Clinical nutrition counselling service in the veterinary hospital: retrospective analysis of equine patients and nutritional considerations.

Nutrition plays a very important role in the healthy and in the ill horse. Although research in this field clearly shows that incorrect nutritional practices may lead to severe pathologies, inappropriate feeding plans often continue to be used. A clinical nutrition counselling (CNC) service could thus be of great use to both horse owners and veterinarians. The aim of this study was to provide information on equine patients referred to the CNC service of the University of Turin and to provide standard dietary protocols as used in our Veterinary Teaching Hospital for the most common nutrition-related pathologies. The data were obtained by retrospective analysis of the nutritional records of referred equine patients. The data collected included information about anamnesis, nutritional assessment, current diet, referring person and follow-up of each patient. Sixty-one horses were included in the study. The majority were adult males. The most common breeds were the Italian Saddle Horse and the Friesian Horse. Old horses (>19 years) had a statistically lower BCS than brood mares or other adult horses (p < 0.01). The most common nutritional pathologies were chronic weight loss (CWL), chronic diarrhoea (CD) and equine gastric ulcer syndrome. All horses received first-cut meadow hay; 85% also ate concentrates. Young horses (<2 years) received more hay as a percentage of body weight (BW) than old horses or adults. The hay percentage of BW per day given to animals with CWL was statistically higher than those with CD (p < 0.01). The concentrate percentage of BW given to old horses was statistically lower compared to that given to young horses (p < 0.05). The concentrate percentage of BW per day given to horses with colic was statistically higher than that given to horses with CD (p < 0.05). 28% of cases were referred by the owner and 72% by a veterinarian. Follow-up evaluation was deemed to be 'good' in 92% cases and 'poor' in 8%. In summary, the CNC service could provide an epidemiological observatory to study the prevalence of nutritional issues in the equine population.

Effects of competition on acute phase proteins and lymphocyte subpopulations - oxidative stress markers in eventing horses.

The aim of the study was to evaluate markers of the acute phase response (APR) in eventing horses by measuring acute phase proteins (APP) (haptoglobin, Hp, and serum amyloid A, SAA), lysozyme, protein adducts such as pentosidine-like adducts (PENT), malondialdehyde adducts (MDA), hydroxynonenal adducts (HNE) and total advanced glycation/glycoxidation end products (AGEs), complete blood count and lymphocyte subpopulations (CD4+, CD8+ and CD21+) both at rest and at the end of an eventing competition. Blood samples were collected from eight Warmblood horses (medium age 10 ± 3) during an official national 2-day event competition at rest (R) and 10 min after the arrival of the cross-country test on the second day. Exercise caused a significant increase in red blood cell number, haemoglobin, packed cell volume, neutrophils, white blood cell and lymphocyte number; however, these values remained within the normal range. The CD4+ and CD8+ cells significantly increased, whereas the CD21+ lymphocytes decreased; a significant increase in serum SAA, lysozyme and protein carbonyl derivates was also observed. Two-day event causes significant changes in APR markers such as lysozyme, protein carbonyl derivates (HNE, AGEs, PENT) and lymphocyte subpopulations. The data support the hypothesis that 2-day event may alter significantly APR markers. Limitations of the study were the relatively small sample size and sampling time conditioned by the official regulations of the event. Therefore, further studies are needed to investigate the time required for recovery to basal values in order to define the possible effects on the immune function of the athlete horse.

Apparent digestibility of broken rice in horses using in vivo and in vitro methods.

The aim of this study was to assess the apparent digestibility of broken rice using total collection of feces and the pepsin-cellulase in vitro technique to provide updated and more accurate digestion coefficients for this by-product when fed to horses. The in vivo digestibility trial was consecutively performed, using five adult geldings, weighing 555.6 kg on average. First, hay was given as the only feedstuff, while second, the experimental diet consisted of the same hay plus broken rice at a forage-to-concentrate ratio of 70/30 (on dry matter (DM) basis). Feces were collected over 6 days preceded by a 14-day adaptation period. The digestibility trial was carried out to determine the digestion coefficients for DM, organic matter (OM), CP and gross energy in both diets, while apparent digestion coefficients for the same parameters were calculated for broken rice alone, using the difference between the two sets of results. At the same time, an in vitro trial was carried out using pepsin-cellulase technique on the samples of hay and broken rice tested during the in vivo trial. As expected, supplementation with broken rice increased digestibility according to all the parameters used. The high OM digestion coefficients of broken rice were confirmed both by the calculated in vivo method and by the predicted results of pepsin-cellulase technique (92.6% and 87.1%, respectively), underlining the high digestibility of this by-product when fed to horses.

Association of the glycoxidative stress marker pentosidine with equine laminitis.

Ponies suffering from recurrent episodes of laminitis when grazed at pasture (pasture-associated laminitis) exhibit phenotypes similar to those associated with human metabolic syndrome. In humans, evidence suggests that the obesity-related morbidities associated with metabolic syndrome, including diabetes and cardiovascular disease, are caused by an increase in the production of advanced glycoxidation end-products (AGEs). These end-products have been recognised as putative pro-inflammatory mediators and are considered a 'risk factor' for human health. However, the evaluation of AGEs in laminitic ponies has not been explored. The aim of this study was to compare plasma concentrations of the AGE pentosidine (PENT) in ponies presenting with clinical features of equine metabolic syndrome (EMS) with a history of recent laminitis and/or showing signs of laminitis at the time of sampling (LP) with those with no prior history of clinical laminitis (NL). Age, body condition score (BCS) and bodyweight were recorded and blood samples collected for the measurement of plasma concentrations of PENT, glucose, insulin, triglycerides (TG), non-esterified fatty acids (NEFA) and cortisol. Insulin sensitivity was assessed by the reciprocal of the square root of insulin (RISQI) and the insulin:glucose ratio. Plasma PENT concentrations were twofold higher (P<0.005) in LP than in NL ponies. Significant (P<0.05) correlations were also evident between PENT and insulin, RISQI, TG and age. These preliminary findings are consistent with the hypothesis that glycoxidation in laminitis is associated with EMS.

Apparent digestibility of wheat bran and extruded flax in horses determined from the total collection of feces and acid-insoluble ash as an internal marker.

Several studies have reported data on comparisons between two methods: the total collection of feces and the internal markers method. The aim of this study was to assess the apparent digestibility of two concentrates and to compare the apparent digestion coefficients using the total collection of feces and acid-insoluble ash (AIA) as the internal marker method. In 2009, six adult geldings aged between 3 and 11 years, with an average weight per trial of 543, 540 and 542 kg, respectively, were used to determine the apparent digestibility by means of three in vivo digestibility trials on hay, hay plus wheat bran (60 : 40) and hay plus extruded flax (80 : 20). Feces were collected over a 6-day period with a previous 14-day adaptation period. The three digestibility trials were carried out to determine the digestion coefficients of the three diets and, indirectly, of the two concentrates. The digestion coefficients of the diets were determined for the dry matter, organic matter, crude protein and gross energy, whereas the apparent digestion coefficients of the same parameters were calculated for wheat bran and extruded flax, by calculating the difference from the previous results. The data were analyzed using the Student t-test for paired samples. The digestion coefficients obtained were similar when the total collection of feces and the AIA method were used. Higher data variability, confirmed by a greater standard deviation, was observed using the AIA method to estimate the apparent digestion coefficients. It can be concluded that the use of AIA as an internal marker in digestibility trials on average leads to values similar to those obtained with the total collection of feces and can therefore be considered a less-expensive method to determine apparent digestion coefficients. Nevertheless, the total collection of feces should still be considered the best choice to determine the digestibility of some specific feedstuffs.

A comparison between the 2N and 4N HCl acid-insoluble ash methods for digestibility trials in horses.

The digestibility of horse feeds and rations can be determined using different techniques such as calculations based on the chemical composition, in vivo or in vitro methods. The marker methods overcome difficulties like discomfort for the animals and longer experimental times encountered using the ingesta/egesta method. In field conditions, a natural indigestible marker like acid-insoluble ash (AIA), with no changes in the normal ration, could be a very useful tool for digestibility trials. A group of six standardbred horses was used in a set of seven apparent digestibility trials. The diets were based on a first-cut meadow hay added to three different cereals (barley for trials 1 and 2; oats for trials 3 and 5 and corn for trials 6 and 7), the hay : concentrate ratio being 60 : 40 or 70 : 30 on a dry matter basis. Feedstuffs and faeces were analysed to determine the AIA content, using 2N HCl or 4N HCl technique. No differences about AIA concentration were found between the two methods for means and accuracy in each diet. Digestion coefficients for each diet did not differ with AIA method, even if in some trials interfering factors consistently lowered the overall values. Consequently, the AIA 2N HCl can be considered the easier and cheaper method to state apparent digestibility in field conditions, and a good tool for digestibility trials in horses fed hay-based diets.

Hepatic diseases in horses.

The concept 'liver disease' includes several pathological conditions affecting liver's functions. It can either consist of a temporary impaired functioning of the liver and/or it can progress to its failure. The purpose of this review is to update the knowledge on hepatobiliary diseases and in particular on equine hyperlipaemia. Hepatobiliary disease's aetiology, clinical signs, diagnosis and nutritional management are thus described in the first part of the review the second part being devoted to hyperlypaemia's lipid metabolism, epidemiology, clinical signs, post-mortem observations and nutritional management. Diagnosis of hepatic disease is usually based on the assessment of the serum activities while hepatic biopsy is considered as the golden standard of diagnosis of hepatic function. Nutritional management is often very useful in management of hepatic diseases: diet should be low in protein (of good biological value) and high in non-structural carbohydrates except for chronic hepatic disease (slightly high protein). Equine hyperlipaemia's mortality is around 70%. It consists of a disorder of lipid metabolism, characterized by increase in plasma triglycerides and deposition of fat on organs. From a nutritional point of view, hyperlipaemia in horses can be approached by maintaining positive energy balance, fighting dehydration and metabolic acidosis, and by the use of lipotropic factors.

Early changes in biomarkers of skeletal metabolism and their association to the occurrence of osteochondrosis (OC) in the horse.

REASON FOR PERFORMING STUDY: Diagnosis of osteochondrosis (OC) is based on clinical signs and radiography, but alternative methods for detection at an early stage would be useful. OBJECTIVES: To determine in the juvenile horse the relationship between serum concentrations of a number of biomarkers that reflect changes in cartilage and bone turnover and age, feeding level, growth, and the occurrence of OC. METHODS: Foals were assigned to a high (n = 20) or moderate (n = 19) feeding level group from birth to age 1 year. Bodyweight, withers height and cannon width were measured. Osteoarticular status was assessed radiographically at 5.5 and 11 months in all foals, and by necropsy at 12 months for 8 foals/group. Serum biomarkers of bone (osteocalcin, CTX-1) and cartilage (CPII, C2C) metabolism were assayed at 8 time points between ages 2 and 52 weeks. Ratios between biomarkers of tissue formation and degradation were calculated at each time point. RESULTS: Consistent age-related patterns in biomarker serum concentrates were found, indicating a markedly higher metabolism before age 20 weeks but concentrations were not affected by feeding level. Bodyweight was correlated negatively to C2C and CTX-1, and withers height was positively correlated to osteocalcin and the osteocalcin/CTX-1 and CPII/ C2C ratios. Osteocalcin concentration at 2 weeks and CPII/ C2C ratio at 20 weeks had strong positive correlations to OC, as diagnosed radiographically at 5.5 months. Osteocalcin had a strong correlation with radiographically detected OC at 11 months but at that time there was no significant relationship between CPII/C2C ratio and OC. CONCLUSIONS: Occurrence of OC lesions is significantly associated with anabolic changes in bone metabolism during the first weeks post partum, given the strong relation with osteocalcin. POTENTIAL RELEVANCE: Measuring osteocalcin concentrations during the first few weeks post partum may have potential value for the prediction of risk for OC development.

Comparison of the blood plasma catecholamines level in thoroughbred and Arabian horses during the same-intensity exercise.

The aim of this study was to compare changes in epinephrine (E), norepinephrine (NE) and dopamine (DA) levels in blood plasma of two racehorses breeds: Arabian and Thoroughbred during moderate intensity exercise performed in the same conditions. The increase in plasma E level just after exercise was higher in Thoroughbreds than in Arabians. During the whole test, the Arabians showed the higher levels of NE and DA as compared to those found in Thoroughbreds.

Comparison of plasma biochemical parameters in Thoroughbred and Purebred Arabian horses during the same-intensity exercise.

The objective of the present study was to compare changes of blood parameters induced by the same work and performed in the same conditions in two racehorse breeds, Thoroughbred and Purebred Arabian. The effect of moderate-intensity exercise was studied in 20 stallions--ten Thoroughbreds, aged 2-3 years and the same number of Purebred Arabians, 3-4 years old. All the horses were administrated the same effort test consisting in 1200 m gallop at a speed typical of the daily training sessions. Three jugular venous blood samples were collected for each horse: at rest, just after the end of the gallop and after 30-minute rest. In the gathered blood, a hemoglobin (Hb) concentration was determined as well as plasma level of glucose (Glc), triacylglycerols (TG), glycerol, free fatty acids (FFA), total plasma proteins (TP) and the activity of creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST). In the Arabian horses, an increase in levels of TP, glycerol, FFA and CK activity measured just after exercise was higher than that in Thoroughbreds. Similarly, after a 30-minute rest, a post-exercise rise of TP, AST, glycerol and FFA proved to be higher in the Arabian horses compared to that in the Thoroughbreds. Only TG plasma concentration measured 30 minutes following the effort was significantly lower in the Arabian horses than in Thoroughbreds. It can be concluded that the Thoroughbred horses adapted better to the effort test applied in this study as compared to the Purebred Arabian horses. The parameters related to lipid metabolism proved to be the most sensitive indicators of breed differences in relation to moderate-intensity exercise.

Amino acid concentrations in blood serum of horses performing long lasting low-intensity exercise.

The aim of this work was to evaluate the changes in the concentrations, after two rides different for distance covered, of different amino acids in endurance horses. Blood samples have been collected from horses just before the start, at the top of a steep slope (819 m difference in height) and just at the end of a 32-km endurance ride. A second group, competing in a 72 km endurance ride, has also been sampled immediately before and after the race. In serum samples, the concentrations of alanine, arginine, asparagine, glycine, isoleucine, histidine, leucine, lysine, methionine, ornithine, phenylalanine, tryptophan, tyrosine and valine have been measured by high-performance liquid chromatography (HPLC). anova and t-test have been used to study the differences in the concentrations of the amino acids. The pre-ride concentrations of the free amino acids were different between the two races, except for methionine and leucine. Differences between start and end race have been found for both groups for all the considered parameters except asparagine, isoleucine, leucine and lysine for the 72 km ride. Increases have been recorded for the shorter and decreases for the longer ride in the blood serum concentrations. Significant increases have also been found between the starting sampling and the second, at the top of the slope, only for alanine, arginine, asparagines, phenylalanine and lysine. The ride length has a significant impact on blood serum amino acids mobilization and uptake; in the shorter race the increases stand only for mobilization, whereas in the longer the decrease can be considered the effect of the onset of the amino acids catabolism.

Blood serum branched chain amino acids and tryptophan modifications in horses competing in long-distance rides of different length.

During long-distance exercise, branched-chain amino acid (BCAA) catabolism could lead to an increase in the blood tryptophan/BCAA ratio and an early onset of 'central fatigue'. Based on these considerations, we studied the modifications of blood serum BCAA and tryptophan (Try) levels in 30 endurance horses competing in rides varying in distance from 20 to 72 km. From all horses, blood samples were drawn just before and just after the end of the ride. Samples were analysed for their leucine (Leu), valine (Val), isoleucine (Iso) and Try levels. Data were processed by anova, using sampling moment and ride as factors, and by LSD post hoc test. Significant differences were recorded among the different distance rides for Leu, Val, Iso, Try, Try/BCAA ratio; the same trend was recorded between samples taken at the start and the end of the race for Val and Leu. The main effect observed was an increase of BCAA levels for all rides, except the 72-km ride; for Try, a significant increase was present in all races, except the 50-km ride. The Try/BCAA ratio decreased in 20- and 50-km races and increased in the others. These data confirm that long-distance exercise involves a mobilization of BCAA. The utilization of BCAA seems to be important in prolonged exercise: in the 72-km ride, we observed a decrease in BCAA blood serum levels, while a major role of Try was indicated by its increase, resulting in a rise of the Try/BCAA ratio.

Accuracy of body weight prediction in Alpine ibex (Capra ibex, L. 1758) using morphometry.

The relationship between weight and body measurements of 227 Alpine ibex Capra ibex (162 males and 65 females, age range: 2-16 years) were analysed by linear and multiple regression. The animals were live-captured across all seasons of the year, in the Western Italian Alps, 1986-1994. The relationship between weight and body measurements changed with sex and season. In male ibex, the best annual estimation of the body weight was obtained using as predictor variables the squared value of the chest girth and age. In females, the best predictive variables were age, total body length and withers height. Age was always selected as a predictor variable, when considered in the prediction models. The use of chest girth and the squared value of the chest girth as predictive variables in the regression equation, being the most highly correlated linear measurements with total weight, did not result in an accurate prediction of ibex body weight. The best prediction was obtained using age and different linear measurements in stepwise multiple regression, nevertheless the standard error of the estimate and the magnitude of the 95% prediction interval were great. The use of linear measurements cannot be considered accurate nor precise predictors of body weight in Alpine ibex.