Apparent Total Tract Nutrient Research Articles

Doses of orange (Citrus sinensis) essential oil for Nellore steers fed with a forage-based diet

The aim was to evaluate whether the doses of orange essential oil supplementation impact on dry matter intake (DMI), ruminal fermentation parameters, apparent nutrient digestibility, and methane production in Nellore steers fed with forage-based diet. A total of 32 rumen-cannulated Nellore steers (initial BW= 335±25 kg; age= 20±1 month) were assigned to individual pens in a randomized complete block design. Within block, steers were randomly assigned to treatments: CON= diet without orange essential oil (EO); 100EO= CON diet plus 100 mg orange EO/kg DM diet; 200EO= CON diet plus 200 mg orange EO/kg DM diet; and 500EO= CON diet plus 500 mg orange EO/kg DM diet. The main active compounds of the orange EO used were limonene (88.0 %) and myrcene (5.79 %). The experimental period lasted 28d, with 22d for adaptation and 6d for sample collection. From d23 to 27, samples of haylage, concentrate, and total fecal production were collected to determine the total tract apparent nutrient digestibility. Ruminal fluid was obtained from d28 at 0, 6, and 12 h after feeding to determine ruminal fermentation parameters and methane production. The difference was considered significant when P ≤ 0.05. No treatment effects were detected (P>0.05) to DMI or specific nutrient intake. The increasing levels of EO did not affect (P>0.05) the total apparent nutrient digestibility. No treatment effects were detected (P>0.05) for ruminal fermentation parameters in vivo. In ex situ, there was a treatment effect for acetate, total short-chain fatty acids (SCFA), methane, and relative energy loss (REL). For acetate, an increasing linear effect was observed for treatments that received EO for the variables production (g/kg) (P = 0.002) and gross energy (MJ/kg) (P = 0.002), with a higher concentration for the 500EO. For the total production of SCFA, there was an increasing linear effect of treatment with a higher concentration for 500EO for the variables production (g/kg) (P = 0.001) and gross energy (MJ/kg) (P = 0.001). For methane, a quadratic treatment effect was observed for the variables production (g/kg) (P = 0.045) and gross energy (MJ/kg) (P = 0.046), with lower concentrations for the 200EO. There was a decreasing linear treatment effect for REL(%) (P<0.001). The results for the use of orange EO as a manipulator of ruminal fermentation were promising and the dose of 500 mg/kg of DM showed a greater capacity to increase the energy efficiency of fermentation, with greater production of acids and lower production of methane, without affecting the voluntary intake of steers.

Replacing alfalfa hay with industrial hemp ethanol extraction byproduct and Chinese wildrye hay: Effects on lactation performance, plasma metabolites, and bacterial communities in Holstein cows.

This trial was designed to investigate the effects of industrial hemp ethanol extraction byproduct (IHEEB) and Chinese wildrye hay (CWH) replacement of alfalfa hay (AH) on digestibility, and lactation performance, plasma metabolites, ruminal fermentation, and bacterial communities in Holstein dairy cows. Nine healthy multiparous Holstein cows (parity = 3) with similar body weights (584 ± 12.3 kg), days in milk (108 ± 11.4), and milk yields (30 ± 1.93 kg; all mean ± standard deviation) were used in a replicated 3 × 3 Latin square design with 3 periods of 21 d. During each period, each group consumed 1 of 3 diets: (1) 0% IHEEB (0IHEEB); (2) 6.0% IHEEB and 1.7% Chinese wildrye hay (6IHEEB); (3) 10.8% IHEEB and 4.3% Chinese wildrye hay (11IHEEB). The diets in each group were isocaloric and isonitrogenous, with similar contents of concentrate and silage but different ratios of IHEEB and CWH to replace AH. The results showed that increasing the substitute did not affect the total-tract apparent nutrient digestibility. There was no difference in lactation performance of dairy cows fed the three diets, except for the cows' somatic cell count (SCC), which decreased with the increase in the amount of the substitute. Cannabidiol and tetrahydrocannabinol were not detected in milk samples of dairy cows in the different treatment groups. 6IHEEB and 11IHEEB-fed cows showed a linear decrease in total volatile fatty acids (VFA) and butyrate compared to the 0IHEEB cows. Plasma IL-1β content quadratically decreased with feeding IHEEB and CWH, and other blood parameters were unaffected. The rumen fluid's relative abundances of Bacteroidota, Fibrobacterota, and Prevotellaceae quadratically increased, while Firmicutes tended to decrease quadratically as the substitution increased. Feeding IHEEB and CWH linearly increased the relative abundances of Firmicutes, Lachnospiraceae, Monoglobaceae, and Butyricicoccaceae in the feces. As the substitution increased, the cost of dairy farming was reduced. In summary, substituting AH with IHEEB and CWH in diets did not affect the total-tract apparent nutrient digestibility, improved milk composition, and plasma immune indices. It changed the bacterial composition in rumen fluid and feces and improved dairy farming benefits.

Influence of encapsulated pepper on ruminal fermentation, nutrient digestibility, and performance in dairy cows

The aim of this study was to evaluate the effects of a feed additive containing encapsulated pepper on total-tract apparent nutrient digestibility, sorting index, ruminal fermentation, milk yield and composition, serum concentrations of urea-N and glucose, purine derivative excretion, and N utilization efficiency in dairy cows. Twenty-two Holstein cows (182 ± 86.3 days in milk, 35.4 ± 4.85 kg/d milk yield), of which 4 were rumen cannulated, were used in a crossover design experiment with 21-d periods (14 days allowed to treatment adaptation and 7 days for sampling). Cows were blocked according to parity, days in milk, and milk yield and randomly assigned to the following treatments: Control (CON), or 1.5 g/d (CAP) of a feed additive containing encapsulated pepper (Capcin; NutriQuest, Campinas, Brazil) added to the concentrate along with minerals. Data were analyzed using the mixed procedure of SAS modeling the fixed effects of treatment, period, and the random effect of animal. Ruminal fermentation data were analyzed as repeated measurements adding the fixed effect of time and its interaction with treatments to the previous model. No differences in intake of dry matter or nutrients were detected. Sorting for feed particles between 19 and 8 mm size was greater in cows fed CAP compared to CON (1.000 and 0.992 kg/kg, respectively). Feeding CAP had no effects on digestibility of dry matter, crude protein, ether extract, or neutral detergent fiber. Nor treatment or interaction effect between treatment and time were observed for ruminal pH, NH3N concentration, or short-chain fatty acids concentration. Yields of milk (35.3 vs 34.3 kg/d) and fat-corrected milk (37.4 vs 36.0 kg/d) were greater for cows under CAP treatment compared to CON. Yield of milk solids (fat, protein, and lactose) was increased when feeding CAP. Milk fat concentration tended to be greater in cows fed CAP than those in CON group (39.5 vs 38.3 g/kg, respectively). Feed efficiency (fat-corrected milk ÷ dry matter intake) tended to be greater in cows fed CAP than CON-cows (1.45 vs 1.40, respectively). Serum concentrations of urea-N and glucose were similar between treatment groups. Feeding CAP did not alter purine derivative excretion (allantoin in urine and milk, and uric acid in urine), as well as the nitrogen excreted (g/g N intake) through feces, milk, or urine. In conclusion, feeding CAP at 1.5 g/d improved performance without altering nutrient digestibility, ruminal fermentation, excretion of purine derivatives, or efficiency of nitrogen utilization in dairy cows.

Effects of narasin supplementation on dry matter intake and rumen fermentation characteristics of Bos indicus steers fed a high-forage diet.

This study evaluated the effects of narasin on intake and rumen fermentation characteristics of Bos indicus steers offered a high-forage diet for 140 d. On day 0 of the study, 30 rumen-fistulated Nellore steers [initial body weight (BW) = 281 ± 21 kg] were assigned to 30 individual pens in a randomized complete block design according to their initial BW. Animals were randomly assigned to 1 of the 3 treatments: 1) forage-based diet without narasin (CONT; n = 10), 2) CONT diet plus 13 ppm of narasin (13NAR; n = 10), and 3) CONT diet plus 20 ppm of narasin (20NAR; n = 10). The forage used was Tifton-85 (Cynodon dactylon spp.), whereas the carrier for narasin was a 50:50 mixture of soybean hull:corn. The experimental period was divided into 5 periods of 28 d each. Throughout the experimental period, total dry matter intake (DMI) was recorded daily, whereas mineral salt intake was recorded weekly. Blood and ruminal fluid samples were collected on day 0 (prior to treatment feeding), 28, 56, 84, 112, and 140 of the study. Moreover, total tract apparent nutrient digestibility was performed for a 5-d period every 28 d. No treatment effects were observed on forage, mineral, concentrate, or total DMI (P ≥ 0.22). Nonetheless, 13NAR tended to have a greater mineral intake vs. 20NAR cohorts (P = 0.08) Narasin-supplemented animals had reduced rumen acetate, Ac:Pr ratio, as well as greater (P ≤ 0.02) rumen propionate concentrations vs. CONT cohorts. Moreover, 13NAR increased rumen propionate and decreased butyrate, Ac:Pr vs. 20NAR cohorts (P ≤ 0.01). Throughout the experimental period, narasin-supplemented animals had reduced ammonia concentrations vs. CONT cohorts (P < 0.01), whereas no differences were observed between 13NAR and 20NAR (P = 0.80). No treatment or dose effects were observed (P ≥ 0.23) on DM, organic matter (OM), protein, neutral detergent fiber (NDF), acid detergent fiber (ADF), and mineral digestibility. Animals fed 13NAR had a reduced mean plasma urea concentration vs. CONT cohorts (P = 0.03), whereas no further differences were observed (P ≥ 0.12). In summary, narasin supplementation to beef steers offered a high-forage diet did not impact forage, mineral, and total DMI, as well as nutrient digestibility, whereas rumen fermentation characteristics, rumen ammonia, and plasma urea concentrations were positively impacted and lasted throughout the experimental period. Additionally, 13 ppm of narasin resulted in a reduced Ac:Pr ratio and rumen ammonia when compared to animals supplemented with 20 ppm.

Effect of feeding broccoli floret residues on leghorn layer performance and egg quality and nutrient digestibility

ABSTRACT1. A study was conducted to determine the effects of dried broccoli floret (DBF) on egg production parameters, egg quality and apparent nutrient digestibility of laying hens. It was hypothesised that feeding DBF can improve egg quality without adversely affecting layer performance.2. Seventy-two White Leghorn layers aged 62 weeks were randomly allotted to 4 dietary treatments (6 cage replicates with 3 hens each) and fed diets containing 0, 40, 80 and 120 g/kg DBF in feed for 56 d.3. Inclusion of DBF had no effect on feed intake, egg production, feed conversion ratio or egg components. However, egg weight increased (linear effect, P < 0.05) as the level of DBF in the diet increased. Egg breakage strength, eggshell strength and Haugh unit were not influenced by dietary treatments. Egg yolk colour (quadratic effect, P = 0.002) and α-tocopherol concentration (quadratic effect, P < 0.0001) improved as a result of DBF inclusion. Egg yolk cholesterol concentration was not altered by DBF inclusion. Apparent total tract nutrient (dry matter, organic matter and crude protein) digestibility coefficients decreased (linear effect, P < 0.05) as the level of DBF increased.4. Feeding DBF to layers up to 120 g/kg of the diet had no negative effects on feed intake, egg production and feed efficiency and improved egg yolk colour and α-tocopherol concentration. However, total tract nutrient digestibility coefficients were negatively decreased as a result of DBF inclusion.

Animal health and greenhouse gas intensity: the paradox of periparturient parasitism

Here we provide the first known direct measurements of pathogen challenge impacts on greenhouse gas production, yield and intensity. Twin-rearing ewes were ad libitum fed pelleted lucerne from day −32 to 36 (day 0 is parturition), and repeatedly infected with 10,000 Teladorsagia circumcincta infective larvae (n=16), or sham-dosed with water (n=16). A third group of 16 ewes were fed at 80% of uninfected ewes’ feed intake during lactation. Methane emissions were measured in respiration chambers (day 30–36) whilst total tract apparent nutrient digestibility around day 28 informed calculated manure methane and nitrous oxide emissions estimates. Periparturient parasitism reduced feed intake (−9%) and litter weight gain (−7%) and doubled maternal body weight loss. Parasitism reduced daily enteric methane production by 10%, did not affect the methane yield per unit of dry matter intake but increased the yield per unit of digestible organic matter intake by 14%. Parasitism did not affect the daily calculated manure methane and nitrous oxide production, but increased the manure methane and nitrous oxide yields per unit of dry matter intake by 16% and 4%, respectively, and per unit of digestible organic matter intake by 46% and 31%, respectively. Accounting for increased lucerne input for delayed weaning and maternal body weight loss compensation, parasitism increased the calculated greenhouse gas intensity per kg of lamb weight gain for enteric methane (+11%), manure methane (+32%) and nitrous oxide (+30%). Supplemented with the global warming potential associated with production of pelleted lucerne, we demonstrated that parasitism increased calculated global warming potential per kg of lamb weight gain by 16%, which was similar to the measured impact of parasitism on the feed conversion ratio. Thus, arising from a pathogen-induced feed efficiency reduction and modified greenhouse gas emissions, we demonstrated that ovine periparturient parasitism increases greenhouse gas intensity. This implies that ewe worm control can not only improve production efficiency but also reduce the environmental footprint of sheep production systems.

Effect of feeding a by-product feed-based silage on nutrients intake, apparent digestibility, and nitrogen balance in sheep.

BackgroundLiterature is lacking on the effects of feeding by-product feed (BF)-based silage on rumen fermentation parameters, nutrient digestion and nitrogen (N) retention in sheep. Therefore, this study was conducted to determine the effect of replacing rye straw with BF-based silage as a roughage source on ruminal parameters, total-tract apparent nutrient digestibility, and N balance in sheep.MethodsThe by-product feed silage was composed of spent mushroom substrate (SMS) (45 %), recycled poultry bedding (RPB) (21 %), rye straw (11 %), rice bran (10.8 %), corn taffy residue (10 %), protected fat (1.0 %), bentonite (0.6 %), and mixed microbial additive (0.6 %). Six sheep were assigned randomly to either the control (concentrate mix + rye straw) or a treatment diet (concentrate mix + BF-based silage).ResultsCompared with the control diet, feeding a BF-based silage diet resulted in similar ruminal characteristics (pH, acetate, propionate, and butyrate concentrations, and acetate: propionate ratio), higher (p < 0.05) ruminal NH3-N, higher (p < 0.05) ether extract digestibility, similar crude protein digestibility, lower (p < 0.05) dry matter, fiber, and crude ash digestibilities, and higher (p < 0.05) N retention (g/d)ConclusionThe BF-based silage showed similar energy value, higher protein metabolism and utilization, and lower fiber digestion in sheep compared to the control diet containing rye straw.

Nutritional Evaluation of Pulses and Soybean Meal in Dogs

Six adult Labrador dogs were used in this experiment to evaluate total tract apparent nutrient digestibility and energy values of some protein feedstuffs. Seven digestibility trials were conducted. The 30% of basal diet was replaced with test ingredient which included one conventional feed ingredient i.e. soybean (Glycine max) meal (SBM) and five pulses (black-eyed pea or roongi (Vigna unguiculata), red lentil or masoor (Lens culinaris) dhuli, moong (Vigna radiata) dhuli, split bengal gram or chana (Cicer arietinum) dal and split black gram or urad (Vigna mungo) dhuli dal). The prepared mash diets were cooked and then fed to each dog as per their body weight and nutrient requirement. The difference/substitution method was used to estimate total tract apparent nutrient digestibility and energy values of these six protein ingredients. The DM, OM, CP, EE digestibility of masoor dhuli dal was significantly (P<0.05) higher than all other protein ingredients. The digestibility of DM, CP, EE, CF and DE in SBM was similar to that in masoor dhuli dal, however, ME value of masoor dhuli dal was higher (P<0.05) than that of SBM. The ME value of chana dal and mung dhuli dal was similar to that of SBM. It was concluded that masoor dhuli dal could be used as an effective protein source in dog diets.

Effect of the particle size of maize, rice, and sorghum in extruded diets for dogs on starch gelatinization, digestibility, and the fecal concentration of fermentation products.

The influence of rice, maize, and sorghum raw material particle size in extruded dry dog food on the digestibility of nutrients and energy and the fecal concentration of fermentation products was investigated. Three diets with similar nutrient compositions were formulated, each with 1 starch source. Before incorporation into diets, the cereals were ground into 3 different particle sizes (approximately 300, 450, and 600 µm); therefore, a total of 9 diets were in a 3 × 3 factorial arrangement (3 cereals and 3 particle sizes). Fifty-four beagle dogs (12.0 ± 0.1 kg BW) were randomly assigned to the diets, with 6 dogs per diet. The digestibility was measured with the chromium oxide method. The data were evaluated with ANOVA considering the carbohydrate source, grinding effect, and interactions. The means were compared with the Tukey test and polynomial contrasts (P < 0.05). With the same grinding procedure, rice was reduced to smaller particles than other cereals. The cereal mean geometric diameter (MGD) was directly related to starch gelatinization (SG) during extrusion. For rice diets, the MGD and SG did not change nutrient digestibility (P > 0.05); only GE digestibility was reduced at the largest MGD (P < 0.01). For maize and sorghum diets, the total tract apparent nutrient digestibility was reduced for foods with greater MGD and less SG (P < 0.01). A linear reduction in nutrient digestibility according to cereal particle size was observed for sorghum (r2 < 0.72; P < 0.01). Higher concentrations of fecal total short-chain fatty acids (SCFA) were observed for sorghum diets (P < 0.05) than for other diets. The rice diets led to the production of feces with less lactate (P < 0.05). The increase in raw material MGD did not influence fecal SCFA for rice diets, but for the dogs fed maize and sorghum foods, an increase in propionate and butyrate concentrations were observed as MGD increased (P < 0.05). In conclusion, for dogs fed different particle sizes of the cereal starches in the extruded diets, the digestibility and fecal characteristics were affected, and this effect was ingredient dependent.

Effects of corn and soybean meal types on rumen fermentation, nitrogen metabolism and productivity in dairy cows.

Twelve multiparous Holstein dairy cows in mid-lactation were selected for a replicated 4×4 Latin square design with a 2 ×2 factorial arrangement to investigate the effects of corn and soybean meal (SBM) types on rumen fermentation, N metabolism and lactation performance in dairy cows. Two types of corn (dry ground [DGC] and steam-flaked corn [SFC]) and two types of SBM (solvent-extracted and heat-treated SBM) with different ruminal degradation rates and extents were used to formulate four diets with the same basal ingredients. Each period lasted for 21 days, including 14 d for adaptation and 7 d for sample collection. Cows receiving SFC had a lower dry matter (DM) and total N intake than those fed DGC. However, the milk yield and milk protein yield were not influenced by the corn type, resulting in higher feed and N utilization efficiency in SFC-fed cows than those receiving DGC. Ruminal acetate concentrations was greater and total volatile fatty acids concentrations tended to be greater for cows receiving DGC relative to cows fed SFC, but milk fat content was not influenced by corn type. The SFC-fed cows had lower ruminal ammonia-N, less urea N in their blood and milk, and lower fecal N excretion than those on DGC. Compared with solvent-extracted SBM-fed cows, cows receiving heat-treated SBM had lower microbial protein yield in the rumen, but similar total tract apparent nutrient digestibility, N metabolism measurements, and productivity. Excessive supply of metabolizable protein in all diets may have caused the lack of difference in lactation performance between SBM types. Results of the present study indicated that increasing the energy degradability in the rumen could improve feed efficiency, and reduce environmental pollution.

Effects of maize conservation techniques on the apparent total tract nutrient and mineral digestibility and microbial metabolites in the faeces of growing pigs

A digestibility trial was conducted to investigate the effects of different maize conservation techniques on the nutrient digestibility of a commercial maize–soybean meal diet fed to growing pigs. The influence on the content of biogenic amines, volatile fatty acids (VFAs) and ammonia in the faeces was also determined. Maize was either dried (dried maize), ensiled after milling (maize silage) or tight-closed-stored (TCS-maize) as a whole grain. Nine growing pigs (35.1±0.8kg) were used in a 3×3 Latin square experiment. They were fed diets based on the different maize conserves, barley and soybean meal to ensure the same content of N, energy and digestible phosphorus (P) in the diet. The apparent total tract digestibility (ATTD) of the DM, ash and starch was improved (P<0.05), and the ATTD of the ether extract tended to be improved (P<0.10) when the maize was fermented. Moreover, based on the results related to the ATTD of P in the different maize conserves of a previous study, less P was added to diets that were based on fermented maize. Nevertheless, the P excretion was reduced without compromising P utilisation. The metabolic products of the gut microorganisms, biogenic amines and most VFAs in the faeces were reduced when the animals were fed fermented maize (P<0.05). The observed effects were more pronounced in the maize silage treatment. In conclusion, the current data suggest that the air-proofed storage of wet maize can be a strategy to improve the feeding value of maize-based diets fed to pigs.

The effect of an exogenous amylase on performance and total-tract digestibility in lactating dairy cows fed a high-byproduct diet

The objective of this experiment was to determine the performance and digestibility response of lactating dairy cows fed a reduced-starch diet containing a commercial amylase product. Treatments consisted of a normal-starch total mixed ration (NS−), a reduced-starch total mixed ration (RS−), and a reduced-starch total mixed ration with exogenous amylase (RS+) added to the concentrate. Treatments were assigned according to a replicated 3×3 Latin square design with 28-d periods. Twenty-three cows completed the study. Starch concentrations in NS−, RS−, and RS+ total mixed rations were 27.7, 23.5, and 22.7%, respectively. Effects of treatment on intake, milk production, milk composition, and total-tract apparent nutrient digestibility were evaluated during the last week of each period. Effects of amylase on in vitro starch digestibility of the NS− and RS− grain mixes were also measured. We hypothesized that the reduction in dietary starch in the RS− ration would decrease diet digestibility and limit milk production compared with NS− due to a decrease in available energy, and that RS+ would alleviate some of this decrease by increasing nutrient digestibility. Contrary to this hypothesis, the RS− diet did not affect intake or milk production relative to the NS− diet, except for increased milk urea nitrogen and a tendency for a decrease in milk protein yield. This lack of response is attributed to both low milk fat concentrations across treatments and greater than predicted dietary energy content preventing the energy deficit that was intended to occur with the reduced-starch rations. Cows fed the RS+ ration had the lowest production performance, with reduced milk, fat-corrected milk, protein, and lactose yields relative to cows fed NS−. Cows fed RS+ also had reduced lactose yield and tended to have reduced milk and fat-corrected milk relative to cows fed RS−. Despite the negative effects of the RS+ treatment on performance, exogenous amylase did increase both in vitro and in vivo measurements of digestibility. Although amylase increased nutrient digestibility, this did not translate into improved milk performance, likely due to the relatively high energy content of experimental diets compared with cow requirements.

Effects of a xylanase and protease, individually or in combination, and an ionophore coccidiostat on performance, nutrient utilization, and intestinal morphology in broiler chickens fed a wheat-soybean meal-based diet

The effects of 2 single exogenous and monocomponent feed enzymes, and their combination, and an ionophore coccidiostat on production performance, feed AME(n), nutrient utilization, and intestinal morphology were studied in broiler chickens. One-day-old unvaccinated and unsexed Ross 308 birds (n = 320) were kept in groups of 8 on wood shavings in pens raised from the floor and fed one of 5 experimental diets, replicated 8 times, for 36 d. Treatments were 1) a wheat-soybean meal-based feed with no added coccidiostats or exogenous enzymes (CON), 2) CON + ionophore coccidiostat (Narasin), 3) CON + xylanase (Ronozyme WX CT; XYL), 4) CON + serine protease (Ronozyme ProAct CT; PRO), or 5) CON + xylanase + serine protease (XYL+PRO). Enzymes were added on top in the feed formulation. Diets contained 0.5% TiO₂ to facilitate estimations of total tract apparent nutrient utilization. Treatments had no effect on BW gain or feed intake, but feed conversion, apparent digestibility of starch and fat, and feed AME(n) were improved with all enzyme treatments. The relative length of the ileum was reduced with XYL+PRO. For all parameters measured, the effects of XYL+PRO were similar to when XYL and PRO were fed individually. Narasin had no effect on production performance or nutrient utilization but reduced the relative lengths of jejunum and ileum. Relative lengths and weights of duodenum and cecum were unaffected by treatments. In conclusion, the improved feed conversion with both a xylanase and a protease was reflected in increased nutrient utilization, but their combination was not superior to when supplied separately. Narasin did not affect performance or nutrient utilization but reduced the relative lengths of the jejunum and ileum.

Digestibility and metabolizable energy of some carbohydrate sources for dogs

A digestibility study was conducted to determine the nutritional value of broken rice, high oil maize, millet, sorghum, maize germ, rice bran and wheat bran as ingredients for dog foods. Eight adult dogs were housed in metabolic cages, and distributed into 8 × 8 Latin square experimental design, with eight diets and eight replicates per diet. The difference, or substitution method was used to estimate ingredient digestibility. A reference diet was formulated based on nutritional requirements of dogs. For each test diet, 300 g/kg of the reference diet was replaced with the ingredient evaluated. All the diets were extruded. The total tract apparent nutrient digestibility for high oil maize, sorghum, millet, broken rice, maize germ, wheat bran and rice bran were, respectively: 0.893, 0.905, 0.859, 0.905, 0.654, 0.593 and 0.550 for dry matter; 0.884, 0.884, 0.803, 0.753, 0.656, 0.682 and 0.729 for crude protein; 0.855, 0.786, 0.821, 0.668, 0.482, 0.538 and 0.852 for fat; 0.503, 0.741, 0.668, 0.744, 0.232, 0.209 and 0.129 for dietary fiber; and 0.986, 0.987, 0.991, 0.992, 0.955, 0.896 and 0.904 for starch. The metabolizable energy (MJ/kg, as-fed basis) was 14.4, 13.1, 13.5, 13.1, 9.1, 9.0 and 12.0, respectively.

Investigation on the effects of adding Direct– fed Microbial on total tract apparent nutrient digestibility in sheep

Growing concern over the use of antibiotics and other growth stimulation in the animal feed industry has increased interest in evaluating the effects of Direct-fed Microbial (DFM) on animal performance (Sullivan and Martin, 1999). Some bacterial direct-fed microbials also seem able to function in the rumen. Depending on the species or combination of species, they can increase digestibility. Modes of action are variable and include native rumen microbiota enhancement through increased substrate breakdown, enhancement of nutrient uptake, stabilising rumen pH and provision of growth factors. The objectives of this study were to evaluate the effects of DFM supplementation on total tract digestibility.

Starch Source Evaluation in Calf Starter: II. Ruminal Parameters, Rumen Development, Nutrient Digestibilities, and Nitrogen Utilization in Holstein Calves

Ruminal parameters, rumen development, nutrient digestibilities, and N utilization were estimated in Holstein calves fed starch from different sources. Ground corn, ground barley, ground wheat, and crimped oats were used to formulate 4 isostarch (25% of starter dry matter) pelleted diets. These diets were randomly allocated to calves (16 calves per treatment, 8 female and 8 male) and fed ad libitum along with mixed grass hay throughout the experiment. Ruminal contents and blood were sampled at d 35, 50, and 70 of age to estimate ruminal parameters and plasma β-hydroxybutyrate, respectively. At d 70, twenty-four male calves (6/treatment) were randomly selected, euthanized, and forestomach weight, papillae length (PL), papillae width (PW), rumen wall thickness (RWT), and papillae concentration were measured. At d 63, twenty-four female calves (6/treatment) were randomly selected and moved to metabolism stalls to estimate total tract apparent nutrient digestibilities and N utilization. Female calves were given 2 wk for adaptation to experimental facilities and then total collections of feces and urine were made from d 77 to 84 of age. Ruminal pH at d 35 of age was higher in calves fed corn and oat diets than in those fed barley and wheat diets. Ruminal pH at d 50 and 70 of age was the lowest in calves on barley diets followed by those on oat and wheat diets and then by those on the corn diet. Ruminal total volatile fatty acid concentrations at d 35 of age were greatest in calves fed corn or wheat diets followed by those fed barley and oat diets. Calves on corn and wheat diets maintained greater ruminal volatile fatty acids concentrations at d 50 and 70 of age. Ruminal ammonia, acetate, propionate, butyrate, and blood β-hydroxybutyrate concentrations were also greater in calves on the corn and wheat diets. Full and empty weights of forestomach, PL, PW, RWT, and papillae concentrations were greater in calves on corn and wheat diets. Daily average intake of nutrients (dry matter, crude protein, neutral detergent fiber, starch, Ca, and P) was greater in calves fed corn and wheat diets than in those fed barley and oat diets. Starch source did not influence the total tract apparent digestibilities of nutrients in calves. Daily N retention (g/d) was greatest on the corn diet followed by the wheat diet and then the barley and oat diets. In conclusion, calves on a corn diet have greater ruminal capacity to accommodate feed bulk. More physically and metabolically functional rumens in calves on corn and wheat diets probably resulted in greater feed consumption and N retention.

Inclusion of oat hulls in diets for young pigs based on cooked maize or cooked rice

AbstractAn experiment was conducted to investigate the influence of the main cereal (cooked maize or cooked rice) and the inclusion of cooked and expanded oat hulls (0, 20 or 40 g/kg) in the diet on total tract apparent nutrient digestibility (TTAD) and productive performance of piglets weaned at 21 days. Each of the six treatments was replicated eight times (five piglets penned together) and the trial lasted for 33 days. From 21 to 41 days of age piglets were given their respective experimental complex diets that contained 530 g/kg cooked cereal and from 41 to 54 days they received a common starter diet based on maize, barley and soya-bean meal. Growth promoters were not included in the diets. The TTAD was determined at 27 and 37 days of age and pig performance was measured at 31, 41 and 54 days of age. Nutrient digestibility increased with age (P&lt;0·001) and in general were higher for rice- than for maize-based diets (P&lt;0·001 for dry matter, organic matter and gross energy andP&lt;0·05 for ether extract). From 21 to 41 days of age piglets given rice had higher food intake (FI,P&lt;0·05) and average daily gain (ADG,P&lt;0·01) than piglets given maize but food conversion ratio was not affected. The differences observed were maintained until the end of the trial. The inclusion of oat hulls in the diet did not affect TTAD of the nutrients but tended to reduce the incidence of diarrhoea from 21 to 41 days of age (P&lt;0·1). Oat hulls inclusion reduced FI and ADG in diets based on maize but had the opposite effect in diets based on rice, indicating that piglets might have a minimum requirement for dietary fibre. It is concluded that cooked rice is an ingredient of choice in pre-starter diets for weanling pigs. Also, the inclusion of moderate levels of fibre as oat hulls reduces the incidence of diarrhoea and might improve productive performance in low fibre diets.