically lower in sheep that consumed grape pomace. The nutritive value of grape pomace varies depending on the proportion of seeds and pulp. The interest of this by-product in sheep feeding could be related to its polyphenol and PUFA content, which could improve meat and milk quality. © 2016 Society of Chemical Industry.

Improving the in situ ruminal degradability of maize stalk using fungal inoculants in dorper × thin-tailed han crossbred ewes

The mono-culture fungal inoculant of Phaerochaete chrysosporium (P. chrysosporium) and the co-culture fungal inoculants of P. chrysosporium and Aspergillius niger (A. niger) or Trichoderma viride (T. viride) were screened for their potential to increase the in situ fiber and crude protein digestibility of maize stalk in sheep. The milled maize stalk samples were inoculated in vitro with the mono-culture and co-culture fungal inoculants (10mL/20g) and incubated under solid state fermentation conditions at 30°C for 10days to determine their fibre-degrading enzyme activity and chemical composition. In situ ruminal degradability was assessed using six ruminally cannulated Dorper×thin-tailed Han crossbred ewes (60.0±1.73kg BW) fed a diet with a concentrate-to-roughage ratio of 69:31(dry matter (DM) basis). The samples were incubated in nylon bags for 0, 6, 12, 24, 48, and 72h in the rumen. The results showed that the inoculation of P. chrysosporium increased in situ ruminal degradation of DM, organic matter (OM), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and hemicellulose in comparison to the control (P<0.05). The maize stalk incubated with P. chrysosporium+T. viride had the greatest in situ degradability of DM, OM, NDF, ADF, ADL and cellulose after incubation for 12h (P<0.05). The inoculation of P. chrysosporium+A. niger increased in situ ruminal crude protein (CP) degradation (P<0.05) in comparison to the other treatments. The in situ DM degradability after fermentation for 72h (72h-DMD) was correlated with the loss of ADL (r=0.870; P<0.05), cellulose (r=0.763; P<0.05), hemicellulose (r=0.864; P<0.05) and the ratio of ADL to hemicellulose (r=0.686; P<0.05). Generally, the co-culture fungal inoculants of P. chrysosporium+T. viride had the greatest effect on improving the availability of nutrients in maize stalks to rumen microbes.

In situ ruminal degradation characteristics of dry matter and crude protein from dried corn, high-protein corn, and wheat distillers grains.

BackgroundThe continuing growth of the ethanol industry has generated large amounts of various distillers grains co-products. These are characterized by a wide variation in chemical composition and ruminal degradability. Therefore, their precise formulation in the ruminant diet requires the systematic evaluation of their degradation profiles in the rumen.MethodsThree distillers grains plus soluble co-products (DDGS) namely, corn DDGS, high-protein corn DDGS (HP-DDGS), and wheat DDGS, were subjected to an in situ trial to determine the degradation kinetics of the dry matter (DM) and crude protein (CP). Soybean meal (SBM), a feed with highly degradable protein in the rumen, was included as the fourth feed. The four feeds were incubated in duplicate at each time point in the rumen of three ruminally cannulated Hanwoo cattle for 1, 2, 4, 6, 8, 12, 24, and 48 h.ResultsWheat DDGS had the highest filterable and soluble A fraction of its DM (37.2 %), but the lowest degradable B (49.5 %; P < 0.001) and an undegradable C fraction (13.3 %; P < 0.001). The filterable and soluble A fraction of CP was greatest with wheat DDGS, intermediate with corn DDGS, and lowest with HP-DDGS and SBM; however, the undegradable C fraction of CP was the greatest with HP-DDGS (41.2 %), intermediate with corn DDGS (2.7 %), and lowest with wheat DDGS and SMB (average 4.3 %). The degradation rate of degradable B fraction (% h−1) was ranked from highest to lowest as follows for 1) DM: SBM (13.3), wheat DDGS (9.1), and corn DDGS and HP-DDGS (average 5.2); 2) CP: SBM (17.6), wheat DDGS (11.6), and corn DDGS and HP-DDGS (average 4.4). The in situ effective degradability of CP, assuming a passage rate of 0.06 h−1, was the highest (P < 0.001) for SBM (73.9 %) and wheat DDGS (71.2 %), intermediate for corn DDGS (42.5 %), and the lowest for HP-DDGS (28.6 %), which suggests that corn DDGS and HP-DDGS are a good source of undegraded intake protein for ruminants.ConclusionsThis study provided a comparative estimate of ruminal DM and CP degradation characteristics for three DDGS co-products and SBM, which might be useful for their inclusion in the diet according to the ruminally undegraded to degraded intake protein ratio.

Variation in ruminal in situ degradation of crude protein and starch from maize grains compared to in vitro gas production kinetics and physical and chemical characteristics

ABSTRACTThe objectives of this study were (1) to evaluate in situ ruminal dry matter (DM), crude protein (CP) and starch degradation characteristics and in vitro gas production (GP) kinetics using a set of 20 different maize grain genotypes and (2) to predict the effective degradation (ED) of CP and starch from chemical and physical characteristics alone or in combination with in vitro GP measurements. Maize grains were characterised by different chemical and physical characteristics. Ruminal in situ degradation was measured in three lactating Jersey cows. Ground grains (sieve size: 2 mm) were incubated in bags for 1, 2, 4, 8, 16, 24, 48 and 72 h. Bag residues were analysed for CP and starch content. Degradation kinetics was determined and the ED of DM, CP and starch calculated using a ruminal passage rate of 5%/h and 8%/h. The GP of the grains (sieve size: 1 mm) was recorded after 2, 4, 6, 8, 12, 24, 48 and 72 h incubation in buffered rumen fluid and fitted to an exponential equation to determine GP kinetics. Correlations and stepwise multiple linear regressions were evaluated for the prediction of ED calculated for a passage rate of 5%/h (ED5) for CP (EDCP5) and starch (EDST5). The in situ parameters and ED5 varied widely between genotypes with average values (±SD) of 64% ± 4.2, 62% ± 4.1 and 65% ± 5.2 for ED5 of DM, EDCP5 and EDST5 and were on average 10 percentage points lower for a passage rate of 8%/h. Degradation rates varied between 4.8%/h and 7.4%/h, 4.1%/h and 6.5%/h and 5.3%/h and 8.9%/h for DM, CP and starch, respectively. These rates were in the same range as GP rates (6.0–8.3%/h). The EDCP5 and EDST5 were related to CP concentration and could be evaluated in detail using CP fractions and specific amino acids. In vitro GP measurements and GP rates correlated well with EDCP5 and EDST5 and predicted EDCP5 and EDST5 in combination with the chemical characteristics of the samples. Equations can be used to obtain quick and cost effective information on ruminal degradation of CP and starch from maize grains.

Determination of degradation in the rumen for dry matter, organic matter and crude protein of alfalfa (Medicago sativa L.) harvested at differentmaturity stages using the in situ nylon bag method

The aim of this study was to determine the degradation in the rumen for the dry matter (DM), organic matter (OM) and crude protein (CP) of alfalfa (Medicago sativa L.) harvested at different maturity stages by using an in situ nylon bag method. Maturity and harvesting effects were observed in ruminally degradable DM, OM and CP. High correlations between in situ degradability and maturity were determined. Alfalfa harvested in the bud period exhibited more extensive ruminal DM, OM and CP degradation than that harvested at other maturity stages. The alfalfa hay’s DM, OM and CP degradability were lowest (62.18%, 59.52% and 76.31%, respectively) in its most mature period of seed setting; its degradability decreased with maturity (17%, 14% and 13%, respectively).

Effects of silage crop and dietary crude protein levels on digestibility, ruminal fermentation, nitrogen use efficiency, and performance of finishing beef cattle

Two trials were conducted to evaluate the effects of silage crop and levels of dietary crude protein (CP) in Nellore beef cattle. The experimental diets consisted of Stylosanthes (StS) or corn silage (CS) with two levels of dietary CP, 110 and 130g CP/kg diet on a dry matter (DM) basis. The forage to concentrate ratio was 50:50 on a DM basis. In Experiment 1, the four bulls that were used had an average initial body weight (BW) of 450±37.9kg, and were surgically cannulated in the rumen and abomasum. The bulls were assigned to a 4×4 Latin square with a 2×2 factorial design of treatments, and four 16-d periods. During this experiment, we collected ruminal fluid, abomasal digesta, feces, urine, and blood. In addition, the kinetic parameters of DM, CP, and neutral detergent fiber (NDF) degradation were estimated. In Experiment 2, 40 bulls with an average initial BW of 374±16.5kg were distributed into a 2×2 factorial in a randomized design with ten replicates. The trial lasted for 99 d and was divided into a 15-d period for adaptation and an 84-d period for data collection. The intake and digestibility of nutrients as well as animal performance were evaluated in Experiment 2. The potentially degradable fractions of DM, CP, and NDF of StS were lower than CS (P<0.004). The diets containing StS showed lower ruminal digestibility of organic matter (OM) and lower total tract digestibility of OM, CP, and NDF than diets containing CS (P<0.050). The StS-based diets showed higher values for ruminal pH in comparison with CS-based diets (P=0.010). The ruminal NH3–N concentration was higher for the level of 130g CP/kg diet in comparison with the 110g CP/kg diet (P<0.001). The dietary CP level affected urea nitrogen in blood (P<0.001) and urine (P=0.017), which were higher in the diets containing StS and CS at the level of 130g CP/kg diet. The diets containing StS showed a higher intake of DM, OM, CP, NDF, and indigestible neutral detergent fiber (iNDF) than diets containing CS (P<0.008). However, the amount of digested nutrients (kg/d) was similar between treatments (P>0.050). The silage crop and dietary CP levels had no effect on productive performance (P>0.050), but the StS-based diet tended to decrease feed efficiency (P=0.085). Thus, StS, as well as the level of 110g CP/kg diet, can be used to feed finishing beef cattle.

Effects of conservation method on condensed tannin content, ruminal degradation, and in vitro intestinal digestion of purple prairie clover (Dalea purpureaVent.)

In situ and in vitro experiments were conducted to evaluate the effect of forage conservation method on the chemical composition, ruminal degradation, and intestinal digestion of purple prairie clover (PPC), which was conserved as freeze-dried forage (FD), silage (SIL), or hay (Hay). In situ dry matter (DM), neutral detergent fiber (NDF), and crude protein (CP) degradabilities were determined by incubating the forages in three rumen-cannulated heifers for 0, 1, 2, 4, 8, 24, 48, and 72 h. Intestinal DM and CP digestions were estimated by incubating 12 h ruminal in situ residues in a modified three-step in vitro procedure. Ensiling decreased (P &lt; 0.001) extractable condensed tannins (CT) but increased (P &lt; 0.001) protein- and fiber-bound CT compared with FD and Hay. The ruminal disappearance of CP at 8 and 24 h was affected by conservation method (P &lt; 0.001), ranked as SIL &gt; FD &gt; Hay. The effective degradability of DM was lower (P &lt; 0.001) for Hay than for FD and SIL. Ensiling lowered (P &lt; 0.001) whereas haymaking increased (P &lt; 0.001) intestinal digestion of CP compared with the fresh PPC. There were no differences in intestinal DM digestion among the three conserved forages. The results suggest that PPC conserved as Hay may conserve the biological activity of CT via preserving extractable CT more than as SIL, thus having the potential to improve protein utilization in ruminants.

SARI inhibits angiogenesis and tumour growth of human colon cancer through directly targeting ceruloplasmin.

SARI, also called as BATF2, belongs to the BATF family and has been implicated in cancer cell growth inhibition. However, the role and mechanism of SARI in tumour angiogenesis are elusive. Here we demonstrate that SARI deficiency facilitates AOM/DSS-induced colonic tumorigenesis in mice. We show that SARI is a novel inhibitor of colon tumour growth and angiogenesis in mice. Antibody array and HUVEC-related assays indicate that VEGF has an essential role in SARI-controlled inhibition of angiogenesis. Furthermore, Co-IP/PAGE/mass spectrometry indicates that SARI directly targets ceruloplasmin (Cp), and induces protease degradation of Cp, thereby inhibiting the activity of the HIF-1α/VEGF axis. Tissue microarray results indicate that SARI expression inversely correlates with poor clinical outcomes in colon cancer patients. Collectively, our results indicate that SARI is a potential target for therapy by inhibiting angiogenesis through the reduction of VEGF expression and is a prognostic indicator for patients with colon cancer.

Variation between individual cows in in situ rumen degradation characteristics of maize and grass silages

Different numbers of animals have been used in different studies to cover the variation between individual animals in in situ rumen degradation characteristics of maize and grass silages. The objective of this study was to determine whether three cows are sufficient or not to cover the variation between individual cows in in situ rumen degradation characteristics of dry matter (DM), organic matter (OM), crude protein (CP), starch and neutral detergent fibre (NDF) for maize and grass silages. Fifteen maize and 15 grass silage samples, with a broad range in chemical composition, were selected. The maize and grass silage samples were incubated in the rumen for 2, 4, 8, 16, 32, 72 and 336h, using the nylon bag technique. Three cows were used for nylon bag incubation of maize silages and three other cows for grass silages. The variation between individual cows was found significant (P<0.05) for degradation rate (kd) of DM, OM and CP, and the effective rumen degradation (ED) of DM and CP of maize silages whereas non-significant (P>0.05) differences were found for all other parameters of DM, OM, CP, starch and NDF. The variation between individual cows was found non-significant (P>0.05) for rumen undegradable fraction (U), potentially rumen degradable fraction (D), kd and ED of DM, OM, CP and NDF of grass silages. The results of this study indicate that the use of three cows for nylon bag incubations of grass silages is sufficient whereas the use of three cows for nylon bag incubations of maize silages is not sufficient to cover variation between the individual cows.