Estimation of maintenance energy requirements in German shepherd and Labrador retriever dogs in Bangalore,India

Maintenance energy requirements (MERs) were calculated for 17 German shepherd and 20 Labrador retriever adult dogs using an in‐home prospective dietary trial. The dogs were fed the same dry pet food and body weight, food intake, body condition score and physical activity were monitored for 10 weeks. Labrador retrievers were significantly heavier and had higher body condition scores than German shepherd dogs, but there was no difference between males and females within each group. Body weights remained stable over the study period, with an average daily gain of 9.1 g. Mean (SD) MER was 103.4 (16.3) kcal/kg BW^0.75, which was some 20% lower than that currently suggested for moderately active young adult dogs. Individual MER ranged from 66.8 to 141 kcal/kg BW^0.75. There were no significant differences in MER between the two breeds, or between males and females within and between the two breeds. There was a significant inverse relationship between MER and body condition score, reflecting the lower energy expenditure of adipose tissue. The lower MER of dogs in this study, relative to previous observations, may reflect climatic and environmental differences and highlight the necessity for accurate estimates of MER in relation to the production and feeding of pet foods.     

Metabolizable energy intake of client‐owned adult dogs

A post hoc analysis of the metabolizable energy (ME) intake of privately owned pet dogs from the authors' nutrition consultation practice (Years 2007–2011) was carried out to identify if current ME recommendations are suitable for pet dogs. Data on 586 adult dogs were available (median age 5.5, median deviation from ideal weight 0.0), 55 of them were healthy; the others had various diseases. For ration calculation, a standardized questionnaire and the software diet‐check Munich^? was used. ME was predicted according to NRC (2006). Data were evaluated for the factors disease, breed, size, age, gender and type of feeding. The mean ME intake of all adult dogs amounted to 0.410 ± 0.121 MJ/kg metabolic body weight (BW^0.75) (n = 586). There was no effect of size and disease. Overweight dogs ate 0.360 ± 0.121 MJ/kg BW^0.75, and underweight dogs ate 0.494 ± 0.159 MJ/kg BW^0.75. Older dogs (>7 years, n = 149, 0.389 ± 0.105 MJ/kg BW^0.75) had a lower ME intake than younger ones (n = 313, 0.419 ± 0.121 MJ/kg BW^0.75), and intact males had a higher ME intake than the others (p < 0.001). Some breeds were above average: Jack Russell Terrier, Dalmatian, small Munsterlander and Magyar Viszla, Bearded Collies, Sight Hounds, German Boxers, English foxhounds, Rhodesian Ridgebacks and Flat‐Coated Retrievers with a mean ME intake of 0.473 ± 0.121 MJ/kg BW^0.75. The following breeds were below average: Dachshunds, Bichons, West highland White Terrier, Collies except Bearded Collies, Airedale Terriers, American Staffordshire terriers and Golden Retrievers with a mean ME intake of 0.343 ± 0.096 MJ/kg BW^0.75. The mean maintenance energy requirements of pet dogs are similar to that of kennel dogs which do not exercise very much. These results suggest that opportunity and stimulus to exercise provided for pet dogs are lower than for kennel dogs. Lower activity in pet dogs may reduce part of potential effects of breed, medical history and age groups.     

Body weight and range usage affect net energy utilisation in commercial free-range laying hens when evaluated in net energy chambers

Within a given free-range flock, some hens prefer to spend the majority of their time in the shed (stayers), while others frequently access the range (rangers). Laying performance has been associated not only with the development of these sub-populations but also with different body weights (BW). The purpose of this study was to determine if range usage, BW or a combination of both is associated with energy metabolism and as such contribute to improved hen performance. Forty-eight Lohmann Brown hens at 74 wk of age were selected from a commercial free-range farm based on their BW and range usage over a 56-week period. Using a 2 × 2 factorial arrangement, hens were either classified as heavy (mean ± SEM; 2.01 ± 0.02 kg, n = 24) or light (1.68 ± 0.01 kg, n = 24), and also classified as rangers (accessed the range for 84.1% of available days, 242 ± 3.75 d; n = 24) or stayers (accessed the range for 7.17% of available days; 23.4 ± 6.08 d, n = 24). Stayers had significantly higher metabolizable energy (ME) intake per metabolic BW per d (0.852 vs. 0.798 MJ/kg BW^0.75 per d; P = 0.025), higher heat production (0.637 vs. 0.607 MJ/kg BW^0.75 per d; P = 0.005), higher heat increment (0.267 vs. 0.237 MJ/kg BW^0.75 per d; P = 0.005) and retained more nitrogen (1.59 vs. 1.46 g/hen per d; P = 0.023) compared to the rangers. Light hens had significantly higher metabolic energy intake per metabolic BW (0.854 vs. 0.796 MJ/kg BW^0.75 per d; P = 0.018), net energy (NE) intake (0.595 vs. 0.551 MJ/kg BW^0.75 per d; P = 0.032), and retained energy (0.225 vs. 0.181 MJ/kg BW^0.75 per d; P = 0.032), as well as lower heat production (0.936 vs. 1.003 MJ/hen per d; P = 0.002) compared to heavier hens. An interaction was observed across levels of analysis i.e. between light stayers and light rangers. The light rangers had significantly higher NE intake compared to the light stayers (9.77 vs. 9.27 MJ/kg BW^0.75 per d; P = 0.024). In conclusion, light hens were more energy efficient compared to heavy hens. Moreover, light rangers had a more efficient feed utilisation compared to the light stayers.     

Metabolisable energy intake and growth of privately owned growing dogs in comparison with official recommendations on the growth curve and energy supply

The correct assumption of metabolisable energy (ME) requirement is essential for the nutrition consultation and diet formulation. In young dogs, too high energy supply can accelerate growth and thus lead to developmental orthopaedic diseases. The aim of the present study was to collect the data on ME intake and body weight (BW) development in privately owned growing dogs in order to compare these data with the current recommendations. Our hypothesis was that the actual ME intake of healthy young dogs would be lower than the actual recommendation. The data of 493 privately owned puppies (median age at first consultation 21 weeks, the median expected mature BW 30 kg) on ME intake, actual and expected mature BW were collected and compared with recommendations of the Society of Nutrition Physiology (GfE, Meyer and Zentek and NRC). In 243 dogs, there was a follow‐up. The actual BW did not deviate systematically from the calculated expected BW (R² = .929). The ME intake significantly decreased with age (p < .05) and significantly increased with expected mature BW (p < .05). There was no significant interaction between these two parameters (p > .05). Sex had no effect on the ME intake (p > .05). The ME intake of young dogs with a history of skeletal problems or of food allergy did not differ systematically from healthy dogs of similar age and expected mature BW. The ME intake was considerably below NRC recommendations, especially in younger puppies (>8–17 weeks: 78%, >17–26 weeks: 83% of NRC recommendation). A predictive linear equation for ME intake was developed: ME intake (MJ) = (1.063 ? 0.565 × [actual BW/expected mature BW]) × actual BW^0.75.     

Phytoestrogen treatment induces testis alterations in dogs. Potential use in population control

Dog overpopulation is considered a human health risk; they are the terrestrial vector of rabies and reservoirs for other human diseases. Surgical neutering and intratesticular injections have been used in male dogs. Physiological and morphological alterations in reproductive organs can be induced by phytoestrogens. Our goal was to evaluate the effect of oral coumestrol on dog ejaculates and testis histology. Two groups of 5 healthy adult dogs were used. One coumestrolcontaining biscuit was given once a week for a 4 week period to the experimental group. Ejaculates were obtained and evaluated. After treatment, testis were obtained and processed for histology. Compared to controls, treated dogs have reduced tubules (462 ± 1.4 vs 336 ± 2 μ²), spermatogenic epithelium (49.1 ± 0.01 vs 13.3 ± 0.01 μ²), and lumen opening (891 ± 1.4 vs 530 ± 26.9 μ). Ejaculates from treated animals have increased numbers of abnormal spermatozoa and reduced sperm concentration.     

Digesta passage and nutrient digestibility in Boran steers at low feed intake levels

The present study evaluated the effects of energetic undernutrition on liquid and solid digesta passage and on nutrient digestibility as well as their interdependencies. Using a 4 x 4 Latin square design, 12 growing Boran steers (183 ± 15.2 kg live weight) were allocated to four levels of metabolizable energy (ME) supply fixed at 100, 80, 60 and 40% of individual maintenance energy requirements (MER) during four experimental periods. Each period comprised three weeks of adaptation, two weeks of data collection and two weeks of recovery. Diets MER80, MER60 and MER40 only consisted of Rhodes grass hay (RGH), whereas diet MER100 contained (as fed) 83% RGH, 8% cotton seed meal and 9% sugarcane molasses. Feed intake differed between treatments (p < .001) and ranged from 40 ± 0.6 g dry matter (DM) per kg of metabolic weight (kg^0.75) in MER40 to 81 ± 1.3 g DM in MER100. Digestibility of neutral and acid detergent fibre (NDF, ADF) was highest at MER80, whereas rumen retention time of liquid and solid digesta was longest at MER40. The correlation of rumen retention time of liquid and solid digesta with the digestibility of proximate diet components was weak but positive, whereas the correlation of liquid and solid rumen retention time with quantitative feed and nutrient intake was strong (p < .01) and negative. Our results suggest that tropical cattle are able to buffer a moderate energy deficit by prolonging rumen retention time of digesta and hence improve diet digestibility. Conversely, a severe energy deficit cannot be buffered by digestive adaptation mechanisms and will inevitably lead to productivity losses.     

Corneal innervation in mesocephalic and brachycephalic dogs and cats: assessment using in vivo confocal microscopy

Objective To determine the density of the canine and feline corneal neural network in healthy dogs and cats using in vivo confocal microscopy (IVCM). Animals examined A total of 16 adult dogs (9 Mesocephalic breeds, 7 Brachycephalic breeds) and 15 cats (9 Domestic Short-haired cats (DSH), 6 Persian cats) underwent IVCM. Procedure Animals were examined with a confocal corneal microscope (HRTII/RCM; Heidelberg Retina Tomograph II/Rostock Cornea Module^®, Heidelberg Engineering, Dossenheim, Germany). The investigations focused on the distribution of the corneal nerves and quantification of central subepithelial and subbasal nerve plexus. Results The corneal stromal nerve trunks, subepithelial and subbasal nerve plexus were observed. The nerve fiber density (NFD) quantified in nerve fiber length in mesocephalic dogs were 12.39 ± 5.25 mm/mm² in the subepithelial nerve plexus and 14.87 ± 3.08 mm/mm² in the subbasal nerve plexus. The NFD of the subepithelial nerve plexus in DSH cats was 15.49 ± 2.7 and 18.4 ± 3.84 mm/mm² in the subbasal nerve plexus. The subbasal NFD of DSH cats was significantly higher than in mesocephalic dogs (P = 0.037). The subepithelial NFD in brachycephalic dogs, and Persian cats were 10.34 ± 4.71 and 9.50 ± 2.3 mm/mm², respectively. The subbasal NFD measured 11.80 ± 3.73 mm/mm² in brachycephalic dogs, and 12.28 ± 4.3 mm/mm² NFD in Persian cats, respectively. The subepithelial and subbasal NFD in Persian cats were significantly lower than in DSH cats (P = 0.028, respectively, P = 0.031), in contrast to brachycephalic vs. mesocephalic dogs. Conclusion The noninvasive IVCM accurately detects corneal innervation and provides a reliable quantification of central corneal nerves.     

RELATIONSHIP BETWEEN AGE,PLASMA RENIN ACTIVITY,AND RENAL RESISTIVE INDEX IN DOGS

The renal resistive index (RI) value of 0.73 has been proposed as the upper limit in normal adult dogs. In humans, changes in RI with age are associated with plasma renin activity. There are relatively few equivalent reference data for dogs. We obtained reference RI data from 22 clinically healthy dogs <4 months of age and 33 healthy dogs between 4 months and 7 years of age. An association between the RI and plasma renin activity was investigated. The mean RI in the older dogs was 0.65 ± 0.05 vs. 0.75 ± 0.05 in dogs <4 months of age. The mean plasma renin activity in the older dogs was 1.18 ± 1.03 vs. 4.23 ± 3.09 ng/ml/h in dogs <4 months of age. There was a weak linear relationship between the RI and plasma renin activity (r²=0.280, P<0.01) in dogs <4 months of age. Also in these younger dogs, RI was negatively correlated with age (r²=0.682, P<0.01). The RI was higher in dogs <4 months of age than in older dogs. Therefore, the mean renal RI is slightly higher in young dogs than reported for an older population and interpretation of the RI must include an assessment of patient age.     

Net energy content of five fiber‐rich ingredients fed to pregnant sows

The present study was conducted to determine the net energy (NE) values and energy efficiency of wheat bran (WB), sugar beet pulp (SBP), corn gluten feed (CGF), soybean hulls (SBH), and defatted rice bran (DFRB) fed to pregnant sows. Thirty‐six multiparous pregnant sows were randomly assigned to six dietary treatments with six replicates per treatment. Each period lasted for 21 days including 14 days for adaptation. On day 15, sows were moved into respiration chambers for heat production (HP) measurement and provided feed at 544 kJ/kg BW^0.75/day. On day 20, sows were fasted to measure the fasting heat production (FHP). Experimental diets included corn‐soybean meal basal diet and five diets containing 29.20% WB, SBP, CGF, SBH, and DFRB, respectively. Results showed that inclusion of WB, SBP, CGF, SBH, and DFRB to basal diet decreased (p < 0.05) the apparent total tract digestibility of energy and nutrients. The average adjusted total HP and FHP were 418 kJ/kg BW^0.75/day and 326 kJ/kg BW^0.75/day, respectively. The average NE:ME ratio of experiment diets was 82.5%. In conclusion, the NE values of WB, SBP, CGF, SBH, and DFRB were 9.05, 8.59, 8.37, 7.64, and 7.93 MJ/kg DM, respectively.     

Metabolizable energy intake of client‐owned adult cats

A retrospective analysis of the metabolizable energy (ME) intake of privately owned pet cats from the authors’ nutrition consultation practice (years 2007–2011) was carried out to test whether current recommendations are suitable for pet cats. Data of 80 adult cats (median age: 9.0 years, median deviation from ideal weight: +22.5%, majority neutered) at maintenance were available. Six percentage of the cats were healthy and the others were affected by various chronic diseases. A standardized questionnaire was used, cat owners weighed cat and food. For ration calculation, the software Diet Check Munich^? was used (ME prediction according to National Research Council, 2006: Nutrient Requirements of Dogs and Cats. National Academy Press, Washington, DC). Data were analysed for the factors deviation from ideal weight, breed, age, gender, disease and type of feeding [prepared food (dry, wet) vs. home‐made]. Over‐ or underweight were defined as ≥15% deviation from ideal body weight (BW) according to Kienzle and Moik (British Journal of Nutrition 2011, 106, Suppl 1: S113). Cat owner's estimation of ideal BW was higher than literature data from Kienzle and Moik (2011). Based on literature data, 26.3% of the pet cats were normal weight, 63.7% overweight and 10% underweight. The mean ME intake of all adult cats amounted to 0.40 ± 0.14 MJ/kg actual BW^0.67 (n = 80). When the data were analysed according to normal, over‐ and underweight, there was a significant effect with normal weight cats eating 0.46 MJ/kg BW^0.67. Underweight cats ate even more (0.49 MJ/kg BW^0.67), whereas overweight cats ate considerably less (0.36 MJ/kg BW^0.67). The other factors had no influence on ME intake of adult cats.     

Effects of intrauterine growth restriction during late pregnancy on the ovine fetal renal function and antioxidant capacity

This study investigated the effects of intrauterine growth restriction during late pregnancy on the ovine fetal renal function and renal antioxidant capacity. Eighteen ewes pregnant were randomly divided into control group (CG, ad libitum, 0.67 MJ ME·BW^−0.75·day⁻¹, n = 6), restricted group 1 (RG1, 0.18 MJ ME·BW^−0.75·day⁻¹, n = 6), and restricted group 2 (RG2, 0.33 MJ ME·BW^−0.75·day⁻¹, n = 6). At 140 days, the fetal blood, allantoic fluid and kidney tissue were collected to determinate fetal renal function and renal antioxidant capacity. The results showed that the fetal weight, kidney weight, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), aquaporin-2 (AQP-2) and aquaporin-3 (AQP-3), and total antioxidant capacity (T-AOC) in RG1 group were decreased compared with the CG (P < 0.05), but the contents of β2-Microglobulin (β 2-MG), cystatin C (Cys-C), filtered sodium excretion fraction (FENa), malondialdehyde (MDA), and hydroxyl radical (OH) in RG1 group were increased (P < 0.05). The impaired ovine fetal renal growth, antioxidant imbalance and dysfunction of glomerulus ultrafiltration, and the renal tubules reabsorption were induced by maternal malnutrition during late pregnancy.     

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.     

Inotropic and lusitropic effects of incremental doses of dobutamine in dogs with right ventricular apical pacing‐induced cardiac dysfunction

This study aimed to assess the effects of incremental doses of dobutamine on diastolic function in healthy and rapid ventricular apical pacing (RVAP)‐induced cardiac dysfunction anesthetized dogs. Inotropic and lusitropic effects of dobutamine (2, 4, 8, and 12 μg kg^?1 min^?1) were assessed through left ventricle (LV) pressure–volume relation and Doppler echocardiography in six female dogs before and after 8 weeks of RVAP. Peak rate of LV pressure fall (?dP/dt_min) improved with doses >4 μg kg^?1 min^?1 in healthy (4,490 ± 970 vs. 3,265 ± 471 mmHg/s, p < 0.05) and >8 μg kg^?1 min^?1 in RVAP dogs (3,385 ± 1,122 vs. 1,864 ± 849 mmHg/s, p < 0.05) while the time constant of relaxation (tau) reduced with doses >4 μg kg^?1 min^?1 in both groups (healthy: 24.0 ± 3.7 vs. 28.2 ± 4.9 ms; RVAP: 32.6 ± 8.5 vs. 37.5 ± 11.4 ms, p < 0.05) comparing with baseline. Indices of relaxation (?dP/dt_min and tau) suggested preserved lusitropic response in contrast with markedly reduced indices of contractility in the RVAP group compared with healthy group at same infusion rates. Doppler echocardiography showed significant reduction of elastic recoil in failing hearts. The results of this study demonstrated maximal positive lusitropic effects of dobutamine at a dose of 8 μg kg^?1 min^?1 in ventricular pacing‐induced cardiac dysfunction without further impairment of ventricular filling.     

Concentrations of platelet α2-adrenoceptors,lymphocyte muscarinic receptors,and blood monoamines in dogs (Canis familiaris) affected by canine cognitive dysfunction syndrome

Canine cognitive dysfunction syndrome (CDS) is a neurodegenerative disorder of aged dogs characterized by a progressive decline in cognitive function. In humans and laboratory animals, a variety of neurotransmitter abnormalities have been described in patients affected by age-related dementia. Specifically, the regulatory role of the catecholaminergic, serotonergic, and cholinergic systems has been outlined. The aim of the present study was to measure blood monoamine levels, platelet α₂-adrenergic receptors, and lymphocyte muscarinic receptors in healthy adult and aged dogs and in dogs affected by canine cognitive dysfunction. Based on clinical and behavioral examination, 40 dogs were divided into 3 groups: healthy adults (n = 14), aged dogs (n = 17), and aged dogs affected by canine cognitive dysfunction (n = 9). A significant reduction in plasma levels of norepinephrine and dopamine was observed both in aged dogs (0.16 ± 0.02 ng/mL, P < 0.01; 0.11 ± 02 ng/mL, P < 0.01, respectively) and in CDS dogs (0.14 ± 0.03 ng/mL, P < 0.05; 0.10 ± 00.005 ng/mL, P < 0.01, respectively) compared with adults (0.29 ± 0.04 ng/mL and 0.15 ± 0.02 ng/mL, respectively). No significant differences were observed among groups for α₂-adrenergic receptor concentrations. Canine lymphocytes express 2 distinct classes of muscarinic receptors, characterized by high (HA) and low affinity (LA) for [³H]-N-methyl-scopolamine. A significant age-dependent decrease in HA muscarinic receptors was observed. However, no differences were found between aged dogs (87.65 ± 11.08 sites/cell × 10²) and in CDS dogs (90.17 ± 6.75 sites/cell × 10² ) for HA muscarinic receptor concentrations. As far as LA muscarinic receptors are concerned, CDS dogs showed a significant increase (393.48 ± 63 sites/cell × 10²; P < 0.05) with respect to healthy adult dogs (188.84 ± 16.50 sites/cell × 10²). Our results suggest that the reduction in HA muscarinic receptor-binding sites could be representative of the physiological aging process, whereas the increase in lymphocyte LA muscarinic receptor levels could be related to the cognitive decline.     

Investigation of pharmacokinetic interaction between ivermectin and praziquantel after oral administration in healthy dogs

The purpose of this study was to determine the pharmacokinetic interaction between ivermectin (0.4 mg/kg) and praziquantel (10 mg/kg) administered either alone or co‐administered to dogs after oral treatment. Twelve healthy cross‐bred dogs (weighing 18–21 kg, aged 1–3 years) were allocated randomly into two groups of six dogs (four females, two males) each. In first group, the tablet forms of praziquantel and ivermectin were administered using a crossover design with a 15‐day washout period, respectively. Second group received tablet form of ivermectin plus praziquantel. The plasma concentrations of ivermectin and praziquantel were determined by high‐performance liquid chromatography using a fluorescence and ultraviolet detector, respectively. The pharmacokinetic parameters of ivermectin following oral alone‐administration were as follows: elimination half‐life (t_1/2λz) 110 ± 11.06 hr, area under the plasma concentration–time curve (AUC_0–∞) 7,805 ± 1,768 hr^.ng/ml, maximum concentration (C_max) 137 ± 48.09 ng/ml, and time to reach C_max (T_max) 14.0 ± 4.90 hr. The pharmacokinetic parameters of praziquantel following oral alone‐administration were as follows: t_1/2λz 7.39 ± 3.86 hr, AUC_0–∞ 4,301 ± 1,253 hr^.ng/ml, C_max 897 ± 245 ng/ml, and T_max 5.33 ± 0.82 hr. The pharmacokinetics of ivermectin and praziquantel were not changed, except T_max of praziquantel in the combined group. In conclusion, the combined formulation of ivermectin and praziquantel can be preferred in the treatment and prevention of diseases caused by susceptible parasites in dogs because no pharmacokinetic interaction was determined between them.     

Comparison of Nutrient Digestibility Between Adult and Aged Horses

There is little published work comparing digestibility in healthy adult versus healthy aged horses. Researchers hypothesized that there would be no differences in macronutrient digestibility between eight adult (5–12 years) and nine aged (19–28 years) horses fed three diets in a Latin square design. Seventeen stock-type mares were randomly assigned for a 5-week period to one of three diets: hay only (HAY), hay plus a starch- and sugar-rich concentrate (CHO), or hay plus a fat- (oil) and fiber-rich concentrate (FF). Each diet period comprised 3 weeks of outdoor group drylot feeding, 2 weeks of indoor stalled individual feeding, followed by a 72-hour digestibility trial including total urine and fecal collection. Feed, fecal, and/or urine samples were analyzed to determine dry matter, crude protein, fat, energy, calcium, and phosphorus apparent retention as well as apparent digestibility. Neutral detergent fiber digestibility was also determined. Mean body weight was lower in aged than in adult horses (455 ± 12 kg vs. 500 ± 13 kg; P = .02), but body condition score (BCS) did not differ between groups (aged horses, 4.8 ± 0.2 BCS and adult horses, 5.1 ± 0.2 BCS; P = .20). No age differences in digestibility, apparent digestibility, or apparent retention were seen for any of the variables measured. Based on the results of this study, total tract macronutrient digestibility appears to be similar between healthy adult and aged horses.     

Total antioxidant capacity and protein peroxidation intensity in seminal plasma of infertile and fertile dogs

The aim of this study was to evaluate the total antioxidant capacity and protein peroxidation intensity in seminal plasma of infertile and fertile dogs. The study was conducted on 10 infertile and 10 fertile dogs of various breeds. Infertility was defined as conception failure at least three matings with different bitches. Semen was collected by manual manipulation. The sperm concentration and motility parameters were evaluated using CASA Hamilton Thorne, Vers. IVOS 12.3. The morphology of spermatozoa and the percentage of live and dead sperm cells were assessed microscopically, total antioxidant capacity and the content of SH‐groups in seminal plasma were determined spectrophotometrically, the contents of protein peroxidation markers in seminal plasma, bityrosine and formylokinurenine, were determined using spectrofluorimetric methods. Sperm concentration and total sperm count were significantly (p < 0.05) lower in infertile dogs than in fertile dogs (99.92 ± 3 0.05 × 10⁶/ml vs. 282.07 ± 48.27 × 10⁶/ml; 214.19 ± 114.74 × 10⁶ vs. 747.57 ± 210.94 × 10⁶, respectively). The percentage of spermatozoa with normal morphology and the most determined motility parameters differed significantly (p < 0.05) between both groups. The mean values of total antioxidant capacity in the seminal plasma were significantly (p < 0.05) lower (19.95 ± 20.94 vs. 25.66 ± 23.18 µmol/g protein), whereas the mean contents of bityrosine and formylokinurenine in seminal plasma were significantly (p < 0.05) higher in infertile dogs than in fertile dogs (3.71 ± 4.83 µg/mg protein vs. 1.55 ± 2.00 µg/mg protein and 0.37 ± 0.45 µg/mg protein vs. 0.14 ± 0.08 µg/mg protein, respectively). In conclusion, the obtained results suggest that the poor semen quality and infertility in dogs could be associated with lowered total antioxidant capacity and increased protein peroxidation in seminal plasma as a consequence of oxidative stress.     

Pharmacokinetics and dynamics of mycophenolate mofetil after single‐dose oral administration in juvenile dachshunds

Mycophenolate mofetil (MMF) is recommended as an alternative/complementary immunosuppressant. Pharmacokinetic and dynamic effects of MMF are unknown in young‐aged dogs. We investigated the pharmacokinetics and pharmacodynamics of single oral dose MMF metabolite, mycophenolic acid (MPA), in healthy juvenile dogs purpose‐bred for the tripeptidyl peptidase 1 gene (TPP1) mutation. The dogs were heterozygous for the mutation (nonaffected carriers). Six dogs received 13 mg/kg oral MMF and two placebo. Pharmacokinetic parameters derived from plasma MPA were evaluated. Whole‐blood mitogen‐stimulated T‐cell proliferation was determined using a flow cytometric assay. Plasma MPA C_max (mean ± SD, 9.33 ± 7.04 μg/ml) occurred at <1 hr. The AUC_0–∞ (mean ± SD, 12.84±6.62 hr*μg/ml), MRT_inf (mean ± SD, 11.09 ± 9.63 min), T1/2 (harmonic mean ± PseudoSD 5.50 ± 3.80 min), and k/d (mean ± SD, 0.002 ± 0.001 1/min). Significant differences could not be detected between % inhibition of proliferating CD5+ T lymphocytes at any time point (p = .380). No relationship was observed between MPA concentration and % inhibition of proliferating CD5+ T lymphocytes (R = .148, p = .324). Pharmacodynamics do not support the use of MMF in juvenile dogs at the administered dose based on existing therapeutic targets.     

Assessment of cardiac output measurement in dogs by transpulmonary pulse contour analysis

Objective – To determine if metatarsal artery pressure (COmet) is comparable to femoral artery pressure (COfem) as the input for transpulmonary pulse contour analysis (PiCCO) in anesthetized dogs, using the lithium dilution method (LiDCO) as a standard for cardiac output (CO) measurement. Design – Prospective randomized study. Setting – University research laboratory. Animals – Ten healthy purpose‐bred mixed breed dogs were anesthetized and instrumented to measure direct blood pressure, heart rate, arterial blood gases, and CO. Interventions – The CO was measured using LiDCO and PiCCO techniques. Animals had their right femoral and left distal metatarsal artery catheterized for proximal (COfem) and distal (COmet) PiCCO analysis, respectively. Measurements were obtained from each animal during low, normal, and high CO states by changing amount of inhalant anesthetics and heart rate. Measurements were converted to CO indexed to body weigh (CI_BW=CO/kg) for statistical analysis. Agreement was determined using Bland and Altman analysis and concordance correlation coefficients. Measurements and Main Results – Thirty paired measurements were taken. The LiDCO CI_BW (± SD) was 68.7 ± 30.3, 176.0 ± 53.0, and 211.1 ± 76.5 mL/kg/min during low, normal, and high CO states, respectively. There was a significant effect of CI_BW state on bias and relative bias with COmet (P<0.001 and P=0.003, respectively). Bias of the COmet method (± SD) was ?116.6 (70.5), 20.1(76.4), and 91.3 (92.0) mL/kg/min at low, normal, and high CI_BW, respectively. Bias of the COfem (± SD) was ?20.3 (19.0), 8.6 (70.9), and ?2.9 (83.0) mL/kg/min at low, normal, and high CI_BW, respectively. The mean relative bias for COfem was ?6.7 ± 44% (limits of agreements: ?81.2 to 67.9%). Conclusion – Compared with lithium dilution, the pulse contour analysis provides a good estimation of CO, but requires femoral artery catheterization in anesthetized dogs.     

Establishing an essential amino acid profile for maintenance in poultry using deletion method

This study aimed to estimate the essential amino acid profile and the ideal ratio for the maintenance of poultry by deletion method. A nitrogen balance (NB) trial was conducted using 198 adult roosters, housed individually in metabolic cages. The treatments were 33 purified diets being 11 diets with an amino acid mixture providing high protein intake of 500 mg N/BW_kg^0.75 per day, 11 diets providing medium protein intake of 250 mg N/BW_kg^0.75 per day (in each diet, one amino acid tested was diluted 50%) and 11 diets providing low protein intake of 125 mg N/BW_kg^0.75 per day (made by omitting the amino acid tested). Each treatment had six replicates. After 48 h of fasting receiving water plus sucrose, the roosters were fed 40 g of the diets by tube once a day for 3 days. The excreta were collected within 72 h after the first feeding. The diets and excreta were analysed for nitrogen content. For each amino acid studied, a linear regression was fitted by NB and amino acid intake (AAI). The maintenance requirements were estimated as the AAI to maintain the NB equal to zero. The daily amino acid requirements for maintenance were estimated to be Lys 11, Met 29, Thr 23, Trp 5, Arg 50, Val 29, His 6, Gly 54, Phe 49, Leu 78 and Ile 21 mg/BW_kg^0.75 per day. Therefore, the amino acid ratio for maintenance was concluded to be Lys 100, Met 276, Thr 220, Trp 48, Arg 467, Val 275, His 60, Gly 511, Phe 467, Leu 735 and Ile 198% independent of the scale. The essential amino acid profile and the ideal ratio for the maintenance of poultry estimated in this study contributed to improve the factorial model for estimating essential amino acid requirements for poultry.