Transit time and digestibility of two experimental diets in the maned wolf (Chrysocyon brachyurus) and domestic dog (Canis lupus)

Recent research involving nutritional management of clinical disease secondary to cystinuria in captive maned wolves (Chrysocyon brachyurus) in the United States resulted in the production of a commercially manufactured maintenance diet and subsequently, a further modified experimental diet. These two diets differed only in their protein sources and sodium concentrations. The purpose of this study was to further investigate these diets by determining their digestibility and transit time in maned wolves, and also to compare these results to the digestibility and transit time of the diets in domestic dogs. The experiment consisted of two diets (maned wolf commercial maintenance diet and experimental diet) and two species (maned wolf and domestic dog [beagle]) arranged as a 2 × 2 factorial design. For the transit time study, titanium dioxide (TiO₂, 5 g/kg diet) was administered as a pulse dose and total collection of feces was carried out for 50 hr. There was no effect of diet or species on initial Ti recovery time (IRT), the amount of Ti recovered at IRT, or the time to reach 50% of Ti excretion in the feces. Maned wolves had lower total percent recovery (P<0.01) of Ti than dogs and shorter time to last recovery of Ti in the feces (P<0.05), however, marker excretion in the maned wolves may not have been complete. For the digestibility study, in which chromic oxide was used as a marker, fecal samples were collected on 2 consecutive days immediately after 12 days of being fed the diets and then analyzed for dry matter, energy, protein, and minerals. Crude protein, calcium, phosphorus, and zinc apparent digestibilities were unaffected by species or diet (P>0.05). Apparent digestibility of dry matter (P<0.05) and energy (P<0.01) were higher in the experimental diet and in the dogs. Both dogs and maned wolves fed the maintenance diet exhibited a greater apparent retention of copper, iron, and magnesium (P<0.01). Dogs had a higher apparent retention of magnesium and sodium than the maned wolves. Zoo Biol 0:1–13, 2006. © 2006 Wiley‐Liss, Inc.     

Effects of lactoferrin supplementation on ileal and total tract nutrient digestibility,gastrointestinal microbial populations,and immune characteristics of ileal cannulated,healthy, adult dogs

Abstract

Orally supplemented lactoferrin derived from bovine milk is purported to have beneficial effects on gut health of animals. Bovine lactoferrin (0, 60, or 120 mg/d) was fed to ileal cannulated, adult dogs in a replicated 3 × 3 Latin square design with 14 d periods. Control dogs tended (p = 0.06) to have higher fecal DM concentrations compared with dogs supplemented with 120 mg/d lactoferrin (34.5 vs. 32.9%). Fecal scores ranged from 3.0 – 3.3, suggesting that feces of all dogs was near the desired consistency, with dogs supplemented with 120 mg/d lactoferrin tending (p = 0.08) to have higher fecal scores. Ileal azoreductase activity tended (p < 0.10) to be higher in dogs supplemented with 60 or 120 mg/d lactoferrin (609 vs. 592 nmol/h per g ileal DM, respectively) as compared with unsupplemented dogs (272 nmol/h per g ileal DM). The following bacterial groups were measured: bifidobacteria, Campylobacter spp., Clostridium spp., eubacteria, Escherichia coli, Lactobacillus spp., Staphylococcus spp., and Streptococcus spp. Fecal streptococci concentrations were lower (p < 0.05) for dogs receiving 60 mg/d lactoferrin (8.60 log₁₀ cfu/g fecal DM) as compared with unsupplemented dogs (9.19 log₁₀ cfu/g fecal DM) or dogs receiving 120 mg lactoferrin/d (9.43 log₁₀ cfu/g fecal DM). Dogs supplemented with 120 mg/d lactoferrin tended (p = 0.08) to have higher fecal indole concentrations as compared to unsupplemented dogs (1.80 vs. 1.46 μmol/g fecal DM). Because most bacterial groups measured were unaffected, it appears that lactoferrin did not exhibit prebiotic activity, and based on the data collected, lactoferrin also did not appear to have major effects on indices of health in the dog.     

Evaluation of nutrient digestibility and fecal characteristics of exotic felids fed horse‐ or beef‐based diets: use of the domestic cat as a model for exotic felids

The objective of this study was to determine the effects of feeding commercially available beef‐ and horse‐based diets on nutrient digestibility and fecal characteristics of large captive exotic felids and domestic cats. Four species of large exotic felids including cheetahs, Malayan tigers, jaguars, and Amur tigers, and domestic cats were utilized in a crossover design. Raw meat diets included a beef‐based diet (57% protein; 28% fat) and a horse‐based diet (51% protein; 30% fat). All cats were acclimated to the diet for 16 days followed by a 4 day collection period, where total feces, including one fresh sample, were collected. All feces were scored on collection. Intake did not differ due to diet, but fecal output was greater when cats consumed the horse‐based diet. Total tract apparent dry matter (DM) digestibility was higher (P<0.05) and organic matter (OM) and crude protein (CP) digestibilities were lower (P<0.05) when cats were fed the beef‐based diet compared with the horse‐based diet. CP digestibility was similar in domestic cats and cheetahs, and greater (P<0.05) than Amur tigers. Fecal scores were lower and fecal DM was greater (P<0.05) when cats consumed the horse‐based diet compared with the beef‐based diet. Domestic cats had lower (P<0.05) fecal ammonia concentrations compared with all other species. Fecal ammonia concentrations were lowest (P<0.05) when cats were fed the horse‐based diet. Fecal total short‐chain fatty acid (SCFA), branched‐chain fatty acid (BCFA), and butyrate concentrations were higher (P<0.05) when cats consumed the beef‐based diet. Our results suggest that the domestic cat serves as an appropriate model for large exotic felid species, but differences among the species exist. Decreased nutrient digestibility by tigers and jaguars should be considered when developing feeding recommendations for these species based on domestic cat data. Zoo Biol 29:432–448, 2010. © 2009 Wiley‐Liss, Inc.     

Influence of feeding raw or extruded feline diets on nutrient digestibility and nitrogen metabolism of African wildcats (Felis lybica)

The African wildcat is one of the closest ancestors to the domestic cat and is believed to have similar nutrient requirements, but research is lacking. The objective of this study was to determine the effects of feeding a high‐protein extruded kibble diet vs. a raw meat diet on nutrient digestibility, nitrogen metabolism, and blood metabolite concentrations in African wildcats. Five wildcats were randomized onto either a high‐protein (>50% crude protein) extruded kibble diet or a raw meat diet. The study was executed as a crossover design, with 21‐d periods, consisting of a 16‐d adaptation phase followed by a 4‐d total fecal and urine collection phase. Cats were housed individually in metabolism cages and fed to maintain body weight (BW). A fresh fecal sample was collected for short‐chain fatty acid (SCFA) and branched‐chain fatty acid (BCFA) analyses. Blood was analyzed for serum chemistry and leptin concentration. Food intake (as is) did not differ (P>0.05) between diets. Food intake and fecal output (g/d DMB) were greater (P<0.05) when cats consumed the kibble diet. Protein digestibility was higher (P<0.05) when cats were fed the raw meat diet vs. the kibble diet. Nitrogen intake was greater (P<0.05) when cats consumed the kibble diet, and more (P<0.05) nitrogen was present in the feces; however, the percentage of nitrogen retained and nitrogen balance did not differ (P>0.05). Fecal scores, ammonia, SCFA, and BCFA concentrations did not differ (P>0.05) between diets. Fecal butyrate molar ratio was higher (P<0.01) when cats consumed the kibble diet. Blood analyses demonstrated few differences between diets, but alanine aminotransferase activity and bicarbonate were higher (P<0.05) when cats consumed the commercial raw meat diet. Owing to lack of differences, these data indicate that African wildcats can readily utilize a high protein extruded kibble diet, and may be able to replace a commercial raw meat diet. Zoo Biol 29:676–686, 2010. © 2010 Wiley‐Liss, Inc.     

Gastrointestinal and immunological responses of senior dogs to chicory and mannan-oligosaccharides

Thirty-four senior dogs (pointers 8 - 11 years, beagles 9 - 11 years) were used to evaluate the effects of oligosaccharides on nutritional and immunological characteristics. Dogs were randomly allotted to treatments [1% chicory (CH), 1% mannan-oligosaccharide (MOS), 1% chicory + 1% MOS (CM), or no supplementation (control, CON)] in a parallel design with a 4 week baseline period followed by a 4 week treatment period. Dietary supplementation with MOS or CM tended (P = 0.07) to increase food intake due, in part, to an increase in fermentable fibre and a decrease in energy content of the diet. Although wet faecal output increased (P < 0.05) for dogs supplemented with MOS or CM, when corrected for food intake, no differences were noted. The CM treatment increased (P < 0.05) faecal score (1 = hard and dry, 5 = watery liquid), although these scores remained in a desirable range (3 to 3.5). Chicory supplementation increased (P = 0.07) fat digestibility. Chicory or MOS increased (P  0.05) faecal bifidobacteria concentrations 0.4 and 0.5 log₁₀ cfu/g DM, respectively, compared to the CON, while MOS decreased (P < 0.05) faecal E. coli concentrations. Oligosaccharides did not affect white blood cell (WBC) concentrations, but CH and CM tended to increase (P = 0.10) neutrophil concentrations compared to control dogs. Peripheral lymphocyte concentrations were decreased in dogs supplemented with MOS (P = 0.06) and CM (P < 0.05). Chicory and MOS alter faecal microbial populations and certain indices of the immune system of senior dogs.     

Nutritional quality and digestibility of sorghum-broiler litter silages

Broiler litter and sorghum forage were ensiled in the proportions of 0:100, 25:75, 35:65 and 45:55 (wet basis), respectively. Samples of initial mixtures showed the presence of total (0.01–1.20×10⁶) and fecal (0.001–3.190×10⁴) colony forming units (CFU). Salmonellae, Shigella and Proteus were also present. Ensiling was effective in complete elimination of all the pathogens. Dry matter (DM), crude protein (CP) and ash contents were increased linearly (P<0.01) with the increase of broiler litter in the silages (35–57.5%; 6.4–14.8% and 3.2–9.0%; DM basis, respectively). Water soluble carbohydrate (WSC) for initial mixtures were 7.7%, 6.7%, 6.2% and 5.9%; DM basis, respectively. Ensiling decreased the pH and WSC for all the silages and the decrease was higher for sorghum ensiled alone than for sorghum ensiled with broiler litter. Lactic acid concentration in the silages increased linearly (P<0.01) with the increase of broiler litter. The nutritive value of the silages was evaluated in a digestion trial with 24 wethers. The apparent digestibilities of DM, OM and CP for the animals fed sorghum silage alone were, 49.6%, 51.6% and 49.7%, respectively. However, digestibilities of all the components were higher (P<0.01) for the animals fed silages containing broiler litter. Among the litter containing diets, the digestibilities of all the components showed a quadratic effect (P<0.01), increasing for silages containing 25% and 35% broiler litter and decreasing, when the level of litter increased from 35% to 45%. The results indicated that broiler litter could be used up to 35% in a ruminant's diet as a source of N without any adverse effect on health of the animals. Ensiling appeared to be a feasible and effective method for eliminating the pathogens present in broiler litter and improving its nutritive value.     

Effects of feeding corn bran and soybean hulls on nutrient digestibility,rumen microbial protein synthesis,and growth performance of finishing lambs

Some grain processing by-products rich in digestible fiber are good feed resources for ruminants. This experiment was conducted to investigate the effects of replacing a portion of corn and corn stover with the combinations of corn bran and soybean hulls in the diet of fattening lambs on nutrient digestion, rumen microbial protein synthesis, and growth performance. A total of 36 Dorper × Small Thin-Tailed crossbred ram lambs (BW = 22.2 ± 0.92 kg; mean ± SD) were randomly divided into three groups, and each group was fed 1 of 3 treatment diets: 1) 0% corn bran and soybean hulls (control); 2) 9% corn bran and 9% soybean hulls (18MIX); and 3) 17% corn bran and 17% soybean hulls (34MIX). The feeding experiment was conducted for 70 days, with the first 10 days for adaption. The DM intake was higher for 34MIX (1635.3 g/d) than for control diet (1434.7 g/d; P = 0.001). Lambs fed 18MIX and 34MIX diets (230.2 and 263.6 g/d, respectively) had higher average daily gain and feed efficiency than those fed control diet (194.8 g/d; P < 0.01). Dry matter and NDF digestibility for 34MIX group (60.9 and 49.5%) were higher than for control (55.2 and 41.3%; P < 0.01). No difference was observed in nitrogen digestibility among treatment diets (P = 0.778). The lambs fed 34MIX diet excreted more urinary purine derivatives, indicating that more microbial protein was yielded than those fed control diet (P < 0.01), while 18MIX was not different from the other two diets (P > 0.05). The metabolizable protein supplies were improved with increasing co-products inclusion rate. The results indicated that corn bran and soybean hulls in combination can effectively replace a portion of corn and corn stover in the ration of finishing lambs with positive effect on nutrient digestion and growth performance.     

An investigation of the relationship between fecal and rumen bacterial concentrations in sheep

With no acceptable method for collecting fresh rumen fluid from zoo ruminants, it was proposed that fecal bacterial concentrations may be correlated with rumen bacteria. If so, fecal bacterial concentrations could be used to study both the effects of diet on rumen bacteria as well as rumen abnormalities. Total and cellulolytic bacterial concentrations were determined in whole rumen contents and feces of sheep using a most‐probable‐number (MPN) assay. In a Latin square design, four crossbred ewes were fed diets of 100% long or chopped orchardgrass hay (OH) and 60% ground or whole shelled corn plus 40% chopped OH. In a second trial, the sheep were fed a pelleted complete feed at varying levels of intake i.e., control at 2.0% of body weight and at 1.8, 1.6, and 1.2% of body weight. Higher total rumen bacterial concentrations (P<0.01) were found on the high concentrate diets as compared with the high forage diets. Grinding the corn also increased total bacterial concentrations (P<0.05). Fecal concentrations of total bacteria were higher (P<0.01) with the high concentrate diets. Chopping the forage decreased the concentration of fecal cellulolytic bacteria (P<0.05) but had no effect on their concentration in the rumen. An inverse linear relationship (P<0.01) was observed between total bacterial concentrations in the feces and diet intake. Although relationships were observed between the rumen and feces for total and cellulolytic bacterial concentrations, they were dependent on diet, particle size, and level of intake. Thus, fecal bacterial concentrations cannot be used to reliably predict rumen bacterial concentrations. Zoo Biol 27:100–108, 2008. © 2008 Wiley‐Liss, Inc.     

Intake,digestibility and nitrogen utilization of Robinia pseudoacacia foliage fed to growing goat wethers

Black locust (BL; Robinia pseudoacacia L.), a native tree of southeastern USA known to contain substantial levels of condensed tannins (CT), was fed to 32, 4 month old (20.4 kg BW) Boer cross wether goats in two randomized complete block design trials. The objectives were to examine the effects of feeding hay diets containing several levels of fresh BL foliage on intake, digestibility, and N metabolism. First year (1999) diets were H_E (100% Eastern gamagrass [EGH; Tripsacum dactyloides L.] hay), H_EG (70% EGH and a 30% mixture of 59% ground corn [GC; Zea mays L.], 36% soybean meal [SBM; Glycine max L.], and 5% minerals), 25BL99 (75% EGH and 25% BL leaves), and 50BL99 (50% EGH and 50% BL leaves). Second year (2000) diets were H_O (100% orchardgrass [OGH; Dactylis glomerata L.] hay), H_OG (70% OGH and a 30% mixture of 63% GC, 37% SBM, and 5% minerals), 50BL00 (50% OGH and 50% BL leaves), and 75BL00 (25% OGH and 75% BL leaves). In 1999, apparent digestibilities of the diets in the order listed above were 62.4, 68.2, 58.0, and 60.6% (P = 0.001) for DM and 62.8, 72.5, 56.0, and 59.1% (P = 0.001) for crude protein (CP). Acid detergent lignin digestibilities were negative for diets 25BL99 (−56.7%) and 50BL99 (−49.3%), apparently due to the formation of insoluble tannin and lignin complexes during passage through the digestive tract. Intakes of DM were similar across diets. In 2000, apparent digestibilities of diet DM (64.4, 71.7, 64.8 and 65.4%) and CP (70.0, 76.0, 66.6, and 66.5%) did not differ. Lignin digestibilities were positive for diets 50BL00 (9.4%) and 75BL00 (29.6%) unlike those for year 1999. Overall, BL contained 10% CT and 18–34% hydrolyzable tannins. In 1999, N intake, urinary N (UN) excretion and N retained were higher for diet H_EG (P = 0.01) than diet H_E whereas fecal N excretion (FN) was similar for diets H_EG, 25BL99 and 50BL99. In 1999, FN excretion as a percentage of N intake was higher (P < 0.02) in the BL diets, although UN as a percentage of N intake did not differ among diets. In 2000, N intake and FN output were higher for BL diets compared to diets H_O (P = 0.01) and H_OG (P = 0.02). Fecal N as a percentage of N intake was lower (P = 0.01) for diet H_OG (24.0%) than for diets 50BL00 (33.4%) and 75BL00 (33.5%). Conversely, urinary N as a percentage of N intake was higher for diets H_O and H_OG compared to the BL diets (P = 0.02). Increased levels of dietary BL increased FN, suggesting that tannins formed insoluble protein complexes thus hindering digestibility.     

The effect of lipid supplements on ruminal bacteria in continuous culture fermenters varies with the fatty acid composition

A single flow continuous culture fermenter system was used in this study to investigate the influence of dietary lipid supplements varying in their fatty acid content on the DNA concentration of selected rumen bacteria. Four continuous culture fermenters were used in a 4×4 Latin square design with four periods of 10 d each. Treatment diets were fed at 45 g/d (DM basis) in three equal portions during the day. The diets were: 1) control (CON), 2) control with animal fat source (SAT), 3) control with soybean oil (SBO), and 4) control with fish oil (FO). Lipid supplements were added at 3% of diet DM. The concentrations of total volatile fatty acids and acetate were not affected (P>0.05) by lipid supplements. Concentrations of propionate, iso-butyrate, valerate and iso-valerate were highest (P<0.05) with the FO diet compared with the other treatment diets. The concentration of til C18:l (vaccenic acid, VA) in effluents increased (P<0.05) with SBO and FO diets and was highest with the SBO diet. The concentrations of C18:0 in effluents were lowest (P<0.05) for the FO diet compared with the other treatment diets. Concentrations of DNA for Anaerovibrio lipolytica, and Butyrivibrio proteoclasticus in fermenters were similar (P>0.05) for all diets. The DNA concentrations of Butyrivibrio fibrisolvens and Ruminococcus albus in fermenters were lowest (P<0.05) with the FO diet but were similar (P>0.05) among the other treatment diets. Selenomonas ruminantium DNA concentration in fermenters was highest (P<0.05) with the FO diet. In conclusion, SBO had no effect on bacterial DNA concentrations tested in this study and the VA accumulation in the rumen observed on the FO diet may be due in part to FO influence on B. fibrisolvens, R. albus, and S. ruminantium.     

Partial replacement of barley grain for corn grain: Associative effects on lambs’ growth performance

Our objective was to study the positive effects of partial replacement of barley grain for corn in high concentrate diets on growth performance of growing lambs, and to determine the minimum amount of corn needed to produce such effects. Thirty-three male Awassi lambs weaned at 60 days of age were divided into three groups of 11 according to their live weight and offered three isonitrogenous diets. The control diet (B) contained 81 and 14% barley grain and wheat straw, respectively (DM basis). Corn grain replaced barley grain at 10 and 20% of dietary DM for low (LC) and high (HC) corn diets, respectively. Barley had a higher (P < 0.05) rate of digestion (11.5%/h) compared with corn (8.3%/h). The in vitro 30-h digestion extent was also higher (P < 0.05) for barley. The digestion rate for the B diet was higher (P < 0.05) compared with the HC diet, whereas the value for the LC diet was intermediate. Lambs fed LC and HC diets consumed more (P > 0.05) DM (average = 855 g/day) compared with lambs fed B diet (757 g/day). DM and CP digestibilities were similar among diets and averaged 67.0 and 64.2%, respectively. Final BW, BW change and average daily gain (ADG) for lambs fed HC were higher (P < 0.05) compared with B and LC. Moreover, lambs that consumed LC tended (P = 0.12) to grow faster than lambs fed B. Feed to gain ratio was lower (P < 0.05) for lambs fed HC (4.6) compared with B and LC (5.2). In summary, positive associative effects of partial replacement of barley with corn in high concentrate diets for fattening sheep were detected. However, a minimum of 20% replacement of dietary DM from barley with corn was needed to positively improve both performance and feed efficiency.     

Effects of lactoferrin supplementation on ileal and total tract nutrient digestibility, gastrointestinal microbial populations, and immune characteristics of ileal cannulated, healthy, adult dogs

Orally supplemented lactoferrin derived from bovine milk is purported to have beneficial effects on gut health of animals. Bovine lactoferrin (0, 60, or 120 mg/d) was fed to ileal cannulated, adult dogs in a replicated 3 x 3 Latin square design with 14 d periods. Control dogs tended (p = 0.06) to have higher fecal DM concentrations compared with dogs supplemented with 120 mg/d lactoferrin (34.5 vs. 32.9%). Fecal scores ranged from 3.0 - 3.3, suggesting that feces of all dogs was near the desired consistency, with dogs supplemented with 120 mg/d lactoferrin tending (p = 0.08) to have higher fecal scores. Ileal azoreductase activity tended (p < 0.10) to be higher in dogs supplemented with 60 or 120 mg/d lactoferrin (609 vs. 592 nmol/h per g ileal DM, respectively) as compared with unsupplemented dogs (272 nmol/h per g ileal DM). The following bacterial groups were measured: bifidobacteria, Campylobacter spp., Clostridium spp., eubacteria, Escherichia coli, Lactobacillus spp., Staphylococcus spp., and Streptococcus spp. Fecal streptococci concentrations were lower (p < 0.05) for dogs receiving 60 mg/d lactoferrin (8.60 log10 cfu/g fecal DM) as compared with unsupplemented dogs (9.19 log10 cfu/g fecal DM) or dogs receiving 120mg lactoferrin/d (9.43 log10 cfu/g fecal DM). Dogs supplemented with 120mg/d lactoferrin tended (p = 0.08) to have higher fecal indole concentrations as compared to unsupplemented dogs (1.80 vs. 1.46 micromol/g fecal DM). Because most bacterial groups measured were unaffected, it appears that lactoferrin did not exhibit prebiotic activity, and based on the data collected, lactoferrin also did not appear to have major effects on indices of health in the dog.     

Evaluation of sodium bisulphate and phosphoric acid as uine acidifiers for cats

Eighteen cats were used to compare the urine acidifying properties of sodium bisulphate to phosphoric acid. Acidifying agents were added at one of three concentrations (0.4, 0.6, or 0.8%, as-is basis). Cats were offered a commercial diet to determine basal urinary pH, and then again for a 1 week period between blocks 1 and 2. Cats were acclimated to the diets for 6 days, and urine samples were collected on day 7 at 0, 4, and 8 h post-feeding to obtain pre- and postprandial urinary pH. Intakes of diets containing sodium bisulphate tended (P < 0.07) to be lower than intakes of diets containing phosphoric acid. Cats consuming the 0.8% phosphoric acid diet had higher (P < 0.05) food intakes than cats consuming either the 0.4 or 0.6% phosphoric acid-containing diets. There was significant (P = 0.01) linear and quadratic response for food intake in cats consuming the sodium bisulphate-containing diet. Cats consuming the 0.4 and 0.8% phosphoric acid-containing diets tended (P = 0.07) to have higher water intakes than cats consuming the 0.6% phosphoric acid-containing diet. There were no differences (P > 0.05) in urine pH and specific gravity between cats fed the different acidifier types. Cats consuming the 0.6% phosphoric acid-containing diet tended (P = 0.07) to have a higher urine pH 8 h post-feeding than cats consuming the 0.4 and 0.8% phosphoric acid-containing diets. Urine pH was highest at 4 h post-feeding except for cats fed the 0.4% sodium bisulphate- and the 0.6% phosphoric acid-containing diets. No differences (P > 0.05) between acidifiers were found in faecal score or in faecal dry matter and organic matter concentrations. A quadratic response was detected in faecal score for cats consuming the phosphoric acid-containing diets. Cats consuming the 0.6% phosphoric acid diet tended (P = 0.06) to have a lower faecal score than cats consuming the 0.4 and 0.8% phosphoric acid diets. For faecal dry matter, a linear trend was detected in cats consuming the sodium bisulphate (P = 0.08) and phosphoric acid-containing (P = 0.04) diets. Sodium bisulphate and phosphoric acid generally behaved in a similar fashion when incorporated in dry cat diets.     

Energy metabolism and protein balance in growing rats fed different levels of dietary fibre and protein

A study was performed to investigate the effect of different levels of dietary fibre (DF) and dietary protein on visceral organ size, digestibility, nitrogen balance and energy metabolism in rats. Thirty-six male Wistar rats, initial body weight about 76 g, were used in a factorial design consisting of three levels of DF (low, 100 g/kg DM; medium, 250 g/kg DM and high, 290 g/kg DM) and two levels of dietary protein (low, 120 g/kg DM and high, 223 g/kg DM). The added fibre source was soybean hulls and Danish fish meal was used as sole source of dietary protein. Measurements of gas-exchange were done on six rats (one group) while urine and faeces were collected individually. The ratio of food/empty body gain increased (P < 0.05) with increasing DF and decreasing levels of dietary protein. The weight of the digestive tract was larger (P < 0.05) in rats fed the high fibre diet than in those fed the low fibre diet. The digestibility of nutrients and energy decreased linearly with increasing level of soybean fibre (P < 0.05). An increased intake of DF was associated with a concomitant loss of protein and energy to faeces. The microbial degradation of NSP and other unabsorbed carbohydrates caused considerably changes in N metabolism of the colon. In rats fed the low protein diets increased levels of DF decreased N excretion in urine and increased N excretion in faeces, while the ratio of retained/digested protein remained constant. When rats were fed the high protein diet protein retention dropped in response to DF both absolute and relative to digested amount, indicating that energy intake could be a limiting factor. Heat production as a percentage of metabolizable energy (HP/ME) was higher (P < 0.05) in rats fed the low protein diet than in rats fed the high protein diet, but no significant difference was found among DF levels.     

Rumen fermentation patterns and nutrient digestion in lambs fed cottonseed meal supplemental diets

Twenty crossbred 3–4-month-old male lambs of uniform body weight were used to assess the effect of raw and processed cottonseed (Gossypium) meals (CSM) on nutrient utilisation and rumen fermentation patterns. Lambs were assigned to five dietary treatments in a completely randomised design and fed isonitrogenous and isocaloric concentrate mixtures containing 30% deoiled groundnut cake (DGNC) (control), 40% of either raw, 45 min cooked, 1% calcium hydroxide (Ca(OH)₂) or iron (1 part free gossypol (FG):0.3 parts iron) treated CSM. The concentrate mixtures were fed to meet 80% of crude protein requirements (NRC, 1985) with ad libitum access to chopped maize hay (Zea mays). A metabolic trial of 6 days duration was conducted after 135 days of feeding, and rumen liquor was collected for 2 days at its end. Incorporation of 40% raw CSM resulted in reductions (P<0.01) in the digestibility of dry matter and organic matter in comparison to control fed lambs. Cooking and Ca(OH)₂ treatment of CSM improved digestibilities of these nutrients, to levels comparable to those in control fed lambs. The ether extract (P<0.05) and energy (P<0.01) digestibilities in lambs fed Ca(OH)₂ treated CSM were higher compared to those lambs fed raw CSM diets. Acid detergent fibre and cellulose digestibilities were lower (P<0.05) on cooked and iron treated CSM fed lambs. Retention of nitrogen and energy did not differ among diets. The digestible and metabolisable energy content of the Ca(OH)₂ treated CSM incorporated diet was higher (P<0.01) than the other CSM containing diets, but similar to DGNC containing ration. Rumen pH and total volatile fatty acid concentration was similar among diets, but NH₃–N was lower (P<0.05) on the cooked CSM diets versus the control. Feeding of lambs with raw CSM amounting to 17.9% of total dry matter intake (i.e. 303 mg FG intake per day) adversely affected utilisation of nutrients and rumen fermentation. This depression was alleviated to the greatest extent by 45 min cooking and 1% calcium hydroxide treatment. Iron treatment of CSM had little overall benefit.     

Effect of ruminally protected fat on in vitro fermentation and apparent nutrient digestibility in buffaloes (Bubalus bubalis)

Experiments were conducted to evaluate effects of supplementation of calcium salts of long chain fatty acids (Ca-LCFA) as a rumen inert fat (PF) on in vitro fermentation and apparent nutrient digestion in adult buffaloes fed wheat straw based diets. For the in vitro fermentation study, five total mixed rations (TMR) consisting of a concentrate mixture (CM), green Sorghum bicolor, WS and supplemented without (C) or with 30 g/kg dry matter (DM) rice bran fatty acid oil (RBO) (30 RBO) or 20 g/kg RBO + 10 g/kg PF (20 RBO/10 PF) or 10 g/kg RBO + 20 g/kg PF (10 RBO/20 PF) or 30 g/kg PF in the DM in the ratio of 340:50:580:30 were prepared. The in vitro DM degradability (IVDMD), TN, trichloro acetic acid precipitable N (TCA-N), non-protein N (NPN) and ammonia N (NH₃-N) were similar among groups. Within the fat supplemented groups, total volatile fatty acid (TVFA) concentration increased linearly (P=0.025) with PF supplementation. Apparent nutrient digestibility was determined on 20 adult buffaloes divided into five equal groups fed CM supplemented without (C) or with 300 g RBO (30 RBO) or 200 g RBO + 100 g PF (20 RBO/10 PF) or 100 g RBO + 200 g PF (10 RBO/20 PF) or 300 g PF (30 PF) along with limited green S. bicolor and WS maintaining forage: concentrate ratio of 650:350. Fat supplementation had no effect on the DM intake and apparent digestibilities of DM, organic matter (OM), crude protein (CP), total carbohydrate (TCHO) and neutral detergent fiber (aNDF). Within fat supplemented groups, inclusion of PF increased digestibilities of DM, OM, ether extract (EE), TCHO, aNDF and ADF. Supplemental fat also increased the digestible energy (DE) and metabolizable energy (ME) content of the diet, which also increased linearly with PF supplementation. All buffaloes were in positive N, Ca and P balances. We conclude that 200–300 g supplemental PF in the form of Ca-LCFA can be included in straw based diets fed to buffaloes to increase its energy density without adversely affecting DM intake and digestibility.     

Influence of supplemental high molecular weight pullulan or γ-cyclodextrin on ileal and total tract nutrient digestibility,fecal characteristics,and microbial populations in the dog

Abstract

This study was conducted to determine if supplemental pullulan and γ-cyclodextrin affect canine nutrient digestibility, microbial populations, and fecal characteristics. Ileal cannulated dogs were fed a commercial diet, and treatments were administered daily in a 5×5 Latin square design: (i) no supplement; (ii) 2 g pullulan; (iii) 4 g pullulan; (iv) 2 g γ-cyclodextrin; (v) 4 g γ-cyclodextrin. Ileal and fecal samples were collected the last 4 d of each 14-d period. Increasing pullulan tended (p < 0.10) to linearly increase ileal bifidobacteria and lactobacilli and quadratically increase fecal lactobacilli. A similar response was noted in ileal bifidobacteria and lactobacilli with γ-cyclodextrin. γ-Cyclodextrin resulted in a quadratic decrease (p < 0.05) in fecal Clostridium perfringens. Increasing pullulan linearly increased (p < 0.05) fecal score, while γ-cyclodextrin resulted in a linear decrease (p < 0.05). Pullulan and γ-cyclodextrin supplementation may have beneficial effects on the microbial ecology of dogs.     

Effects of replacement of Moringa oleifera for berseem clover in the diets of Nubian goats on feed utilisation,and milk yield,composition and fatty acid profile

Replacement of conventional feedstuffs with cheap non-conventional ingredients may improve livestock performance and the quality of their products, particularly milk. The study considered the effects of Moringa oleifera (MO) foliage in replacement of berseem clover (BC) on feed utilisation and lactational performance in Nubian goats. A total of 16 lactating Nubian does, weighing 36.2±0.8 kg, were randomly assigned to four experimental treatments containing 0, 125, 250 and 375 g of MO per kg diet to replace 0 (M0), 25 (M25), 50 (M50) and 75% (M75) of BC (on dry matter (DM) basis) in a quadruplicated 4×4 Latin square design. The MO diets increased (P<0.01) feed intake and nutrient digestibility. Feeding MO diets improved (P<0.01) ruminal volatile fatty acids, acetate and propionate but reduced (P<0.01) valerate and iso-butyrate. Moringa diets increased (P<0.01) serum total protein, albumin and glucose but decreased (P<0.05) cholesterol and triglycerides. Milk yield and energy corrected milk, and milk total solids, fat and energy content were increased (P<0.01) in MO diets. Yields of milk components and energy were greater (P<0.05) for MO diets than for control diet. Milk total saturated fatty acids and athrogenicity index were lower (P<0.01), and unsaturated fatty acids, conjugated fatty acids and UFA/SFA ratio higher (P<0.05) for MO diets. It is concluded that feeding MO to replace 75% DM of BC improved feed utilisation, ruminal fermentation, and milk yield and quality in lactating Nubian goats.     

Effects of replacing grass silage with either maize silage or concentrates during late pregnancy on the performance of breeding ewes fed isonitrogenous diets

A study was undertaken to investigate the performance of breeding ewes fed a range of forage and concentrate-based diets in late pregnancy, balanced for supply of metabolizable protein (MP). For the final 6 weeks before lambing, 104 twin-bearing multiparous ewes were offered one of four diets: ad libitum precision-chop grass silage + 0.55 kg/day concentrates (GS); ad libitum maize silage + 0.55 kg/day concentrates (MS); a 1 : 1 mixture (on a dry matter (DM) basis) of grass silage and maize silage fed ad libitum + 0.55 kg/day (GSMS); or 1.55 kg/day concentrates + 50 g/day chopped barley straw (C). The CP content of the concentrates was varied between treatments (157 to 296 g/kg DM) with the aim of achieving a daily intake of 130 g/day MP across all treatments. Compared with ewes fed GS, forage DM intake was higher (P < 0.05) in ewes fed MS (+0.21 kg/day) and GSMS (+0.16 kg/day), resulting in higher (P < 0.001) total DM intakes with these treatments. C ewes had the lowest total DM intake of all the treatments examined (P < 0.001). C ewes lost more live weight (LW; P < 0.001) and body condition score (BCS; P < 0.05) during the first 3 weeks of the study but there were no dietary effects on ewe LW or BCS thereafter. The incidence of dystocia was lower (P < 0.01) in C ewes compared with those offered silage-based diets (7.5% v. 37.4% ewes), and was higher (P < 0.01) in ewes fed MS compared with GS or GSMS (50.7%, 34.7% and 26.9%, respectively). There were no significant dietary effects on the plasma metabolite concentrations of ewes in late pregnancy, pre-weaning lamb mortality, weaned lamb output per ewe or on lamb growth rate. The results of this study demonstrate that both maize silage and all-concentrate diets can replace grass silage in pregnant ewe rations without impacting on performance, provided the supply of MP is non-limiting. The higher incidence of dystocia in ewes fed maize silage as the sole forage is a concern.     

Evaluation of protein supplementation for growing cattle fed grass silage-based diets: a meta-analysis

The objective of this meta-analysis was to develop empirical equations predicting growth responses of growing cattle to protein intake. Overall, the data set comprised 199 diets in 80 studies. The diets were mainly based on grass silage or grass silage partly or completely replaced by whole-crop silages or straw. The concentrate feeds consisted of cereal grains, fibrous by-products and protein supplements. The analyses were conducted both comprehensively for all studies and also separately for studies in which soybean meal (SBM; n=71 diets/28 studies), fish meal (FM; 27/12) and rapeseed meal (RSM; 74/35) were used as a protein supplement. Increasing dietary CP concentration increased (P<0.01) BW gain (BWG), but the responses were quantitatively small (1.4 g per 1 g/kg dry matter (DM) increase in dietary CP concentration). The BWG responses were not different for bulls v. steers and heifers (1.4 v. 1.3 g per 1 g/kg DM increase in dietary CP concentration) and for dairy v. beef breeds (1.2 v. 1.7 g per 1 g/kg, respectively). The effect of increased CP concentration declined (P<0.01) with increasing mean BW of the animals and with improved BWG of the control animals (the lowest CP diet in each study). The BWG responses to protein supplementation were not related to the CP concentration in the control diet. The BWG responses increased (P<0.05) with increased ammonia N concentration in silage N and declined marginally (P>0.10) with increasing proportion of concentrate in the diet. All protein supplements had a significant effect on BWG, but the effects were greater for RSM (P<0.01) and FM (P<0.05) than for SBM. Increasing dietary CP concentration improved (P<0.01) feed efficiency when expressed as BWG/kg DM intake, but decreased markedly when expressed as BWG/kg CP intake. Assuming CP concentration of 170 g/kg BW marginal efficiency of the utilisation of incremental CP intake was only 0.05. Increasing dietary CP concentration had no effects on carcass weight, dressing proportion or conformation score, but it increased (P<0.01) fat score. Owing to limited production responses, higher prices of protein supplements compared with cereal grains and possible increases the N and P emissions, there is generally no benefit from using protein supplementation for growing cattle fed grass silage-based diets, provided that the supply of rumen-degradable protein is not limiting digestion in the rumen.