Effect of dietary cation-anion balance in mineral balance in anaerobically exercised and sedentary horses

Eight geldings and four mares were randomly assigned treatments within three 4x4 Latin square design experiments to study the effects of dietary cation-anion balance (DCAB) on mineral balance and dry matter digestibility in sedentary and anaerobically exercised horses. Four diets with an average DCAB (calculated as meq ((Na+K+) - Cl-)/kg of diet dry matter) of +24 (Low, L), +127 (Medium Low, ML), +227 (Medium High, MH) and +352 (High, H) were fed for a 21 day adjustment period followed by a 72 hour collection period. Diets consisted of a pelleted base concentrate of com, soybean meal and cottonseed hulls fed with either native prairie grass or bermuda grass hay in a 60:40 ratio. Diet L was formed by adding calcium chloride and ammonium chloride to the base concentrate, diet ML was formed by adding calcium chloride, and diet H was formed by adding potassium citrate and sodium bicarbonate. Diet MI-I received no supplementation and served as the control. Representative samples of feed, feces and urine were analyzed for mineral content and mineral balances were calculated by difference. Fecal output was greater (p <.05), and thus, dry matter digestibility was lower in exercised homes consuming diet L versus diet H. Sodium balance was greater (p <.05) in sedentary horses consuming diet MH as compared to those consuming diets ML and L Sodium balance was greater (p <.05) in exercised homes consuming diet H as compared to those consuming diets ML and L Potassium balance was greater (p <.05) in sedentary horses consuming diet H as compared to those horses consuming diet ML, however, potassium balance was not affected by DCAB in exercised horses. No significant differences were detected in chloride or magnesium balances in the sedentary horses, although chloride balance was greater (p <.05) and magnesium balance was lower (p <.05) in exercised homes consuming diet L as compared to all other diets. In sedentary homes, phosphorus balance was reflective of intake with differences (p <.05) observed between all treatments. However, in exercised homes, phosphorus balance was lower (p <.05) oniy for those consuming diet L. Calcium balance decreased significantly as DCAB decreased between all treatments in sedentary horses, while calcium balance in exercised homes was greater (p <.05) for homes consuming diet H as compared to those consum- ing diet L.Previous research from our laboratory has shown that both exercised and sedentary horses consuming diets with a low DCAB experience a nutritionally induced metabolic acidosis. The current data indicate that anaerobically exercised and sedentary horses consuming these diets excrete significantly more calcium in the urine resulting in decreased calcium balances. Prolonged consumption of diets with a low DCAB may lead to a significant demineralization of bone and a subsequent weakening of the skeleton.     

Effects of different fresh-cut forages and their hays on feed intake, digestibility, heat production, and ruminal methane emission by Boer x Spanish goats

Twenty-four yearling Boer × Spanish wethers were used to assess effects of different forages, either fresh (Exp. 1) or as hay (Exp. 2), on feed intake, digestibilities, heat production, and ruminal methane emission. Treatments were: 1) Sericea lespedeza (SER; Lespedeza cuneata), a legume high in condensed tannins (CT; 20% and 15% in fresh forage and hay, respectively), 2) SER supplemented with polyethylene glycol (SER-PEG; 25 g/d), 3) alfalfa (Medicago sativa), a legume low in CT (ALF), and 4) sorghum-sudangrass (Sorghum bicolor), a grass low in CT (GRASS). Experiments were 22 d, which included 16 d for acclimatization followed by a 6-d period for fecal and urine collection, and gas exchange measurement (last 2 d). Intake of OM was 867, 823, 694, and 691 g/d (SEM = 20.1) with fresh forage, and 806, 887, 681, and 607 g/d with hay for SER, SER-PEG, ALF, and GRASS, respectively (SEM = 46.6). Apparent total tract N digestion was greater for SER-PEG vs. SER (P < 0.001) with fresh forage (46.3%, 66.5%, 81.7%, and 73.2%; SEM = 1.71) and hay (49.7%, 71.4%, 65.4%, and 54.8% for SER, SER-PEG, ALF, and GRASS, respectively; SEM = 1.57). Intake of ME was similar among treatments with fresh forage (8.24, 8.06, 7.42, and 7.70 MJ/d; SEM = 0.434) and with hay was greater for SER-PEG than ALF (P < 0.03) and GRASS (P < 0.001) (8.63, 10.40, 8.15, and 6.74 MJ/d for SER, SER-PEG, ALF, and GRASS, respectively; SEM = 0.655). The number of ciliate protozoa in ruminal fluid was least for SER with fresh forage (P < 0.01) (9.8, 20.1, 21.0, and 33.6 × 10(5)/ml; SEM = 2.76) and hay (P < 0.02) (6.3, 11.4, 13.6, and 12.5 × 10(5)/ml for SER, SER-PEG, ALF, and GRASS, respectively; SEM = 1.43). Methane emission as a percentage of DE intake was lower (P < 0.01) for SER vs. ALF and GRASS with fresh forage (6.6, 8.3, 9.4, and 9.2%; SEM = 0.64) and hay (4.3, 4.9, 6.4, and 6.7% for SER, SER-PEG, ALF, and GRASS, respectively; SEM = 0.38). In summary, methane emission in this short-term experiment was similar between a legume and grass low in CT as fresh forage and hay. The CT in SER markedly decreased N digestibility and elicited a moderate decline in ruminal methane emission. Supplementation with PEG alleviated the effect of CT on N digestibility but not ruminal methane emission, presumably because of different modes of action. In conclusion, potential of using CT-containing forage as a means of decreasing ruminal methane emission requires further study, such as with longer feeding periods.     

The effect of leucaena hay as a source of effective fibre and nutrients in diets with forage palm for finishing sheep in semi-arid regions

The present study was conducted to evaluate the intake, digestibility and nitrogen balance of diets for finishing sheep, containing leucaena hay as a source of effective fibre and forage palm. Twenty-one male sheep were used in a randomized block design with three treatments, represented by total diets, where the forage was leucaena hay and forage palm in natura in proportions 350:650, 450:550 and 550:450 g/kg respectively. For the pH and NH₃-N in the ruminal fluid, and urea in the blood serum, plots split in time were adopted. Dry matter and nutrient digestibility, and the nitrogen balance were not influenced (p > .05) by the diets. The neutral detergent fibre digestibility decreased (p < .05) as the proportions of leucaena hay in the diets increased. The pH and NH₃-N were suitable for ruminal fermentation, and blood urea was maintained under normal physiological conditions for sheep. Combining 350 to 550 g/kg of leucaena hay with 450 to 650 g/kg of forage palm in total diets with a forage:concentrate ratio of 60:40 in late-maturing sheep meets the nutritional requirements for daily gain 200 g, characterizing leucaena hay as important source of effective fibre and nutrients in diets.     

Effects of pistachio by‐products in replacement of alfalfa hay on populations of rumen bacteria involved in biohydrogenation and fermentative parameters in the rumen of sheep

The objective of this study was to investigate the effect of sundried pistachio by‐products (PBP) as a replacement of alfalfa hay (AH) on blood metabolites, rumen fermentation and populations of rumen bacteria involved in biohydrogenation (BH) in Baluchi sheep. Four adult male Baluchi sheep (41 ± 1.3 kg, BW) fitted with ruminal cannulae were randomly assigned to four experimental diets in a 4 × 4 Latin square design. The dietary treatments were as follows: (i) control, (ii) 12% PBP (0.33 of AH in basal diet replaced by PBP), (iii) 24% PBP (0.66 of AH in basal diet replaced by PBP) and (iv) 36% PBP (all of AH in basal diet replaced by PBP). The basal diet was 360 g/kg dry matter (DM) alfalfa hay, 160 g/kg DM wheat straw and 480 g/kg DM concentrate. The trial consisted of four periods, each composed of 16 days adaptation and 4 days data collection including measurement of blood metabolites, rumen fermentation and population of bacteria. No differences were observed in rumen pH among the treatments, while rumen ammonia‐N concentrations were decreased (p< 0.05) with increasing PBP by up to 36% DM of the diets. Using of 36% PBP in the diet reduced (p < 0.05) total volatile fatty acids (VFA) concentrations and the molar proportion of acetate, while the concentration of propionate, butyrate and acetate to propionate ratio were similar to all other treatments. The concentration of blood urea nitrogen (BUN) decreased (p < 0.01) with increasing PBP by up to 36% DM in the diets of sheep. However, other blood metabolites were not affected by the experimental diets. It was concluded that PBP in replacement of AH had no effects on the relative abundance of Butyrivibrio fibrisolvens and Butyrivibrio proteoclasticus in relation to the control diet.     

Effect of dietary potassium and anionic salts on acid–base and mineral status in periparturient cows

Dry cow diets based on grassland forage from intensive production contain high amounts of K and could be responsible for a reduced ability to maintain Ca homoeostasis. The aim of this study was to determine whether a moderate anionic salt supplementation to a forage‐based pre‐calving diet with varying native K content affects the mineral and acid–base status in transition cows. Twenty‐four dry and pregnant Holstein cows, without antecedent episodes of clinical hypocalcemia, were assigned to two diets during the last 4 weeks before estimated calving date. Twelve cows were fed a hay‐based diet low in K (18 g K/kg DM), and 12, a hay‐based diet high in K (35 g K/kg DM). Within each diet, six cows received anionic salts during the last 2 weeks before the estimated calving day. After calving, all cows received the high K diet ad libitum. Blood samples were taken daily from day 11 pre‐partum to day 5 post‐partum. Urine samples were taken on days 7 and 2 pre‐partum and on day 2 post‐partum. The anionic salt did not alter feed intake during the pre‐partum period. Serum Ca was not influenced by the dietary treatments. Feeding pre‐partum diets with low K concentrations induced a reduced metabolic alkalotic charge, as indicated by reduced pre‐partum urinary base–acid quotient. Transition cows fed the low K diet including anionic salts induced a mild metabolic acidosis before calving, as indicated by higher urinary Ca, lower urinary pH and net acid–base excretion. Although serum Ca during the post‐partum period was not affected by dietary treatment, feeding a low K diet moderately supplemented with anionic salts to reach a dietary cation–anion difference close to zero permitted to obtain a metabolic response in periparturient cows without altering the dry matter intake.     

Renal energy excretion of horses depends on renal hippuric acid and nitrogen excretion

The prediction of renal energy excretion is crucial in a metabolizable energy system for horses. Phenolic acids from forage cell walls may affect renal energy losses by increasing hippuric acid excretion. Therefore, the relationships were investigated between renal energy, nitrogen (N) and hippuric acid excretion of four adult ponies (230–384 kg body weight (BW)) consuming diets based on fresh grass, grass silage, grass cobs (heat‐dried, finely chopped, pressed grass), alfalfa hay, straw, extruded straw and soybean meal. Feed intake was measured; urine and faeces were quantitatively collected for three days. Feed was analysed for crude nutrients, gross energy, amino acids and neutral‐detergent‐insoluble crude protein (CP); faeces were analysed for crude nutrients and cross energy; urine was analysed for N, hippuric acid, creatinine and gross energy. Renal energy excretion (y; kJ/kg BW^0.75) correlated with renal N excretion (x₁; g/kg BW^0.75) and renal hippuric acid excretion (x₂; g/kg BW^0.75): y = 14.4 + 30.2x₁+20.7x₂ (r = .95; n = 30; p < .05). Renal hippuric acid excretion was highest after intake of fresh grass and lowest after intake of soybean meal. The ratio of hippuric acid to creatinine in urine and the excretion of hippuric acid per gram of dry matter intake was significantly higher for fresh grass than for all other rations. There was no relationship between aromatic amino acid intake and renal hippuric acid excretion. The results of the present study and literature data suggest that feed can be categorized into four groups with regard to the energy losses per gram CP intake: (i) protein supplements (e.g., soybean meal): 4.2–4.9 kJ/g CP intake (ii) alfalfa hay, grains, dried sugar beet pulp: 6.4 kJ/g CP intake, (iii) hay, preserved grass products, straw: 5.2–12.3 kJ/g CP intake (mean 8) and (iv) fresh grass. For group (iii) a negative relationship was observed between renal energy losses per gram of CP and the content of CP or neutral‐detergent‐insoluble CP in dry matter.     

Effects of forage source and particle size on chewing activity,ruminal pH,and saliva secretion in lactating Holstein cows

The present study investigated the effects of dietary forage source (quality) and particle size on chewing activity, saliva secretion, and ruminal pH. Twelve multiparous lactating Holstein cows, four of which were ruminally cannulated, were used in a replicated 4 × 4 Latin square experimental design with a 2 × 2 factorial arrangement of treatments. Cows fed wild‐rye hay diets had longer daily eating times than cows fed oaten hay diets. Treatments had no effect on ruminating time; therefore, resting time varied inversely to eating time. Neither the rate nor the amount of saliva secretion while eating, ruminating, or resting was affected by diet, resulting in similar total daily saliva secretions across treatments (231 L/day). Total volatile fatty acids (VFAs) in the ruminal fluid from animals fed oaten hay diets were higher than those from animals fed wild‐rye hay diets; further, VFAs increased with decreasing forage particle size (FPS). Consistent with elevated VFA concentrations, reducing FPS and including oaten hay in the diet decreased mean ruminal pH and increased the daily time of ruminal pH under 5.8. Results of this study suggest that forage source and particle size affect ruminal pH might be via variations in VFA production rather than increased salivary recycling of buffering substrates.     

Food and water intake and selective feeding in rabbits on four feeding regimes

Diet plays an important role in maintaining rabbit health. Feeding an incorrect diet, particularly a low fibre diet, has been linked with digestive, dental and urinary tract disease. However, food intake and dietary requirements have been poorly studied in pet rabbits. This study assessed the effects of two commonly fed pet rabbit diets [extruded nuggets with hay (EH) and muesli with hay (MH)] alongside hay only (HO) and muesli only (MO) on food and water intake in 32 Dutch rabbits. Dry matter (DM) intake was greater in the HO group and lower in the MO group than in the EH and MH groups (p < 0.001). The portion of the diet made of hay was greater in the EH group than in the MH group (p < 0.001). Water intake was positively correlated with DM intake and was greatest in the HO group (p < 0.001). Selective feeding occurred in all rabbit groups fed muesli, whether or not hay was also available. Pellets were rejected, and grains and extrudates selected. The presence of selective feeding in all rabbits fed muesli leads to the consumption of an unbalanced diet. In addition, hay intake and water intake were lower when muesli was fed. Conclusions drawn from this study are based on general recommendations for pet rabbits, and clinical disease may have developed by feeding the study diets over a longer time period, as many diet‐related conditions typically present in older rabbits. However, the study demonstrates that the feeding of muesli diets cannot be recommended.     

Fermentation of six different forages in the semi-continuous fermentation technique Caesitec

The aim of the present study was to compare carbohydrate degradation of forages which store carbohydrates either predominantly as fructan or starch, in horses’ hindgut. The effects of an abrupt change from hay‐based feeding to green fodder‐based feeding on the caecal flora were tested with the in vitro hindgut simulation technique ‘Caesitec’. Six trials with different forages (English ryegrass, tall fescue, grass mixture‐horses, grass mixture‐cows, lucerne, white clover) were conducted. During a 4‐day stabilisation period, samples were taken once a day before loading the fermenters with hay. After diet‐change to forage‐based feeding, samples were taken four times a day. Ammonia and pH‐value were measured before and 1, 2 and 6 h after loading the ‘Caesitec’. Gas formation was measured daily. Bacterial numbers, lactate and short chain fatty acids were detected at four time‐points of each trial. The grass mixtures contained the highest amounts of fructan. The pH‐values were in the physiological range from pH 6 up to 7 (6.58–6.83) by feeding all forages. Gas formation, anaerobic and aerobic bacterial numbers increased after diet change from hay to any forage. The maximum amount of fructan (3.75 g/kg) in swiss pasture did not cause a permanent pathological change in the hindgut‐flora.     

Effect of a commercial anion dietary supplement on acid-base balance, urine volume, and urinary ion excretion in male goats fed oat or grass hay diets

OBJECTIVE: To determine whether feeding a commercial anionic dietary supplement as a urinary acidifier to male goats may be useful for management of urolithiasis. ANIMALS: 8 adult sexually intact male Toggenburg, Saanen, and Nubian goats. PROCEDURE: Goats were randomly assigned by age-, breed-, and weight-matched pairs to an oat or grass hay diet that was fed for 12 days. On days 13 to 14 (early sample collection time before supplementation), measurements were made of blood and urine sodium, potassium, calcium, magnesium, chloride, phosphorus, and sulfur concentrations; blood and urine pH; urine production; and water consumption. During the next 28 days, the anionic dietary supplement was added to the oat and grass hay diets to achieve a dietary cation-anion difference of 0 mEq/100g of dry matter. Blood and urine samples were analyzed during dietary supplementation on days 12 to 13 (middle sample collection time) and 27 to 28 (late sample collection time). RESULTS: Blood bicarbonate, pH, and urine pH of goats fed grass hay and goats fed oat hay were significantly decreased during the middle and late sample collection times, compared with the early sample collection time. Water consumption and urine production in all goats increased significantly during the late sample collection time, compared with the early sample collection time. CONCLUSIONS AND CLINICAL RELEVANCE: The anionic dietary supplement used in our study increases urine volume, alters urine ion concentrations, and is an efficacious urinary acidifier in goats. Goats treated with prolonged anionic dietary supplementation should be monitored for secondary osteoporosis from chronic urinary calcium loss.     

Effect of feeding Lagerstroemia speciosa and conventional fodder based rations on nutrient utilization,ruminal metabolites and body weight gain in mithun (Bos frontalis)

The aim of the present study was to evaluate the effect of feeding green fodder, rice straw and concentrate‐based total mixed rations (TMR) on dry matter (DM) intake (DMI), nutrient utilization, rumen fermentation patterns and body weight (BW) gain (BWG) in mithun (Bos frontalis) calves. In a randomized block design, male mithun calves (n = 18, 8–10 months of age, 121 ± 2 kg BW) were randomly divided into three experimental equal groups (six animals in each group) and fed isonitrogenous TMRs ad libitum for 120 days. The TMR₁ contained 30% Napier grass and 30% rice straw, TMR₂ contained 60% rice straw and TMR₃ contained 30% tree leaves (Lagerstroemia speciosa) and 30% rice straw (DM basis). All the TMRs contained 40% concentrate mixture (DM basis). The results indicated that the BWG, DMI and feed conversion efficiency were significantly (p < 0.01) increased with the inclusion of green fodder in TMRs. The apparent digestibility of DM, crude protein, ether extract, crude fibre and nitrogen free extract were also improved significantly (p < 0.01) with the inclusion of green fodder in TMRs. The higher concentration of total nitrogen and total volatile fatty acid in rumen liquor, but low ruminal pH were evident in animals fed green fodder supplemented TMRs. An increased (p < 0.01) molar proportion of acetic acid was evident in animals fed rice straw‐based TMR. In contrast, the molar proportion of propionic and butyric acids were significantly (p < 0.01) higher in animals fed green fodder supplemented TMRs. On the basis of higher DMI and higher daily BWG, it is concluded that Napier grass and L. speciosa tree leaves may be incorporated upto 30% (DM basis) in TMR of growing mithuns for feeding in complete confinement system.     

Alfalfa hay improves nursing performance of Awassi ewes and performance of growing lambs when used as a source of forage compared with wheat straw

Tropical Animal Health and Production - Two experiments were conducted to evaluate the effect of replacing wheat straw (WS) with alfalfa hay (ALF) in diets fed to Awassi lactating ewes (exp. 1) and...     

Nitrogen metabolism in sheep fed protein sources of various solubilities with low quality roughages

Four rumen-cannulated, mature crossbred wethers were used in a 4 x 4 latin square experiment designed to examine the effects on protein metabolism of protein sources with various solubilities fed with low quality roughages. Four diets were used: (1) grass hay plus oat straw (control), (2) control plus urea, (3) control plus soybean oil meal (SBOM) and (4) control plus sunflower oil mean (SFOM). The diets were isocaloric, isofibrous and isonitrogenous (1.60% except for the control, which contained 1.09% N). The protein solubility means determined by three solvents (Burroughs' mineral mixture, McDougal's artificial saliva and sodium chloride) were 23.7, 50.5, 18.2 and 24.2% for the respective diets. The average protein solubilities of SBOM and SFOM were 20.5 and 35.4%, respectively. Apparent crude protein digestibilites were higher (P less than .05) for diets with higher protein solubility. The Urea diet (highest protein solubility) resulted in higher urinary N excretion (P less than .05) and lower N retention than the SBOM and SFOM diets. N retention was similar for the animals fed the SBOM and SFOM diets. Ruminal NH3-N and plasma urea N levels were higher (P less than .05) in animals fed the urea diet. The protein source altered VFA concentrations but not C2 to C3 ratios of VFA. The SBOM and SFOM produced more branched chain fatty acids. These data illustrate that protein sources of higher solubility result in higher crude protein digestion and higher N loss in the urine. N balance was similar with SFOM and SBOM. SFOM and SBOM can be used interchangeably on an equal protein basis for sheep fed high roughage diets.     

Use of post‐harvest common bean (Phaseolus vulgaris L.) residues in diet of lambs and its effect on finishing performance,rumen fermentation,protozoa population and meat characteristics

The aim of the experiment was to investigate the replacement value of common bean residues in the diet of finishing lambs as an inexpensive fodder instead of wheat straw or maize silage. Forty Arabi male lambs with average body weight of 18.90 ± 0.6 kg were randomly divided into five treatments with eight replications. The five experimental treatments consisted of control diet, and 50% and 100% replacement of bean residues with wheat straw or 25% and 50% replacement with maize silage in the control diet respectively. Lambs were slaughtered at the end of the experiment to evaluate carcass traits and meat characteristics. Dry matter intake, blood glucose, urea nitrogen, cholesterol and triglyceride concentration were not affected by the experimental treatments. Apparent digestibility of nutrients; total concentration of volatile fatty acids, acetate and butyrate; and total rumen protozoa population were linearly increased by increasing the levels of bean residues, as replacement with wheat straw (p < .05). Replacement of bean residues in control diets instead of wheat straw or maize silage caused a positive linear incremental trend for average daily gain and total weight gain. There was no significant difference in daily gain, final weight and feed conversion ratio among the treatments. Instead of wheat straw or maize silage, replacement bean residues linearly increased chewing, ruminating and eating activities per neutral detergent fibre intake (p < .05). Carcass traits and physicochemical characteristics of meat were not affected by the treatments. It is advisable to use bean residues in the diet of lambs as an alternative to the wheat straw or maize silage, because no adverse effects were observed on rumen fermentation, blood metabolites and performance; moreover, improvement in average daily gain, total weight gain and digestibility of nutrients, and the fact that bean residue is less expensive than wheat straw and maize silage.     

Nutrient intake, acid base status and growth performance of growing male buffalo calves fed varying level of dietary cation anion difference

Influence of + 110, + 220 and + 330 mEq/kg of dry matter (DM) dietary cation anion difference (DCAD) on growth performance of growing male buffalo calves was examined in a randomized complete block design. Three DCAD diets were randomly allotted to three groups, ten calves in each group. A linear increase in nutrient intake was recorded with increased DCAD level. However, digestibilities of nutrients remained unaltered across all diets. Calves fed + 330 DCAD diet had higher nitrogen balance than those fed + 110 DCAD diet. Blood pH and serum HCO₃ increased with increased DCAD level. Serum chloride was high in calves fed + 110 DCAD diet, while serum (Na + K) − (Cl + S) increased linearly with increased DCAD level. Serum calcium increased with decreased DCAD level while serum magnesium and phosphorus remained unaffected. Ca balance remained unaltered by calves fed varying level of DCAD. Urine pH increased with increased DCAD level. Calves fed + 220 and + 330 DCAD diets gained more weight than those fed + 110 DCAD diet. In conclusion, increased DCAD level not only increased dry matter intake but also weight gain in growing buffalo calves.     

Growth,carcass yield and meat quality attributes of Red Maasai sheep fed wheat straw-based diets

Thirty-two castrated Red Maasai sheep (12.7 kg initial body weight, aged 12–18 months), were used in an 84-day experiment to evaluate diets based on treated straw upon growth performance, carcass yield and meat quality. The animals were blocked by weight into four similar groups and randomly allotted into four dietary treatments, with eight individually fed animals per treatment. The dietary treatments were ad libitum untreated wheat straw (UTS), wheat straw treated with urea and lime (TS), straw and ad libitum hay (UTSH), and TS and ad libitum hay (TSH). In addition, each experimental animal received 220 g/day (on as fed basis) of a concentrate diet. Treatment of straw increased (P < 0.05) dry matter intake (42.3 vs. 33.7 g/kg W ⁷⁵/day), energy intake (4.6 vs. 3.7 MJ ME/d) and the average daily gain (40.7 vs. 23.1 g). Animals on TS produced heavier (P < 0.05) carcasses (6.6 vs. 5.4 kg) with superior conformation than animals on UTS. Percentage cooking loss was higher in carcasses from animals fed TS compared to those from other diets. Except M. longissimus dorsi and M. semitendinosus, tenderness of muscles was not affected by diet but ageing of meat improved (P < 0.001) tenderness. Overall, straw treatment increased carcass yields with limited effects on meat quality attributes.     

Plasma and urine electrolyte and mineral concentrations in Thoroughbred horses with recurrent exertional rhabdomyolysis after consumption of diets varying in cation-anion balance

OBJECTIVE: To determine whether plasma, urine, and fecal electrolyte and mineral concentrations differ between clinically normal horses and Thoroughbreds with recurrent exertional rhabdomyolysis (RER) after consumption of diets varying in cation-anion balance. ANIMALS: 5 Thoroughbred mares with RER and 6 clinically normal mixed-breed mares. PROCEDURE: Each of 3 isocaloric diets designated as low, medium, and high on the basis of dietary cation-anion balance (DCAB) values of 85, 190, and 380, respectively, were fed to horses for 14 days. During the last 72 hours, 3 horses with RER and 3 control horses had daily urine and fecal samples obtained by total 24-hour collection. Remaining horses had urine samples collected daily by single catheterization. RESULTS: For each diet, no differences existed between horses with RER and control horses in plasma pH, electrolyte concentrations, and creatine kinase activity or in urine pH and renal fractional excretion (FE) values. Plasma pH, strong ion difference, bicarbonate and total carbon dioxide concentrations, and base excess decreased and plasma chloride and ionized calcium concentrations increased with decreasing DCAB. Urine pH decreased with decreasing DCAB. The FE of chloride and phosphorus were greatest for horses fed the low diet. The FE values for all electrolytes exept magnesium did not differ between urine samples obtained by single catheterization and total 24-hour collection. Daily balance of calcium, phosphorus, sodium, chloride, and potassium did not differ significantly among horses fed the various diets. CONCLUSIONS: In clinically normal horses and in horses with RER, the DCAB strongly affects plasma and urine pH and the FE of sodium, potassium, chloride, and phosphorus.     

Influence of diet and water supply on mineral content and pH within the large intestine of horses with enterolithiasis

To determine the effects of two diets and water supplies on intestinal pH and mineral concentrations in the colon of horses, and to identify whether differences in these parameters exist in horses with and without enterolithiasis, surgical fistulation of the right dorsal colon was performed in six adult horses, three with and three without enterolithiasis. Each horse underwent four feeding trials: grass hay and untreated water, alfalfa hay and untreated water, grass hay with filtered/softened water, and alfalfa hay with filtered/softened water. Samples of colonic contents were analyzed for pH, dry matter, and mineral concentrations.Horses with enterolithiasis had higher calcium, magnesium, phosphorus and sulfur concentrations and higher pH in colonic contents than controls. Horses fed alfalfa had lower colonic sodium and potassium, higher calcium, magnesium, phosphorus and sulfur concentrations, and a more alkaline pH than those fed grass. Grass hay consumption leads to reduced concentrations of select minerals and a more acidic colonic environment compared with alfalfa, probably beneficial in the prevention of enterolithiasis. Under controlled dietary and management conditions, horses with enterolithiasis have differences in colonic mineral and pH parameters that may be consistent with physiological differences between horses with and without the disease.     

Utilization of macro-nutrients and minerals in captive greater one-horned rhinoceros fed season-specific diets

This experiment was conducted to study nutrient and mineral utilization in greater one-horned rhinoceros fed season-specific diets. Nine adult greater one-horned rhinoceros (774–2407 kg BW) of Sanjay Gandhi Biological Park, Patna, Bihar, India, were used in this experiment. Three digestion trials of 60-d duration were conducted per animal, out of which 55 days was adaptation period and 5 days was collection period. The amount of concentrate was kept constant during all the trials. Green fodder sources were sugarcane, berseem (Trifolium alexndrinum) and chari (Sorghum bicolor) during trials I, II and III respectively. Green fodders were offered 20% in excess of previous day's intake in the afternoon. Apparent digestibility of dry matter and crude fibre was higher (p < .01) in group II as compared to other groups. Apparent digestibility of crude protein was lowest (p < .01) in group I, followed by group III, and the highest value was observed in group II. Apparent digestibility of Ca and P was lower in greater one-horned rhinoceros fed sugarcane and sorghum as green fodder source. In spite of this, sugarcane and sorghum-based diets were able to meet the requirement of Ca, P, Fe and Mn. Berseem supplied Ca in excess of requirement. All the diets were deficient in Zn. Hence, a suitable supplement of Zn should be added to the conventional zoo diet of greater one-horned rhinoceros.     

Effects of a new molasses byproduct, concentrated separator byproduct, on nutrient digestibility and ruminal fermentation in cattle.

Continuous chromatographic separator techniques have allowed the extraction of more simple sugars from molasses (MOL). The resultant byproduct, concentrated separator byproduct (CSB), has reduced readily fermentable carbohydrates but elevated CP and mineral content. The feed value of CSB was compared to that of MOL in two separate trials. In Trial 1, a chopped forage mixture containing 84% meadow grass hay and 8% alfalfa hay was mixed with either CSB or MOL at 7.3% of DM. Diets were administered to four ruminally cannulated cows in a single reversal design. digestibility of DM, ADF, NDF, and CP were measured. Ruminal pH, ammonia nitrogen (NH3), VFA, total viable bacteria (TVB), cellulose-xylan fermenting bacteria (CXFB), and ciliated protozoa (PTZ) were evaluated. Blood profiles of electrolytes were also measured. Digestibility of DM, ADF, NDF, and CP were 69.03, 68.58; 57.48, 57.77; 65.62, 64.75; and 67.63, 65.07% for the MOL and CSB diets, respectively. Only CP digestibility differed (P less than .02). Ruminal pH, NH3, VFA, TVB, CXFB, and PTZ were 6.97, 6.93; 14.21, 16.71 mg/dL; 74.30, 74.78 mumol/mL; 26.79, 27.36 x 10(9)/mL; 21.72, 21.36%; and 13.90, 7.80 x 10(3)/mL for the MOL and CSB diets, respectively. Ruminal measurements did not differ. Blood electrolyte profiles were not altered. Trial 2 was similar to Trial 1 except the basal diet used was 47% barley grain, 35% alfalfa hay, and 10% barley straw. Either MOL or CSB was added at 7.3% of the DM. Digestibilities of DM, ADF, NDF, and CP were 69.52, 71.33; 35.96, 37.11; 27.93, 33.47; and 71.10, 73.66% for the MOL and CSB diets, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)