Digestibility Of Undegraded Protein Research Articles

Performances and nutritional values of a new hooded barley (cv. Mochona) and a high yield triticale (cv. Titania) as hay or silage for sheep under Mediterranean conditions

The hooded barley phenotype produces an extra sterile flower in spikelets instead of awns. Hence, it might improve the nutritive value of the whole plant. The aim of this work was to evaluate a new variety of hooded barley (cv. Mochona) and a high yield triticale (cv. Titania) harvested and processed as hay and silage during 2 consecutive years for sheep. Digestibility was determined using 32 ewes which were distributed in 2 balanced groups by treatment, and fed with hay and silage sequentially. Results showed differences in the chemical composition of hay and silage according to harvesting year, but no differences were found on voluntary intake by year, species, or their interaction. Both forages showed high sheep fill values (sFV) either as hay or as silage (2.65 ± 0.030 and 3.09 ± 0.042 sFV/kg DM, on average, respectively). Impact on apparent nutrient digestibility coefficients varied according to preservation method, the digestibility of hays being mainly affected by the harvesting year, and that of silages by species. Digestible undegradable protein values were greater in hooded barley than in triticale for silages. In conclusion, marked compositional differences between years, but slight differences between species, were observed. Consequently, intake was similar, although triticale revealed slightly greater nutritive values than hooded barley. The obtained values for hooded barley as forage were greater than those reported in the literature for common fodder barley.

Effect of processing with ozone on in vitro and in situ ruminal degradability and intestinal digestibility of feather meal protein

This study aimed to investigate the effect of processing feather meal (FM) with ozone (O3) gas on nutrient content, ruminal degradability, and intestinal digestion of crude protein (CP) using in vitro and in situ techniques. Experimental treatments were designed as control (not-processed), O3-processed FM for 12 h (h; treat 1), O3-processed FM for 24 h (treat 2), and O3-processed FM for 48 h (treat 3). Five Ghezel sheep equipped with ruminal cannulas were used to measure the nutrient degradability and to obtain ruminal fluid for in vitro gas production. Processing with O3 gas significantly decreased dry matter (DM), ether extract (EE), and Ash content of the FM compared to the control (P < 0.05). Processing FM by O3 increased the volume of in vitro gas production (P < 0.05). The soluble and potentially degradable fractions of the DM and CP showed a significant increase with increasing processing time (P < 0.05). Processing with O3 gas increased quickly degradable protein (QDP), rumen degradable protein (RDP), effective rumen degradable protein (ERDP), and digestible undegradable protein (DUP) content as a proportion of feather meal CP. Still, undegradable dietary protein (UDP) decreased significantly. Intestinal digestibility of rumen undegradable protein (RUP) and Metabolize Protein (MP) content of the FM was also significantly increased with increased processing time and the highest values were achieved after 48 h of processing (P˂0.05). According to the results of this experiment, it can be concluded that processing FM using O3 for 48 h increases its nutritional value in ruminant nutrition.

Effect of dietary digestible undegradable protein and amino acid concentration on the growth and development of post-pubertal dairy heifers

Effect of dietary digestible undegradable protein and amino acid concentration on the growth and development of post-pubertal dairy heifers

Comparing the yield and nutritional value of ensiled amaranth (Amaranthus hypochondriacus) cultivars with corn silage (Zea mays) in doublecropping condition.

Yield, chemical composition, and fermentation variables were compared for amaranth silages (AMS) from five cultivars (A5, A12, A14, A28, and Maria) and corn (Zea mays; CS). In vitro methane production, organic matter disappearance, microbial protein, ammonia-N concentration, volatile fatty acid levels, cellulolytic bacteria and protozoa populations, and in situ dry matter (DM) and crude protein (CP) degradability were evaluated. All crops were harvested when the plant was at the mid-milk line stage, then chopped, placed in sealed 5 L plastic bags and stored for 60 days. Data analysis was carried out using the PROC MIXED method of SAS with a randomized complete block design. The mean DM forage yield of CS was higher than the average DM yield of the amaranth cultivars (P < 0.001). In comparison with CS, the AMS had higher CP, lignin, ether extract, ash, calcium, phosphorus, magnesium, total phenolics and metabolizable protein (P < 0.001), but had lower DM, neutral detergent fiber, non-fiber carbohydrates, organic matter disappearance, lactic acid (P < 0.01) and in vitro methane production (P = 0.001). The AMS had higher (P < 0.01) pH, ammonia-N concentration, in vitro microbial protein, in situ digestible undegradable protein, and metabolizable protein compared to CS. Overall, in comparison to CS, the amaranths produced a silage of medium-quality.

Canola as a potential forage.

The nutritive quality of four cultivars of canola forage (Brassica napus L.), Orient, Midas, Global, and Hybrid (Cobra × Regent), which were harvested in the early-spring period, were compared with green-winter barley (GWB) in terms of their yields, chemical composition, in vitro gas production variables, in situ crude protein (CP) degradation, and predicted dry matter intake (PDMI). Data were statistically analyzed using a completely randomized design with four replications and three samples per replication. The study was based on a randomized complete block design, and data were analyzed using SAS, general linear model procedure for normal distribution. The canola dry matter (DM) yield was highest in Orient cultivar and lowest in Midas (P < 0.05). Organic matter (OM), CP, neutral detergent fiber (NDF), and lignin(sa) concentration of the four cultivars ranged from 862 to 865, 218 to 247, 295 to 340, and 35 to 53 g/kg DM, respectively. The estimated OM disappearance (OMD), effective degradability of CP, effective rumen degradable protein (ERDP), digestible undegradable protein, and metabolizable protein (MP) of the forages were from 636 to 671 g/kg, 878 to 910, 172 to 193, 1.9 to 3.4, and 112 to 126 g/kg DM, respectively. Compared to Global and Hybrid cultivars, Orient and Midas contained higher CP, OMD, ERDP, MP concentration, and PDMI, but lower NDF, acid detergent fiber (ADF), and lignin(sa) concentrations (P < 0.05). The level of glucosinolates in the forages ranged from 0.38 to 1.51 µmol/g DM, which is below the detrimental level for ruminants. Compared to winter canola cultivars, GWB had higher DM yield (P < 0.003), NDF, lignin(sa), PDMI (P < 0.01), and digestible undegradable protein (P < 0.04), but had lower OMD (P < 0.03), ERDP (P = 0.01), and MP (P < 0.009). Based on the obtained results, the variation in the nutritive quality among the canola cultivars is relatively small, and the Orient cultivar, which is most comparable to GWB, was judged to be nutritionally the best among the cultivars.

The nutritional value and yields of amaranth (Amaranthus hypochondriacus) cultivar silages compared to silage from corn (Zea mays) harvested at the milk stage grown in a hot-humid climate

Amaranth forage requires less water than corn forage. Moreover, the yield and nutritional value of plants grown in different geographical areas may vary. Therefore, the aim of this study was to compare silages from amaranth cultivars (Maria, A28, A14, A12, and A5), grown in hot-humid conditions, with corn forage (Zea mays) (CS) in terms of yield, chemistry, silage characteristics, in vitro fermentation, and in situ degradability. The crops were harvested at the mid-milk stage, chopped, and ensiled in five-liter containers for a 45-days period. The yield, chemical composition, and silage characteristics of the plants were determined. In vitro gas production, organic matter disappearance (OMD), methane production, microbial crude protein (MCP), ammonia-N, volatile fatty acids (VFA), cellulolytic bacteria and protozoa populations, and in situ dry matter (DM) and crude protein (CP) degradability were measured using fistulated sheep. Data were analyzed using PROC MIXED of SAS in a randomized complete block design. Average DM yield of amaranth forages from different varieties was lower (P < 0.01) than corn forage. Among amaranth forages, the highest (P < 0.01) DM yield was observed for A12. Compared to CS, amaranth silages (AMS) had lower (P < 0.01) mean values of DM, OM, and metabolisable protein (MP) yields. The AMS contained higher (P < 0.01) concentrations of CP, ash, calcium, phosphorus, nitrate, and total phenolics, but lower (P < 0.01) neutral detergent fiber, lignin, non-fiber carbohydrates, and lactic acid. Compared to CS, the in vitro incubation of AMS resulted in lower (P < 0.01) OMD, methane production, total VFA, cellulolytic bacteria, and protozoa population, but higher (P < 0.01) MCP. The in situ protein effective degradability, digestible undegradable protein, and MP of AMS were higher (P < 0.01) than CS. Overall, amaranth cultivars made a medium-quality silage when grown in hot-humid conditions, though, silage of A12 cultivar could be used instead of CS.

Evaluation of rumen protected rapeseed expeller (NovaPro) as an alternative to soya bean meal in dairy cow diets

There are environmental, social and economic pressures to reduce the use of soya bean meal in ruminant diets by using alternative protein sources, such as those derived from rapeseed. A new protected form of rapeseed (NovaPro) has been developed to provide similar quantities of digestible undegradable protein (DUP) compared to soya bean meal. NovaPro is hot pressed expelled rapeseed (no hexane solvent used), treated with a specific wood derived xylose-rich lignosulphonate in the presence of elevated moisture and heat to increase DUP. The objective of this study was to evaluate NovaPro as a protein supplement for high yielding dairy cows.Four diets were formulated to supply similar quantities of metabolisable energy and protein but containing different dominant protein sources. The main protein sources were: Control – soya bean and rapeseed meals; NP1 – NovaPro and wheat dried distillers grains with solubles (DDGS); PR – protected solvent-extracted rapeseed meal and wheat-DDGS; NP2 - NovaPro and SoyPass. Diets were fed to 44 cows using a Latin square design with four feeding periods of 28 days each.Milk yield was significantly higher when cows were fed on rapeseed treatment diets (mean 42.7 kg/d) than when fed on the control diet (mean 41.1 kg/d), as was energy-corrected milk (ECM) yield (mean 43.2 versus 41.7 kg/d). Dry matter intake was higher when cows were fed on NP1 and NP2 (mean 25.0 kg/d) than when they were fed on the control diet (mean 23.9 kg/d); dry matter intake for PR was intermediate (mean 24.4 kg/d). Concentrations of milk fat and protein reflected differences in milk yield, and there was no difference between treatments in fat or protein yield, although fat plus protein yield was higher when cows were fed on rapeseed treatment diets (mean 2.84 kg/d) than when fed on the control diet (mean 2.72 kg/d).Differences in rumen fluid and blood composition were commensurate with differences in diet composition, nutrient intake and milk yield. Retrospective calculation of metabolisable energy and protein supplies showed that these were within 3% of requirements for observed responses. Calculation of amino acid profiles suggested that profiles, particularly methionine, were better for the rapeseed treatment diets.Results of this study support the hypothesis that cows fed on NovaPro and other rumen protected rapeseed proteins will have similar or improved milk production compared to a control (soya-based) diet. Improved milk yield was accompanied by increased dry matter intake, but it is likely that intake was driven by milk yield rather than vice versa. The most likely explanation for improved milk yield when cows were fed on the rapeseed treatment diets is that amino acid balance was improved compared to control.

Yield, chemical composition, fermentation characteristics, in vitro ruminal variables, and degradability of ensiled amaranth (Amaranthus hypochondriacus) cultivars compared with corn (Zea mays) silage.

Silages from four amaranth varieties (A5, A12, A14, and A28) were compared with corn silage (CS) in terms of their yield, chemical composition, phenolic compounds, oxalic acid and nitrate levels, silage fermentation characteristics, in vitro methane production, organic matter disappearance (OMD), microbial crude protein (MCP), ruminal ammonia (NH3-N), pH, volatile fatty acids, cellulolytic bacteria numbers, protozoa counts, and in situ dry matter (DM) and crude protein (CP) degradability were determined. Forages were harvested 93 d after planting, chopped, and ensiled in plastic buckets for 60 d. The study was based on a randomized complete block design, and data were analyzed using SAS, general linear model (GLM) procedure for normal distribution. Compared with CS, amaranth silages (AMS) had lower ash-free neutral detergent fiber nitrate, OMD (P < 0.001), phosphorus (P = 0.003), and metabolizable energy (ME) (P = 0.043) but higher (P < 0.001) CP, calcium, non-fiber carbohydrates (NFC), acid detergent lignin, ether extract, ash, total phenolics, pH, NH3-N concentration, MCP, digestible undegradable protein (DUP), and metabolizable protein (MP). Fresh, OM, OMD, ME (P < 0.001), and DM (P = 0.032) yields of AMS from different varieties were higher than CS, with the exception of A5. Overall, amaranth made good quality silage, with some variation, and A28 had the highest yield and nutritional value (CP, NFC, MCP, DUP, and MP). The yield, CP concentration, and nutritional value of A28 silage were higher than CS. Although these in vitro results are promising, they also need to be validated with future in vivo research.

Can the amount of digestible undegraded protein offered to ewes during late pregnancy affect the performance and immune response of their offspring to gastrointestinal nematodes?

Maternal nutrition during pregnancy is a major environmental influence on foetal development with consequent effects on postnatal performance. We hypothesised that the level of intake of digestible undegraded protein (DUP) by the dam in late pregnancy would impact on the effectiveness of the immune response by offspring to gastrointestinal nematode infection. Eighty-five twin/triplet-bearing ewes, which were indoors from mid-pregnancy, were randomly assigned to 4 treatment groups for the final 6 weeks of pregnancy. Treatments were silage plus one of two iso-energetic and iso-nitrogenous concentrates (differing in DUP concentration; 29 and 94g/kg DM) offered at one of two feed levels (18/30 and 24/35kg in total for twin/triplet-bearing ewes, respectively). Ewes with triplets had one lamb removed at birth so that all ewes nursed 2 lambs when put to pasture as one flock in a 5-paddock rotational grazing system; all lambs were slaughtered after 29 weeks. Faecal egg count (FEC) and levels of serum IgA and IgE specific for Teladorsagia circumcincta were assessed for all lambs at various time points between 10 weeks of age and slaughter. Animal performance (live weight, live-weight gain, carcass weight) was recorded for all lambs. Worm burden at slaughter was determined for a sample of 12 lambs from each treatment. Nematodirus spp. FEC, ‘other strongyles’ FEC, and serum IgA and IgE specific for T. circumcincta were unaffected either by the concentration of DUP in the concentrate or by the level of concentrate offered to ewes in late pregnancy (P>0.1). Likewise, the dietary regime of the dams had no effect on lamb performance (P>0.1). It is concluded that increasing the DUP intake of ewes in late pregnancy had no effect on the immune response of their offspring to gastrointestinal nematode infection acquired through grazing naturally infected pasture.

Can the amount of digestible undegraded protein offered to ewes in late pregnancy affect the periparturient change in resistance to gastrointestinal nematodes?

Ewes experience a temporary decline in resistance to gastrointestinal nematodes (GIN) during the periparturient period, characterised by a rise in faecal egg count (FEC) that represents a major source of pasture contamination for naïve progeny. The aim of this study was to assess the effect of level of supplementation with digestible undegraded protein (DUP) during the last 6 weeks of pregnancy on periparturient FEC and the performance of ewes with a naturally acquired parasite infection. Eighty-five Belclare and Belclare x Scottish Blackface twin/triplet-bearing ewes were allocated to 1 of 4 dietary groups representing the combination of 2 concentrates (DUP concentration 29 and 94g/kg dry matter) with 2 levels of concentrate during the final 6 weeks of gestation (18 and 30kg in total for ewes with twins; 24 and 35kg for ewes with triplets). All ewes were housed during the pre-partum feeding period and offered grass silage ad libitum; food intake was recorded daily. The intake of DUP varied from 26 to 72g/d among treatments and was reflected in variation of 0.76 to 1.20 in metabolizable protein supply as a proportion of requirements. After lambing, ewes and lambs grazed on permanent sheep pasture, without concentrate supplementation, until weaning (14 weeks post lambing). The variables studied, from week 6 pre-lambing up to week 10 post-lambing, included: FEC, serum pepsinogen concentration, body weight (BW) and body condition score (BCS). The effect of week (relative to lambing date) on FEC was highly significant (P<0.001). However, diet did not influence FEC (P>0.05) at any stage either pre- or post-partum. Pepsinogen concentration also varied with time but was not influenced by dietary treatment (P>0.05). The changes in BW and BCS from 6 weeks before lambing to weaning were not affected by the concentration of DUP in the supplement but ewes on treatments involving the higher level of supplementation lost less BW and BCS (P<0.001). The results of this study indicate that the level of DUP supplementation during the last 6 weeks of pregnancy does not affect FEC, BW or BCS of housed ewes with a naturally acquired GIN infection.

Effect of Harvesting Gliricidia Sepium at Different Cutting Frequencies on Quantity and Quality of Herbage Biomass for Dairy Cattle Nutrition.

Herbage quantity and quality response of Gliricidia sepium to pruning intervals (1.0 to 6.0 months) was evaluated. Chemical composition of coppice re-growth was estimated and herbage was incubated in three rumen fistulated Friesian steers for 3, 6, 12, 24, 48, 72, 96 and 120 h. Herbage dry matter yield tended to follow linear response (P= 0.0689) with increasing coppice re-growth maturity and ranged between 36.2 tones/ha/year to 49.1 tones/ha/year. Protein content (291 g/ kg DM to 220 g/kg DM) decreased following a quadratic trend. However, fibre content increased following a curvilinear trend as herbage matured but levels of lignification increased linearly with delayed harvesting. Additionally, fraction ‘b’ of dry matter degradability (548 to 716 g/kg DM) decreased linearly with herbage maturity. Herbage potential degradability (a+b) (926 to 785 g/kg CP) was indicative of high protein solubility and rumen degradable protein (RDP) decreased with increasing maturity. Consequently, microbial protein synthesis and net energy of lactation (NEL) decreased linearly while rumen undegradable protein (RUP) and digestible undegradable protein (DUP) increased linearly with increasing herbage maturity. These results are interpreted to mean that G. sepium herbage quantity and quality is influenced by pruning management.

Effects of supplementation with digestible undegradable protein in late pregnancy on ewe colostrums production and lamb output to weaning

The aim of this study was to investigate the effects of supplementation with digestible undegradable protein (DUP) in diet during late pregnancy on colostrum production, lamb survival and growth. For 3 weeks prior to lambing, 41 Afshari ewes were assigned at random to three dietary treatments, namely a control (CDUP), moderate (MDUP) and high (HDUP) DUP group. The ewes (n = 14) in CDUP group were fed a protein maintenance level for pregnant ewes [83 g metabolizable protein (MP)/kg dry matter (DM)], while ewes in the MDUP (n = 13) and HDUP (n = 14) groups were fed diets provided 14% (94.7 g MP/kg DM) and 24% (104.3 g MP/kg DM) MP in excess of these requirements respectively, which this increment was coming from DUP (DUP/MP ratio 43.8; 51.0% and 57.6% respectively). All diets were isoenergetic (12 MJ ME/kg DM). All ewes received the same lactation diet after lambing. Ewes in HDUP tend to produce more colostrums (p < 0.1) and had higher protein, fat, and solids non-fat content (p < 0.05) in colostrums during the first 24 h after lambing. MDUP group had higher colostrum yield compared to CDUP (p < 0.1). The changes in body weight and body condition score of ewes were similar for all diets but placenta weight was higher in MDUP group (p < 0.05) than for HDUP and CDUP ewes. Lamb body weight at weaning was higher for males compared to females (p < 0.05), but was not different between treatments. HDUP ewes had higher blood glucose concentration in the pre-lambing period than other treatments (p < 0.05). In this period, increasing the level of DUP in diet increased the content of blood urea nitrogen (p < 0.05). It was concluded that increasing the DUP content of diet for 3 weeks prior to lambing above the standard requirements resulted in an increase in colostrums production but had no effect on lamb outcome to weaning.

Effect of extrusion on in situ ruminal protein degradability and in vitro digestibility of undegraded protein from different feedstuffs

AbstractBACKGROUND: The effect of extruding maize, barley, whole soybean (WSB), peas, lupins and soybean meal (SBM) on their in situ ruminal protein degradability and in vitro digestibility of the rumen undegraded protein (RUP) was studied. Two mixtures containing 0.75 WSB or lupins and 0.25 maize were also formulated.RESULTS: Extrusion of maize resulted in an increase of its effective protein degradability from 0.538 to 0.734 (P &lt; 0.001), whereas the opposite occurred with barley (from 0.854 to 0.797; P &lt; 0.001). Extrusion increased the in vitro digestibility of the RUP of both cereals, increasing therefore the amount of barley crude protein (CP) digested in the intestines (PDI) from 62 to 176 g kg−1 CP (P &lt; 0.01), whereas maize resulted in lower (332 versus 229 g kg−1 CP; P &lt; 0.01). Extrusion decreased (P &lt; 0.001) the protein degradability of the three legume seeds and increased (P &lt; 0.001) the in vitro digestibility of the RUP, resulting in a PDI increase (P &lt; 0.001), from 60 to 367 g kg−1 CP for peas, from 69 to 265 g kg−1 CP for WSB and from 107 to 205 g kg−1 CP for lupins. This effect was enhanced when WSB was extruded jointly with maize. The extrusion of SBM also resulted in an increase in the PDI from 296 to 384 g kg−1 CP (P &lt; 0.001).CONCLUSION: Extrusion decreases the rumen protein degradability of legume seeds, soybean meal and barley, and increases the digestibility of the RUP, resulting in an increase in the feed protein digested in intestine. The extrusion of soybean seeds together with maize enhances these effects. Copyright © 2008 Society of Chemical Industry

Effects of digestible undegradable protein (DUP) supply and fish oil supplementation of ewes during late pregnancy on colostrum production and lamb output

Studies in pregnant ewes have shown that fish oil supplementation during late pregnancy can increase lamb vigour at birth and may provide a means of reducing neonatal mortality in the sheep flock. However, fish oil also reduces colostrum production by the ewe which could offset the developmental benefits for lamb survival. To counteract the detrimental effects on colostrum, an experiment was carried out to investigate the effects of supplementing late gestation ewes with fish oil and digestible undegradable protein (DUP) on colostrum output and lamb performance. For 6 weeks prior to lambing, 32 twin-bearing ewes were offered grass silage ad libitum plus 550 g/d of one of four concentrates. The concentrates were iso-nitrogenous (195 g crude protein/kg dry-matter) and were formulated to supply 0 or 40 g/ewe/d fish oil and 55 g DUP/kg dry-matter (High, H) or 25 g DUP/kg dry-matter (Low, L) giving a total of four treatments: H0, H40, L0 and L40. Ewes offered fish oil had depressed intakes of silage dry-matter (DM), metabolisable energy (ME) and crude protein (CP) ( P<0.001) and lost on average 3.8 kg more live weight ( P<0.001) between 6 weeks pre-lambing and 24 h post-lambing. Mean plasma concentrations of globulin ( P<0.05) and urea ( P<0.001) during late pregnancy were elevated by fish oil. L40 ewes produced 681 g less colostrum ( P<0.01) and had lower energy ( P<0.001), total solids ( P<0.01), crude protein ( P<0.05) and ash ( P<0.05) outputs in colostrum during the first 18 h after lambing than all other treatments. Total lamb birth weights of ewes were similar for all diets but lamb output at weaning was 16.5 kg lower ( P<0.05) for L40 ewes, due to a reduction in litter size at weaning of 0.51 lambs/ewe ( P<0.05). Despite depressed forage intakes, the results of this study indicate that late gestation ewes can be supplemented with 40 g/d fish oil without detrimental effects on colostrum production or lamb output, providing the intake of metabolisable protein is maintained by increasing the level of DUP in the concentrate portion of the diet.

Avaliação da digestibilidade de nutrientes, em bovinos, de alguns alimentos concentrados pela técnica de três estádios

Este trabalho foi realizado com o objetivo de determinar a digestibilidade de componentes nutricionais não-degradados no rúmen por meio da técnica de três estádios. Foram avaliados oito alimentos concentrados: grão de girassol integral (GI), torta de girassol com uma (TG1x) e com duas passagens pela prensa (TG2x), grão de soja integral (SI) e parcialmente desengordurado (SD), farelo de soja (FS), farelo de gérmen de milho desengordurado (GM) e concentrado comercial (CC) com 36% de PB. Os alimentos foram incubados no rúmen de bovinos por 33, 20 e 12 horas, correspondendo a taxas de passagens de 3, 5 e 8%/h, respectivamente. Os resíduos não-degradados no rúmen foram submetidos à digestão com solução de pepsina com pH 1,9 durante 1 hora e, posteriormente, em solução de pancreatina com pH 7,8 durante 24 horas, ambas a 38ºC. Nos resíduos desta incubação, foram determinados a MS, MO e os teores de nitrogênio total. A digestibilidade intestinal in vitro da MS não degradada no rúmen, considerando taxa de passagem de 5%/h, variou de 7,88 a 37,72%, sendo que o CC e a SI apresentaram as maiores digestibilidades. A digestibilidade da PB não-degradada no rúmen variou de 13,67 a 81,76% para mesma taxa de passagem. O GI apresentou a menor e o CC e o FS as maiores digestibilidades da PB. A digestibilidade da MO variou de 7,93 a 37,14% para a mesma taxa de passagem, sendo que o GI foi o menos digestível e o CC e a SI, os mais digestíveis. Os menores valores para a proteína digestível não degradável no rúmen (PNDR D), em g/kgMS, foram obtidos nas tortas de girassol com uma ou duas passagens, sugerindo que estes alimentos não devem ser empregados quando se deseja maiores teores de PNDR D.

Effects of microwave irradiation on ruminal protein degradation and intestinal digestibility of cottonseed meal

The objectives of this study were to determine the effects of microwave irradiation on ruminal degradability and intestinal digestibility of crude protein (CP) and to monitor the fate of true proteins of cottonseed meal (CSM) in the rumen. Duplicate nylon bags of untreated or irradiated CSM (microwave power of 800 W for 2, 4 and 6 min) were suspended in the rumen of four non-lactating Holstein cows for up to 48 h, and resulting data were fitted to non-linear degradation model to calculate degradation parameters of CP. Proteins of untreated and treated CSM bag residues were fractionated by gel electrophoresis. Intestinal digestibility of CP was measured using the mobile nylon bag technique. From in situ results, microwave irradiation decreased ( P < 0.05) the water soluble fraction and degradation rate, but increased the potentially degradable fraction of CP. The effective degradability of CP decreased ( P < 0.05) as processing period increased. Irradiation for 2 and 4 min increased ( P < 0.05) intestinal digestibility of ruminally undegraded CP, but extending to 6 min lowered ( P < 0.05) the beneficial effect that 4 min had on intestinal CP digestibility. Electrophoretic results indicated that globulin 9S in untreated CSM (whereas globulin 9S, globulin 5S and albumin 2S in microwave irradiated CSM) make the bulk of escaped protein. Based upon these results, microwave irradiation at a power of 800 W for 4 min had the greatest potential to increase digestible undegraded protein.

The effect of digestible undergradable protein (DUP) content of concentrates on colostrum production and lamb performance of triplet-bearing ewes on grass-based diets during late pregnancy

AbstractAn experiment was carried out to investigate the effects of increasing the digestible undegradable protein (DUP) concentration of concentrates on colostrum production and lamb output from prolific ewe breed types. Sixty triplet-bearing ewes with a mean condition score of 3.75 were allocated to one of five treatments (no. =; 12) for the final 6 weeks of pregnancy. Four of the treatments were offered a restricted grass diet (0.6 kg dry matter (DM) per day) plus one of four isoenergetic and isonitrogenous concentrates (0.56 kg DM per day) that were formulated to provide 25 (P25); 40 (P40); 75 (P75) and 95 (P95) g DUP/kg DM. Control ewes were offered a grass-only diet with the aim of achieving an equivalent total DM intake (1.16 kg DM per day). Concentrate composition had no effect on total diet DM, crude protein or metabolizable energy intakes, but the intake of DUP increased with increasing concentrate DUP level (P&lt; 0.001). Supplementing grass with concentrates led to significant reductions in plasma β-hydroxybutyrate (P&lt; 0.05) and non-esterified fatty acids(P&lt; 0.001) concentrations. Plasma urea concentration tended to be negatively and linearly related to the concentrate DUP level (P&lt; 0.1). Colostrum production and composition were not affected by concentrate type, except for the concentration of gross energy which was highest for P40 ewes. Concentrate feeding led to significant (P&lt; 0.05) increases in colostrum yield 18 h post lambing and colostral outputs of ash, crude protein, total solids and gross energy but resulted in a lower (P&lt; 0.05) colostral immunoglobulin G concentration. Lamb birth weight and total litter weight were not affected by late pregnancy feeding regime. However lamb survival to weaning was reduced significantly (P&lt; 0.05) for P25 and control ewes, resulting in lower levels of lamb output at weaning. The results from this study indicate that offering rumen undegradable rather than rumen degradable protein has no effect on colostrum production and lamb performance when ewes are offered high quality grass-based diets in late pregnancy.

Effect of digestible undegradable protein (DUP) concentration of concentrates offered to ewes on grass-based diets in late pregnancy on colostrum production and lamb performance

Nutrition of ewes during late pregnancy is a key factor influencing lamb survival and subsequent lamb growth and performance. Results from on-farm trials indicate that the superior lamb output from highly prolific compared with moderately prolific ewe breed types is less in grass-based compared with indoor lambing systems (Carson and Dawson, 2002). This is as a result of higher mortality rates of triplet lambs in outdoor systems with lower levels of intervention. Feeding and management strategies to maximise lamb viability for multiple births are required for grass-based lambing systems. Protein nutrition is likely to be a key factor, particularly considering that energy intakes in late pregnancy in triplet-bearing ewes are unlikely to meet requirements (Robinson, 1983). At sub-optimal energy intakes the supply of rumen undegraded protein is a major determinant of colostrum production and lamb birth weight. The objectives of this experiment were to investigate the effect of supplementing grass-based diets with concentrates with a range of digestible undegradable protein concentrations on colostrum production and lamb output.

Effect of type of supplement offered out of parlour on grazing behaviour and performance by lactating dairy cows grazing continuously stocked grass swards

AbstractTwo 4-week experiments were conducted to examine the effect of type of supplement, offered through automatic feeders at pasture, on supplement intake and grazing behaviour by multiparous spring-calving Holstein-Friesian cows grazing continuously stocked grass pastures. Four supplement formulations were used: a dairy concentrate containing 180 g crude protein per kg fresh weight (treatment DC), a high digestible undegraded protein supplement (treatment HP), a high starch, low protein supplement (treatment HS) and a high fibre supplement (treatment HF). In experiment 1, groups of eight cows were provided with access to one of diets DC, HP or HS, with a maximum of 4 kg being available during each of two periods, between 16:00 and 03:30 h and between 03:30 and 14:30 h. During experiment 2, groups of eight cows were provided access to diet DC, HP, HS or HF, up to a maximum of 8 kg between 16:00 and 14:30 h the following day. Detailed measurements of grazing, ruminating and supplement eating behaviour were made using jaw movement recorders and the transponder-controlled out-of-parlour feeder software. Treatment had no effect on intake rate per min or daily intake of supplement in either experiment, but did affect the temporal pattern of concentrate meals. Treatment did not affect grazing bite mass, bite rate or intake rate in either experiment. During experiment 1, compared with treatment DC, treatment HS reduced total eating time, total grazing jaw movements and daily herbage intake and increased ruminative mastications per bolus and ruminative mastications per kg grass OM intake. In experiment 2, compared with treatment DC, only treatment HS reduced total eating time, total grazing jaw movements and daily herbage intake. Treatments HS and HF both increased ruminative mastications per bolus. The results indicate that when supplements are available at pasture there is a conflict between the time required to consume supplements and herbage and that supplement type can affect both the temporal pattern of supplement intake and subsequent grazing activity.

Increasing the digestible undegraded protein intake of lactating dairy cows by feeding fishmeal or a rumen protected vegetable protein blend

An experiment was conducted to investigate the effect on milk yield and composition of increasing the digestible undegraded protein (DUP) supply to dairy cows in early-lactation either by inclusion of fishmeal (FM) or a blend of rumen protected vegetable protein in the diet. The vegetable protein blend was formulated to supply a balance of amino acids similar to that of FM. Thirty-two Holstein–Friesian dairy cows in early-lactation were assigned to one of the four dietary groups of eight cows. Cows were offered a basal diet consisting of grass silage, maize silage and brewers grains, together with a fixed daily allowance of 1 kg molassed sugar beet nuts and 7.5 kg per day concentrates. Each group was fed a different experimental concentrate: concentrate C was a cereal based control containing rapeseed meal and soyabean meal; FM contained 30 g kg −1 FM; VP-L and VP-H contained 60 and 120 g kg −1 rumen protected protein blend respectively. FM had no effect upon milk yield, but milk protein output was 60 g per day higher ( P<0.01) compared with control (C) cows. Concentrate VP-L did not increase milk yield, but milk protein output increased by 110 g per day ( P<0.01). Concentrate VP-H increased milk production by 2.0 kg per day ( P<0.05) and milk protein output by 110 g per day ( P<0.01). Retrospective calculations of protein and amino acid supplies to the intestinal absorptive site suggested that rumen degradable protein was slightly limiting with all diets and that leucine supply may have been limiting for diets C and FM. The vegetable protein blend replaced FM in diets for the dairy cows without any adverse effects on milk protein output.