Total Fecal Collection Research Articles

Duckweed protein as an alternative plant-based protein source for dog and cat dry diets.

Duckweed has attracted increasing attention as a high-quality and sustainable novel plant-based protein source. However, little research has been conducted in dogs and cats. We evaluated the effects of inclusion of duckweed protein (Lemna; MCSelect; Parabel; Vero Beach, FL) primarily in replacement of pea protein in dog diets at 0%, 5%, and 10% and cat diets at %, 10%, and 15% on stool quality, nutrient digestibility, and palatability. We hypothesized that duckweed protein would be a viable protein source in both dog and cat diets by showing no detriment to nutritional outcomes. All feeding tests were conducted at an independent research facility (Susquehanna, PA). A standard 2-bowl palatability test over a 2-d period was conducted with adult animals (n = 30 each) to determine intake ratio between test diets (duckweed-containing diets) and control diets (0% duckweed protein). Apparent total tract nutrient digestibility was conducted with 18 adult dogs and 21 adult cats (n = 6 to 7 per diet) with 5 d of diet acclimation followed by 5 d of total fecal collection. Stool quality was evaluated on a 1 to 5 scale where 1 = non-formed or diarrhea and 5 = hard, formed. Palatability data were analyzed using paired t-test (daily consumption) and chi-square test (first choice). All other data were analyzed by ANOVA and contrast (SAS version 9.4). For cats, 10% duckweed had greater (P < 0.05) palatability than control, while no difference was observed between 15% duckweed protein and control. For dogs, 5% and 10% duckweed protein had (P < 0.05) lower palatability, demonstrating a preference to control. Both cats and dogs fed duckweed diets had acceptable stool quality (Mean = 3.4 and 3.3, respectively). No detriments in nutrient digestibility were observed in dogs fed 5% and 10% duckweed protein; however, cats fed 10% and 15% duckweed protein had (P < 0.05) lower dry matter, protein, and energy digestibility vs. control. In conclusion, the data collected indicate that duckweed can be a viable replacement for other plant-based proteins in dog diets at inclusion levels up to 10%; more development is needed for duckweed protein inclusion into cat diets.

Valor nutritivo das folhas secas de Cratylia argentea na alimentação de coelhos em crescimento

Abstract Nutrition in rabbit farming accounts for about 70% of all costs; in this sense, C. argentea is an excellent alternative as a feed, due to its bromatological composition. Our goal is to evaluate the nutritional value of diets formulated with the dried leaves of C. argentea to feed growing rabbits. Twenty-eight white rabbits of the New Zealand breed, 55 days old, of both sexes, were used. Two treatments (n = 14, 7 males, and 7 females) were evaluated in a randomized block experimental design in a 2 x 2 factorial scheme. The control diet (CTRL) was formulated to meet the nutritional requirements of growing rabbits, and the test diet (DRY) was obtained by replacing 20% of the CTRL diet with dried leaves of C. argentea. The experimental period was comprised of 11 days, with seven days of adaptation and four days of total feces collection. The average daily gain, dry matter intake, feed conversion, and final body weight were not affected by replacing the CTRL diet with the dried leaves of C. argentea. The coefficient of dry matter digestibility showed better results in CTRL rabbits (female: 72.19%, male: 72.48%). Rabbits fed with the CTRL diet exhibited a higher consumption of crude protein compared to those fed with the DRY diet, however, these rabbits showed higher elimination and lower retention of crude protein. It is concluded that C. argentea presents values of 1,400.67 kcal per kg of dry matter, digestible energy, and 3.34% digestible protein per kg of dry matter.

Intake, digestibility, rumen fermentation and nitrogen balance in sheep offered alfalfa silage with different proportions of the tannin-rich legume sericea lespedeza

Dietary manipulations to include tannins can change the proportion and amounts of nitrogen (N) excreted in the urine and feces as well as improve nitrogen use efficiency by ruminants. This study was conducted to investigate the effects of adding different proportions of sericea lespedeza (Lespedeza cuneate) hay (SL) containing tannins (16.8% total condensed tannins; CT) to alfalfa (Medicago sativa) silage. Alfalfa silage was either offered alone (0 g/kg; CONT) or mixed with chopped SL to provide 90 (LOW), 180 (MED), or 270 g/kg SL (HIGH) or 15, 30, or 45 g CT/kg on a dry matter (DM) basis. These diets were offered randomly for ad libitum consumption to 16 Dorper ewe lambs (42.1 ± 1.15 kg BW; Period 1; 41.7 ± 1.12 kg BW; Period 2) in a randomized complete block design experiment where each treatment was offered to four lambs during each of two periods. The same 16 lambs were used in both periods, resulting in eight total observations/treatment. Each period consisted of a 14-d dietary adaptation period followed by 5 d of total fecal and urine collection. Data were analyzed using PROC MIXED of SAS. Dry matter (DM), organic matter (OM), neutral detergent fiber (aNDF) and acid detergent fiber (ADF) digestibility as well as digestible DM and OM intake (g/day or g/kg BW) decreased linearly (P < 0.05) with increasing SL in the diet. Ruminal acetate and butyrate molar proportions increased quadratically (P = 0.01), whereas ruminal isobutyrate and isovalerate decreased linearly (P = 0.02) with increasing SL in the diet. Apparent N absorption (g/kg N intake) decreased linearly (P < 0.05) with increasing SL in the diet. Urinary N excretions (g/kg N intake) tended (P = 0.10) to respond quadratically while fecal N (g/kg N intake) increased linearly (P < 0.01) with increasing SL proportion in the diet. In this study, supplementation with sericea lespedeza as a tannin source to alfalfa silage decreased forage digestibility without affecting feed intake, and significantly increased N excreted in feces and tended to decrease urine N excretion without affecting N balance. Therefore, feeding tannins in diet can alter N excretion route from urine to feces but may not improve N-use efficiency by the animal.

Extruded diet macronutrient digestibility: plant-based (vegan) vs. animal-based diets in client-owned healthy adult dogs and the impact of guardian compliance during in-home trials

IntroductionPlant-based (vegan) diets for dogs are commercially available, however, research investigating long-term nutritional adequacy of these diets is scarce. Use of client-owned animals has become increasingly popular for apparent total-tract nutrient digestibility (ATTD) studies, yet low guardian compliance with the study protocol, such as providing daily dietary intake information, is a challenge. However, the impact of low diet reporting compliance on the overall ATTD results is unknown.MethodsSixty-one, client-owned healthy adult dogs completed a randomized, double-blinded longitudinal study. Dogs were randomly assigned into two groups that were fed either a commercial extruded meat-based diet (MEAT, n=30) or an experimental extruded vegan diet (PLANT, n=31) for 12 weeks. At the end of the study, pet guardians performed a 72-hour total fecal collection for ATTD assessment. Pet guardians were asked to complete a food diary for the duration of the trial, however only a subset of guardians (n=35) provided this food diary at the end of the study.ResultsNo evidence of an association between pet guardians providing a food diary and apparent digestibility coefficients (ADC) of crude protein (CP) (p=0.14), crude fat (EE) (p=0.72), and dry matter (DM) (p=0.68) was found. Apparent digestibility coefficients for CP (p=0.52), EE (p=0.78), and DM (p=0.43) did not differ between PLANT and MEAT. Body weight and age were found to be associated with CP (p=0.03) and DM (p=0.01) digestibility, but no association with EE (p=0.07) digestibility was present.DiscussionThese results indicate that vegan- and animal-based diets with similar nutrient profiles can have comparable nutrient digestibility. Moreover, presence or absence of a guardian-reported food diary had no effect on the overall results of the ATTD study. Further studies investigating guardian compliance for ATTD trials are needed to develop a standardized protocol and reduce current challenges and limitations related to pet guardian’s participation in digestibility trials.

Growing pigs’ diets with increased phytase activity and reduced available phosphorus resulted in similar performance and environmental impacts

The objective of this study was to evaluate, through a life cycle assessment, the environmental impacts of the postweaning growth of pigs fed with diets with reduced levels of available phosphorus and increased phytases. In Trial I (nitrogen and phosphorus balance), 25 crossbreed barrow pigs (BP 400 × BM 500 Biriba’s®), with an average weight of 23.05 ± 3.24 kg and average starting age of 60.75 ± 4.73 days, were assigned to five dietary treatments using a randomized block design, with five replications and each animal as an experimental unit. Five experimental diets were evaluated: each increasing phytase activity units (FTU) (control [0], 250, 500, 750 and 1 000 FTU) and decreasing levels of available phosphorus (0.435, 0.375, 0.315, 0.255 and 0.195%), respectively. Due to phytase supplementation, all diets meet the requirements for available phosphorus. The pigs received two daily meals. Total collection of feces was performed, adding 2 g of ferric oxide as a fecal marker. Feces were collected daily, stored in plastic bags and frozen. All excreted urine was collected in plastic buckets containing 20 mL of HCl (1:1), and a 20% aliquot was frozen for further analysis. In Trial II (performance), 40 crossbreed barrow pigs (BP 400 × BM 500 Biriba’s®) with an initial average weight of 15.11 ± 0.67 kg, average starting age of 50.63 ± 0.81 and finishing age of 72.43 ± 2.07 days were assigned using a randomized block design to five dietary treatments, with eight replications and each animal as an experimental unit. The pigs were weighed at the beginning and at the end of the trial, as were the feed supplies and refusals. These data were used to calculate the feed conversion ratio, average daily gain and average daily feed intake. The life cycle analysis was based on the CML 2001 (baseline) method V3.02, as implemented in the Simapro software, version 8.05 (PRé Consultant, 2014). These data may further serve as a reference for the study of the impact of phytase supplementation during other breeding phases, or even in other animals whose environmental impacts are being studied.

Net energy content of hybrid rye fed to growing pigs and effects of particle size on energy values

An experiment was conducted to determine the digestible energy (DE), metabolizable energy (ME), and net energy (NE) contents of hybrid rye fed to growing pigs using indirect calorimetry and to investigate the effects of particle size on energy values. Thirty growing barrows (18.06 ± 0.83 kg initial body weight) were individually housed in metabolism crates and randomly allotted to one of five dietary treatments to give six replicates per treatment. Two hybrid rye varieties (Bono and Gatano) were ground in a hammermill mounted with a 4.0-mm or 3.2-mm screen to obtain coarse and fine particle size, respectively. Dietary treatments included a corn-soybean meal basal diet and four additional diets containing 300 g/kg of the test ingredients in a 2 × 2 factorial based on hybrid rye variety (Bono or Gatano) and particle size (Coarse or Fine). Pigs were fed experimental diets for 15 days, including 10 days for adaptation and 5 days for total fecal and urine collection to determine the DE and ME of the experimental diets. Pigs were then moved into indirect calorimetry chambers to determine 24-h heat production and 12-h fasting heat production. All data were analyzed using the MIXED procedure of SAS with the individual pig as the experimental unit. The geometric mean diameter (Dgw) for coarsely versus finely ground Bono and Gatano were 1111 versus 594 µm and 1210 versus 717 µm, respectively. The coefficient of apparent total tract digestibility (CATTD) of dry matter (DM) and gross energy (GE) were greater (P < 0.05) in diets containing finely than coarsely ground hybrid rye. The DE and ME of finely ground hybrid rye were greater (P < 0.05) than those of coarsely ground hybrid rye, and the NE of finely ground hybrid rye tended to be greater (P = 0.084) than that of coarsely ground hybrid rye. No differences were observed for the DE, ME, and NE contents between Bono and Gatano. The determined NE for coarsely and finely ground Bono were 11.06 and 11.77 MJ/kg DM, and the respective NE values for coarsely and finely ground Gatano were 11.09 and 11.57 MJ/kg DM. In conclusion, the energy values of different hybrid rye varieties might be comparable. Particle size reduction could significantly improve the DE and ME values of hybrid rye fed to growing pigs, while the NE value was only numerically improved.

PSVIII-15 Saccharomyces Cerevisiae Fermentation Product Influences Indicators of Gut Health and Function in Healthy Adult Cats

Abstract Compared with other species, the gastrointestinal influences of dietary Saccharomyces cerevisiae fermentation product (SCFP) in cats are not well-characterized. In this study, SCFP (TruMune, Cargill, Inc.) was added to an extruded cat food to explore gut-related outcomes in healthy adult cats. Sixty-three cats (mean age = 6.3 ± 2.8 yr; mean BW = 4.4 ± 0.1 kg) were used in a randomized complete block design to evaluate a base diet without SCFP (CON) or supplemented with 150 mg/kg BW SCFP (TRUL) or 300 mg/kg BW SCFP (TRUH). All cats were fed CON during a 21-d adaptation period and subsequently fed their respective diet from d 0 to d 42. Fecal samples were collected at d 0, d 21 and d 42 for analysis of fecal characteristics, fermentation end-products and shotgun metagenomics. A 5-d total fecal collection was performed from d 35 to d 39 for analysis of apparent nutrient digestibility. Data were analyzed using R v.4.1.2. Non-metagenomic data were analyzed using linear and generalized linear mixed models with lme4 and emmeans packages and metagenomic data were analyzed using phyloseq, vegan, lme4, LinDA and emmeans packages. Differences P &amp;lt; 0.05 were considered significant and P &amp;lt; 0.10 as trends after FDR correction. Fecal pH was higher (P = 0.01) for SCFP-supplemented cats vs CON and exhibited a positive linear dose response (P &amp;lt; 0.05) at d 21 and d 42. Fecal score was higher (firmer; P = 0.05) for SCFP-supplemented cats vs CON at d 21 consistent with a linear decrease (P = 0.02) in the binary comparison of fecal moisture between CON vs SCFP-supplemented cats (P = 0.01) during total fecal collection. Fecal ammonia demonstrated a quadratic treatment dose response trend at d 21 (P = 0.09). Fecal butyrate decreased linearly with SCFP dose (P &amp;lt; 0.001) and was less (P &amp;lt; 0.05) for SCFP-supplemented than CON cats at d 21 and d 42. Total short-chain fatty acid (SCFA) decreased linearly (P = 0.08) with SCFP dose and was less (P = 0.05) for SCFP-supplemented than CON cats at d 21. Species level alpha diversity decreased for CON (P = 0.04) but did not change in the TRUL and TRUH groups. Shannon diversity tended to increase in TRUH (P = 0.08) among a subset of 25 butyrate producers identified by the presence of butyrate pathway enzymes. Differential abundance of butyrate producers showed Acidaminococcus timonensis; CAG-83 sp900545495 and Megasphaera elsdenii decreased while Butyricicoccus pullicaecorum and Lawsonibacter 1402 linearly increased over time for TRUH cats (P &amp;lt; 0.05). No differences in alpha diversity or abundance were detected for any other butyrate producing taxa in TRUH nor between CON and TRUL cats. These results suggest SCFP influences several gastrointestinal outcomes in adult cats including pathways associated with SCFA production, cross-feeding, and/or absorption.

325 Understanding Variation in Residual Feed Intake of Brahman Steers Fed Two Different Diets

Abstract Improving feed efficiency in cattle is a long-standing aim of the beef industry. However, discrepancies in the ranking of bulls based on the diets used and calculation methods employed for defining feed efficiency have been observed. Hence, the objective of this research was to assess the extent to which different factors influence feed efficiency in Brahman steers. Individual DMI and ADG were measured, and residual feed intake (RFI) calculated using linear regression of DMI on ADG and midtest metabolic body weight. Eight-nine steers were initially fed a low-protein diet (LP, 8.8% CP) for 70 days, followed by a high-protein (HP, 13.5% CP) diet for another 70 days. The genetic variation among steers and the proportion of Bos indicus genes were determined using the GGP Indicus 50K assay (Neogen Corporation, Ipswich, Australia). Rumen bacteriome variation was determined with 16S rRNA gene sequencing of rumen fluid collected before and after feeding. Daily diet refusals were visually scored for the proportion of pellets versus hay and expressed as a diet selection index (1 to 3). Organic matter digestibility (OMD) was determined using total feces collection in metabolism crates. Plasma urea nitrogen (PUN) was measured in blood samples collected at four time points. The diet-animal fractionation of nitrogen isotopes (Δ15Ntail hair) was quantified in tail hair using isotope-ratio mass spectroscopy to indicate differences in nitrogen metabolism. Finally, carcass characteristics were determined at slaughter. Including carcass fat depth improved (P = 0.01) DMI prediction (R2 increased from 78.4 to 80.4%) in the LP diet but had a smaller effect (P = 0.39) in the HP diet (R2 increased from 75.0 to 75.2%). In the LP diet, the variation in carcass fat-correct RFI (RFIc) could be explained by DMI (14.5% of the variation), rumen bacteriome (5.89%), diet selection index (3.08%), PUN (1.88%), genetic distance (0.76%) and OMD (0.50%), accounting for a total of 26.6% of the RFIc variation. In the HP diet, the regression model explained 35.3% of the RFIc variation, with DMI explaining 25.9%, diet selection index 7.19%, rumen bacteriome 1.02%, genetic distance 0.73% and Δ15Ntail hair 0.50%. In conclusion, this study highlights the importance of measuring diet selection to accurately determine RFI in cattle. The results also suggest that variations in the rumen bacteriome and nitrogen metabolism parameters play a role in individual variations of feed efficiency. However, most of the variation in feed efficiency remained unexplained.

333 Using Specific Bacillus Strains to Improve Digestibility and Performance of Growing Steers

Abstract Low fiber digestibility is an important factor restricting the growth performance of cattle in the dry tropics, both during the initial growth phase in grazing systems and later during finishing in high-starch diets. Due to concerns relating to the non-therapeutic use of antibiotics, including ionophores, there is interest in replacing these with probiotics. The objective was to evaluate the effects of specific strains of Bacillus spp. (Bovacillus, Chr. Hansen, Denmark) on intake and total tract nutrient digestibility of two diets. The first diet was forage based [100% Rhodes grass hay with 69% neutral detergent fiber (NDF)], the second was a high-energy diet (20% Rhodes grass hay, 40% finisher pellet, 30% peanut hull fiber pellet, 10% ground barley, 47% NDF, 18% starch). Twelve Bos indicus steers (267 ± 7.5 kg) were blocked by initial body weight and randomly assigned to receive the diets either without probiotic supplementation (n = 6, Control) or the diets plus 3 g per head of a probiotic containing a mixture of Bacillus licheniformis and Bacillus subtilis (3.2 x 109 CFU/g) for the duration of the trial. Each diet was fed for a 34-d period in individual pens followed by a 7-d sampling period during which the steers were housed in metabolism crates for total collection of urine and feces. On the high-fiber diet, supplementing with the probiotic increased organic matter digestibility by 7.8% (49.9 vs. 53.8%) and NDF digestibility by 8.4% (49.7 vs. 53.9%) resulting in greater (P &amp;lt; 0.05) digestible fiber intake (1.62 vs. 1.72 kg/d). There was no effect of probiotic supplementation on intake or digestibility in the high starch diet, and Bacillus supplements did not change rumen microbial protein synthesis in both diets. In conclusion, supplementing steers with a Bacillus-based probiotic has the potential to improve the nutrient digestibility and performance of beef steers, especially in tropical grazing systems.

211 Evaluation of Beef Heifer Variability in the Ability to Eat and Digest a High Forage Diet

Abstract This study evaluated beef heifers selected for high or low digestible fiber intake (DFI) and investigated its relationship with methane production, residual feed intake (RFI), and total tract digestibility. Sixteen recently weaned black Angus beef heifers (n = 8/treatment) were selected from a group 64 heifers (224 ± 17.2 kg) fed a high forage-based diet [70% barley silage:30% pelleted concentrate (DM basis)]. The 64 heifers were fed in 6 outdoor pens equipped with GrowSafe bunks to monitor feed intake for 60 d (14 d adaptation + 46 d for data collection). Individual fecal samples and BW, and feed samples were taken once weekly. Fecal samples were pooled by animal. Feed and fecal samples were analyzed for dry matter (DM), neutral detergent fibre (NDF), and undigested neutral detergent fiber (uNDF) content. The internal marker uNDF was used to estimate total tract diet DM and NDF digestibility. The 8 heifers with the greatest and the 8 with the least digestible NDF intake (g/kg BW0.75) were selected and used for methane measurements using the GreenFeed system (42 d) and in a total-tract digestibility trial with total fecal and urine collection using the same high forage based diet. Results from the GrowSafe selection trial indicated no differences between the average BW of low and high DFI heifers (264 vs. 274 kg, P = 0.20). Heifers selected for high DFI had greater (P &amp;lt; 0.01) DM and NDF intake (kg/d or % of BW), and digestibility (49.6 vs. 42.1% NDF digestibility). The heifer groups differed in RFI (P &amp;lt; 0.01), with high DFI categorized as inefficient (+0.84 RFI) and low DFI as efficient (-0.34 RFI). No differences in ADG were observed between low and high DFI heifers during this short 46 d study period (0.614 vs 0.773, P = 0.16). High DFI heifers had lower methane production than low DFI heifers (15.9 vs. 19.0 g/kg of DMI, P = 0.02). The results of the total-tract digestibility trial showed that the high DFI heifers had a greater DMI compared with the low DFI heifers (10.9 vs. 10.2 kg/d; P = 0.04). The DMI intake was not different between groups when expressed as a % of BW (2.06 vs 2.04, P = 0.65). There was also no difference observed for DM digestibility (73.0 vs 73.1%) between the two groups. It is important to note that in the digestibility study, the DMI was less than in the GrowSafe selection trial (2.5 vs 3.2% BW) and this may have influenced results. Heifers with high DFI were heavier than low DFI heifers (533 vs. 505, P = 0.02) during the digestibility trial. Results suggest that selecting heifers for high DFI may increase growth rate and reduce methane production.

PSXIII-3 Trace Mineral Source Matters to Reduce Trace Mineral Excretion and Maximize Mineral Retention in Growing Pigs

Abstract The study objective was to determine differences between a methionine hydroxy analog chelated trace mineral blend [MHAC; MINTREX Trace Minerals (Novus International Inc., St. Charles, MO)] and sulfate (inorganic) sources of trace minerals (ITM) on the apparent total tract digestibility (ATTD) of dry matter (DM) and mineral utilization in growing pigs. A total of 10 growing gilts (PIC North America, Hendersonville, TN) weighing 50.5 ± 2.6 kg were randomly assigned to either an MHAC or an ITM dietary treatment. Supplemental Zn, Cu, and Mn levels for both treatments were 100, 20, and 40 mg/kg, respectively. Diets were corn-soy-based with phytase added to release 0.09% standardized total tract digestible P. Pigs were housed in metabolism crates for 7-d, including 5 for adaptation and 2 for total fecal and urine collection. Data were analyzed using the MIXED procedure of SAS. Results showed that pigs fed MHAC had a numerical increase in the ATTD of DM compared with ITM (90.9 vs. 89.4%; P = 0.180). Pigs fed MHAC had greater ATTD of Zn than those fed ITM (36.4 vs. 16.8%; P = 0.013), greater Zn retention (87.1 vs. 36.9 mg/d; P = 0.011), and decreased Zn excretion than those fed ITM (159.1 vs. 209.3 mg/d; P = 0.013). Pigs fed MHAC had increased Zn retention:intake compared with ITM (0.353 vs. 0.152; P = 0.014). There was a numerical increase in Zn retention:absorption in pigs fed MHAC compared with ITM (0.977 vs. 0.796; P = 0.128). Pigs fed MHAC had greater ATTD of Cu than those fed ITM (52.5 vs. 30.7%; P = 0.012), had increased Cu retention (25.6 vs. 14.4 mg/d; P = 0.012) and less Cu excretion than those fed ITM (24.1 vs. 35.3 mg/d; P = 0.016). Pigs fed MHAC had increased Cu retention:intake compared with ITM (0.513 vs. 0.293; P = 0.017) and tended to increase Cu retention: absorption (0.980 vs. 0.944; P = 0.057). Pigs fed MHAC had greater ATTD of Mn than ITM (35.8 vs. 14.5%; P = 0.019), had increased Mn retention (42.4 vs. 16.5mg/d; P = 0.017), and less Mn excretion than ITM (77.2 vs. 103.0mg/d; P = 0.017). Pigs fed MHAC had increased Mn retention:intake compared with ITM (0.353 vs. 0.141; P = 0.018). There were no differences between MHAC and ITM in Mn retention:absorption (0.986 vs. 0.986; P = 0.993). Pigs fed MHAC had a numerical increase in the ATTD of P (69.3 vs. 62.9%; P = 0.373), numerically less P excretion (2.94 vs. 3.57g/d; P = 0.348), and numerically greater P retention (6.44 vs. 5.80; P = 0.376) than those fed ITM. In conclusion, pigs fed MHAC had greater Zn, Cu, and Mn availability than ITM. This is likely due to the distribution and utilization of these trace minerals where they are needed. Furthermore, MHAC decreased the excretion of these minerals to nourish the pigs and reduce their impact on the environment through nutrient losses.

PSIX-10 Influence of Graded Levels of Microbially Enhanced Protein on Nutrient Digestibility of Extruded Cat Foods

Abstract Pet food ingredients that bring extra nutrition and health benefits are much better accepted than being simply an economic choice by the manufacturer. Microbially enhanced protein (MEP) from soybeans is a fermented ingredient that is believed to promote nutrient utilization. The objective of this study was to determine the effect of increasing levels of MEP on nutrient digestibility of extruded cat food. Four extruded dietary treatments differing by level of MEP in exchange for soybean meal (15%; SBM) at 5, 10 and 15% (5MEP, 10MEP and 15MEP, respectively) were randomly assigned to 12 individually housed adult domestic shorthair cats (6 castrated males and 6 spayed females) of similar age (0.9 ± 0.23 months) and body weight (4.35 ± 0.87). The study was designed as a 4 × 4 replicated Latin square with 9-day adaptation followed by 5-day total fecal collection for each period. Data were analyzed using a mixed model through SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and square (i.e., replicate), period, and cat(square) as random effects. Treatment means were separated by Tukey’s test. The 15MEP increased fecal moisture content (P&amp;lt;0.05) while 5MEP and 10MEP made no difference compared with SBM. No differences were observed for food intake, fecal dry matter output, fecal score, fecal pH or apparent total tract digestibility of dry matter, organic matter, crude protein or gross energy for MEPs compared with SBM. However, crude fat digestibility of cats fed 5MEP was lower (P&amp;lt;0.05) than cats fed with10MEP and 15MEP but not different from cats fed with SBM. These results suggest that MEP did not have adverse effects on nutrient digestibility when added to extruded diets at up to 15% in healthy adult cats.

PSIV-7 Optimization of Indigestible Neutral and Acid Detergent Fiber Measurement Protocols

Abstract Dry matter digestibility (DMD) is a factor that impacts nutrient use efficiency and growth performance of beef cattle. Indigestible neutral (INDF) and acid detergent fiber (IADF) are internal markers commonly used to estimate DMD. The objective of this experiment was to optimize existing protocols for determination of INDF and IADF in feedlot rations and feces. This experiment implemented a 2×2×4 factorial arrangement with a starter or finisher diet, with or without a pepsin and HCl pre-digestion of the diets, and with four ruminal incubation lengths (72, 96, 120, or 288 h). The samples used in this experiment were from diets fed and total fecal collections obtained from 6 steers consuming the starter or finisher diet. Fecal and diet marker concentrations were analyzed using a mixed model ANOVA with ruminally canulated steer (n = 2) as a random effect and diet, pre-digestion, marker, time, and possible interactions as fixed effects. A two-sided t-test was used to test if marker fecal recoveries differed from 100%. When diets were pre-digested, a plateau in dietary marker concentration was achieved, where concentrations of both markers were not different (P ≥ 0.10) when incubated for 120 h compared with 288 h. When diets were not predigested, the dietary content of both markers continued to decrease with increasing ruminal incubation length so that marker content of 120-h incubations were significantly greater (P &amp;lt; 0.01) than 288-h incubations, except for IADF content of the finisher diet where the 120 and 288 h were not different (P = 0.77). The dietary content of INDF and IADF for samples that were not pre-digested and incubated for 288 h were not different (P ≥ 0.64) from the samples that were pre-digested and incubated for 120-h. For the INDF marker across both diets, fecal concentrations were lowest (P ≤ 0.01) when ruminally incubated for 288 h compared with all other ruminal incubation durations. The fecal concentrations of IADF were less (P &amp;lt; 0.01) when incubated for 288 h compared with those incubated for 120 h for the starter diet, but only tended (P = 0.07) to be less at those same time points for the finisher diet. When pre-digestion was conducted, only 120-h ruminal incubations had fecal recoveries that were not different (P ≥ 0.26) from 100% for all markers and diet types. If a pre-digestion was not conducted, then only the 288 h length provided fecal recoveries that were not different (P ≥ 0.12) from 100% for all diets and markers. Based on these results, using a pepsin and HCl pre-digestion followed by a 120-h ruminal incubation shortens time requirements and provides acceptable measurements of INDF and IADF concentrations in feeds and feces. If pre-digestion of diet samples is not possible then a 288-h ruminal incubation length is required.

40 Effect of Soybean Meal Inclusion on Grow-Finish Pig Performance and Nitrogen Balance

Abstract Mixed-sex pigs (n = 240 PIC 337×1050; initial BW = 23 ± 4.7 kg) were used to evaluate the effects of soybean meal (SBM) inclusion on the growth performance and nitrogen balance of grow-finish pigs. Pigs were assigned across 60 split-sex pens, and pens were randomly assigned to one of three dietary treatments (10 pens∙treatments-1∙sex-1). Diets were formulated with increasing SBM for an approximate 3% incremental difference in crude protein (CP) between treatments. The treatments were: 1) low SBM (L-SBM) corn-soy diet supplemented with synthetic amino acids, 2) medium SBM diet (M-SBM) with SBM formulated to replace all synthetic lysine and equal to L-SBM in SID lysine, and 3) high SBM diet (H-SBM) contained excess levels of all amino acids. Diets were fed in four feeding phases ranging from approximately 25-50, 51-75, 76-105, and 106-135 kg for phases 1-4, respectively. From phases 1 to 4, SBM inclusion ranged from approximately 26-48% (SID Lys 1.06-1.32%), 19-41% (SID Lys 0.89-1.15%), 15-35% (SID Lys 0.76-1.01%), and 13-29% (SID Lys 0.68-0.86%), respectively. Additionally, diets within each phase were isocaloric. Pig BW and feed intake were measured for each phase to calculate ADG, ADFI, and G:F. On day 66, 18 gilts (n =6/treatment) were placed into metabolism stalls for total urine and feces collection over a 72 h period to assess CP digestibility and nitrogen balance. Pigs were marketed at approximately 134 kg BW, and carcass weight, backfat depth, and loin depth were measured at the harvest facility. Data were subject to ANOVA in SAS 9.4. Pen was the experimental unit, and the results were significant at P ≤ 0.05. Overall (d 0-98) pig ADFI, ADG, or G:F did not differ across treatments (P ≥ 0.202). However, there was a significant diet-by-phase interaction for ADG (P = 0.045) and G:F (P = 0.008), where H-SBM fed pigs grew faster in phase two compared with the M-SBM (1.07 vs. 1.02 kg/d; P = 0.026) or L-SBM (1.07 vs. 1.02 kg/d; P = 0.028) fed pigs. Consequently, in phase two, H-SBM pigs had improved G:F compared with M-SBM (0.47 vs. 0.44; P = 0.005) or L-SBM pigs (0.47 vs. 0.44; P = 0.001). However, these effects were not evident in the other phases. Apparent total tract digestibility of CP and nitrogen retention were similar between treatments (P ≥ 0.762). However, as expected, nitrogen retention as a proportion of intake, linearly decreased (P &amp;lt; 0.001) as SBM inclusion increased, which translated to an approximate 130% increase in total nitrogen excretion in pigs fed H-SBM compared with L-SBM (40.8 vs. 17.7 g/d; P &amp;lt; 0.001). In conclusion, low and high SBM formulations did not alter grow-finish pig overall performance. However, linearly increased nitrogen excretion was reported as SBM levels increased.

PSVI-5 Using Red Clover Extract to Mitigate Tall Fescue Toxicosis

Abstract Tall fescue toxicosis is caused by ergot alkaloids produced by the fungus Neotyphodium coenophialum that resides within the majority of the tall fescue plants in the Southeastern and lower Midwestern US. Tall fescue (Festuca arundinacea) toxicosis is estimated to cost livestock producers over $1 billion dollars annually through reduced growth and reproductive performance. Improvements in performance by cattle grazing toxic tall fescue can have substantial economic advantages for livestock producers throughout the tall fescue region. Numerous methods to mitigate tall fescue toxicosis have been tried over the past 60+ years, but a practical solution to this problem has not been discovered to date. Forages used to dilute fescue include clovers which will not compete on much of the marginal sites that tall fescue predominates. As mentioned above, clovers have been used to dilute toxic fescue and have shown to be a good mitigation strategy if the clovers persist. Red clover extract (RCE) has shown promise in the mitigation of symptoms related to tall fescue toxicosis, but effective dosages have not yet been determined to date. Dorper ewe and wether lambs (n = 30, 34 ± 0.97 kg initial BW) were weighed and assigned randomly to one of five diets in a 2-period study. Diets consisted of a positive control of non-toxic tall fescue seed with no RCE (CONT), a negative control of toxic tall fescue seed with no RCE (E+0) and toxic tall fescue seed with RCE supplemented at 0.33 (E+33), 0.67 (E+67), and 1 (E+100) percent of the diet. Fescue seed was mixed with liquid molasses to ensure consumption, and seed, DDGS and RCE was offered at approximately 0800 and 1600 h, and bermudagrass hay was offered for ad libitum consumption. Lambs were housed in individual 1 × 1.5 m pens in an enclosed building where temperature was maintained at 27° C (80° F). The animal had an ad libitum access to water. Each period consisted of a 14-day adaptation period followed by 7 d of total fecal and urine collection. Diets were offered for ad libitum consumption during the first 12 days of each period and then held constant during the remaining 9 days. Dry matter (DM) and organic matter (OM) intake was greater (P &amp;lt; 0.05) from CONT than all other treatments and E+33 was greater (P &amp;lt; 0.05) than E+10 and E+67. Digestibility of DM and OM were greater (P &amp;lt; 0.05) from CONT than all other treatments. By contrast, the diets did not influence (P &amp;gt; 0.05) nitrogen balance, urinary nitrogen losses, fecal nitrogen losses and nitrogen retained. Overall, results demonstrated that RCE inclusion into the diet of toxic tall fescue did not significantly change growth and performance parameters in sheep.

PSVI-3 Effects of Different Concentrate Inclusion Levels in Diets Containing Agri002E Sorghum Silage on Intake and Digestibility in Growing Nellore Bulls

Abstract The sorghum hybrid, AGRI002E, sorghum was developed for high dry matter (DM) production per area. However, there are no reports in the literature evaluating the use of this silage with different inclusion levels of concentration on the ingestive and digestive variables of beef cattle. Therefore, this study aimed to access the effects of different concentrate levels in diets containing AGRI002E sorghum silage (SS) on feed intake, ruminal and apparent total tract digestibilities of organic matter (OM), neutral detergent fiber corrected for contaminant ash and protein (apNDF), and starch. Nellore rumen-cannulated bulls (n = 5; BW = 242 ± 5 kg) were used in a 5×5 Latin square design. The experimental treatments consisted of five concentrate levels (0, 200, 400, 600, and 800 g of concentrate/kg of diet DM) in SS-based diets. The concentrates used in the experimental diets were based on corn, soybean meal, sulfated urea, virginiamycin, and mineral supplement. The diets were formulated to provide approximately 120 g of crude protein per kg dietary DM. In the 0% concentrate diet, the protein level was adjusted with sulfated urea. All diets contained the same amount of virginiamycin and mineral supplement. Each experimental period lasted 24 d, with 17 d adaptation, 4 d of total feces collection, and 3 d collection to obtain omasal flow using a double marker technique (indigestible NDF and Co-EDTA). Data were analyzed using MIXED-SAS. Starch and OM intake linearly increased (P &amp;lt; 0.001) with increasing concentrate inclusion. Intake of apNDF decreased linearly (P = 0.018) and tended to be quadratically influenced (P = 0.022) with increasing concentrate inclusion (Table 1). Ruminal digestibility of OM increased linearly (P &amp;lt; 0.001) with increasing concentrate inclusion. Starch ruminal digestibility decreased linearly (P = 0.003) and tended to be influenced quadratically (P = 0.0015) with increasing concentrate inclusion. Ruminal digestibility of apNDF tended to decrease linearly (P = 0.057) with increasing concentrate inclusion. Total apparent digestibility of OM increased linearly (P &amp;lt; 0.001) and apNDF and starch total apparent digestibility decreased linearly (P ≤ 0.002) with increasing concentrate inclusion. Increasing inclusion of concentrate in AGRI002E sorghum silage-based diets increased OM and starch intake, and ruminal and total apparent OM digestibility and decreased apNDF intake and ruminal and apNDF and starch total apparent digestibility.

Effect of feeding diets containing levels of ginger (&lt;i&gt;Zingiber officinale&lt;/i&gt;) on digestibility and nitrogen balance of red Sokoto bucks

The apparent digestibility and nitrogen balance of nutrients in isocaloric and isonitrogenous diets containing 0, 250, 500 and 750 g ginger inclusion levels was studied in a 14-day trial involving twenty (20) red Sokoto bucks (RSB) weighing on the average 17.86 kg. The treatments were replicated five times in a completely randomized design. The animals were individually fed at 4% of their body weight for both the concentrate (1.5% as supplement) and Digitaria smutsii hay (2.5% as basal diet). The trial consisted of 7-day adjustment period followed by a 7-day total collection of faeces and urine. Nutrient digestibility, faecal and urine outputs were recorded. Results indicated a similar dry matter intake across the treatments. Crude protein and crude fiber intakes were significantly (P&lt;0.05) affected by ginger inclusion levels with higher values recorded in the group fed 250 g. Dry matter digestibility significantly (P&lt;0.05) increased with increase in ginger levels. Nitrogen retention was significantly (P&lt;0.05) higher in bucks fed with 750 g ginger. It was therefore concluded that, varying inclusion levels of ginger improved nutrient digestibility and nitrogen retention of RSB. RSB can be fed up to 750 g/100 kg diet ginger.

Postprandial metabolism and gut permeability in calves fed milk replacer with different macronutrient profiles or a whole milk powder

Significant differences exist in the composition of current milk replacers (MR) and bovine whole milk. This study investigated how the macronutrient profile of 3 different MR formulations containing varying amounts of fat, lactose, and protein, and a whole milk powder (WP), affect postprandial metabolism and gut permeability in male Holstein calves. Sixty-four calves (45.4 ± 4.19 kg [mean ± SD] and 1.8 ± 0.62 d of age) were blocked in order of arrival to the facility and within each block, calves were randomly assigned to 1 of 4 treatments. Treatments included a high-fat MR (HF: 25.0% dry matter [DM] fat, 22.5% protein, 38.6% lactose; n = 14), a high-lactose MR (HL: 44.6% lactose, 22.5% protein, 18.0% fat; n = 17), a high-protein MR (HP: 26.0% protein, 18.0% fat, 41.5% lactose; n = 17), and WP (26.0% fat, 24.5% protein, 38.0% lactose; n = 16). Calves were fed 3.0 L (135 g/L) 3 times daily at 0600, 1200, and 1800 h with a teat bucket. Milk intake was recorded daily for the first 28 d after arrival, and blood sampling and body weight measurements were performed at arrival and on d 7, 14, 21, and 27. Gut permeability was estimated from fractional urinary excretion of indigestible markers (Cr-EDTA, lactulose, and d-mannitol) administered as a single dose on d 21 instead of the morning milk meal. Digestibility was determined simultaneously from a total collection of feces over 24 h. Postprandial dynamics were measured on d 28 by sequential blood sampling over 7.5 h. Dry matter intake of MR over 28 d was slightly greater in calves fed HL and HP than in WP. Recovery of Cr-EDTA and d-mannitol over a 24-h urine collection was greater in calves fed WP and HP than HL calves. Apparent total-tract digestibility of crude ash, protein, and fat did not differ among treatments; however, DM digestibility was lower in calves fed WP than in other treatment groups. In addition, abomasal emptying, as indicated by the area under the curve (AUC) for acetaminophen, was slower in calves fed WP than in calves fed HF and HL. The AUC for postprandial plasma glucose was lower in calves fed HL than WP and HF and lower in calves fed HP than WP. The AUC for postprandial serum insulin was greater in calves fed HP than WP and HF, whereas calves fed HL did not differ from the other treatments. Postprandial triglycerides were greater in calves fed WP, and postprandial adiponectin was higher in calves fed HL than other treatments. The high content of lactose and protein in MR had a major effect on postprandial metabolism. This raises the possibility of optimizing MR formulations to maintain metabolic homeostasis and influence development.

Comparing the effects of corn fermented protein with traditional distillers dried grains fed to healthy adult dogs on stool quality, nutrient digestibility, and palatability

Traditional distillers dried grains, co-products from the ethanol industry, can be utilized as sustainable ingredients for pet food. However, negative consumer perception prevents their widespread use. Corn fermented protein (CFP) is produced using post-fermentation separation technology, resulting in a high protein ingredient, which may increase consumer appeal compared to traditional distillers dried grains. The study objective was to compare the effect of CFP with that of traditional distillers dried grains on stool quality, nutrient digestibility, and palatability when fed to dogs. The control diet (CON) contained 15% soybean meal and the experimental diets contained 3.5% brewer’s dried yeast (BDY), 2.5% brewer’s dried yeast plus 17.5% distillers dried grains with solubles (BDY+DDGS), or 17.5% corn fermented protein (CFP). Experimental diets were fed to adult dogs (n = 12) in a 4 × 4 replicated Latin square design. Dogs were adapted to the diets for 9 days; this was followed by 5 days of total fecal collection. Titanium dioxide (0.4%) was added to all diets as an external marker to estimate digestibility. Data were analyzed using a mixed model in SAS, with treatment as a fixed effect and dog and period as random effects. Fecal output was greatest (p&amp;lt; 0.05) for dogs fed BDY+DDGS. The feces of dogs consuming CFP were firmer (p&amp;lt; 0.05) than those of dogs consuming CON and BDY+DDGS. Overall, nutrient digestibility was greatest (p&amp;lt; 0.05) for CON and BDY and lowest for BDY+DDGS, with that for CFP being intermediate. There were no differences (p &amp;gt; 0.05) in total short-chain or branched-chain fatty acid concentrations in the fresh fecal samples of dogs fed these dietary treatments. However, the percentage of propionate was higher (p&amp;lt; 0.05) in the fecal samples of dogs fed CON than in those of dogs fed BDY+DDGS, whereas the percentage of valerate was higher (p&amp;lt; 0.05) in the fecal samples of dogs fed CON than in those of dogs fed CFP. In the palatability evaluation, dogs had no preference when CON was compared with BDY or BDY+DDGS. However, dogs appeared to prefer CON over CFP. Overall, CFP resulted in improved stool quality and nutrient digestibility when compared with DDGS, which could increase consumer appeal for inclusion into pet food. The impact of CFP on palatability, however, warrants further investigation.

Evaluation of graded levels of corn fermented protein on extrusion processing and diet utilization in healthy adult dogs

There has been increased interest among pet owners to feed vegetarian diets to their pets. However, the primary protein sources used in pet food today are animal based, warranting a need to evaluate novel plant-based ingredients to meet the protein demand. Corn fermented protein (CFP), a coproduct from ethanol production, may provide a plant-based alternative protein source for pet food. Therefore, the objectives of this study were to determine the effects of increasing levels of CFP on extrusion processing, stool quality, apparent total tract digestibility, and palatability in dog diets. Four extruded diets were fed to 12 adult beagle dogs in a replicated 4 × 4 Latin square design. The control diet contained 15% soybean meal (0C) and CFP was exchanged at either 5%, 10%, or 15% of soybean meal (5C, 10C, and 15C, respectively). Dogs were fed each dietary treatment for 9 days of adaption followed by 5 days of total fecal collection. Feces were scored on a 1–5 scale, with 1 representing liquid diarrhea and 5 representing hard pellet-like. Titanium dioxide (0.4%) was added to all diets as an external marker to estimate digestibility. Data were analyzed using orthogonal contrasts in SAS (version 9.4; SAS Institute, Inc., Cary, NC, USA). Dry bulk density of kibble decreased (P &amp;lt; 0.05), whereas kibble toughness increased (P &amp;lt; 0.05) with CFP inclusion. Fecal dry matter, dry fecal output, and defecations per day increased (P &amp;lt; 0.05) when dogs were fed increased levels of CFP. Dry matter and crude protein digestibility of CFP treatments were comparable (P &amp;gt; 0.05) to 0C. There was a decrease (P &amp;lt; 0.05) in organic matter, crude fat, gross energy, and total dietary fiber digestibility in the CFP treatments compared with 0C. A cubic relationship (P &amp;lt; 0.05) was observed in the digestibility of all nutrients except crude fat, indicating that 10C resulted in the lowest digestibility. For the palatability assessment, dogs had no preference when comparing the 5C treatment with the 0C treatment. Even with the differences in dietary treatments, inclusion of CFP at 5%, 10%, and 15% still resulted in acceptable processing parameters, kibble characteristics, and utilization when fed to dogs.