Fecal Particle Size Research Articles

Impact of a two-stage rumen cannulation on the health and rumen function of six lactating dairy cows.

To determine the impact of a two-stage rumen cannulation on the health and rumen function of lactating dairy cows. Experimental study. Six lactating Holstein cows. We performed a two-stage rumen cannulation in six Holstein cows that were 49 ± 11 days in milk. The following clinical health parameters and digestion-associated variables were analyzed on seven measurement days, from before the first surgery until 28 days after the second surgery: body temperature, heart rate, respiratory rate, pain score, rumen fill score, fecal score, wet sieving, auscultation and palpation of the rumen, bodyweight, body condition score, and activity. The pain score of the cows was constantly zero. Similarly, the body temperature and respiratory rate remained within physiological ranges, whereas the heart rate was slightly higher immediately after the second surgery. No differences were observed in rumen fill (2.00-2.67; p = .10) and fecal consistency scores (2.17-2.67; p = .42). The fecal particle size distribution showed negligible differences. The cows lost approximately 43 kg of bodyweight during the experiment (p < .01), which was reflected in a 0.5-point body condition score loss (p < .01). A temporary minimal negative effect of a two-stage rumenostomy on the health and body condition of early lactating Holstein cows was observed, whereas digestion was unaffected. Considering the limited sample size, further studies are required to substantiate these findings. Given that animals are appropriately medically managed, experimental rumenostomy of lactating dairy cows may not compromise their health or rumen function.

Faecal particle size distribution in relation to forage type and digestibility in horses: preliminary results

The study aimed to explore the connection between horses’ total tract apparent dry matter digestibility (ttaDMD) of various roughages and faecal particle size (FPS), to develop a tool to rank roughage digestibility. Six horses, varying in size and breed, were fed six distinct roughages (four cuts of fescue, perennial ryegrass/clover mix, and straw). Each feeding period lasted 16 days, with a 14-day adaptation phase. Faecal samples underwent wet sieving analysis. Roughage chemical composition was evaluated using NIRs. Faecal and roughage acid insoluble ash content were used to estimate ttaDMD and FPS was determined by wet sieving using a set of 6 sieves of different mesh sizes (S1 to S6; 6.50, 4.50, 2.36, 1.18, 0.6 and 0.15 mm respectively). The effects of roughage ttaDMD on FPS across sieves were analysed using GLM. Linear regressions and correlations were performed between faecal residues on each sieve and mesh sizes of the sieves to create a mathematical tool to rank ttaDMD based on FPS distribution. Increased ttaDMD was associated with larger FPS, with perennial ryegrass/clover mix (ttaDMD 74.44%) and straw (ttaDMD 44.57%) resulting in smaller and larger faecal particles respectively. Correlations were observed between ttaDMD, S1 and S2 (r = 0.639 and 0.668; p ≤ 0.001). The angular coefficient of the linear function between faecal residues on each sieve support the idea to estimate roughages digestibility from FPS (R2 = 0.4153). Consequently, determining faecal residues across sieves of varying mesh sizes could serve as an indirect method for ranking roughages digestibility.

Effect of odontoplasty on intake, nutrient digestibility, and intake time of tifton hay in ponies

We aimed to evaluate the effects of dental correction on voluntary nutrient intake, time of intake, apparent digestibility and fecal particle size in Brazilian ponies. Twelve mares, with no history of previous dental treatments, housed in individual pens and fed a diet based on tifton 85 were used. The study comprised two consecutive experimental phases, pre and post dental treatment. Each phase consisted of 15 days for adaptation to the pen and treatment and 5 days for data collection, totaling 20 days. To calculate nutrient intake and digestibility coefficients, samples of diets, leftovers, and feces were analyzed for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude fat (CF), mineral matter (MM), organic matter (OM), and non-fiber carbohydrates (NFC). Food intake time was recorded using a digital video recorder. Fecal particles were analyzed by wet sieving. Dental correction did not influence the intake of DM, CP, NDF, CF, and OM by the animals. However, there was an increase in NFC intake from 0.12 kg to 0.14 kg and in food intake time from 654.50 ± 138.98 to 774.95 ± 167.14. There was a decrease in the digestibility of CP from 0.08 kg to 0.04 kg and an increase in the digestibility of NDF from 0.65 kg to 0.82 kg. Although odontoplasty increased the time of hay intake and the digestibility of the fibrous fractions of the feed of ponies, it did not influence the intake of nutrients and the size of the fecal particles.

Practical implications of lowering dietary starch content on waste management in recirculating aquaculture systems operated with drum filtration or sedimentation in yellowtail kingfish (Seriola lalandi)

Dietary starch negatively affects faecal removal efficiency by sedimentation in yellowtail kingfish (Seriola lalandi). In general, research on waste management in recirculating aquaculture systems (RAS) is conducted on solid removal by sedimentation. However, most commercial farms operate with screen filtration. Compared to sedimentation, where the efficiency of removed faeces depends on faecal particle size and density, faecal removal by screen filtration is based on particle size and its stability. Accordingly, this study investigated the effect of dietary starch level on solid waste loading and faecal removal efficiency by different solid removal techniques, namely drum filtration and sedimentation. This was tested in six individual operating RAS over an experimental period of 47 days. The experimental period was divided into two consecutive phases (Phase 1 and Phase 2). During Phase 1 (42 days), the six independent RAS were operated with drum filtration, while during Phase 2 (5 days), the same RAS were operated with sedimentation. Two experimental diets, one with low starch (LS; 0% gelatinized wheat flour inclusion) and one with high starch (HS; 20% gelatinized wheat flour inclusion) levels, were formulated to test the effect of dietary starch level. HS diet negatively affected the apparent faecal waste production, apparent faecal removal efficiency by sedimentation, and the apparent amount of non-removed faeces. No dietary treatment effect was observed when RAS were operated with drum filtration. However, to achieve similar apparent faecal removal efficiency by drum filtration, the backwash frequency was on average 110% higher at HS RAS compared to LS RAS. This is likely to be related to both an increased apparent faecal waste production and the tendency for increased clogging of the drum filter screen at HS RAS throughout the experimental period. Overall, lowering dietary starch level has the potential to reduce solid loading (sedimentation) or improve drum filter performance (water usage) in RAS for yellowtail kingfish.

Interplay between particle size and microbial ecology in the gut microbiome.

Physical particles can serve as critical abiotic factors that structure the ecology of microbial communities. For non-human vertebrate gut microbiomes, fecal particle size (FPS) has been known to be shaped by chewing efficiency and diet. However, little is known about what drives FPS in the human gut. Here, we analyzed FPS by laser diffraction across a total of 76 individuals and found FPS to be strongly individualized. Contrary to our initial hypothesis, a behavioral intervention with 41 volunteers designed to increase chewing efficiency did not impact FPS. Dietary patterns could also not be associated with FPS. Instead, we found evidence that human and mouse gut microbiomes shaped FPS. Fecal samples from germ-free and antibiotic-treated mice exhibited increased FPS relative to colonized mice. In humans, markers of longer transit time were correlated with smaller FPS. Gut microbiota diversity and composition were also associated with FPS. Finally, ex vivo culture experiments using human fecal microbiota from distinct donors showed that differences in microbiota community composition can drive variation in particle size. Together, our results support an ecological model in which the human gut microbiome plays a key role in reducing the size of food particles during digestion. This finding has important implications for our understanding of energy extraction and subsequent uptake in gastrointestinal tract. FPS may therefore be viewed as an informative functional readout, providing new insights into the metabolic state of the gut microbiome.

Uncovering the impact of sea mud-containing diet on fecal fragmentation and its potential environmental risks in recirculating aquaculture system of Apostichopus japonicus

A deep understanding of fecal characteristics and fragmentation mechanism is crucial for effectively removing the solid particles in recirculating aquaculture system (RAS) of Apostichopus japonicus, however, the underlying mechanism was still unclear. This study investigated the effects of diet with different sea mud addition on the fecal characteristics and microbiota. The experimental diet were the mixture of commercial feed and sea mud at the ratio of 1:1, 1:2, 1:3, 1:4 and 1:5, in which the added amount of sea mud was 50 %, 66.67 %, 75 %, 80 % and 83.33 %, respectively. The results showed that, at the end of aquaculture, Dx(50) in group 1:3 was the highest, while group 1:5 was the lowest. The fecal particle size distribution (PSD) appeared multi peak with the increase of sea mud addition. At the end of aquaculture, group 1:3 possessed the highest microbial diversity. BugBase phenotype prediction found that the microbial phenotypes in group 1:4 were mainly involved in functional expression, such as stress tolerance and potential pathogenicity. Significant correlation between environmental factors and fecal microbiota were found. Correlation analysis between fecal particle size and fecal microbiota showed that the abundance of pathogenic bacteria such as Vibrio, was higher on fecal particles with dispersed PSD. And NH4+-N removal rate decreased when Dx(10) decreased and Dx(90) increased. Thus, it was recommended that sea mud addition in diet should be <75 % in A. japonicus RAS.

Improved fecal particle size profile in Rainbow Trout fed feeds containing different ratios of animal meal and plant protein concentrates: Effect on nitrogen and phosphorus partitioning

AbstractObjectiveOur objective in this study was to evaluate the effects of fish meal replacement with plant and animal protein sources accompanied by a feed binder on nitrogen (N) and phosphorus (P) partitioning in Rainbow Trout Oncorhynchus mykiss feces.MethodsThree diets in which fish meal (FM; reference diet) was completely replaced with a combination of poultry meal (PM), corn protein concentrate, soy protein concentrate, and guar gum (binder) were evaluated to determine the portioning of N and P in fecal particle size‐classes (fines: &lt;0.6 mm; mid‐size particles: 0.6–1.2 mm; large particles: &gt;1.2 mm) and compared with a commercial feed for Rainbow Trout. Feces were evaluated for particle size composition and the content of total N (TN) and total P (TP) in each size‐class.ResultThere was a significant difference in fecal particle size composition for trout fed the experimental diets compared to those given the commercial feed. Fish that received the four experimental diets produced feces with approximately 43% large particles and 24% fines compared to 6% and 67% for trout that were fed the commercial diet. The TN in feces was significantly higher for trout that were fed the FM diet (3.84%) than for trout fed the FM‐free diets, and TN also declined linearly (2.68, 1.91, and 1.59%) as the content of PM was replaced with plant‐based protein. A diet × particle size interaction effect on fecal N content was also observed in which a significant increase in TN from large particles compared with fines occurred for the experimental FM diet, but there was little difference between size‐classes for the non‐FM‐based feeds. The feces of trout fed the FM diet contained more TP (100,007 μg/g) than the feces of fish receiving the FM‐free diets (46,751–72,659 μg/g), likely due to higher dietary P content of FM. However, TP concentrations followed a similar trend as TN in the FM‐free feeds, declining as the proportion of plant protein sources increased (and as PM decreased). The large fecal particles (72,235 μg/g) contained more TP than the mid‐size particles (68,926 μg/g) or fines (61,974 μg/g), which could be due to leaching in the latter two particle size‐classes, as the potential for solubility likely increased as particle size decreased.ConclusionThese findings may have important implications for improving the fecal particle size profile for sedimentation and removal of regulated nutrients through the formulation of Rainbow Trout feeds in replacement of FM with plant protein.

Dental Correction Does Not Alter Postprandial Nutrient Concentrations in Healthy Mares

Irregular wear patterns are theorized to cause poor feed digestion and weight loss in the horse. The objective of this study was to test the hypothesis that dental correction would increase postprandial nutrient concentrations and reduce fecal particle size (FPS) in clinically healthy mares. The study was conducted in 16 mares of mature age (4–17) who had not received dental care in the previous year. A diet consisting of ad libitum Coastal Bermudagrass hay and 1.36 kg of a pelleted feed was fed daily prior to and during the study. Eight mares received dental work and eight served as untreated controls. While the consumption of a concentrate meal increased plasma concentrations of glucose and amino acids at 90 minutes postfeeding (P < .001), dental correction did not have an influence on plasma nutrient concentrations (P > .1). On day 56, untreated control horses had a larger percent of large FPS than horses having received dental correction (14.7 ± 0.1 vs. 12.5 ± 0.1; P = .028). Dental correction may improve mechanical digestion of feed, but this does not translate to altered postprandial plasma nutrient concentrations following the consumption of a concentrate meal.

Dietary starch level affects nutrient digestibility, faecal waste production and characteristics in yellowtail kingfish (Seriola lalandi) depending on the level of fish meal replacement

Yellowtail kingfish have a poor faecal integrity when fed with pelleted diets which may be due to the presence of dietary starch. Moreover, whether dietary starch interacts with plant protein ingredients, is not known. In this study, we investigated the effect of dietary starch level, protein source and their interaction effect on faecal waste production and characteristics (visual appearance, faecal removal efficiency and particle size distribution (PSD)). Four diets were formulated according to a 2 × 2 factorial design (starch level × protein source). The effect of starch level was tested by either including 0% (LS - low starch, 4% starch) or 20% gelatinized wheat flour (HS - high starch, 20% starch). FM diets contained fish meal as protein source, whilst at FM/P diets approximately 65% of the fish meal was replaced by plant protein ingredients. Twelve tanks were stocked with 21 fish (mean initial weight 53 g) and fish performance, nutrient digestibility, faecal waste production and characteristics were evaluated over a 36-day experimental period. Both starch level and protein source affected the organic matter digestibility (p < 0.05). The effects of starch and protein source were additive regarding macro nutrient digestibility indicated by the absence of an interaction effect (p > 0.05). Growth was similar between the FM and FM/P at low starch diets (p < 0.05), but was reduced at the FM/P at high starch inclusion level (p < 0.05). The high starch and FM/P diets resulted in more faecal waste production (p < 0.05). Faecal integrity of yellowtail kingfish was adversely affected by starch inclusion. Fish receiving low starch diets excreted faecal pellets and short strings, while faecal waste collected from fish receiving high starch diets was classified as inconsistent. This was also reflected in a higher faecal removal efficiency and larger faecal PSD for fish receiving the low starch diets compared to the high starch diets (p < 0.05). No protein source or interaction effect was observed for faecal removal efficiency (p > 0.05). Consequently, lowering starch level and excluding plant protein ingredients reduced the amount of non-removed faeces by 71.1% and 30.6%, respectively. In summary, our study showed that the reduction of dietary starch offers possibilities to replace fish meal with plant protein ingredients without limiting growth performance in yellowtail kingfish. Moreover, lowering dietary starch level may have the potential to reduce solid loading in recirculating aquaculture systems for yellowtail kingfish.

Dietary Exogenous α-Amylase Modulates the Nutrient Digestibility, Digestive Enzyme Activity, Growth-Related Gene Expression, and Diet Degradation Rate of Olive Flounder (Paralichthys olivaceus).

In this study, a 12-week feeding experiment was conducted to characterize the effects of exogenous α-amylase on the growth, feed utilization, digestibility, plasma α-amylase activity, feed degradation rate, and fecal particle size of olive flounder (Paralichthys olivaceus). Diet was supplemented with 0 (AA0; control), 100 (AA100), 200 (AA200), or 400 (AA400) mg/kg of α-amylase, respectively. Fish (273.1 ± 2.3 g) were stocked into 12 tanks (25 fish/1,000-L tank) and 3 tanks were randomly selected for each diet group. As a result, α-amylase was found to have no significant effects (p ≥ 0.05) on the growth, feed utilization parameters, and whole-body proximate compositions. α-Amylase-treated fish exhibited only a significant increase in the apparent digestibility coefficient of carbohydrates compared to the controls. In addition, in vitro analyses revealed that α-amylase dose-dependently increased (p < 0.05) the feed degradation rate, while photographs of the intestinal content after 2, 4, and 8 h of feeding demonstrated an improved degradation rate in the α-amylase-treated groups. Plasma α-amylase content was higher in the AA200 and AA400 groups, whereas the control group produced significantly larger-sized fecal particles (90% size class) than these two groups. In the intestine, no changes were observed in the expression levels of the immune-related TNF-α, IL-1β, IL-2, immunoglobulin-M, HSP-70, lysozyme, and amylase alpha-2A. However, growth-related genes IGF-1, IGF-2, TGF-β3, and growth hormone genes were upregulated in muscle tissues. Collectively, exogenous α-amylase has positive roles in the modulation of the digestibility coefficient, blood α-amylase concentration, growth-related gene expression, and diet degradation for improved digestion in olive flounder.

73 Comparison of fecal particle size of Thoroughbred broodmares and their yearlings

Fecal particle size (FPS) may be an indicator of chewing efficiency and digestive function in horses. The objective of this study was to evaluate the effect of horse age on FPS by comparing FPS measured by wet sieving analysis between 6 mares (12.8 ± 2.8 y) and their yearlings (1.18 ± 0.06 y). Both groups were housed on pasture with access to alfalfa hay and fed 2.73–3.64 kg/d of concentrate feed formulated for breeding and growing horses. Feces were collected by free catch, and divided into subsamples. One subsample was used for dry matter (DM) determination and the remaining samples were frozen until analysis. Before analysis, samples were thawed and duplicate aliquots containing 3.8 g of DM were soaked overnight in 200 mL of water. The amount of sample needed to contain 3.8 g of DM was calculated using the predetermined sample DM. Samples were washed over a set of 203.2 mm stainless steel sieves (VWR, Radnor, PA) with sieve openings of 4, 2, 1, 0.5, 0.25, 0.125 and 0.063 mm using a standardized water flow rate of 6 L/min for 5 min. Each sieve was rinsed clean into a beaker from which particles were filtered onto dried, pre-weighed filter paper for DM determination. Particles passing the smallest sieve were not collected but the amount was calculated by difference between total DM sieved and DM retained on all sieves.Weighted mean FPS and percent DM retained on each sieve as a percent of total DM sieved were analyzed using paired t-test procedure in SPSS V28. There was no difference in weighted mean FPS between mares (1.59 mm ± 0.09) and yearlings (1.47 mm ± 0.06) (P > 0.05). There was no difference in the percentage of DM retained on the 3 largest and 2 smallest sieves between mares and yearlings (P > 0.05). Compared with yearlings, there were trends for mares to have greater DM retained on sieves with diameter 0.5 mm (P = 0.096) and 0.25 mm (P = 0.08). Mean ± SE percent DM retained for mares and yearlings, respectively, was 9.6% ± 1.6 and 6.95% ± 1.2 (4 mm sieve), 12.70% ± 1.09 and 10.65% ± 1.08 (2 mm sieve), and 12.48% ± 0.89 and 12.19% ± 1.7 (1 mm sieve). Soluble DM calculated by difference as DM escaping the smallest sieve was greater in yearling samples compared with mare samples (37.02 vs 29.88%; P = 0.019). The small sample size of this study is a limitation but suggests there may be differences in fecal particle size distribution between mare and yearling pairs that warrant further investigation.

A simple approach to monitor faecal particle size in the Asian elephant - A proof of concept study

A simple approach to monitor faecal particle size in the Asian elephant - A proof of concept study

Practical low-fishmeal diets for rainbow trout (Oncorhynchus mykiss) reared in RAS: Effects of protein meals on fish growth, nutrient digestibility, feed physical quality, and faecal particle size

To evaluate strategies for optimizing waste in recirculating aquaculture systems, 1020 rainbow trout (initial live weight 17.2 ± 7.50 g/fish) were distributed into 12 tanks after 21 d of acclimation and fed during 84 days with four practical diets (crude protein: 49% DM; crude fat 26% DM; gross energy: 23 MJ kg-1) containing different rates of fishmeal and alternative protein meals, i.e. Diet FM (307 g kg-1 fishmeal, 61.2 g kg-1 poultry by-product meal); diet PBM (183 g kg-1 fishmeal, 168 g kg-1 poultry by-product meal); diet FeM (198 g kg-1 fishmeal, 61.2 g kg-1 poultry by-product meal, 76.5 g kg-1 hydrolysed feather meal); diet FeM+RM (171 g kg-1 fishmeal, 61.2 g kg-1 poultry by-product meal, 76.5 g kg-1 hydrolysed feather meal, 60.4 g kg-1 rapeseed meal). High structural integrity of extruded pellets and low oil leakage were measured in all diets, while the lowest water turbidity at 15 min after feed administration was recorded for FeM diet (2.7 vs. 12.7 mg L-1; p < 0.05). Diets did not affect fish specific growth rate (2.16% d-1). The lowest apparent digestibility of protein was measured with diet FeM (79.6%) and the highest with diet PBM (86.0%) (p < 0.001); apparent digestibility of lipids was higher in fish fed diets FM and PBM than the other diets (84.4% and 85.5% vs. 66.4% vs. 71.1%; p < 0.001). Fish fed diet PBM showed a higher percentage of retained faeces at mesh sizes 0.5–0.8 mm (33% vs. 30%; p < 0.005) and 0.3–0.5 mm (64% vs. 59%; p < 0.001) compared with the other diets. The replacement of fishmeal with poultry by-product- meal had positive effects on nutrient digestibility and faecal particle size. The replacement with hydrolysed feathers and rapeseed meals impaired nutrient digestibility but had positive implications for water turbidity.

Variations in fecal pH and fecal particle size due to changes in dietary starch: Their potential as an on-farm tool for assessing the risk of ruminal acidosis in dairy cattle

This study evaluated the variations in fecal pH and particle size due to changes in dietary starch, and the potential of these variations as a tool to detect the risk of subacute ruminal acidosis (SARA) in dairy cows. Nine ruminally cannulated, non-lactating, non-pregnant Holstein cows were used in two 6-week experimental periods. In each period, cows were first fed a forage diet for 1 wk., then transitioned over 1 wk. to a 65% concentrate ration, which they consumed for 4 wk. continuously. Measurements were conducted when cows consumed 17.3, 21.9 and 28.8% dietary starch. Fecal pH and particle size were measured at 0, 4, 8 and 12 h relative to feeding in days 7, 11, 21, 28, 35, and 42 of each period. Ruminal pH was measured every 15 min. Data were analyzed with SAS, the statistical model included concentrate level, time of sampling and period as fixed effects and cow was considered as random effect. Data showed an interaction between dietary starch level and time relative to feeding on fecal pH, with a shift in its pattern due to diet change. Specifically, during low starch feeding (17.3%), fecal pH was highest before feeding and decreased thereafter, reaching lowest value 12 h post-feeding (P < 0.05). With the 21.9% starch diet, fecal pH did not change significantly after feeding. However, during high starch feeding (28.8%), fecal pH decreased, being lowest before feeding and increased (P < 0.05) during the day reaching highest values at 8 and 12 h post-feeding. Fecal pH was lower (P < 0.01) during the days of high starch feeding; though, it was maintained relatively stable through this timeframe. Increasing dietary starch decreased the proportion of small fecal particles (0.5 to 1.18 mm), but increased the proportion of large (>1.18 mm) and soluble particles (<0.5 mm). There were significant correlations among ruminal pH, fecal pH and fecal particle size of feces collected before feeding. For example, fecal pH was correlated with minimum and daily mean ruminal pH; the proportion of fecal particles 0.5 to 1.18 mm correlated with minimum and daily mean ruminal pH (P < 0.01). Log-linear dependency analyses indicated a strong effect of starch intake on fecal pH so that for every kg increase in starch intake, there was a reduction in fecal pH by 0.38 units. In addition, regression analysis showed that the proportion of fecal particles between 0.5 and 1.18 mm showed strong dependency on the ratio dietary physically effective fiber to starch (P < 0.01). Ruminal pH also correlated with fecal particle size of frozen/thawed samples, but with lower strength than fresh samples. Overall, evaluating variations of fecal pH and particle size holds potential as a non-invasive on-farm tool for assessing rumen pH and SARA risk.

Effect of dietary protein source and ingredient grinding size on fish performance, faecal waste production and characteristics of yellowtail kingfish (Seriola lalandi) fed restrictively and to apparent satiation

Recently, yellowtail kingfish (Seriola lalandi) is being cultured in recirculating aquaculture systems (RAS). Yellowtail kingfish have a poor faecal integrity, which makes the removal of faeces by traditional RAS technology difficult. Reducing the faecal waste load in RAS can be achieved by reducing the amount of faeces produced (e.g., increasing digestibility) and/or increasing the removal of faeces. This study assessed the effect of partial fish meal replacement by plant ingredients and the effect of ingredient grinding size on the amount of faecal waste produced and faecal characteristics, like faecal removal efficiency and particle size distribution (PSD), in yellowtail kingfish. This was investigated during two 35-d experiments, where fish were fed restrictively (experiment R) or to apparent satiation (experiment S). For each experiment, individual batches of four experimental diets were produced according to a 2 × 2 factorial design (protein source × ingredient grinding size). The formulas used were identical for both experiments. FM100 diets contained only fish meal as protein source, whilst at FM30-P70 diets approximately 70% of the fish meal were replaced by plant protein ingredients. The effect of ingredient grinding size was tested by including 40% of either a fine or coarse grinding mixture. Tanks were stocked with 20 fish and 27 fish for experiment R and experiment S, respectively. For each tank, fish performance, faecal waste production, faecal removal efficiency and faecal PSD were measured. During both experiments, ingredient grinding size did not affect the faecal removal efficiency or PSD, whilst fish fed the fine FM30-P70 diets restrictively showed a lower faecal waste production. The inclusion of plant ingredients resulted in a lower absolute growth and higher FCR. Furthermore, fish fed the FM30-P70 diets showed a higher faecal waste production, a smaller PSD and a lower faecal removal efficiency. This ultimately resulted in a higher amount of non-removed faeces by 58.3% and 37.1% compared to FM100 diets for the experiment R and experiment S, respectively. In conclusion, the replacement of fish meal with plant ingredients in yellowtail kingfish diets is challenging due to the adverse effects on fish performance, faecal waste production and faecal characteristics. However, feeding yellowtail kingfish to apparent satiation partly reduced these adverse effects of plant ingredient inclusion in terms of faecal waste production and faecal characteristics. Reducing the ingredient grinding size of yellowtail kingfish diets tended to lower the faecal waste production, whilst not negatively affecting the fish performance or faecal characteristics.

PSI-10 Relationships Between Fecal Characteristics, Rumen pH, and Intake During an Acidosis Challenge

Abstract The objectives were to: 1) determine the relationship of fecal particle size with rumen pH, fecal pH, dry matter intake (DMI) and 2) determine the ability of fecal characteristics to predict rumen pH and DMI. Decreased ruminal pH during an acidotic bout may reduce fiber digestion and increase subsequent washed fecal particle size. Data were collected in a metabolism experiment using18 ruminally cannulated steers. The study was a completely randomized design evaluating the effect of a lactate adaption before an acidosis challenge. Ruminal pH, DMI, and fecal characteristics (fecal pH and washed fecal particle size) were measured for 4 d after the acidosis challenge. Fecal particle size was measured with 7 sieves with diameters ranging from 4,750 to 600 µm. Average rumen pH over 4 d was associated (r = 0.60; P &amp;lt; 0.01) with mean fecal particle size. However, rumen pH was not correlated with fecal pH (P &amp;gt; 0.1). Fecal pH was not correlated with mean fecal particle size (P &amp;gt; 0.1). Mean fecal particle size was correlated with days after the acidosis challenge (r = 0.36; P &amp;lt; 0.01). Multiple regressions were performed with the GLMSELECT procedure of SAS 9.4 using stepwise selection. Rumen pH was best predicted (r2 = 0.22) by fecal particle size between 1,700 and 1,400 µm, 1,180 and 850 µm, and less than 600 µm. Dry matter intake was best predicted (r2 = 0.17) by fecal particle size between 2,360 and 1,700 µm, 1,400 and 1,180 µm, and 850 and 600 µm. Overall, results indicated mean fecal particle size was correlated with rumen pH and days after the acidosis challenge. Additional data are needed for fecal characteristics to accurately predict ruminal pH and DMI.

Chemical composition and physical characteristics of faeces in horses with and without free faecal liquid \u2013 two case-control studies

BackgroundFree faecal liquid (FFL) is a condition in horses characterised by two-phase (one solid and one liquid) separation of faeces. Causes of the condition are unknown, but disturbed hindgut fermentation has been suggested as it may alter biochemical composition and appearance of faeces in equines. However, information on faecal composition in horses with FFL is scarce. Faecal chemical composition (dry matter, osmolality, ash, macro minerals, short-chain fatty acids (SCFA) and pH) and physical characteristics (free liquid, sand, water holding capacity and particle size distribution) were compared in horses with (case) and without (control) FFL in two sub-studies. In sub-study I, faeces from 50 case-control horse pairs in Sweden and Norway were sampled in three sampling periods (SP1-SP3). In sub-study II, faeces from 32 case-control horse pairs in Germany were sampled on one occasion.ResultsIn sub-study I, faecal concentration and proportion of lactic acid (of total short-chain fatty acids, SCFA) and water holding capacity was lower in case compared to control horses. Other variables (content of dry matter, ash, sodium, calcium, phosphorous, magnesium, sulphur, and concentrations of i-butyric, n-valeric and total SCFA, ammonia-N as proportion of total N, and pH) were similar in faeces from case and control horses. In sub-study II, all analysed variables were similar in faecal samples from case and control horses. Faecal particle size distribution was similar in case and control horses, but the proportion of larger particles (2 and 1 mm) were lower and proportion of smaller particles (< 1 mm) was higher in sub-study I compared to in sub-study II.ConclusionsTo the authors’ knowledge, this is the first study to investigate faecal chemical composition and physical characteristics in horses with FFL. Case and control horses had similar total SCFA, pH and osmolality, indicating that hindgut fermentation was similar. However, small differences in concentration and proportion (of total SCFA) of lactic acid and water holding capacity of faeces were shown and are of interest for further studies of horses with FFL.

Effect of Soy Protein Products and Gum Inclusion in Feed on Fecal Particle Size Profile of Rainbow Trout

Replacement of fishmeal (FM) with alternative plant proteins, especially soybean meal (SBM), can cause a diarrhea-like symptom in rainbow trout (RBT), characterized by very fine fecal particles. These fines do not settle out in raceway effluent for collection and can contribute to pollution of receiving waters. In this study, two experiments were conducted. Experiment 1 examined effects of nine protein sources (sardine meal, menhaden meal, soy protein concentrates (SPC) (three types), SBM (regular and high protein), corn protein concentrate (CPC), and poultry by-product meal (PBM)) on fecal particle size distribution. Results showed that all five soy-based diets produced feces in RBT having 75.7–89.3% fines and only about 1.0% large particles, while the remaining four diets yielded feces having a balanced particle size distribution. Oligosaccharides present naturally in soy products, thought to contribute fecal fines, were not correlated to fecal particle size classes. Instead, high crude fiber content in soy-based diets was found to be responsible for unbalanced fecal particle distribution in RBT. Experiment 2 examined if improvements in formulation could reduce the negative effect of soy-based ingredients. Eight practical diets (FM, SPC, SPC + 0.3% guar gum, PBM + CPC, PBM + CPC + 20 or 30% SPC, and PBM + CPC + 20 or 30% SPC + 0.3% guar gum) were formulated to contain 40% protein and 20% lipid. Results showed that diets containing mixtures of PBM, CPC, and 20% or 30% SPC plus guar gum produced trout feces with the highest percentage of large particles and lowest of fines, while the diet containing SPC alone (56%) plus guar gum resulted in trout feces having the highest content of mid-size particles. It was concluded that crude fiber in soy protein products (SBM and SPC) caused undesirable fecal particle profiles in RBT, and the addition of guar gum could significantly alleviate this negative effect.

Increasing food intake affects digesta retention, digestibility and gut fill but not chewing efficiency in domestic rabbits (Oryctolagus cuniculus).

In ruminants, the level of food intake affects net chewing efficiency and hence faecal particle size. For nonruminants, corresponding data are lacking. Here, we report the effect of an increased food intake of a mixed diet in four domestic rabbit does due to lactation, and assess changes in particle size (as determined by wet sieving analysis) along the rabbit digestive tract. During lactation, rabbits achieved a distinctively higher dry matter intake than at maintenance, with a concomitant reduction in mean retention times of solute and particle markers, an increase in dry matter gut fill, a reduction in apparent digestibility of dry matter, and an overall increase in digestible dry matter intake. By contrast, there was no change in faecal mean particle size (mean ± SD: 0.58 ± 0.02 vs. 0.56 ± 0.01 mm). A comparison of diet, stomach content and faecal mean particle size suggested that 98% of particle size reduction occurred due to ingestive mastication and 2% due to digestive processes. Very fine particles passing the finest sieve, putatively not only of dietary but mainly of microbial origin, were particularly concentrated in caecum contents, which corresponds to retention of microbes via a ‘wash‐back' colonic separation mechanism, to concentrate them in caecotrophs that are re‐ingested. This study gives rise to the hypothesis that chewing efficiency on a consistent diet is not impaired by intake level in nonruminant mammals.

Apparent digestibility, fecal particle size, and mean retention time of reduced lignin alfalfa hay fed to horses.

Reduced lignin alfalfa (Medicago sativa L.) has the potential to provide a higher-quality forage source for livestock by improving forage digestibility. This study was conducted to evaluate apparent digestibility when feeding reduced lignin and nonreduced lignin alfalfa hay to adult horses, and to examine mean fecal particle size (MFPS) and mean retention time (MRT) between alfalfa forage types. In 2017, reduced lignin ("54HVX41") and nonreduced lignin ("WL355.RR") alfalfa hay was harvested in Minnesota at the late-bud stage. Alfalfa hays were similar in crude protein (CP; 199 g/kg), neutral detergent fiber (NDF; 433 g/kg), and digestible energy (2.4 Mcal/kg). Acid detergent lignin concentrations were lower for reduced lignin alfalfa hay (74 g/kg) compared to nonreduced lignin alfalfa hay (81 g/kg). Dietary treatments were fed to six adult, stock-type horses in a crossover study. Experimental periods consisted of a 9-d dietary adaptation phase followed by a 5-d total fecal collection phase, during which horses were housed in individual boxstalls and manure was removed on a continuous 24-h basis. At 12-h intervals, feces were thoroughly mixed, subsampled in duplicate, and used for apparent digestibility and MFPS analysis. On day 2 of the fecal collection phase, horses were fed two indigestible markers, cobalt (Co) and ytterbium (Yb), which were fed as Co-ethylenediaminetetraacetic acid and Yb-labeled NDF residue, respectively. Additional fecal samples were taken at 2-h intervals following marker dosing until 96-h post-dosing to evaluate digesta MRT. Data were analyzed using the MIXED procedure of SAS, with statistical significance set at P ≤0.05. Dietary treatment (i.e., alfalfa hay type) was included as a fixed effect, while experimental period and horse were considered random effects. Dietary treatments were similar in dry matter intake (1.6% bodyweight) and time to consumption (7.6 h). Apparent dry matter digestibility (DMD) was greater for reduced lignin alfalfa (64.4%) compared to nonreduced lignin alfalfa (61.7%). Apparent CP and NDF digestibility did not differ between dietary treatments, averaging 78% and 45%, respectively. Dietary treatments were similar in MFPS (0.89 mm) and MRT for both liquid (23.7 h) and solid (27.4 h) phase material. These results indicate an improvement in DMD for reduced lignin alfalfa hay when fed to adult horses, with no change in forage consumption, fecal particle size, or digesta retention time.