Domenico Bergero

Studies of apparent digestibility in horses and the use of internal markers

Abstract The digestibility of horse feeds and rations can be determined by means of different techniques: calculations from the chemical composition of feeds, in vitro and in vivo methods. The aim of this research is to compare indigestible internal markers (acid-insoluble ash (AIA) and acid detergent lignin (ADL)) and total collection techniques for apparent digestibility estimation in horses. Analyses were carried out on two diets, different in concentrate quality, for dry matter, crude protein, crude fiber, ether extract, ash, fiber fractions NDF and ADF, AIA, nitrogen-free extract, organic matter and gross energy. Digestibility of all the parameters, excluding AIA and ash, were calculated on the basis of the total faeces collection and using alternatively AIA or ADL markers. Analysis of variance (ANOVA) was performed to study the different digestibility coefficients. The digestibility coefficients obtained using AIA are very close to those obtained with total collection. Both methods can then be used for digestibility trials in horses. The two diets involved different digestibility levels. Apparent digestibility cannot be estimated using ADL as an internal marker, because of the lack of recovery and consequent great underestimation of digestibility rates.

Temperature constraints on foraging behaviour of male Alpine ibex (Capra ibex) in summer

In arctic and alpine environments, warm summer temperatures may force a reduction in foraging time of large herbivores, whose tolerance for heat is lower than for species adapted to warmer weather. We constructed time budgets for marked ibex (Capra ibex) males over two summers to test whether warm temperatures constrained foraging behaviour and forced altitudinal migrations. As daily temperature and solar radiation increased, feeding activity was reduced at midday and evening, but increased in the early morning, probably to anticipate for an expected reduction in foraging later in the day. With increasing temperature and solar radiation, ibex moved to higher elevations where they spent very little time feeding. Changes in forage quality and availability could not explain altitudinal migration. Temperatures above 15–20°C apparently result in heat discomfort in male Alpine ibex. As temperature and solar radiation increased, older and larger ibex spent less time feeding during daylight and showed a steeper decrease in feeding time than younger and smaller ibex. Larger males may be more sensitive to temperature and solar radiation, or may have more flexibility in allocating time to different activities, given their lower relative energetic requirements.

Intake and apparent digestibility of perennial ryegrass haylages fed to ponies either at maintenance or at work

Different lots of perennial ryegrass haylages were controlled for dry matter, buffering capacity, pH, soluble and ammonia nitrogen, lactic and monocarboxylic acids, alcohols, crude protein, crude fiber, gross energy, and ash. Net energy (UFC), and organic matter, were calculated. These forages were then fed to seven ponies, weighing on average 330 kg, during two different digestibility trials at maintenance or submitted to different workloads. Voluntary intake was measured, and digestibility coefficients were calculated for dry matter, organic matter, gross energy, crude fiber, and crude protein, using acid-insoluble ash as internal marker. Differences were found for the chemical composition of the three studied haylages; these differences can be ascribed to the different vegetative stage of the perennial ryegrass at harvesting. The conservation quality of these haylages was good or very good. Intakes were similar to those observed with hays. The OM digestibility of the haylages have been found to be lower than those measured for silages, and similar to those measured for good hays in literature. Increasing workloads decreases the dry matter and organic matter digestibilities; the same trend was found for gross energy, and crude fiber.

Apparent digestibility of Mediterranean forages determined by total collection of faeces and acid-insoluble ash as internal marker

The characteristics of the Mediterranean forages used in Italy could determine some differences between their energy values and the data of other similar forages listed in the table values of INRA; an accurate determination of at least organic matter digestibility must be performed. For the determination of apparent digestibility coefficients, the total collection method, that is the reference method in the French system, could be replaced by the more easy internal markers method using acid insoluble ash (AIA). In this study we determined the apparent digestibility rates of some Mediterranean forages using both total collection of faeces and acid-insoluble ash (AIA) as internal marker. The digestibility coefficients, obtained by the AIA method and the total collection method are in the same range as those listed in the INRA tables: for the organic matter, the values obtained by the AIA method range from 42.4 to 62.2%, while those obtained by total collection range from 44.8 to 58.0%. The values obtained by the two methods are comparable, as shown also by regression equations, except for the coefficients obtained for crude protein, which are the most variable. For digestibility coefficients fast assessments, the AIA method can be considered suitable, but for the introduction of Mediterranean forages in the French nutritive value tables of feeds for horses the total collection method must be considered the correct choice.

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.

Effect of dietary polyunsaturated fatty acids and Vitamin E on serum oxidative status in horses performing very light exercise

Abstract In sporting horses the use of dietary polyunsaturated fatty acids (PUFAs) could enhance performance because these fatty acids are very important in membrane permeability, and in particular they seem to increase the possibility of long chain fatty acids entering mythochondria to be burnt. The composition of cellular membranes and lipoprotein fatty acids composition is strictly related to dietary fat quality; percentages of polyunsaturated fatty acids and amount of antioxidants also affect tissue susceptibility to lipid peroxidation. Six horses were used in a latin square design in which three homogeneous groups were subsequently assigned three different dietary treatments for one month each: Control group (C): basic diet; Oil group (O): Basic diet + 200g/day oil rich in PUFAs (Crossential GLA TG20, Croda ®); Vitamin E group (O+E): basic diet + 200 g/day oil rich in PUFAs (Crossential GLA TG20, Croda ®) + 5 g/day α-toco-pheryl-acetate (Egon-E, Acme ®). At the end of each experimental period blood samples were taken by jugular vein puncture. Serum oxidative status was evaluated by TBARs and d-ROMs assessment. Oxidative markers showed the highest mean values for the oil group, even if no statistically significant differences were found.

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.

Feather picking in pet parrots: sensitive species, risk factor and ethological evidence

Abstract The goals of this study were to estimate the prevalence of feather picking (FP) in Italian pet parrots and evaluate the risk factors and possible ethological correlation. A web survey was created and addressed to owners of all species of companion parrots, distributed through on line parrots association websites, social networks and by mail. The survey was available for compilation from June to October 2014. In 292 compiled surveys, 20 different parrots genera were indicated; Psittacus spp. (24.3%), Agapornis spp. (19.5%), Nymphicus hollandicus (18.0%) and Amazona spp. (9.0%) were the most represented species. Our study showed a FP prevalence of 17.5%, with the highest prevalence in Agapornis spp. (26.3%) and Psittacus spp. (22.5%). Living with other parrots was positively associated to FP (p < 0.05), such as being fed in neonatal age and weaned by the breeder and not by the final owner (p < 0.001). Moreover, 2.9% of non-FP parrots and 10.0% of FP parrots lived always caged (p = 0.06). A significant difference in the feather picking site was detected (p < 0.001). The most affected body region was the chest (58.8%), followed by the rump (41.2%) and under wing regions (25.4%). At the same time, we conducted another study to better understand some information from the hand-raised parrots through a comparison with the parent-raised parrots. We recorded 1488 parent-raised parrots, and only 1.3% were affected by feather loss. This finding confirm that FP is be considered a multi-factorial behavioral pathology in which factors of different origin may cause behavioral disorders associated to self-injuries.

Effects of abrupt housing changes on the welfare of Piedmontese cows

Abstract The Italian Piedmontese cattle breed is traditionally housed in tie-stalls and, to a lesser extent, in loose housing systems with free stalls. The present study has compared the same group of 15 cattle before and after stable renovation (tie-stall vs free-stall housing) funded by Regulation (EU) No. 1305/2013. All the animals remained healthy during the trial, no clinical signs were observed and no mastitis occurred. The tested parameters were: locomotion scoring system, salivary cortisol, blood parameters, serum acute phase protein (albumin, haptoglobin, serum amyloid A and lysozyme). Samples were collected 3 times: before the change (T1), 3 days later (T2), 40 days later (T3). The change in housing determined noteworthy variations in the stress parameters: albumin and total protein displayed the lowest value at T2, while lysozyme displayed the lowest value at T3. Among the App, SAA and Hp were not affected by the sampling time. Salivary cortisol displayed the highest value at T1. This study suggests that tie-stall housing can endanger the welfare of animals, and it is hoped that this farming system will be abandoned in the future.

Estimation of the workload in horses during an eventing competition

The aim of this study was to evaluate workload using suitable parameters related to the physical effort exerted by horses involved in eventing competitions in order to describe the workload intensity and energy demands placed upon such horses. Heart rate (HR), running speed (S), distance covered (Dist), performance duration (D) and blood lactate (Lact) concentrations were measured in horses competing at either the intermediate level (IL) or advanced level (AL) in order to identify workload differences between experience classes. Ten warmblood horses were monitored during an official two-day eventing competition; mean HR (HRmean, bpm), maximum HR (HRmax, bpm), mean S (Smean, m/min), max S (Smax, m/min), D (min) and Dist (m) were assessed during the warm-up and competition phases of each eventing test (dressage, show jumping, cross country). To calculate heart rate recovery (HRR), HR data were collected within the first 3 minutes following the completion of each of the 3 competition phases. Energy expenditu...