Fecal Nitrogen Excretion Research Articles

Effect of Reduced Crude Protein Level on Fecal Nitrogen Excretion and Blood Profile in Finishing Pigs

The purpose of this experiment was to evaluate the effects of a low-protein diet on the selected variables of protein and energy metabolism in the blood serum as well as on the indicators of fermentation in the faeces (fecal crude protein, ammonia, pH, volatile fatty acids, and dry matter). Twelve finishing pigs (initial body weight: 64.6 ± 3.35 kg) were randomly divided into two groups and fed basal diets with crude protein (CP) levels of 13.6% and 15.4%, respectively. The Lysine, Methionine, Threonine, and Tryptophan levels in the 13.6% CP group were the same as those in the 15.4% CP group after the addition of four crystalline amino acids—Lysine, Methionine, Threonine, and Tryptophan to the diet. The blood and faeces samples were taken from the cranial vena cava and from the rectum at the end of the study period (44 days). The results showed that with the decrease in dietary CP level from 15.4% to 13.6% (a decrease of 1.8%), the fecal crude protein, the fecal ammonia, as well as the blood urea level decreased in the experimental group compared to the control group (P< 0.05 and 0.01, respectively).

Impact of ileal indigestible protein on fecal nitrogen excretion and fecal microbiota may be greater compared with total protein concentration of diets in growing pigs.

In the current study, we hypothesized that an increase in dietary ileal indigestible protein concentration induces an increase in hindgut nitrogen utilization and nitrogen excretion and a shift in fecal microbiota in growing pigs, when compared to pigs given a high total protein diet. Three diets were prepared: 1) standard protein diet based on corn and soybean meal, 2) high-indigestible protein diet in which autoclaved, low-digestible soybean meal replaced soybean meal in the first diet, and 3) high protein diet where the inclusion rate of soybean meal was greater than that of the other diets. The 3 diets were fed to 18 barrows that were fitted with T-cannula at the ileo-cecal junction (initial body weight = 63.4 ± 8.0 kg) in a randomized complete block design with body weight as a blocking factor. Pigs were individually housed in pens and the experiment lasted for 23 d. On days 7 and 21, fecal samples were collected by rectal massage for microbiota analysis. Grab samples of feces were collected on days 20 and 21, and ileal digesta were collected on days 22 and 23 for the determination of energy and nitrogen utilization. Lower apparent ileal digestibility of nitrogen in the high-indigestible protein diet containing autoclaved soybean meal resulted in greater ileal indigestible nitrogen concentration (P < 0.05). Apparent total tract digestibility of nitrogen was lower (P < 0.05), and correspondingly nitrogen concentration and daily fecal nitrogen output were greater (P < 0.05) in the high-indigestible protein diet compared with the other diets. Apparent post-ileal digestibility and hindgut disappearance of nitrogen and gross energy were the greatest (P < 0.05) in the high protein diet, whereas a statistical difference was not observed in those variables between the standard protein diet and the high-indigestible protein diet. Beta diversity metrics of feces in the high-indigestible protein diet on day 21 were different (q < 0.05) from those in the other two diets, which indicates a shift in microbial communities. According to the results of the DESeq2, the direction of microbiota shift induced by the high-indigestible protein diet may have reduced fiber utilization in the hindgut. In conclusion, an increase in dietary ileal indigestible protein concentration increased fecal nitrogen excretion and shifted fecal microbial communities but did not increase nitrogen utilization in the hindgut.

Feeding encapsulated pepper to dairy cows during the hot season improves performance without affecting core and skin temperature.

Peppers (Capsicum spp.) contain capsaicin, an organic compound with a group of alkaloids that has shown thermoregulation properties in humans and mice, and may influence glucose and lipid metabolism in ruminants. An experiment was conducted to evaluate different doses of a feed additive containing encapsulated pepper on milk yield and composition, dry matter intake, feed sorting index, total-tract apparent digestibility of nutrients, purine derivatives excretion, and serum concentrations of urea-N and glucose, N excretion, respiration rate, rectal temperature, and skin temperature in different regions (forehead, face, and rumen). Thirty-six Holstein cows (150 ± 102.1 d in milk and 29.3 ± 5.81 kg/d milk yield) were used in a 9-wk randomized complete block (n = 12) design experiment. Following a 2-wk covariate period, cows were blocked according to parity, days in milk, and milk yield and were randomly assigned to the following treatments: 0 (CAP0), 0.75 (CAP75), or 1.5 (CAP150) g/d of a feed additive containing encapsulated pepper (1 g/kg, Capcin; NutriQuest) added to the concentrate along with minerals. Treatment differences were evaluated through orthogonal contrasts (CAP0 vs. CAP75 + CAP150 or CAP75 vs. CAP150). The average temperature-humidity index during the experiment was 72.0 ± 2.07. Dry matter intake was greater in cows fed a feed additive containing encapsulated pepper (CAP) treatments (CAP75 and CAP150) compared with CAP0. Cows fed CAP150 tended to have greater dry matter intake than those in CAP75 group. Feeding CAP decreased sorting for feed particles with size between 8 and 4 mm. An interaction effect between treatment and week was observed for crude protein digestibility whereas cows fed CAP150 had the greatest digestibility on the third week of experiment. Orthogonal contrasts did not detect differences in serum concentrations of glucose and urea-N, or purine derivatives excretion. Nitrogen excretion (as % of N intake) in milk, urine, and feces was not altered by treatments. Feeding CAP increased yields of 3.5% fat-corrected milk, fat, protein, and lactose. A tendency toward greater milk protein content was observed for cows fed CAP150 than CAP75. No differences were detected on respiration rate, rectal temperature, and skin temperature of cows. A feed additive containing encapsulated pepper fed at 0.75 or 1.5 g/d can improve yield of fat-corrected milk and milk solids by increasing feed intake without affecting nutrient digestibility and body temperature of lactating cows during the hot season.

Effect of non-encapsulated and encapsulated mimosa (Acacia mearnsii) tannins on growth performance, nutrient digestibility, methane and rumen fermentation of South African mutton Merino ram lambs

The use of mimosa tannins as feed additives in contemporary ruminant nutrition studies has gained wider acceptance, because of their potential to reduce enteric methane and enhance dietary protein utilization. However, tannin’s astringency and quick dissolution decrease feed intake and digestibility. Microencapsulation technology could be adopted to neutralize the astringency and ensure controlled tannin solubility across ruminant digestive tract. The present study examined the influence of supplementing unencapsulated and encapsulated Mimosa (Acacia tannin) tannins on growth performance, digestibility, methane (CH4) and rumen fermentation in South African mutton Merino sheep. A total of 40 weaned Merino ram lambs of 96 days old (34 −35 kg body weight, BW) were randomly allocated to one of the four dietary treatments in a randomized complete block design as follows: total mixed ration, (T1, TMR alone); TMR + Monensin at 75 mg/kg feed dry matter, DM (T2, Monensin); TMR + unencapsulated Mimosa tannin at 20 g/kg DM (T3, UMT) and TMR + encapsulated Mimosa tannin in sunflower oil at 20 g/kg DM equivalent (T4, EMTS). The lambs were adapted to the diets over a period of 28 days thereafter, feed intake and weight changes were recorded for 77 days. The lambs were moved to metabolic crates and assessed for digestibility followed by methane measurement in open-circuit respiratory chambers. Finally, the animals were slaughtered, rumen fluids sampled and analysed for volatile fatty acids (VFAs) and ammonia nitrogen (NH3-N). Inclusion of UMT and EMTS did not affect (P > 0.05) feed intake and weight gain. Compared with the TMR alone, UMT and EMTS increased intake of DM (T1, 1328 g/day vs T3, 1578.1 and T4, 1569 g/day; P = 0.05), DM adjusted to BW (T1, 69.3 g/kg BW vs T3, 83.8 and T4, 83.7 g/kg BW; P = 0.04), organic matter, OM (T1, 1254 g/kg vs T3, 1494 and T4, 1490 g/day; P = 0.04), neutral detergent fibre, NDF (T1, 344 g/day vs T3, 434 and T4, 416 g/day; P = 0.01) and acid detergent fibre, ADF (T1, 174 and T3, 241 g/day vs T4, 218 g/day; P = 0.02), compared with the control. However, only UMT decreased (P = 0.01) digestibility of DM (T3, 640 g/kg vs T1, 746 g/kg), OM (T3, 655 g/kg vs T1, 761 g/kg) and CP (T3, 734 g/kg vs T1, 829 g/kg). Furthermore, UMT increased (P = 0.01) faecal nitrogen (N) excretion (T3, 13.7 g/head/day vs T1, 8.03 g/head/day and T3, 266 g/kg N-intake vs T1, 171 g/kg N-intake). UMT and EMTS reduced CH4 in g/kg DM-intake (T3, 15.3 and T4, 14.8; vs T1, 18.9; P = 0.04). However, NH3-N and total VFAs concentrations were not influenced (P > 0.05) by the inclusion of UMT and EMTS. It was concluded that UMT and EMTS could be utilized in mitigating enteric CH4 while enhancing nutrient intake when supplemented at 20 g/kg DM of feed. Among the two, however, EMTS reduced more CH4 without affecting digestibility compared to equivalent proportion of UMT. Further studies should be conducted on the total tannin concentration of the encapsulated mimosa tannin in sunflower oil.

Effects of Dietary Fiber, Crude Protein Level, and Gestation Stage on the Nitrogen Utilization of Multiparous Gestating Sows

Simple SummaryTwo major concerns for sustainable swine production are the shortage of protein feed resources and the excretion of nitrogen and phosphorus into the environment. Those concerns can be partly alleviated by increasing nitrogen utilization by improving nutrition for pigs. This study observed that a low crude protein and dietary fiber supplemented diet can improve nitrogen utilization and reduce urinary nitrogen excretion. Additionally, late gestating sows have greater nitrogen utilization than those of early gestation, characterized by reduced nitrogen in urine and lower amino acids in serum. These findings offer nutritional solutions for improving nitrogen utilization.To investigate the effects of dietary fiber (DF), crude protein (CP) level, and gestation stage on nitrogen utilization, 28 Landrace-Yorkshire cross gestating sows at parity two were randomly divided into four dietary treatments with seven duplicates of one pig with a repeated-measures design. The diets comprised one with normal crude protein (CP) of 13.3%, one with a low CP diet of 10.1%, and two diets, one with dietary fiber (DF) supplementation of inulin and cellulose at the ratio of 1:1 and one without DF. The total litter size, litter size alive, and newborn birthweight of piglets did not differ between treatment groups. Sows that received high DF levels had greater nitrogen output in feces, lower urinary nitrogen, and increased nitrogen retention. Sows that received a low CP diet had reduced nitrogen excretion in feces and urine, lower nitrogen retention, and an unchanged nitrogen retention ratio. Sows at the late stage of gestation on days 95 to 98 had lower nitrogen excretion in urine and greater nitrogen retention than in the early stage of gestation on days 35 to 38, associated with a significant decrease in serum amino acids in late gestation. Maternal protein deposition was increased by high DF, decreased by low CP, and lower in late gestation compared with early gestation. Collectively, DF improved nitrogen utilization by decreasing urine nitrogen output, and nitrogen utilization increased as gestation advanced.

Crude glycerin and cottonseed cake replacing common energy and protein sources on the metabolism of feedlot lambs

This study proposed to evaluate the effects of replacing ground corn by crude glycerin and soybean meal by cottonseed cake, in association or not, on nutrient intake, apparent digestibility, feeding behavior, ruminal fermentation, nitrogen utilization, and blood metabolites of feedlot lambs. Eight ruminally-cannulated lambs (average age: 1 year; initial body weight: 51.10 ± 8.94 kg) were randomly distributed in a 4 × 4 double Latin square design, in a 2 × 2 factorial scheme, with 21-day periods (last six days for data collection). Four experimental diets were tested with different sources or combinations of energy and protein ingredients in the concentrate, respectively: 1) ground corn and soybean meal; 2) ground corn and cottonseed cake; 3) crude glycerin and soybean meal; 4) crude glycerin and cottonseed cake. An interaction effect between energy and protein sources occurred on nutrient intake and digestibility of ether extract (EE; P < 0.05). The lowest values of nutrient intake other than EE were observed in lambs fed with crude glycerin (P < 0.05). Higher intake of neutral detergent fiber (NDF) was observed in lambs fed with cottonseed cake (P < 0.05). Higher apparent digestibilities of crude protein (CP) and EE, and lower non-fibrous carbohydrates (NFC) and total digestible nutrients (TDN) were observed in lambs fed with crude glycerin (P < 0.05). No differences were observed in the time spent in feeding, rumination, idling activities, chewing, number and time per period spent doing the activities, as well as the feeding and rumination efficiencies of DM and NDF (P > 0.05). Diet and time effects were observed on ruminal fermentation parameters (P < 0.05). An interaction effect occurred between the energy source and time was observed for pH, acetate, and butyrate concentrations, and acetate:propionate ratio (P < 0.05). Lambs fed with crude glycerin showed lower intake and fecal excretion of nitrogen than those fed ground corn (P < 0.05). The triglyceride concentration was affected by the energy source (P < 0.05); with higher concentrations being observed when crude glycerin replaced ground corn. Furthermore, there was an interaction effect between energy and protein sources in the concentrations of total proteins (P < 0.01) and globulin (P < 0.01); with lower values in diets with ground corn and cottonseed cake. Cottonseed cake can replace 100% of soybean meal in diets without affecting the ingestive behavior and metabolism of feedlot lambs. On the other hand, replacing 100% ground corn with crude glycerin has potential for use in lamb feedlot diets; however more studies need to be performed. Furthermore, we recommend the use of these alternative sources, since the combination of crude glycerin and cottonseed cake can replace 100% of ground corn and soybean meal in sheep diets.

Effects of Increasing Levels of Palm Kernel Oil in the Feed of Finishing Lambs.

Simple SummaryPalm kernel oil (PKO) is extracted from an oleaginous seed fruit (Elaeis guineenses Jacq.) commonly cultivated in Brazil and can be used strategically as a ruminal fermentation modulator to improve animal performance. We conducted three experimental trials by increasing PKO levels in the diets of lambs. Although we observed low consumption of most nutrients, we also observed that feed conversion improved as the PKO inclusion level increased, indicating that the animals needed to consume less food to gain 1.0 kg of body weight. In addition, we observed that nutrient digestibility was not affected by the inclusion levels of PKO. We also did not observe differences in ruminal fermentation parameters but noted a reduction in the protozoan population. Therefore, we conclude that the inclusion of palm kernel oil may be beneficial to lambs and can lower the cost of feed in regions that contain an abundance of this byproduct.The aim of this study was to evaluate the effects of the inclusion of palm kernel oil (PKO) in a lamb diet on nutrient intake, digestibility, ingestive behavior, nitrogen balance, blood metabolites, rumen fermentation parameters, and animal performance. Three experimental trials were conducted. The treatments consisted of varying levels of PKO included in the diet, with PKOzero = no PKO inclusion, PKO1.3 = 1.3% addition, PKO2.6 = 2.6% addition, PKO3.9 = 3.9% addition, and PKO5.2 = 5.2% addition, based on the total dry matter (DM) of the diet. With the inclusion of PKO in the diet, linear decreases in DM (p < 0.001), crude ash (p < 0.001), crude protein (CP) (p < 0.001), neutral detergent fiber (NDF) (p < 0.001), nonfibrous carbohydrate (NFC) (p < 0.001), and total digestible nutrient (TDN) (p = 0.021) intake were observed, as was an increase in ether extract (EE) intake (p < 0.001). The digestibility coefficients of NDF and NFC were not affected by PKO addition to the diet. However, the digestibility of DM (p = 0.035), EE (p < 0.001), CP (p < 0.001), and TDNs (p < 0.001) increased when PKO was added to the lambs’ diet. Reductions in N intake (p < 0.001), fecal nitrogen excretion (p < 0.001), and microbial protein production (p < 0.001) were noted with increasing PKO levels. Serum cholesterol increased (p < 0.001) while serum GGT enzyme concentrations in the blood decreased (p = 0.048) with increasing PKO levels. PKO addition had no effect on total weight gain and average daily gain; however, feed conversion improved (p = 0.001) with increasing PKO levels. The intake, digestibility, ingestive behavior, and growth performance of lambs with PKO1.3 added to their diet were similar to animals that did not receive PKO, meaning that PKO could be an alternative energy source for growing lambs because it does not harm animal performance and can lower the cost of feed.

Effect of Grape Marc Added Diet on Live Weight Gain, Blood Parameters, Nitrogen Excretion, and Behaviour of Sheep.

Simple SummaryThis experiment explored how feeding grape wine production waste product grape marc impacts on sheep production. Forty merino sheep were divided into two groups; one group received a sheep industry standard diet (control), and one group received a treatment diet which had 20% of the control diet replaced by grape marc. The results showed that the grape marc diet led to a higher intake and faecal nitrogen/urinary nitrogen ratio, but no difference in sheep live weight gain, behaviour, and parasitic egg count compared with control diet-fed sheep. Overall, the results showed that feeding grape wine production waste product grape marc as a cheap feed, to replace 20% of the control ration, can maintain sheep productivity, health, and environmental sustainability.A 39-day field experiment was conducted to assess the effect of grape marc (GM) feeding on sheep productivity, health, and environmental sustainability. Forty merino sheep were divided into two dietary groups, each having five replications (n = 4 sheep/replication). Experimental diet consisted of: (i) control: 55% lucerne hay + 40% wheat grain + 5% faba bean; (ii) GM treatment: control diet with 20% replaced by GM on a dry matter (DM) basis. The GM treatment contained 2–10% higher phytochemical contents than the control. The DMI from the GM treatment was 15% higher than the control (p < 0.001). No difference was found in sheep live weight gain, behaviour, and quality between groups (p > 0.05). No difference was found in total faecal production, faecal organic matter, and nitrogen contents (p > 0.05) and parasitic egg count. The GM treatment led to higher nitrogen intake (23.1 vs. 27.2 g/d) and faecal nitrogen excretion (6.3 vs. 8.7 g/d) compared to the control. Urinary creatinine, allantoin, and purine derivatives were lower in the GM treatment than control (p < 0.05). However, both groups had similar purine derivatives/DMI (i.e., indicator of rumen microbial protein synthesis efficiency; p > 0.05). Overall, the results showed that GM can replace 20% of the control ration to maintain sheep productivity, health, and environmental sustainability.

Digestibilidade, desempenho e eficiência econômica de dietas contendo fitase e grãos secos de destilaria com solúveis para suínos em crescimento

ABSTRACT This study aimed to evaluate the effects of phytase enzyme and distillers dried grains with solubles (DDGS) on the digestibility, performance and economic viability of growing pigs. Two experiments were conducted with a reference diet (RD) based on corn and soybean meal: RD with 200 g kg -1 DDGS (DDGS); RD + 1,000 units of phytase (PHY); and RD + 200 g kg-1 DDGS + 1,000 units of phytase (D+P). In experiment 1, eight castrated male pigs weighing 29.35 ± 5.74 kg were used through the total collection method and replicates in time for digestibility evaluation. In experiment 2, 40 castrated male pigs 47.65 ± 3.99 kg, with five replicates of two animals per experimental unit, were used for performance and economic evaluation. DDGS increased the excretion of nitrogen and energy in feces and urine, impairing the digestibility coefficients and metabolizability of dietary energy. The animals that consumed diets with DDGS presented the worst performance, while phytase did not influence the results. Diets with the inclusion of 200 g kg -1 DDGS and 1,000 units of phytase did not differ in cost per kilogram compared to the control diet.

Supplementation of exogenous β-mannanase to low-protein diets improves feed conversion efficiency in lactating dairy cows

Context Supplementation of exogenous enzymes has been used to improve nutrient utilisation and reduce environmental impacts of excess nutrient release to the environment in swine, poultry and, to a lesser extent, ruminant production systems. Aims We aimed to determine effects of supplementation with a fibrolytic enzyme, β-mannanase, on feed conversion efficiency (FCE) and milk yield in cows fed a diet relatively low in crude protein (CP) concentration. Methods Twelve mid-lactation multiparous Holstein cows producing 40.5 ± 3.6 kg milk/day were assigned to three dietary treatments in a three-period crossover design. Treatment sequences were balanced using 3 × 3 Latin squares to mitigate possible carryover effects. Treatments, fed in a total mixed ration, were high CP (16.1%), low CP (14.6%), and low CP supplemented with commercially available β-mannanase at 0.1% of concentrate dry matter (DM). Key results β-Mannanase supplementation did not affect DM intake, milk yield, or milk component yield and composition. Milk urea-nitrogen was significantly lower in cows fed diets with low CP. Somatic cell counts were reduced in cows supplemented with β-mannanase compared with the other treatments. Apparent total tract digestibilities of DM, organic matter, CP, acid and neutral detergent fibre, starch and ash were unaffected by treatment. Cows receiving β-mannanase showed better FCE than those receiving high CP (13.4% improvement, P = 0.003) or unsupplemented low CP (11.0% improvement). Cows receiving β-mannanase used dietary CP more efficiently to synthesise milk protein than cows receiving high CP (milk protein:CP intake, 0.34 vs 0.30). Nitrogen intake was significantly reduced in the low CP treatments, leading to reduced fecal and urinary nitrogen excretions. Conclusion β-Mannanase supplementation at 0.1% of dietary DM improved FCE and lowered somatic cell counts of dairy cows without affecting milk yield or component yield and composition, while reducing nitrogen excretion. There were potential daily savings of US$1.03/cow compared with a high CP diet. Implications Improvement in FCE can be achieved along with reduced dietary CP content and somatic cell counts without compromising milk production through use of β-mannanase, suggesting a potential economic benefit. Furthermore, reductions in nitrogen excretions with low CP diets are beneficial to the environment.

Polysaccharides from fermented coix seed modulates circulating nitrogen and immune function by altering gut microbiota

Coix lachryma-jobi L. seed is an important food item in Asia with culinary and medicinal values. The effects of non-fermented coix seed (NFC), fermented coix seed with Lactobacillus plantarum NCU137 (FC) and polysaccharides from NFC, FC (FCP) on mice circulating nitrogen and immune disorder induced by high relative humidity (RH, 90 ± 2%) exposure were compared. All the treatments reduced circulating nitrogen (BUN and ammonia) might via increasing excretion of fecal nitrogen induced by altering gut microbiota. In comparison, FC and FCP restored erythrocyte morphology by promoting erythrocyte Na+/K+ ATPase activity more effectively, and immune function was modulated by reducing plasma IgM and IFN-γ levels, up-regulating IL-4 and IL-6 levels. Herein, these results indicated that FCP, as the main active ingredient in FC, modulated circulating nitrogen through altering gut microbiota, and restored immune homeostasis by regulating Th1/Th2 cytokines in mice receiving high RH exposure.

No apparent effects of a viscous, superabsorbent hydrogel on appetite, energy intake, or fecal excretion in overweight adults

As the obesity epidemic continues, there is a great need for safe and effective weight loss aids. A superabsorbent hydrogel device administered as a capsule demonstrates potential for weight loss, but its mechanism of action remains unclear. The present study's goal was to determine the mechanisms of action of the hydrogel through the investigation of its effects on appetitive sensations, eating behavior, energy intake, and fecal excretion of energy. Overweight and obese adults (n = 18) participated in a double-blind, randomized, crossover-design study in which they were provided all meals for a week in a supervised setting (i.e., controlled-feeding) and were required to either consume the hydrogel or a placebo with 16-oz of water 20 min before lunch and dinner. No differences in appetite (all, p > 0.05), total fecal nitrogen excretion (p = 0.74), total fecal fat excretion (p = 0.54), or total fecal energy excretion (p = 0.76) were identified when comparing the hydrogel to a placebo. Affect towards food (i.e., mood, emotions) was more positive in the hydrogel group compared with the placebo group. A subset of the controlled-feeding group (n = 10) then participated in another double-blind, randomized, crossover-design study in which they provided their own food for a week (i.e., free-feeding) and were required to either consume the hydrogel or a placebo with 16-oz of water 20 min before lunch and dinner. No differences in appetite (all, p > 0.05), energy intake (p = 0.95), diet quality (all, p > 0.05), or eating behavior (all, p > 0.05) were determined when comparing the hydrogel to the placebo. Future studies with greater statistical power should confirm these findings and investigate other potential mechanisms of action of the hydrogel.

Supplementation with mesquite alkaloids extract in diets for lambs fed Bermuda grass improves growth performance

The aim of this study was to evaluate the effects of different concentrations of enriched mesquite piperidine alkaloid extract (MPA levels): 0 (control), 2.3, 4.6 and 9.2 mg/kg; and to compare monensin (MON) 2.1 mg/kg, MPA 0 and MPA 2.3 mg/kg of diet dry matter composed of Tifton 85 (Bermuda grass) hay and concentrate (corn meal, soybean meal, urea and mineral salt). Nutrient intake, digestibility, growth performance, microbial synthesis efficiency, and nitrogen (N) balance were evaluated. Thirty Dorper × Santa Inês lambs, with an initial body weight of 17.50 ± 0.43 kg, were assigned to a completely randomized design. There was no difference (P > 0.10) for the intake of nutrients and metabolizable energy (11 MJ/day) between the diets. The digestibility of DM, OM, CP, EE and, NDFap was lower (P < 0.05) for MPA 2.3 compared to MON and the control diet. Non-fiber carbohydrates (NFC) digestibility tended to be lower (P < 0.10) in comparison with MON and showed quadratic variation (P < 0.05) with MPA levels. MPA 2.3 did not differ (P> 0.10) of the MON and control diets for daily weight gain, but it presented a higher (P < 0.05) efficiency of feeding conversion than MON. There was a linear increase (P < 0.05) for final body weight with MPA levels. There was maximum (P < 0.05) nitrogen excretion in feces and minimum (P < 0.05) digested nitrogen (g/100 g of ingested nitrogen) at the mean dose of MPA 5.7 mg/kg. The results indicate that MPA has potential as a feed additive because it improves growth performance.

Digestibility and nitrogen and water balance in horses fed rhizoma peanut hay.

Rhizoma peanut (RP, Arachis glabrata) hay has the potential to meet horses' crude protein (CP) requirements with less nitrogen excretion than other legumes. This study aimed to evaluate nutrient intake, apparent digestibility, and nitrogen balance of RP "Florigraze" hay compared with alfalfa (ALF, Medicago sativa L. "Legendary XHD") and bermudagrass (BG, Cynodon dactylon L. "Coastal") hays when fed to maintenance horses at 2% body weight/d on a dry matter (DM) basis. We hypothesized that nutrient intake would be comparable between the legume hays and lesser for BG and that RP would result in reduced nitrogen excretion compared with ALF. Six mature Quarter Horse geldings (593 ± 40 kg; mean ± SD) were randomly assigned to one of the hays in a replicated 3 × 3 Latin square with 21-d periods. A 14-d adaptation phase was followed by a 3-d total fecal and urine collection. Days 18 to 21 were used for a companion study. Intake of nutrients is reported on a DM basis. Digestible energy (DE) intakes from ALF (29.91 Mcal/d) and RP (29.37 Mcal/d) were greater (P < 0.0001) than BG (20.78 Mcal/d). CP intake was greater (P < 0.0001) for ALF (2.5 kg/d), followed by RP (1.9 kg/d) and BG (1.5 kg/d). All hays exceeded maintenance requirements for DE, CP, Ca, and P. Apparent digestibility of DM and CP was greatest (P < 0.0001) for ALF (69% and 84%), intermediate for RP (61% and 72%), and least for BG (46% and 64%). Apparent digestibility of neutral detergent fiber did not differ (P = 0.2228) among hays, while digestibility of acid detergent fiber (P = 0.0054) was least for RP but similar for ALF and BG. Water intake (kg/d) for ALF (57) was greater (P = 0.0068) than RP (45) and BG (41). Greater (P = 0.0271) water retention (kg/d) was observed for ALF (13.5), followed by RP (10.8) and BG (7.5). There was a difference in nitrogen excretion, with greatest urinary nitrogen excretion for ALF (P < 0.0001) and greatest fecal nitrogen excretion for BG (P = 0.0001). Total nitrogen excretion was greater (P < 0.0001) for ALF (278 g/d), followed by RP (211 g/d) and BG (179 g/d). Nitrogen retention was greater (P = 0.0005) for ALF when represented as g/d (ALF: 129, RP: 86, and BG: 57 g/d) but similar (P = 0.0377) to RP when presented as percent of nitrogen intake (ALF: 32%, RP: 29%, and BG: 24%). Results indicate that RP hay is a suitable legume for horses by meeting DE and CP requirements and having a significant reduction in nitrogen compared with ALF.

Dietary lysine supplementation improves growth performance and skeletal muscle development in rabbits fed a low protein diet

The purpose of this study was to investigate the effects on growth of Lysine (Lys) supplementation in a low protein diet. We also investigated the gene or protein expression related to skeletal muscle development and intestinal amino acid transporters, and determined the major signalling associated with Lys-regulating skeletal muscle development. 1000healthy, weights averaging 938.6±6.54g weaned rabbits were randomly divided into five groups (five replicates in each group and 40 rabbits in each replicate). These groups consisted of the normal protein group (NP group, consuming a diet containing 16.27% protein), the low protein group (LP group, 14.15%-14.19% protein) and the LP group with an addition of 0.15%, 0.3% or 0.45% Lys. The trial included 7 d of pre-feeding and 28 d of exposure to the treatment. Compared with NP diet and LP diet, LP+0.3% Lys group improved growth performance (p<0.05), full-bore weight and half-bore weight of rabbits (p<0.05). The LP+0.3% Lys group also resulted in a decrease in the excretion of faecal nitrogen and urinary nitrogen (FN; UN; p<0.05), and an increase in nitrogen utilisation rate (NUR; p<0.05). LP diet increased the mRNA expression of MSTN and WWP1, and decreased the mRNA expression of IGF1 (p<0.05). LP diet decreased the protein expression of P-P70S6K1, P-4EBP1 and P-S6 (p<0.05). LP+0.3% Lys group attenuated the effects of LP diet on the expression of MSTN, WWP1, IGF1, P-P70S6K1, P-4EBP1 and P-S6 (p<0.05). LP+0.3% Lys group resulted in an increase in mRNA expression of MyoD and protein expression of P-mTOR relative to the NP and LP groups (p<0.05). In summary, the addition of Lys to a LP diet provides a theoretical basis for the popularisation and application of Lys in rabbit production.

Evaluation of nitrogen excretion equations for ryegrass pasture-fed dairy cows

Accurate and precise estimates of nitrogen (N) excretion in faeces and urine of dairy cattle may provide direct tools to improve N management and thus, to mitigate environmental pollution from dairy production. Empirical equations of N excretion have been evaluated for indoor dairy cattle but there is no evaluation for cows fed high proportions of fresh forage. Therefore, the objective of the current study was to evaluate N excretion equations with a unique data set of zero-grazing experiments. Through literature searches, 89 predictive equations were identified from 13 studies. An independent data set was developed from seven zero-grazing experiments with, in total, 55 dairy Holstein-Friesian cows. Models’ performance was evaluated with statistics derived from a mixed-effect model and a simple regression analysis model. Squared sample correlation coefficients were used as indicators of precision and based on either the best linear unbiased predictions (R2BLUP) or model-predicted estimates (R2MDP) derived from the mixed model and simple regression analysis, respectively. The slope (β0), the intercept (β1) and the root mean square prediction error (RMSPEm%) were calculated with the mixed-effect model and used to assess accuracy. The root mean square prediction error (RMSPEsr%) and the decomposition of the mean square prediction error were calculated with the simple regression analysis and were used to estimate the error due to central tendency (mean bias), regression (systematic bias), and random variation. Concordance correlation coefficient (CCC) were also calculated with the simple regression analysis model and were used to simultaneously assess accuracy and precision. Considering both analysis models, results suggested that urinary N excretion (UN; R2MDP = 0.76, R2BLUP = 0.89, RMSPEm% = 17.2, CCC = 0.82), total manure N excretion (ManN; R2MDP = 0.83, R2BLUP = 0.90, RMSPEm% = 11.0, CCC = 0.84) and N apparently digested (NAD; R2MDP = 0.97, R2BLUP = 0.97, RMSPEm% = 5.3, CCC = 0.95) were closely related to N intake. Milk N secretion was better predicted using milk yield as a single independent variable (MilkN; R2MDP = 0.77, R2BLUP = 0.97, RMSPEm% = 6.0, CCC = 0.74). Additionally, DM intake was a good predictor of UN and ManN and dietary CP concentration of UN and ManN. Consequently, results suggest that several evaluated empirical equations can be used to make accurate and precise predictions concerning N excretion from dairy cows being fed on fresh forage.

Lactational performance, rumen fermentation, and enteric methane emission of dairy cows fed an amylase-enabled corn silage

This study investigated the effects of an amylase-enabled corn silage on lactational performance, enteric CH4 emission, and rumen fermentation of lactating dairy cows. Following a 2-wk covariate period, 48 Holstein cows were blocked based on parity, days in milk, milk yield (MY), and CH4 emission. Cows were randomly assigned to 1 of 2 treatments in an 8-wk randomized complete block design experiment: (1) control corn silage (CON) from an isogenic corn without α-amylase trait and (2) Enogen hybrid corn (Syngenta Seeds LLC) harvested as silage (ECS) containing a bacterial transgene expressing α-amylase (i.e., amylase-enabled) in the endosperm of the grain. The ECS and CON silages were included at 40% of the dietary dry matter (DM) and contained, on average, 43.3 and 41.8% DM and (% DM) 36.7 and 37.5% neutral detergent fiber, and 36.1 and 33.1% starch, respectively. Rumen samples were collected from a subset of 10 cows using the ororuminal sampling technique on wk 3 of the experimental period. Enteric CH4 emission was measured using the GreenFeed system (C-Lock Inc.). Dry matter intake (DMI) was similar between treatments. Compared with CON, MY (38.8 vs. 40.8 kg/d), feed efficiency (1.47 vs. 1.55 kg of MY/kg of DMI), and milk true protein (1.20 vs. 1.25 kg/d) and lactose yields (1.89 vs. 2.00 kg/d) were increased, whereas milk urea nitrogen (14.0 vs. 12.7 mg/dL) was decreased, with the ECS diet. No effect of treatment on energy-corrected MY (ECM) was observed, but a trend was detected for increased ECM feed efficiency (1.45 vs. 1.50 kg of ECM/kg of DMI) for cows fed ECS compared with CON-fed cows. Daily CH4 emission was not affected by treatment, but emission intensity was decreased with the ECS diet (11.1 vs. 10.3 g/kg of milk, CON and ECS, respectively); CH4 emission intensity on ECM basis was not different between treatments. Rumen fermentation, apart from a reduced molar proportion of butyrate in ECS-fed cows, was not affected by treatment. Apparent total-tract digestibility of nutrients and urinary and fecal nitrogen excretions, apart from a trend for increased DM digestibility by ECS-fed cows, were not affected by treatment. Overall, ECS inclusion at 40% of dietary DM increased milk, milk protein, and lactose yields and feed efficiency, and tended to increase ECM feed efficiency but had no effect on ECM yield in dairy cows. The increased MY with ECS led to a decrease in enteric CH4 emission intensity, compared with the control silage.

Growth performances, nutrient digestibility, ruminal fermentation and energy partition of Thai native steers fed exclusive rice straw and fermented sugarcane bagasse with Lactobacillus, cellulase and molasses.

The study aimed to evaluate the effect of sugarcane bagasse feeding treated with Lactobacillus casei TH14 (L. casei TH14), cellulase and molasses (BG) on nutrient digestibility, ruminal fermentation, energy partition and growth performances of Thai native steers compared to conventional feeding of rice straw (RS). Eight Thai native steers (144±19.5kg of initial body weight) were randomly allocated to two roughage sources in a completed randomized design: RS (n=4) and BG (n=4). The feeding trial lasted for 90days plus 21days for treatment adaptation. The results showed that the BG group showed (p<0.05) greater intake (2.34 vs 2.02kg/day), total intake (3.90 vs 3.55kg/day) and average daily gain (0.27 vs 0.23kg/day) while feed conversion ratio was lower compared to RS group. The BG group had a greater (p<0.05) organic matter and acid detergent fibre intake than the RS group as well as dry matter and neutral detergent fibre digestibility. The steers fed RS and BG were significantly (p<0.05) different for total volatile fatty acids and propionic acid at 4h after offering the diet. The intake of nitrogen (g/day) and apparent nitrogen absorption was significantly (p<0.05) higher for BG than the RS group while nitrogen excretion in faeces was significantly lower in RS than the BG group. BG group showed significantly (p<0.05) greater gross energy intake and digestible energy partition when compared to the RS group. In conclusion, feeding BG enhanced feed utilization, growth performance, ruminal fermentation, nitrogen utilization and energy utilization.

Low-tannin sorghum grain could be used as an alternative to corn in diet for nursery pigs.

This study was conducted to test the hypothesis that low-tannin sorghum grain produced in China as a potential substitute for corn in diets could not impair the performance of nursery pigs. A total of 60 pigs (7.2±1.2kg) were randomly assigned to 2 diets with 5 replicate pens per treatment. Corn-based diet (CBD) included 60% corn grain during the overall experimental period, and sorghum-based diet (SBD) consisted of 30% (d 1 to 14) or 60.55% (d 15 to 28) sorghum grain in partial or total replacement of corn grain. Both diets were formulated to contain the same amount of digestible energy and indispensable amino acids. The results demonstrated no differences in growth performance or apparent digestibility of gross energy between treatments over the whole period. However, the substitution of corn by sorghum reduced (p<0.05) or tended to reduce (p=0.09) apparent digestibility of crude protein associated with an increased faecal nitrogen excretion per weight gain (p<0.05). Pigs fed SBD had higher contents of urea nitrogen, total triglyceride and insulin in serum than those fed CBD (p<0.05). Visceral organ weights or antioxidant enzyme activities in serum or liver were not different between treatments. Compared with CBD, SBD increased or tended to increase amylase activity in jejunal mucosa (p<0.05) or trypsin activity in duodenal mucosa (p=0.08). Replacement of corn by the low-tannin sorghum in diets did not influence the microbiota community based on alpha and beta diversity in caecal and colonal digesta. Overall, the home-grown low-tannin sorghum could be an alternative energy source in diets for pigs without adverse effects on growth performance.

Sanguinarine improved nutrient digestibility, hepatic health indices and productive performance in laying hens fed low crude protein diets.

A major mean to minimize feeding costs and faecal nitrogen excretion on poultry farms is to decrease the supplied dietary protein content. This, however, is associated with the declines in productive performance and systemic health indices. Sanguinarine may improve protein efficiency via decreasing the intestinal amino acid decarboxylation and stimulating the tryptophan‐serotonin pathway. The present study was carried out to investigate the effects of dietary supplementation of sanguinarine on the performance, egg yolk biochemical parameters, serum enzyme activities, nutrient digestibility, ovarian follicles, and hepatic health indices in laying hens fed decremental levels of crude protein (CP). For this purpose, 180 laying hens were allocated into nine dietary treatments with four replicates of five birds each. The experimental treatments consisted of three levels of CP (85.0%, 92.5%, and 100% of Hy‐Line W‐36 manual recommendation) and three levels of sanguinarine (0.00, 3.75, and 7.50 mg/kg) in a 3 × 3 factorial arrangement administered during a 70‐day feeding trial. Results showed that the decremental levels of CP led to significant increases in serum aspartate aminotransferase (p < .05), alanine aminotransferase, and alkaline phosphatase (p < .01) activities, egg yolk cholesterol concentration (p = .064), and hepatic fat and malondialdehyde (MDA) contents (p < .05). It also caused the significant declines in ileal dry matter (DM) digestibility (p < .05) and eggshell strength (p < .05), and also tended to decrease CP digestibility (p = .071), Haugh unit (p = .057) and egg production percentage (p = .062). The interaction effects of the experimental factors indicated that dietary supplementation of sanguinarine, especially at 7.50 mg/kg, led to significant improvements in serum aspartate aminotransferase and alanine aminotransferase activities (p < .01), egg yolk cholesterol (p < .001) and triglyceride (p < .05) concentrations, eggshell strength (p < .001), Haugh unit (p < .05), hepatic fat (p < .001) and MDA (p = .059) contents, ileal DM and CP digestibility (p < .01) as well as egg production, egg mass and feed conversion ratio (FCR; p < .05) in birds receiving decremental levels of CP. Taken together, the results indicate that dietary administration of sanguinarine could enhance productive performance via improving nutrient digestibility, hepatic health indices and fortifying systemic antioxidant capacity in laying hens fed low‐CP diets.