Total Tract Dry Matter Research Articles

In situ, in vitro and in vivo nutritive value assessment of Barberry leaf as a roughage for goat feeding

This study was carried out to evaluate nutritive value of Berberis vulgaris leaf (BVL) by in situ and in vitro experiments and to investigate the effects of replacing alfalfa hay with BVL on performance, milk composition, blood metabolites and antioxidant capacity of lactating crossbred goats. Rumen dry matter (DM) degradability of BVL was assessed using two fistulated mature goats and incubation of BVL samples at specified times in the rumen. Modified 3-step procedure (TSP) was performed for determination of post-rumen DM digestibility. For the in vivo experiment (during six weeks), 21 lactating crossbred goats (55±15 DIM and 26±2.8kg BW) were randomly allocated to one of three dietary treatments of BVL at levels of 0, 17 and 34% of DM. The results of in situ and in vitro experiments indicated that rumen DM degradability, post-rumen digestibility of DM undigested in the rumen and total tract DM digestibility of BVL were 65.46%, 12.84% and 69.90%, respectively. In vivo results revealed that DMI increased (P<0.05) as BVL level in the diet raised. Also, milk fat increased (P<0.05) with increasing BVL level in the diets, but milk protein, SNF and lactose content were not affected by the diets (P>0.05). Goats fed BVL showed greater antioxidant capacity than goats fed control diet (P<0.05) and no significant difference was found in plasma malondialdehyde (MDA) content (P>0.05). Results of this study revealed that BVL has high nutritional value and might be utilised in diet of lactating goats as an inexpensive alternative roughage.

Effects of partial replacement of corn and alfalfa silage with tall fescue hay on total-tract digestibility and lactation performance in dairy cows

Our objective was to evaluate the effects of replacing either corn or alfalfa silage with tall fescue hay on total-tract neutral detergent fiber (NDF) digestibility and lactation performance in dairy cows. Twenty-four primiparous (75±35 d in milk) and 40 multiparous (68±19 d in milk) Holstein cows were blocked by parity and randomly assigned to 1 of 4 treatment groups in a pen equipped with 32 feeding gates to record intake by cow. Each gate was randomly assigned to 1 treatment group; thus, each cow had access to all 8 gates within the respective treatment and cow was the experimental unit. Treatments were formulated to replace either corn silage (CS) or alfalfa silage (AS) with tall fescue hay (TF) as follows (DM basis): 33% AS and 67% CS (control; 33AS67CS), 60% TF and 40% AS (60TF40AS), 60% TF and 40% CS (60TF40CS), and 33% TF and 67% CS (33TF67CS). The experiment was a 7-wk continuous lactation trial with a 2-wk covariate period. Milk production did not differ among treatments and averaged 40.4 kg/d. Fat yield and concentration and protein yield and concentration did not differ among treatments and averaged 1.58 kg/d, 3.94%, 1.28 kg/d, and 3.15%, respectively. Dry matter intake was greater for 33AS67CS (24.5 kg/d) compared with 60TF40CS (22.1 kg/d) and 33TF67CS (22.7 kg/d), and tended to be greater than 60TF40AS (23.2 kg/d). In vivo total-tract dry matter digestibility did not differ among treatments and averaged 66.2%. In vivo total-tract NDF digestibility was lower for 33AS67CS (37.8%) compared with 60TF40AS (44.4%) and 33TF67CS (45.3%), and similar to 60TF40CS (42.4%). In vivo total-tract NDF digestibility and an estimate of in situ total-tract NDF digestibility were similar between techniques across all treatment diets (42.3 vs. 42.6%, respectively). Inclusion of tall fescue grass hay increased the total-tract NDF digestibility of the diet and has the potential to replace corn silage and alfalfa silage and maintain milk production if economically feasible based on current market prices.

Does the effect of pelleting depend on the wheat sample when fed to chickens?

Experimental comparisons of the nutritional value of different wheat cultivars commonly use feeds in meal form even though the large-scale broiler producers use steam pelleted feeds. The aim of this experiment was to examine the effect of steam pelleting on the performance, dietary N-corrected apparent metabolisable energy (AMEn), total tract dry matter retention (DMR), nitrogen retention (NR) and fat digestibility (FD) coefficients, and digestive tract development of broilers fed four different wheat samples in complete diets. Four European wheat samples, with different chemical composition and endosperm characteristics, were used in a broiler experiment. The wheat samples were milled through a 5 mm screen and four basal feeds containing 670 g/kg of each selected wheat sample were mixed. The basal feeds were then split into two batches and one of them was steam pelleted resulting in eight experimental diets. Each diet was fed ad libitum to eight pens of two male Ross 308 broilers from 10 to 24 days of age. Feeding pelleted diets improved (P<0.001) feed intake and weight gain, and daily water intake of the birds. Pelleting also improved dietary AMEn and FD (P<0.001) and DMR (P<0.05). An interaction (P<0.05) was observed between wheat samples and steam pelleting for NR. Steam pelleting improved (P<0.05) NR in the wheat sample with high starch and protein and hard endosperm but not in the rest of the wheat samples. Similar interactions (P<0.05) were also observed between wheat sample and steam pelleting for gain to feed (G : F) and water to feed (W : F) ratios. Pelleting improved G : F ratio the greatest in the wheat sample with high starch and protein and hard endosperm. Feeding the same wheat sample also decreased (P<0.05) W : F but only in the mash diets. Regardless of the wheat sample the values of dietary AMEn did not differ (P>0.05). Feeding different wheat types and pelleting did not (P>0.05) change the development of the gastrointestinal tract of the birds. The study showed that there were differences between four wheat samples when they were fed in pelleted complete feed, but no differences were observed when fed in mash form complete diets. Research on the interaction between pelleting and wheat chemical and quality characteristics is warranted.

Impact of water addition, germination, ensiling and their association on sorghum grain nutritive value

The objective of this study was to evaluate the effects of water addition, germination, ensiling and/or their association with respect to chemical composition and nutritive value of dry sorghum grain. Five commercial paddocks of sorghum grain were harvested dry and evaluated for chemical composition, digestion site and in vitro gas production under six treatment conditions: dry ground (dry), soaked for 24h (SG), germinated for 5 days (G), germinated for 5 days and then ensiled for 21 days (G&E), ensiled for 21 days as whole grain (EWG) or ensiled for 21 days as ground grain (EGG). Soaked, EWG and G&E treatments led to a lower starch content compared to dry grains (P<0.05). Reconstituted and ensiled treatments (either as whole or ground grain) decreased the tannin concentration compared to dry grains (P<0.05). The dry matter (DM) digestion site and total tract digestibility were similar among dry grains, G and EWG. However, compared to these treatments, G&E and EGG increased ruminal and total DM digestibility (P<0.05). Total tract DM digestibility did not differ between SG and dry grains; however, SG affected DM digestion site (P<0.05). Starch digestion site and total tract digestibility were similar between dry grains and EGG. Although G&E and EWG had similar total starch digestibility in comparison with dry grains, these treatments affected the digestion site (P<0.05). Soaked and G treatments reduced total tract digestibility and changed the starch digestion site compared to dry grains (P<0.05). In vitro fermentation of dry grains was similar to SG and EWG. Although the total in vitro gas production was less for G&E and EGG than dry grains (P<0.05), these treatments fermented more rapidly than dry grains (P<0.05). The soaking, the germination process, or the ensiling of whole sorghum grain as sole factors, produced changes in the chemical composition but did not improve the nutritive value of sorghum grain. However, the combination of germination and ensiling resulted in changes in the chemical composition and improved the digestibility of sorghum grains. The grinding of grain before reconstitution and ensiling is an alternative to increase the sorghum grain digestibility and nutritive value.

Performance of early-lactation dairy cows as affected by dietary starch and monensin supplementation

The objective of this study was to evaluate the effect of postpartum dietary starch content and monensin supplementation throughout the periparturient period and into early lactation on production performance of dairy cows during early lactation. Prior to parturition, primiparous (n=21) and multiparous (n=49) Holstein cows were fed a common controlled-energy close-up diet with a daily topdress of either 0 or 400mg/d monensin. From d 1 to 21 postpartum, cows were fed a high-starch (HS; 26.2% starch, 34.3% NDF, 22.7% ADF, 15.5% CP) or low-starch (LS; 21.5% starch, 36.9% NDF, 25.2% ADF, 15.4% CP) total mixed ration with a daily topdress of either 0mg/d of monensin or 450mg/d monensin (MON), continuing with prepartum topdress treatment assignment. From d 22 through 63 postpartum, cows were fed HS and continued with their assigned daily topdress. Interactions of starch content and MON supplementation were not significant for any of the variables measured. Cows fed HS from wk 1 to 3 postpartum had higher early-lactation milk yields (starch × week interaction) compared with LS cows, but HS cows also had lower percentages of milk fat, true protein, lactose, and total solids during the same period, resulting in similar yields of energy-corrected milk (ECM) between starch treatments. Cows fed HS had higher early-lactation dry matter intake (DMI; starch × week interaction) and lost less body condition score during wk 1 to 3, contributing to improved energy balance postpartum. No effect of starch treatment was observed on apparent total-tract dry matter or starch digestibilities assessed during d 18 to 19 (±2) postpartum, although cows fed the LS diet had greater apparent total-tract NDF digestibility compared with cows fed the HS diet. Cows fed MON had higher DMI and higher milk yields during the first 9 wk of lactation. However, all cows had similar yields of ECM because of trends for lower milk fat content during early lactation. In part because of similar yields of ECM between these treatments and higher DMI for cows fed MON, ECM per DMI during the first 9 wk of lactation was not affected by MON treatment. There was no effect of MON treatment on apparent total-tract dry matter, NDF, or starch digestibilities. Overall, cows fed more propiogenic diets in early lactation (HS or MON) had increased milk yield and DMI during the immediate postpartum period, indicating that diets with greater propiogenic capacity do not have detrimental effects on early-lactation DMI.

Extrusion of sorghum starch enhances ruminal and intestinal digestibility, rumen microbial yield and growth in lambs fed on high-concentrate diets

This study consisted of two experiments that investigated the effect of extrusion of sorghum starch on in situ ruminal and post-ruminal disappearance of dry matter (DM), starch and nitrogen (N) and the effects of substituting barley by the extruded sorghum on digestion characteristics, microbial N supply and growth in finishing lambs. Sorghum was extruded using the following four temperature and pressure combinations: T1=90°C/17bars, T2=115°C/24bars, T3=150°C/55bars and, T4=175°C/95bars. Ruminal, intestinal and total tract DM content, starch and N degradability of the extruded sorghum (T1, T2, T3, T4), unprocessed sorghum (T0; control) and barley grain (B) were determined using nylon bag and mobile bag techniques in a completely randomized block design (CRBD). Extrusion under T3 conditions increased in vitro ruminal digestibility, solubility (a), fractional disappearance rate (c) and effective degradability (ED) of DM and starch in sorghum to near similar to those of B. T3 also had higher (P<0.05) ruminal and intestinal digestion rates for DM, starch and N compared to T0, T1, T2 and T4 suggesting that extruding sorghum under T3 conditions could be used as replacement of barley in lamb diets. In the second experiment, eighteen male Iranian Baluchi lambs were randomly allocated into three dietary treatments in a complete randomized design (CRD). Dietary grain in the treatment-concentrates were barley (B) as control, barley and extruded sorghum (under T3 conditions) in equal proportion (BSE) and extruded sorghum (SE). Dry matter and N intakes were not affected by source of grain, but because of the higher starch content in sorghum, lambs on SE diet had greater starch intake (995g/d) and higher (P<0.01) starch (291g/d) and N (53.1g/d) outflow to the small intestine. Of the total input of starch to the small intestine, higher (P<0.01) amount (253g/d) disappeared in SE compared to B and BSE lambs which was reflected by the higher glucose concentration in the portal vein of SE lambs. Lambs fed SE diet also had greater ruminal microbial N (MN) yield (24.1g/d), although ruminal pH and total VFA did not show any significant difference among treatments. Consequently, SE lambs recorded greater averaged daily gain (ADG) and more efficient (P<0.01) feed conversion ratio (FCR) compared to B or BSE lambs. It can be concluded that extrusion under 150°C/55bars improves digestibility of sorghum starch and provides an option to completely replace barley in lambs.

Lactation performance and digestibility of forages and diets in dairy cows fed a hemicellulose extract

Inclusion of hemicellulose extract (HE) in cattle diets have shown potential for improving fiber digestibility and production efficiency. The objective of this research was to evaluate production and digestibility effects of a HE on midlactation cows. Twelve multiparous Holstein cows (142±44 d in milk, 685±19kg of body weight) including 4 with ruminal fistula were used in a 2 × 2 Latin square design with 21-d periods. Cows were fed a control (CON) diet containing 55% forage [dry matter (DM) basis, 2/3 corn silage and 1/3 alfalfa hay] or a similar diet where 1.0% of the diet DM was replaced with HE (TRT). Dry matter intake averaged 27.1 and 26.9kg/d, for CON and TRT respectively, and was not affected by addition of extract. The percentage of milk protein (3.40 vs. 3.29%) was greater, whereas the percentage of milk fat (3.91 vs. 3.80%) tended to be greater, for cows fed the CON compared with the TRT diet. Because of numerically greater milk production (38.8 vs. 39.2kg/d) for cows fed the TRT diet, no differences were observed in component yields other than lactose (1.86 vs. 1.94kg/d), which tended to be greater for cows fed the TRT ration. Treatment improved neutral detergent fiber (NDF) digestibility (38.6 vs. 48.1%) for the TRT diet compared with the CON diet but did not affect apparent total-tract DM (67.8 vs. 68.5%), crude protein (67.2 vs. 67.9%), acid detergent fiber (ADF; 37.1 vs. 43.3%), or starch (92.8 vs. 92.2%) digestibility. For in situ determinations, Dacron bags containing corn silage, alfalfa hay, and either the CON or TRT ration were incubated in triplicate in the rumens of the cannulated cows at 0, 3, 6, 9, 12, 24, and 48h on d 18 of each period. Each total mixed ration was incubated only in cows assigned to the corresponding diet. For corn silage, the rate of disappearance of NDF (1.70 vs. 4.27%) and ADF (1.79 vs. 4.66%) increased for cows fed the TRT diet. For alfalfa hay, the disappearance of fraction A of DM, NDF, and ADF decreased and fraction B of DM and NDF increased with treatment. The rate of disappearance for DM (8.03 vs. 11.04%), NDF (6.30 vs. 10.28%), and ADF (5.52 vs. 9.19%) increased for the alfalfa hay in rumens of treated cows. For the total mixed ration, the disappearance of the A fraction of NDF and ADF increased for cows fed the TRT diet. Supplementing diets of lactating dairy cows with an HE has beneficial effects on fiber degradation characteristics and provides opportunities for improving animal performance.

Effects of feeding different levels of dietary fiber through the addition of corn stover on nutrient utilization of dairy heifers precision-fed high and low concentrate diets

The objective of this experiment was to assess the effects of manipulating dietary fiber by replacing corn silage (CS) with lower quality forage as corn stover (CST) when used in high concentrate (HC) and low concentrate (LC) diets for precision-fed dairy heifers. Eight Holstein heifers (335.6±7.41kg of body weight) were randomly assigned to 2 levels of concentrate: HC (20% forage) and LC (80% forage), and to a forage type sequence [0% of forage as corn stover (CST), 100% corn silage (CS); 20% CST, 80% CS; 40% CST, 60% CS; and 60% CST, 40% CS] within concentrate level administered according to a split-plot, 4×4 Latin square design (21-d periods). Heifers fed HC had higher apparent total-tract dry matter digestibility (DMD). Increasing the fiber level by increasing the amount of CST in the diet resulted in a linear decrease of DMD and organic matter digestibility. Heifers fed LC diets had higher neutral detergent fiber (NDF) digestibility and tended to have lower acid detergent fiber (ADF) digestibility than those fed HC diets. Substituting CS with 20% CST resulted in the highest NDF and ADF digestibilities. Digestibility of N was not different, but N retention increased for HC and decreased quadratically for LC diets. Heifers fed HC diets decreased fecal output, and CST linearly increased these parameters. Urine volume tended to be higher for HC-fed heifers, and increasing dietary fiber through CST inclusion tended to decrease urine output. This shift in water excretion resulted in similar total manure output. Total purine derivative excretion did not differ between treatments, but interacted with CST addition, resulting in a linear increase in microbial protein flow to the duodenum in HC-fed heifers and in a linear decrease in LC diets as CST increased. In conclusion, increasing dietary fiber through CST decreased DMD and organic matter digestibility linearly, whereas NDF and ADF digestibility were maximized when 20% CST was added to HC and LC diets. Microbial protein synthesis increased and decreased linearly with CST addition in HC and LC diets, respectively. Retention of N increased and decreased quadratically with CST addition in HC and LC diets, respectively. Total manure excretion was not different between HC or LC diets.

Effect of storage system and tarpaulin color on nutritional quality and digestibility of stored lucerne hay in the irrigated Sonoran Desert

A field trial and a steer digestion trial were conducted to evaluate the effect of tarpaulin color on the quality and digestive attributes of lucerne ( Medicago sativa) hay during a 20 week summer storage period in the irrigated Sonoran Desert of northwestern Mexico and the southwestern US. Lucerne hay was subjected to six treatments (four repetitions per treatment): stored roadside uncovered (UC), stored roadside and covered with a white plastic tarpaulin (WT), stored roadside and covered with a black plastic tarpaulin (BT), stored roadside and covered with a silver-colored plastic tarpaulin (ST), stored outside under a plastic hay barn (BC), and stored in an air-conditioned room (AC). During the 20 week storage period, daily maximum temperatures exceeded 38 °C for more than 16 weeks. Internal bale temperatures were 44.9, 44.1, 43, 42.9, and 40.7 °C for BT, UC, ST, WT, and BC, respectively, during the storage period. UC, WT, BT, and ST, at the end of the field trial, were heat damaged as indicated by an acid detergent insoluble nitrogen/nitrogen ratio greater than 0.14. BT bales had the greatest (P<0.05) heat damage of all treated hay. Total tract dry matter (DM) digestible contents were 668.0, 644.8, 651.5, 597.7, and 562.0 g/kg DM for BC, WT, ST, UC, and BT, respectively. Total tract crude protein (CP) digestible contents were 796.6, 786.2, 773.7, 720.8, and 71.90 g/kg CP for BC, WT, ST, UC, and BT, respectively. The authors concluded that valuable hay products, such as lucerne, should be protected from harsh environmental extremes during storage in hot desert climates. Protecting lucerne with a roof structure (BC) provided the best protection against the heat. Covering the hay with tarpaulins is another viable option, but not all tarpaulin colors are equally efficient. BT did no better than the negative control (UC). The white tarpaulin (WT) did a satisfactory job in protecting lucerne against the heat in comparison to BT and ST. Valuable hay products, such as lucerne, if stored during the summer in hot desert climates, should include an acid detergent insoluble nitrogen analysis to detect the presence of heat damage.

Postprandial Lipid-Related Metabolites Are Altered in Dogs Fed Dietary Diacylglycerol and Low Glycemic Index Starch during Weight Loss1–3

In this study, we investigated a combination of a low glycemic index starch (LGIS) and diacylglycerol (DAG) on lipid, lipoprotein (LP) metabolism, and weight management. Obese, intact female adult Beagle dogs were assigned to 1 of 4 starch/oil combination diets [LGIS/DAG (LD); LGIS/triacylglycerol (TAG); high glycemic index starch (HGIS)/DAG; and HGIS/TAG (HT)] and fed for 9 wk (n = 6/group) using an incomplete 4 × 4 Latin square design. Each dog was fed 1 of 2 opposite starch/oil combination diets (e.g. LD and HT). At wk 1 and 8, postprandial blood was collected for plasma triacylglycerol (TG), β-hydroxybutyrate (BHB), total cholesterol (TC), and LP analyses. During the same week, dogs were overnight feed-deprived and post-heparin blood was collected for LP lipase and hepatic lipase activity determinations. At wk 1, 4, and 8, blood was drawn from overnight feed-deprived dogs for plasma TG, BHB, TC, LP, leptin, and adiponectin measurements. Feces were collected at wk 3 for digestibility calculations. The LGIS diets resulted in lower carbohydrate, protein, total tract dry matter digestibilities, and metabolizable energy compared with the HGIS diet groups (P < 0.05). Thus, the LGIS groups lost more body weight (P = 0.001), which was positively correlated with plasma leptin concentrations (r2 = 0.427; P < 0.001). Moreover, the LGIS diet lowered TC concentrations in combination with DAG. The DAG diet groups decreased postprandial TG and increased BHB concentrations (P < 0.05). Starch/oil types did not alter lipase activities or adiponectin concentrations. In conclusion, the LGIS diet demonstrated potential as a weight management tool in dogs by decreasing postprandial TG and increasing BHB in combination with DAG.

Maturity of coastal bermudagrass and alfalfa affects ruminal in situ and total tract dry matter and phosphorus disappearance in cannulated steers

Variability of phosphorus (P) availability among forage species and plant maturity is largely ignored when formulating ruminant diets. To determine if variability in P availability changes with forage species and/or maturity, ruminal in situ and total (ruminal+post-ruminal) dry matter (DM) and phosphorus disappearance (PD) from alfalfa (ALF; Medicago sativa) and coastal bermudagrass (CB; Cynodon dactylon) harvested at four stages of maturity was measured in cattle. Forages were hand clipped at 14, 21, 28 and 35 days after first cutting. Ruminal in situ DM disappearance (DMD) and PD were measured after 24 h ruminal incubation in Dacron bags. Total tract DMD and PD were measured using the mobile nylon bag technique. Disappearance of DM and P were greater (p≤0.05) in the rumen than post-rumen for both species regardless of maturity; however, 80 g PD/kg DM in 35-day ALF (9% of total PD) and 224 g PD/kg of 35-day CB (38% of total PD) occurred post ruminally. Alfalfa DM disappeared to a greater (p ≤ 0.05) extent than CB and showed 5% greater total tract PD at 14 days and 13% more at 35 days compared to the grass. Alfalfa total tract PD decreased (p ≤ 0.05) 5.4% from 14- to 35-day maturity while the decrease was far greater for CB, 12.4%. Results from this study indicate that ruminant nutritionists should take into account forage species and maturity when calculating PD in diets; these details can be used to aid in formulating more precise rations that reduce fecal-phosphorus excretion into the environment.

Influence of single-gene mutations, harvest maturity and sample processing on ruminal in situ and post-ruminal in vitro dry matter and starch degradability of corn grain by ruminants

Combined effects of single-gene mutations (G), harvest stage (HS) and sample drying technique (DT) on the proportion of dry matter (DM) and starch degraded ruminally in situ and post-ruminally in vitro were evaluated using four near-isogenic lines in Oh43 inbred background: floury-2 ( fl2), opaque-2 ( o2), sugary-2 ( su2), waxy-1 ( wx1) genes and normal Oh43. The inbreds were grown at the University of Wisconsin West Madison Research Station (Madison, WI, USA) during the summer of 2002 in three row plots of 3.04 m × 0.76 m, in a randomized complete block design with three replications. Harvesting was at four stages (HS1 = 1/2 milk-line; HS2 = 5 d post HS1; HS3 = 10 d post HS1; and HS4 = black layer) with samples split for oven drying at 40 °C for 72 h and freeze drying for approximately 60 h. Dried kernels were ground through a Wiley mill (6 mm screen) for measurement of zero hour DM solubility (i.e., A Fraction) and ruminal in situ DM degradability (RDMD) after 14 h incubations (1.5 g/bag × 8 replicates in 5 cm × 5 cm bags of 50 μm pore size) using two steers. Residue from the 14 h bags proceeded to an 8 h enzymatic post-ruminal degradation, from which the post-ruminal residue was oven dried at 62 °C for 48 h and DM and starch contents determined to provide estimates of total tract DM degradability (TDMD) and total tract starch degradability (TSTARCHD). Three-way interactions for G × HS × DT were observed for the A Fraction (P<0.01) and RDMD (P<0.05). There was compensatory DM degradation post-ruminally from germplasm with low RDMD values ( wx1(Oh43) and Oh43), thereby reducing inbred differences for TDMD. The influence of advancing maturity on degradabilities was greater for wx1, su2 and Oh43, than for o2 and fl2 mutations which have inherently soft endosperm properties. When compared to freeze drying, oven drying at 40 °C reduced the A Fraction, particularly for early harvested samples. The ranking of inbreds for decreasing A Fraction, RDMD and TSTARCHD was o2(Oh43) > fl2(Oh43) ≥ su2(Oh43) > wx1(Oh43) ≥ Oh43. Results identify key properties of corn grain germplasm and their relationships with ruminal in situ and post-ruminal in vitro DM and starch degradability measurements that may be used in advanced corn breeding efforts.

Effects of Planting Date on Fiber Digestibility of Whole-Crop Barley and Productivity of Lactating Dairy Cows

Objectives of the study were to evaluate the effect of planting date on in vitro neutral detergent fiber digestibility (IVFD) of whole-crop barley (Hordeum vulgare) and its effects on productivity of lactating dairy cows. Two cultivars of barley were planted on May 5 (BM) and June 7 (BJ), 2005 at the Edmonton Research Station, University of Alberta. They were harvested at late-dough stage on July 26 and August 25, respectively, for BM and BJ and ensiled. The BJ had greater 30-h IVFD (61.2 vs. 51.9%) and crude protein concentration (12.4 vs. 8.7%) at harvest compared with BM. Thirty lactating cows, including 6 ruminally cannulated cows, in mid to late lactation (183±71.7 d in milk; mean±standard deviation) were fed diets containing BM or BJ at 58.5% of dietary DM in a crossover design with 19-d periods. The dietary neutral detergent fiber concentration was 30.6 and 28.8% for BM and BJ diets, respectively. Dry matter intake and milk yield were not affected by treatment and averaged 20.2 and 27.2 kg/ d, respectively. The lack of responses could have been attributed to the low-energy demands for cows used in this experiment; ruminal physical fill might not have limited dry matter intake. However, cows fed BJ had greater total tract dry matter digestibility (68.9 vs. 66.1%) and tended to increase body weight gain (864 vs. 504 g/d) compared with those fed BM. Delaying the planting date of barley altered its growing environment and affected nutrient composition and IVFD of whole-crop barley and energy availability to animals. Further research is needed to confirm if the planting date consistently affects nutrient composition and IVFD of barley at harvest.

Relationships between kernel vitreousness and dry matter degradability for diverse corn germplasm: II. Ruminal and post-ruminal degradabilities

Correlations between kernel vitreousness and ruminal in situ (RDMD) and total tract dry matter (TDMD; sum of ruminal in situ and post-ruminal in vitro measurements) degradabilities were determined for 33 diverse corn germplasm sources. These included a wide range of endosperm characteristics from opaque 2 (o2) types to densely packed flint types, and a number of intermediates. Harvests were done at two growth stages; 1/2 milk-line (ML) and black-layer (BL). Kernels from middle portion of ears were oven dried at 40 °C for 72 h and ground through a Wiley mill (6 mm screen) for measurement of in situ RDMD after 0 and 14 h of incubation using two steers (1.5 g/bag × 8 replicates per time point per steer in 5 cm × 5 cm bags of 50 μm pore size). Residue from the 14 h bags proceeded to an 8 h in vitro enzymatic post-ruminal digestion after which the residue was oven dried at 62 °C for 48 h and dry matter content determined. Inbred by harvest-stage interactions were observed for 0-h disappearance and TDMD. Vitreousness had strong negative correlations with degradability measurements, particularly for more mature (BL) samples (−0.728, −0.770 and −0.603) versus ML (−0.569, −0.541 and −0.338) for 0 h disappearance, RDMD and TDMD, respectively. Vitreousness was highly correlated with corn degradability, especially at a black-layer stage of harvest, in this diverse corn germplasm.

Whole Body Nutrient Accretion, Growth Performance and Total Tract Nutrient Retention Responses of Broilers to Supplementation of Xylanase and Phytase Individually or in Combination in Wheat-Soybean Meal Based Diets

Growth performance, total tract nutrient retention and whole body nutrient accretion rates responses of broilers to supplementation of enzymes containing phytase or xylanase activities were investigated using 300 broilers. At day old, 280 broilers were assigned to 5 dietary treatments which were: 1) positive control (PC) diet which met NRC (1994) nutrient requirement for broilers, 2) negative control (NC) diet which was marginally deficient in phosphorus and ME, 3) NC plus phytase added at 1,000FTU/kg, 4) NC plus xylanase added at 4,000U/kg and, 5) NC plus phytase and xylanase added at 1,000 and 4,000units/kg, respectively. Each treatment had 8 replicate cages with 7 birds per replicate cage. Comparative slaughter technique was used for determination of whole-body nutrient accretion rate. Twenty broilers with the same initial body weight as the 280 broiler chicks used in the growth trial made up the initial slaughter group killed at day 0. A final slaughter group of 40 birds, one bird from each cage, were slaughtered on day 21. The birds selected were those with body weight closest to the average body weight of the birds in each replicate cage. Phytase alone or combined with xylanase improved weight gain and bone ash (P<0.05). Phytase alone improved (P<0.5) total tract P retention and ME, phytase and xylanase combined improved (P<0.01) total tract dry matter and ME. Phytase alone improved (P<0.5) whole body daily accretion rates of dry matter, protein, fat, P, and Ca in comparison to NC treatment. Overall, phytase in wheat-based diet improved growth performance and whole body accretion of minerals and protein, the improvement in protein accretion is an indication of improvement in nutrient utilization resulting from phytase use.

In vivo measurement of flatulence and nutrient digestibility in dogs fed poultry by-product meal, conventional soybean meal, and low-oligosaccharide low-phytate soybean meal

To determine an optimal window for determining peak flatulence and evaluate the effects of oligosaccharides and supplemental beta-mannanase in soybean meal-based diets on nutrient availability and flatulence. 6 dogs. Dogs were used in a 2 x 3 factorial arrangement of treatments in a 6 x 6 Latin square experiment to evaluate the digestibility, flatulence, and fecal odor metabolites of low-oligosaccharide low-phytate soybean meal (LLM), conventional soybean meal (SBM), and poultry by-product (PBP) meal diets with or without supplemental beta-mannanase (5 g/kg). Enzyme supplementation had no effect on total tract dry matter (DM), nitrogen digestibility, or digestible energy; however, differences between protein sources did exist for total tract DM digestibility and digestible energy. The PBP meal had higher DM digestibility and digestible energy (mean, 0.913 and 4,255 cal/g), compared with soy-based diets (mean, 0.870 and 4,049 cal/g). No differences were detected for any treatment regardless of protein source or addition of supplemental enzyme for any flatulence components analyzed. No differences were detected for all fecal odor metabolites regardless of addition of supplemental enzyme; however, differences between protein sources were detected. The PBP meal had lower concentrations of carboxylic acids and esters and higher concentrations of heterocycles, phenols, thio and sulfides, ketones, alcohols, and indoles than LLM and SBM. Diets containing < 22.4 g of stachyose/kg and < 2 g of raffinose/kg did not alter digestibility or increase flatulence in dogs.

Effect of dietary inclusion of hazelnut and soybean meals on microbial protein synthesis

The aim of this study was to compare effects of dietary inclusion of hazelnut meal (HZM) with soybean meal (SBM) on site of digestion and microbial protein synthesis in sheep. Four ruminally and duodenally cannulated female Redkaraman × kıvırcık sheep (initial BW of 44.0 ± 1.02 kg) were utilized in a crossover experiment. Sheep were fed a diet of 60% corn silage (DM basis) and 40% concentrate consisting of barley and SBM or HZM. Feed was fed at 115% of ad libitum intake. Intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were similar between sheep fed SBM or HZM based diets ( P > 0.05). Organic matter intake averaged 1089 (2.37% BW) and 1143 g/day (2.42% BW) for SBM and HZM, respectively. Apparent and true ruminal and total tract DM and OM digestibilities did not differ between diets ( P > 0.05). True ruminal OM digestibility was 74.3 and 74.6% for SBM and HZM based diets, respectively. Total CP entering the duodenum was similar between diets ( P > 0.05). Dietary plus endogenous CP entering the duodenum in grams and as a percentage of total CP was greater ( P < 0.05) for SBM versus HZM. Quantities of microbial protein ( P < 0.15) and NH 3 N ( P < 0.08) flowing to the duodenum tended to be less for SBM versus HZM; percentages of total CP were lower ( P < 0.05) for SBM. Apparent ruminal and total tract CP digestibilities did not differ between diets, but true ruminal CP digestibility and efficiency of microbial protein synthesis tended to be higher in animals fed the HZM based diet compared with the diet based on SBM ( P < 0.13). In conclusion, because total CP entering duodenum did not differ between diets, HZM can be substituted for SBM in sheep fed corn silage and barley based diets with a moderate CP level.

Digestion characteristics and growth of steers fed a corn–grain based supplement compared to a de-oiled rice bran plus cottonseed supplement with or without extrusion processing

This study evaluated ruminal digestion characteristics and performance of beef steers supplemented with either a conventional or co-product based feed, and the effects of extrusion of the co-product supplement. In experiment 1, a 3 × 3 Latin square design was used to evaluate ruminal digestion characteristics in cannulated beef steers fed hay plus (1) corn and cottonseed meal (71:29, w/w DM; CCSM); (2) de-oiled rice bran and whole cottonseed (62:38, w/w DM; DRCS) or; (3) extrusion processed DRCS supplement (EXT) with the de-oiled rice bran and cottonseed supplement being mixed before extrusion. Supplements were offered at 10 g/kg body weight (BW). Contrasts were used to evaluate differences between supplements, (1) CCSM versus the average of the DRCS and EXT and, (2) DRCS versus EXT. Neither supplement type nor processing affected predicted hay dry matter (DM) intake, supplement DM intake, or total DM intake, and supplement DM degradation rate in the rumen did not differ. However, rate of passage of the CCSM (58.4 g/kg/h) supplement was higher ( P = 0.01) than the DRCS (44.1 g/kg/h) and EXT (45.3 g/kg/h) supplements. Passage rate also tended ( P = 0.08) to be higher with EXT versus DRCS. Supplement type or processing did not affect hay DM degradation rate or passage rate ( P > 0.10). Supplement type tended ( P = 0.06) to change the ruminally degradable crude protein to ruminally degradable organic matter (OM) ratio (g/kg, RDP:RDOM) with CCSM supplement having a RDP:RDOM of 185 compared to 114 for DRCS and EXT. Supplement type or processing did not affect overall diet RDP:RDOM or total tract DM digestibility. Seventy-two crossbred beef steers were used in experiment 2. Hay DM intake tended ( P = 0.07) to be higher for CCSM supplemented versus DRCS or EXT supplemented calves. Despite the tendency for higher hay intake of CCSM calves, ADG did not differ. De-oiled rice bran plus whole cottonseed can effectively replace corn plus cottonseed meal as a supplement for growing cattle fed low-quality hay, and extruding the de-oiled rice bran plus cottonseed supplement did not alter animal performance.

Evaluation of soyabean meal as a protein source in canine foods

Eight adult female dogs (18.2±0.4 kg) were used in an experiment to determine the feeding value of soyabean meal (SBM) in a complete food fed to dogs. All foods contained graded concentrations of SBM (151–461 g/kg dry matter (DM)) resulting in foods that were 100, 150, 200 and 250 g/kg crude protein (CP). Daily dry matter intake averaged 296±10 g per day. An increase in SBM resulted in a decrease in fecal moisture from 389 to 265 g/kg (linear; P<0.001) and fecal DM output increased from 49.8 to 131.4 g per day (linear; P<0.001). Ileal DM flow increased from 56.6 to 200.7 g per day (linear; P<0.001). Small intestinal DM digestibility decreased from 0.81 to 0.34 (linear; P<0.001) and total tract DM digestibility decreased from 0.83 to 0.57 (linear; P<0.001) as SBM increased. Large intestinal DM digestibility increased from 0.12 to 0.34 with increasing SBM (linear; P<0.001). Crude protein fecal excretion increased from 10.0 to 27.5 g per day (linear; P<0.001) and ileal flow of CP increased from 10.6 to 38.1 g per day (linear; P<0.001) as SBM increased. Small intestinal CP digestibility decreased from 0.65 to 0.51 (linear; P<0.002) with increasing SBM. Large intestinal CP digestibility increased from 0.05 to 0.27 (linear; P<0.021) with increasing SBM. Total tract CP digestibility was unaffected by treatment ( P<0.267) as SBM increased. Disappearance of all amino acids (AA) (g per day), with the exception of cysteine and tryptophan, increased (linear; P<0.001) with increasing SBM. Glutamate had the highest disappearance ranging from 4.98 to 10.89 g per day. Tryptophan and cysteine had the lowest disappearance ranging from 0.35 to 0.43 g per day and 0.29 to 0.36 g per day, respectively. Arginine had the highest overall digestibility ranging from 0.85 to 0.88 whereas, threonine and cysteine had the lowest digestibility ranging from 0.39 to 0.57 and 0.30 to 0.60, respectively. These data indicate that SBM can adversely affect the digestibility of canine foods in concentrations greater than 150 g/kg of the food.

Corn Silage Management: Effects of Hybrid, Chop Length, and Mechanical Processing on Digestion and Energy Content

Two experiments were conducted to evaluate the effects of chop length and mechanical processing of two hybrids of whole plant corn on digestion and energy content of the total mixed ration (TMR). The experimental designs in experiments 1 and 2 were 6×6 and 4×4 Latin squares, respectively. In the first experiment, Pioneer hybrid 3845 was harvested at three theoretical lengths of cut: 11.1, 27.8, and 39.7mm. At each chop length, corn was harvested with and without mechanical processing using a John Deere 5830 harvester with an onboard kernel processor. In the second experiment, Pioneer hybrid Quanta was harvested at two theoretical lengths of cut: 27.8 and 39.7mm, with and without mechanical processing. In both experiments, the increase in the theoretical length of cut of corn silage increased the average length of cut and tended to increase the percentage of particles greater than 19mm and lower the percentage of particles between 8 and 19mm. In experiment 1, apparent total tract dry matter, organic matter, and neutral detergent fiber (NDF) digestibilities were lower for cows fed diets containing corn silage harvested at a short chop length (11.1mm) than for corn silage harvested at a long chop length (39.7mm). The lower total tract digestibility of nutrients may have contributed to the lower TDN, metabolizable energy (percentage of digestible energy), and NEL concentration of diets containing the short chop length corn silage (experiment 1). In experiment 2, total tract starch digestibility was greater for cows fed medium chop (27.8mm) corn silage diets, and total tract NDF digestibility was greater for cows fed long chop (39.7mm) corn silage diets. The opposing effect of total tract starch and fiber digestibilities between chop lengths may have contributed to the lack of difference in energy content of the diets in experiment 2. The TDN and NEL concentrations of the processed corn silage diets were greater than the unprocessed corn silage diets in experiment 1. The increase in energy concentration for the processed corn silage diet was due to greater total tract digestibility of organic matter and ether extract. Total tract starch digestibility was greater, and total tract NDF digestibility was lower for cows fed processed corn silage diets than unprocessed corn silage diets in experiment 2. The opposing effect of total tract starch and fiber digestibilities between processed and unprocessed corn silage may have contributed to the lack of difference in energy content of the diets.