Tract Digestibility Of Crude Protein Research Articles

Prediction of apparent total tract digestion of crude protein in adult dogs.

To predict the apparent total tract digestibility (ATTD) of crude protein (CP) in dogs we developed an in vitro system using an in vitro digestion method and a statistical analysis. The experimental diets used chicken meat powder as the protein source, with CP levels of 20% (22.01%, analyzed CP value as dry-based), 30% (31.35%, analyzed CP value as dry-based), and 40% (41.34%, analyzed CP value as dry-based). To simulate in vivo digestive processes a static in vitro digestion was performed in two steps; stomach and small intestine. To analyze ATTD the total fecal samples were collected in eight neutered beagle dogs during the experimental period. CP digestibility was calculated by measuring CP levels in dog food, in vitro undigested fraction, and dog feces. In result, CP digestibility at both in vivo and in vitro was increased with increasing dietary CP levels. To estimate in vivo digestibility the co-relation of in vivo ATTD and in vitro digestibility was investigated statistically and a regression equation was developed to predict the CP ATTD (% = 2.5405 × in vitro CP digestibility (%) + 151.8). The regression equation was evaluated its feasibility by using a commercial diet. The predicted CP digestibility which was calculated by the regression equation showed high index of similarity (100.16%) with that of in vivo in dogs. With that, it would be a feasible non-animal method to predict in vivo CP digestibility by using in vitro digestion method and the proposed linear regression equation in adult dogs.

Influences of exocrine pancreatic insufficiency on nutrient digestibility, growth parameters as well as anatomical and histological morphology of the intestine in a juvenile pig model.

In a pig model, pancreatic duct ligation (PL) leads to a complete loss of exocrine function, causing an exocrine pancreatic insufficiency (EPI) without affecting endocrine function, allowing research of clinical effects and therapy options. This study aimed to investigate effects of experimentally induced EPI in juvenile pigs on digestion and intestinal morphology. Eight female juvenile cross-bred pigs (BW 54.8 kg at the start of the study) were included. Three animals were considered as a control (CON group), and in five animals the ductus pancreaticus accessorius was ligated (PL group). During the 10-week trial period, body weight and body measurements were recorded regularly. At the end of the trial, gastrointestinal tract (GIT) was investigated macroscopically and histologically and weight and digesta samples of individual segments were obtained. The pigs in the CON showed a significantly higher apparent total tract digestibility of crude protein and crude fat (87.8 and 79.9%, respectively) compared to PL (52.4 and 16.6%, respectively). Significant differences were noted in relative weights of duodenum, jejunum and colon (with and without digesta) and also in absolute weights of jejunum and colon. The mean number of nuclei in the transverse section in stratum circulare were significantly higher in all intestinal segments in CON compared to PL. Overall, EPI results in impaired nutrient digestibility with a greater filling of the GIT with digesta. The elongation of the small intestine does not represent “stretching” of the intestine, but rather increased synthesis of intestinal tissue.

Effect of zinc sources and experimental conditions on zinc balance in growing wethers.

Three experiments were conducted with growing wethers to evaluate apparent excretion and retention of Zn from various sources. In experiments 1 and 2, Zn-ethylene diamine (ZE), Zn hydroxychloride (ZHYD), Zn-lysine/glutamate (ZAA), and Zn-glycinate (ZG) were used and ZnSO4 (ZS), ZHYD, ZAA, and ZG were used in experiment 3. In experiment 1, eight wethers were used in a replicated 4 × 4 Latin square design. In experiments 2 and 3, 40 wethers were used in a randomized block design. In experiment 1, each period (total four periods) consisted of 14-d diet adaptation and 4 d of total collection of feces and urine. In experiments 2 and 3, wethers received a basal diet for 14 d and received experimental diets for 9 d (diet adaptation), followed by 4 d of total collection of feces and urine. Total collection was conducted in wooden metabolic cages. All data were analyzed using the MIXED procedure of SAS as a Latin square design for experiment 1 and a completed randomized block design for experiments 2 and 3. In all experiments, dry matter intake did not differ among treatments except that it tended to be different in experiment 2. In experiment 1, no difference in Zn excretion (88%) and retention (11%) as proportion of Zn intake was observed among Zn sources. In experiment 2, total tract digestibility of crude protein was greater (P < 0.01) for ZAA than ZE and ZG (82.0% vs. 79.1% and 77.8%, respectively) and greater (P < 0.01) for ZHYD than ZG (80.2% vs. 77.8%). However, total tract digestibility of neutral detergent fiber was low (on average 16%) for all treatments with no difference among treatments in experiment 2. Apparent excretion and retention of Zn as proportion of Zn intake did not differ among treatments, and Zn retention (~1.4% of Zn intake) was very low for all treatments. In experiment 3, ZHYD and ZAA had greater retention of Zn (17.8% vs. 1.5%; P = 0.01) than ZG. Fecal Zn excretion was greater (97.3% vs. 81.2%; P = 0.01) for ZG vs. ZHYD and ZAA, and Zn retention for ZG was only 1.5% of Zn intake. In conclusion, potential increases in Zn absorption and retention were observed for ZHYD and ZAA compared with ZS and ZG in experiment 3 and these differences were not found in experiments 1 and 2. Experiment 1 used a Latin square design and experiment 2 used a diet containing largely undigestible fiber. These experimental conditions may have affected Zn metabolism in wethers. Inconsistent results on Zn balance for ZG among the experiments warrant further studies regarding its bioavailability.

Effects of Microencapsulated Methionine on Milk Production and Manure Nitrogen Excretions of Lactating Dairy Cows.

Simple SummaryMethionine (Met) deficiency in the diet can limit milk protein production and lead to excessive nitrogen (N) excretions to the environment by dairy cows. We demonstrated that the supplementation of a new rumen-protected Met product to a Met deficient diet increased milk protein yield and decreased manure N excretions of high producing dairy cows. Increased blood flow to the mammary glands and increased apparent total tract digestibility of dietary crude protein seem to be the underlying mechanisms for those improvements in production and the environmental sustainability.The study objective was to determine the effects of rumen-protected methionine (Met) by microencapsulation (RPM) on amino acid (AA) supply to the udder, milk production, and manure nitrogen (N) losses of dairy cows. A corn and soybean-based diet deficient in metabolizable Met (~10 g/d) was supplemented with RPM providing 0, 11.0, 19.3, and 27.5 g/d of Met. Dry matter intake (DMI), milk production, plasma essential AA (EAA), mammary plasma flow (MPF), and fecal (FN) and urinary N (UN) outputs (g/d) were determined. The RPM increased linearly milk yield, milk protein yield, and energy corrected milk yield (p < 0.040) without affecting DMI. Milk protein yield increased by 50 g/d for the 19.3 vs. 0 g/d dose (p = 0.006) but the rate of increment decreased for 27.5 g/d dose. Plasma Met, and MPF increased linearly with RPM dose (p < 0.050). Apparent total tract digestibility of crude protein (p = 0.020) and FN (p = 0.081) decreased linearly with RPM. The UN did not change but total manure N decreased linearly with RPM (p = 0.054). The RPM (19.3 g/d) seemed to help cows overcome the metabolizable Met deficiency while mitigating manure N excretions to the environment.

Methane emissions and δ13C composition from beef steers consuming increasing proportions of sericea lespedeza hay on bermudagrass hay diets.

An experiment was conducted to evaluate the effects of different proportions of 'Au Grazer' sericea lespedeza [SL, Lespedeza cuneata (Dum. Cours.) G. Don], a legume rich in condensed tannins (CT), on nutrient intake and digestibility, and to estimate methane (CH4) emissions and 13C isotopic composition (δ13CCH4) from beef steers consuming a forage-based diet. Twenty-five Angus-crossbred steers were distributed in a randomized complete block design (344 ± 48 kg initial BW), and randomly assigned to one of five treatments: 0SL, 25SL, 50SL, 75SL, and 100SL, diets containing 0%, 25%, 50%, 75%, and 100% of SL hay, respectively, mixed with 'Tifton-85' bermudagrass hay (Cynodon spp.). The study was carried out for two experimental periods of 21-d each. The statistical model included the fixed effect of treatment and random effects of block, experimental period, and their interaction. Apparent total tract digestibility of crude protein, neutral detergent fiber, and acid detergent fiber was linearly decreased (P < 0.001) by the inclusion of SL. No effects were observed for total CH4 emissions per day, nor for CH4 relative to organic matter intake or digestible organic matter with the inclusion of SL. However, emission of CH4 in relation to intake of CT was affected by treatment (P < 0.001). A linear (P < 0.001) decrease and a quadratic effect (P < 0.001) were observed for δ13C of diets and gas, respectively, in which diets and enteric CH4 with greater inclusion of SL were more depleted in 13C. Moreover, the difference in δ13C between diets and gas (Δδ13C) had a linear decrease (P = 0.001) with the inclusion of SL. The model developed to predict the C3 proportions in the enteric CH4 fitted to predicted values (P < 0.0001). Therefore, greater proportions of SL resulted in lesser CH4 emission when CT intake was considered and the isotopic composition from enteric CH4 was able to predict the contribution of SL in the emissions.

Effects of Organic acid Blend on Growth Performance, Nutrient Digestibility and Concentration of Volatile Fatty Acids in the Faeces of Young Pigs

Abstract The objective of this experiment was to evaluate the effects of a feeding diet containing a dry organic acid blend (lactic acid—ammonium formate—ammonium propionate—citrate—sorbate) in young pigs on their: performance, the apparent total tract digestibility of nutrients and the concentration of volatile fatty acids in their faeces. A total of 12 crossbred pigs (Slovakian White × Landrace) with an initial live weight of 12.78 ± 1.86 kg were divided into two dietary treatments. The experimental period lasted 28 days. Pigs were fed a control diet (control group) or a diet supplemented with a dry organic acid (OA) blend, 0.6 g per 100 g feed (experimental group). Compared with the control group, the average daily gain (ADG) was improved (P &lt; 0.05) by OA blend over the period of the investigation (0—28 days). For the apparent total tract digestibility determination, ash which is insoluble in hydrochloric acid was used as a marker. The apparent total tract digestibility of crude protein and total ash was improved (P &lt; 0.05) by the OA blend in the experiment. Compared with the control group, the concentration of the total volatile fatty acid in the faeces increased (P &lt; 0.05) in pigs supplemented with the OA blend. The concentration of butyric acid in the faeces tended to be higher (P &lt; 0.01) in pigs supplemented with the OA blend compared with the control group. In conclusion, the addition of 0.6 g per 100 g feed had a positive effect on: growth performance, total tract digestibility of crude protein and the concentration of volatile fatty acids in the faeces of young pigs.

183 Isoquinoline alkaloids increase apparent ileal digestibility of amino acids and crude protein and apparent total tract digestibility of crude protein by finishing pigs fed corn-soybean meal diets

Abstract An experiment was conducted to determine if the inclusion of a preparation of isoquinoline alkaloids (IQ) in corn-soybean meal diets fed to finishing pigs increases the apparent ileal digestibility (AID) of amino acids (AA) and crude protein (CP) and the apparent total tract digestibility (ATTD) of CP and gross energy. Twelve ileal cannulated barrows (BW: 77.2 ± 6.23 kg) were allotted to a triplicated 4 x 3 incomplete Latin square design with 4 diets and 9 replicates per diet. Diets were supplemented with either 0, 40, 80, or 160 mg/kg IQ and with 0.40% titanium dioxide as an indigestible marker. Each collection period lasted 14 d with d 1 through 10 as an adaptation to the diets, fecal samples were taken using the grab sampling technique on d 11 and 12, and ileal digesta were collected for 8 h on d 13 and 14. Data were analyzed using the Proc MIXED procedure of SAS. Contrast statements were used to determine linear and quadratic effects of including IQ in the diets. Results were considered significant at P ≤ 0.05 and considered a trend at 0.05 &amp;lt; P ≤ 0.10. Inclusion of IQ resulted in a quadratic increase (P &amp;lt; 0.05) in the AID of CP and AA in corn-soybean meal diets fed to finishing pigs, with the greatest digestibility values generally observed in the 40 mg/kg IQ treatment. Additionally, IQ resulted in a quadratic increase (P = 0.009) in the ATTD of CP, with the greatest digestibility observed in the 80 mg/kg IQ treatment. Therefore, it was concluded that supplementing corn-soybean meal diets with 40 or 80 mg/kg IQ may increase the AID of CP and AA and ATTD of CP by finishing pigs.

Betaine improves growth performance by increasing digestive enzymes activities, and enhancing intestinal structure of weaned piglets

This study investigated the effects of betaine on digestive enzymes and intestinal structures of weaned piglets. A total of 150 crossbred weaned piglets (Duroc × Landrace × Yorkshire), with an average initial body weight of 8.52 ± 0.26 kg and age of 39 day (weaned on day 25), were randomly divided into three dietary treatments, each of which was replicated five times with ten piglets per replicate/pen (five male piglets and five female piglets in each replicate/pen). The dietary treatments were basal diet supplemented with 0, 1250, 2500 mg/kg betaine, respectively. The experiment lasted 30 days. The results showed that supplementation of betaine in diet linearly increased average daily gain (ADG), decreased diarrhea rate, and improved feed conversion ratio (FCR). Betaine increased the apparent total tract digestibility of crude protein (CP) (linearly) and ether extract (EE) (linearly and quadratically) and the activities of amylase (linearly and quadratically), trypsin (linearly and quadratically), and lipase (linearly) in small intestine. The effect of betaine on digestive enzyme activities was more effective at 2500 mg/kg than that at 1250 mg/kg. In vitro enzymatic reaction studies found that betaine inclusion could boost the affinity of amylase and trypsin with their corresponding substrates, and counteract the inhibitory effect of hyperosmolarity induced by NaCl. Betaine also significantly increased villus height and the ratio of villus height to crypt depth of small intestine. Betaine increased the expression of tight junction proteins while decreased the plasma concentration of diamine oxidase (DAO). The effect of betaine on intestinal structure was more profound at 1250 mg/kg than that at 2500 mg/kg. Besides, betaine also increased the activity of glutathione peroxidase (GSH-Px) in the gut (linearly and quadratically). In conclusion, dietary supplementation of betaine enhanced intestinal structure and reduced diarrhea rate, increased digestive enzyme activities and promoted digestion of nutrients, and therefore, improved the growth performance of weaned piglets.

95 Betaine improves growth performance by increasing digestive enzymes activities, and ameliorating intestinal structure of piglets

Abstract This study was aimed to investigate the effects of betaine on intestinal structures and digestive enzyme activities of piglets. A total of 150 crossbred piglets (Duroc × Landrace × Yorkshire), with an average initial body weight of 8.52 ± 0.26 kg and age of 39-day, were randomly divided into three dietary treatments, each of which was replicated five times with ten pigs per replicate. The dietary treatments were basal diet supplemented with 0, 1250, 2500 mg/kg betaine, respectively. The experiments lasted for 30 days. The results showed that supplementation of betaine in the diet significantly increased average daily gain (P &amp;lt; 0.05), decreased diarrhea rate (P &amp;lt; 0.05), and improved feed conversion rate (P &amp;lt; 0.05) of piglets. The villus height and the ratio of villus height to crypt depth of small intestine were significantly increased with betaine supplementation (P &amp;lt; 0.05). The addition of betaine in diet also increased the expression of tight junction proteins in small intestine (P &amp;lt; 0.05) and decreased the diamine oxidase in plasma (P &amp;lt; 0.05). The apparent total tract digestibility of crude protein and ether extract (P &amp;lt; 0.05) and the activities of amylase, trypsin, and lipase (P &amp;lt; 0.05) in small intestinal were increased with betaine addition. Enzyme kinetic experiments in vitro indicated that hypertonic environment formed by NaCl could inhibit the activities of amylase and trypsin. While betaine addition improved the affinity of amylase and trypsin with their corresponding substrates, thereby counteracted the inhibitory effect of hyperosmolarity. In conclusion, the supplementation of betaine in diet could improve growth performance of piglets by ameliorating intestinal structure, increasing digestive enzymes activities, promoting the digestion of nutrients and decreasing the diarrhea rate.

Effects of folic acid and sodium selenite on growth performance, nutrient digestion, ruminal fermentation and urinary excretion of purine derivatives in Holstein dairy calves

This study evaluated the effects of folic acid (FA) and sodium selenite (SS) supplements on growth performance, nutrient digestion, ruminal fermentation, microbial enzyme activity, microflora and urinary excretion of purine derivatives (PD) in dairy calves. Thirty-six Holstein calves (63 ± 3.4 days of age and 83 ± 2.1 kg of body weight) were randomly assigned to four treatments in a 2 × 2 factorial arrangement. Two levels of FA (0 or 3.0 mg/kg of FA) and SS (0 or 0.3 mg/kg of Se from SS) were added into diets on a dry matter (DM) basis. Nutrient intake and average daily gain increased with FA addition, but were not affected by SS addition. Both supplements increased total tract digestibility of DM, organic matter and neutral detergent fiber. Ruminal pH and ammonia N concentration decreased, but total volatile fatty acids concentration increased with FA or SS addition. Acetate molar proportion and acetate to propionate ratio increased, while propionate molar proportion decreased with FA addition. The unchanged acetate molar proportion, higher propionate molar proportion and lower acetate to propionate ratio were observed with SS addition compared with the control. Activities of xylanase, pectinase, α-amylase and protease as well as populations of total bacteria, protozoa and methanogens were higher for both supplements compared with the control. Carboxymethyl-cellulase activity and Prevotella ruminicola population increased with FA addition. The Ruminobacter amylophilus population decreased with SS addition. The FA×SS interaction was significant for total tract digestibility of crude protein and acid detergent fiber, populations of total fungi, Ruminococcus (R.) albus, R. flavefaciens, Fibrobacter succinogenes and Butyrivibrio fibrisolvens as well as urinary total PD excretion; these variables increased with SS addition and the increase was greater when the diet was not supplemented with FA than with FA supplemented diet. The results indicated that dietary FA and/or SS addition stimulated nutrient digestion, ruminal fermentation, microbial growth and urinary total PD excretion.

Yeast extract could be used as a partial substitute for spray-dried porcine plasma in diets for weaned pigs

The previous study has been identified that yeast extract (YE) could be a potential substitute for spray-dried porcine plasma (SDPP) as a superior protein ingredient in diets for pigs in terms of the available energy and AA digestibility. This experiment was conducted to test the hypothesis that YE as a partial substitute for SDPP in diet could stimulate the immune responses and improve the performance and nutrient digestibility in weaned pigs. A total of 90 healthy pigs weaned at 28 d of age (8.5 ± 1.2 kg) were assigned into 3 treatments according to sex and weight in a randomized complete block design. The dietary treatments consisted of a negative control diet without YE and SDPP supplementation (NCD), NCD supplemented with 40 g/kg SDPP at the expense of soybean meal (SDPPD) or SDPPD supplemented with 20 g/kg YE at the expense of SDPP (YED). During the 28-d experimental periods, pigs fed YED and SDPPD improved average daily gain (P < 0.05) and feed efficiency (P < 0.05) compared with pigs fed NCD. No statistical differences in performance were observed between YED and SDPPD. The apparent total tract digestibility of crude protein was greater in pigs fed SDPPD and YED than those fed NCD (P < 0.05). Compared with pigs fed NCD, pigs fed YED decreased (P < 0.05) or tended to decrease (P = 0.09) urea nitrogen and diamine oxidase contents in serum. The serum IgG and IgM content was greater in pigs fed SDPPD and YED than those fed NCD (P < 0.05). The SDPPD and YED decreased serum tumor necrosis factor-α in comparison with NCD (P < 0.05). The YED decreased serum interleukin-6 (P < 0.05), and SDPPD increased serum interleukin-10 compared with NCD (P < 0.05). No statistical differences in small intestinal morphology or hindgut volatile fatty acids were detected among the treatments. Accordingly, YE could be a partial substitute for SDPP in diets for weaned pigs in terms of positive growth performance and immune function.

Effects of a matrix-coated organic acids and medium-chain fatty acids blend on performance, and in vitro fecal noxious gas emissions in growing pigs fed in-feed antibiotic-free diets

This study evaluated the efficacy of a matrix-coated organic acids and medium-chain fatty acids blend (MCOFA) in growing pigs. Ninety six pigs [(Yorkshire × Landrace) × Duroc] with an average body weight (BW) of 47.71 ± 3.73 kg were used in a 6 wk experiment. Pigs were allotted to diets containing 0 or 2 g kg−1 of MCOFA, and 0 or 2.5 g kg−1 of antibiotic growth promoters (AGP) according to a 2 × 2 factorial arrangement of treatments. Pigs fed diets supplemented with MCOFA had improved growth efficiency compared with those fed a diet without MCOFA (P &lt; 0.05). Pigs receiving the diets supplemented with both AGP and MCOFA had higher apparent total tract digestibility of crude protein, dry matter, fat, and gross energy (P &lt; 0.05). Pigs fed AGP × MCOFA diet had increased serum urea nitrogen (P &lt; 0.05). Pigs fed diets supplemented with AGP had reduced fecal ammonia (NH3) gas emissions compared with those fed without AGP (P &lt; 0.05). Moreover, pigs fed diets supplemented with MCOFA had reduced fecal NH3 and acetic acid gas emissions compared with those fed without MCOFA (P &lt; 0.05). In conclusion, dietary supplementation with MCOFA improved performance in growing pigs.

Ruminal methane emissions, metabolic, and microbial profile of Holstein steers fed forage and concentrate, separately or as a total mixed ration.

Few studies have examined the effects of feeding total mixed ration (TMR) versus roughage and concentrate separately (SF) on ruminant methane production. Therefore, this study compared differences in methane production, ruminal characteristics, total tract digestibility of nutrients, and rumen microbiome between the two feeding methods in Holstein steers. A total six Holstein steers of initial bodyweights 540 ± 34 kg were divided into two groups and assigned to a same experimental diet with two different feeding systems (TMR or SF) in a crossover design with 21 d periods. The experimental diet contained 73% concentrate and 27% forage and were fed twice a day. The total tract digestibility of crude protein, neutral detergent fibre, and organic matter were not affected by the two different feeding systems. Steers fed TMR emitted more methane (138.5 vs. 118.2 L/d; P < 0.05) and lost more gross energy as methane energy (4.0 vs. 3.5% gross energy intake; P = 0.005) compared to those fed SF. Steers fed TMR had greater (P < 0.05) total volatile fatty acid (VFA), ammonia-N concentrations and propionate proportion of total VFA at 1.5 h, whereas lower after that compared to steers fed SF. The greater (P < 0.05) acetate: propionate ratio at 4.5 h for steers fed TMR reflected the shift of H2 sink from propionate towards acetate synthesis. The lower (P < 0.05) isobutyrate and isovalerate proportions of total VFA observed in steers fed TMR implies decrease in net consumption of H2 for microbial protein synthesis compared to SF. There were no differences in both major bacterial and archaeal diversity between TMR and SF, unlike several minor bacterial abundances. The minor groups such as Coprococcus, Succiniclasticum, Butyrivibrio, and Succinivibrio were associated with the changes in ruminal VFA profiles or methanogenesis indirectly. Overall, these results indicate that SF reduces methane emissions from ruminants and increases propionate proportion of total VFA without affecting total tract digestion compared to TMR. There were no evidences that the response differed due to different major underlying microbial population.

Effects of dietary supplementation of spices on forage degradability, ruminal fermentation, in vivo digestibility, growth performance and nitrogen balance in Black Bengal goat.

The objective of the study was to evaluate the effects of spices on forage utilization and nitrogen (N) emission using in vitro and in vivo approach. A 6×5 factorial triplicate arrangement was used to assess the in vitro degradability of rice straw with control (without spices) and individual (40mg/g rice straw) spices (cumin, coriander, clove, black cumin, turmeric) at five different incubation times. In vitro dry matter (DM) and organic matter (OM) degradability of rice straw were highest in presence of spices except for clove. Clove significantly reduced the total volatile fatty acids concentration, molar proportion of acetate and propionate ratio, but increased propionate production. Acetate and butyrate production were not affected by treatments. The ammonia-nitrogen concentration was lowest for clove and turmeric compared to other spices. Rumen pH was unchanged but gradually decreased over the incubation period. For in vivo study, 12 bucks with average live weight 7.65±0.19kg were assigned to a completely randomized design with three treatments and four replicates for a 28-day period. Bucks were fed a total mixed ration without (0g/kg DM) or with (2.5, 7.5g/kg DM) clove supplementation. DM intake, body weight and apparent total tract digestibility of crude protein (CP) and acid detergent fibre (ADF) were not affected by increasing dietary doses of clove but tended (p=.09) to increase DM and OM digestibility. The urinary N and urine urea N concentration of bucks decreased linearly with incremental doses of clove diet. In contrary, clove supplementation had positive effects on plasma urea N and retained N in bucks. We concluded that though some spices had positive effects on ruminal digestion and fermentation, the dosage level assessed in the current study (up to 7.5g/kg DM clove) can be promoted as an effective dietary approach to mitigate N losses in bucks.

The effect of Lupinus albus seeds on digestibility, performance and gastrointestinal tract indices in pigs

The effect of soya bean meal (SBM) substitution in the diet with white lupine (WL) seeds on performances and some parameters of the digestive tract of pigs were studied. The digestibility experiment was performed on 30 pigs using difference method combined with marker method, where one group was offered basal diet and in diet of experimental groups 25% of the basal diet was substituted with SBM or WL meal. The growth experiment was conducted on 48 pigs of approximately 20kg body weight. The animals from the control group were fed with diet containing SBM, whereas in the experimental groups 50% or 100% of SBM was substituted with WL seeds. At the end of the experiment, eight pigs from each group were euthanized, and digesta and tissues were sampled. The apparent total tract digestibility of crude protein and dry matter was higher (p<0.05), but crude fibre and ether extract were lower (p<0.05) in the WL seeds than in SBM. Substituting 50% of SBM in the control diet with WL seeds did not affect significantly pig performance. Total substitution of SBM with WL seeds impacted negatively pigs growth and feed intake (p<0.05), but it did not affect the length of villi and crypt depth. It also significantly increased ileum digesta viscosity and ammonia concentration in the ileum and caecum digesta. In the ileal digesta of animals offered WL seeds, an increased (p<0.05) total bacterial and Enterobacteriaceae numbers were found, whereas reduced number of yeast and mould was found in the caecal digesta. The substitution of 50% SBM with WL seeds in the growing pig diet did not affect pigs' results, but the total substitution significantly decreased the performance of pigs and affected intestinal ecology.

Intake, milk production and heat stress of dairy cows fed a citrus extract during summer heat

Abstract This study determined effects of feeding a citrus extract (CE) to high producing dairy cows during summer heat on measures of heat stress, as well as milk production and composition, in a replicated 2 × 2 Latin square experiment with two 28 d periods on a dairy farm near Hanford (CA, USA). Four ‘high group’ pens were used ( i.e. , cows which had cleared the fresh pen but were not yet confirmed pregnant), each with ∼310 early lactation multiparity cows/pen. The two total mixed rations contained 171 g/kg dry matter (DM) crude protein (CP), 55 g/kg fat, 335 g/kg neutral detergent fiber (aNDF) and 135 g/kg starch, and were the same except for inclusion of the CE at 4 g/cow/d in the treatment diet (CED). Average daily high temperatures during the study were 35 to 37 °C with lows of 16–17 °C. In general, cows showed mild heat stress, but CE feeding had no effect on respiration rate, panting score or rump temperature at any time of the day ( i.e. , 02:45, 09:15, 17:30 h). However at 02:45 h, a higher ( P versus standing) compared with Control cows (68.6 versus 53.7 cows/100 cows), which is an indicator of reduced heat stress. Intake of DM (25.3 kg/d) and whole tract digestibility of CP (703 g/kg) and aNDF (510 g/kg) did not differ between treatments. Milk production (47.3 kg/d) and its fat and true protein levels (35.4, 28.6 g/kg) did not differ, and changes in body condition and locomotion scores were also not impacted by treatment. However mammary health improved based on lower SCC (somatic cell counts; P versus Control cows (160,000 versus 196,000 cells/μL), and lower linear SCC scores ( P versus 2.30). Feeding this CE to lactating dairy cows during summer heat decreased SCC with no impact on other aspects of performance.

Effect of graded levels of dietary betaine on ileal and total tract nutrient digestibilities and intestinal bacterial metabolites in piglets*

The study was conducted to investigate the effects of graded dietary inclusion levels of betaine on ileal and total tract nutrient digestibilities and intestinal bacterial metabolites in piglets. A total of eight barrows with an average initial body weight of 7.9 kg were randomly allocated to one of the four assay diets with two pigs per treatment in four repeated measurement periods. The assay diets included a basal diet based on wheat, barley and soybean meal alone, or supplemented with a liquid betaine product at dietary levels of 1.5, 3.0, or 6.0 g betaine per kilogram diet (as-fed). Ileal digestibilities of dry matter and neutral detergent fibre increased both quadratically and linearly, and ileal digestibility of glycine increased linearly as dietary betaine level increased (p < 0.05). Furthermore, total tract digestibility of crude protein increased quadratically (p < 0.05) and total tract digestibilities of most amino acids tended to increase quadratically (p = 0.06 to p = 0.11) with increasing dietary betaine level. Moreover, there were linear increases in the concentrations of most bacterial metabolites which were significant p < 0.05 for ileal d-lactic acid and for faecal diaminopimelic acid. The results demonstrate that dietary betaine supplementation stimulates bacterial fermentation of fibre in the small intestine and bacterial degradation of crude protein in the large intestine.

A meta-analysis of the effects of supplemental dietary fat on protein and fibre digestibility in the horse

Any associative effects between supplemental dietary fat and nutrient digestibility would have an influence in the calculation of digestible energy and nutrient values of horse diets. However, these effects are inconsistently reported in the literature. The use of meta-analysis, which accounts for variation among studies, could quantify differences in nutrient digestibility caused by fat supplementation. Too few studies have presented data on intake to evaluate the relation between dietary fat intake and nutrient digestibility through a modelling approach. Consequently, unitless standardised effect sizes (Hedges' g) were calculated within studies for differences in digestibility between supplemented and non-supplemented diets. Twenty-two studies were identified that provided 43 comparisons for apparent total tract digestibility of crude protein (CPD), 44 for neutral detergent fibre digestibility (NDFD), and 30 for acid detergent fibre digestibility (ADFD). The calculation of mean effect sizes across studies by fixed effects models presented significant ( P < 0.001) heterogeneity with all outcomes. Given that the causes of heterogeneity could not effectively be identified by meta-regression and subgroup analyses, random effects models, which include between-study and within-study variation, were used to summarise effect sizes. Compared to no supplementation, added fat had no effect (mean effect size = 0.204; 95% confidence intervals = − 0.101 to 0.509; P = 0.191) on CPD. Dietary fat supplementation did not affect NDFD (mean effect size = − 0.126; 95% confidence intervals = − 0.429 to 0.176; P = 0.413); however, it caused a significant ( P = 0.008) decrease in ADFD (mean effect size = − 0.430; 95% confidence intervals = − 0.749 to − 0.111). With the limited value of acid detergent fibre in practical feed formulation, current results indicate that the calculations of digestible energy values of fat supplemented horse diets will not be influenced by associative fibre effects.

Body weight gain and nutrient utilization in starter pigs that are liquid-fed high-moisture corn-based diets supplemented with phytase

A total of 384 starter pigs were used to examine the application of exogenous phytase in high-moisture corn (HMC)-based liquid diets. Pigs were randomly assigned to 24 pens in six blocks. Pens were randomly assigned one of four HMC-based diets formulated to vary in total phosphorus (P) content (Low, Medium and High), with phytase added to only the Low P diet (Phy). Body weight gain and feed intake were monitored until body weight exceeded 20 kg. Apparent total tract digestibility of crude protein and P were measured on day 21 (Phase II) and day 42 (Phase III). At the end of the trial, two pigs from each pen were sacrificed for analysis of carcass composition and evaluation of metacarpals. Pigs fed the Phy treatment had increased digestibility of crude protein (P &lt; 0.05) and P (P = 0.062) in Phase III, and increased metacarpal breaking strength (P &lt; 0.01) and P content (P &lt; 0.05). Average daily gain, feed intake, and carcass composition were not affected by treatment (P &gt; 0.05). In conclusion, performance of starter pigs fed liquid HMC-based diets was maintained at dietary P levels below established requirements, but addition of phytase improved bone strength and mineralization. This study provides evidence for the effectiveness of phytase, and that P requirement for maximum rate of weight gain in pigs is not sufficient for maximum skeletal development.Key words: High-moisture corn, liquid feed, phosphorus, phytase, starter pigs

Zero-tannin faba bean as a replacement for soybean meal in diets for starter pigs

The nutritional value of zero-tannin (ZT) faba bean for starter pigs is poorly characterized. Five mash diets containing 0, 10, 20, 30 or 40% ZT faba bean in substitution for soybean meal were fed to 75 pens of 5-wk-old pigs for 21 d. Increasing the dietary level of ZT faba bean did not affect average daily weight gain, feed intake or feed efficiency (P &gt; 0.05) for each weekly period and the entire study (days 0 to 21). Increasing the dietary level of ZT faba bean linearly increased apparent total tract digestibility of crude protein and P (P &lt; 0.05), but not of dry matter, gross energy and Ca (P &gt; 0.05). In conclusion, young pigs can be fed up to 40% raw, ground ZT faba bean (var. Snowbird) in full substitution for soybean meal in the starter diet.Key words: Digestibility, faba bean, growth performance, soybean meal, starter pig