BackgroundHoof lesions are very common among sows and have been associated with lameness, early removal and compromised welfare and productivity. Although housing conditions and management can have an external effect on hoof health status, the role of trace mineral intake is vital in developing hoof structure and integrity. Therefore, the objective of this study was to investigate the effect of a diet supplemented with organic complexes of trace minerals (Zn, Cu, Mn), partly substituting their inorganic form, on hoof lesions of sows in three Greek swine herds.ResultsA total of 518 sows were initially examined for hoof lesions and their respective severity was scored. For each hoof, the length of toes and dew claws were evaluated and five anatomical hoof sites, the heel, the sole, the white line, the wall and the coronary band, were examined for lesions. Subsequently, the same sows were re-scored after one or two gestations on diets supplemented with organic trace minerals, partly substituting their inorganic salt form (organic form of Zn 45 ppm, Cu 14 ppm and Mn 25 ppm of the total 125 ppm of Zn, 15 ppm of Cu and 40 ppm of Mn, respectively). The odds of the higher versus the lower lesion scores were significantly lower after than before the inclusion of the organic minerals in sows’ diet, for each of the considered foot sites with the exception of the coronary band, with a distinct effect according to foot location. Specifically, on rear feet the improvement of hoof lesions was either smaller (for heel, sole and wall) than on front feet or not significant (for white line, toe and dew claw length). Additionally, for each foot site and herd examined, after the inclusion of the organic minerals, there were more sows with either the same or lower lesion score, with the exception of the toe and the dew claw length in one of the herds.ConclusionsWithin the specific conditions in the three studied herds, our findings highlight the role of chelated trace minerals in sows’ hoof health, suggesting an applicable and rewarding intervention to prevent hoof lesions.

ABSTRACT:Claw lesions, which are nowadays very common in sows, are associated with a high risk of early culling and compromised welfare. In this study, we investigated the associations between the severity of claw lesions and three of the most important reproductive indicators, the number of live-born and weaned piglets and the wean-to-first service interval in three Greek farrow-to-finish herds. All studied sows were individually housed during their previous gestations. Sows were examined for lesions, which were scored on a severity scale, on several anatomical sites of the claws, before farrowing. Data on the examined reproductive indicators were retrieved from productivity databases of the herds. Because scoring of lesions on several claw sites resulted in many correlated variables for each sow examined, we employed factor analysis to create a smaller set of uncorrelated variables (factors) which contained all the information in the original variables and produced the corresponding factor scores. The number of live-born and weaned piglets was associated with the produced factor scores in two multivariable linear regression models, whereas the possible associations between the wean-to-first service interval and the factor scores was modelled with the use of zero-inflated negative binomial regression. The number of live-born piglets was negatively associated with factor scores representing lesions on heel (P ≤ 0.001) and sole of front feet (P = 0.019). The number of weaned piglets was also negatively associated with factor scores representing lesions on heel (P = 0.003) of any foot, on sole of front feet (P = 0.001) and on white line, sole and wall of rear feet (P = 0.008), while the wean-to-first service interval was associated with factor scores representing lesions on heel of any foot (P = 0.02), on sole of front feet (P = 0.02) and of dew claw length of front feet (P = 0.009). Our results indicate that combinations of lesions on the dorsal and ventral part of the claws, negatively affected the reproduction parameters considered, emphasising the importance of general improvement of feet health.

BackgroundHoof lesions in sows have been associated with lameness and poor hoof horn quality. The mechanical strength and quality of hoof horn is determined by the density and diameter of horn tubules, which were recently associated with the severity of lesions on the hoof wall of sows. Histologic changes that have previously been described in cases of bovine laminitis, have also been observed in the dermis and epidermis of the sows’ claws. Trace elements, particularly zinc, copper and manganese, occupy important roles as enzyme catalysts in the process of keratin synthesis which determines the quality and the integrity of the hoof epidermis. Therefore, the objective of this study was to investigate the effect of diet supplementation with chelated zinc, copper and manganese, partially substituting their inorganic form, on sow claw health and hoof horn quality assessed by macroscopic, histologic and morphometric examination.ResultsClinically, the total claw lesion score was significantly lower in claws of sows which received the “organic” diet compared to those of sows on the “inorganic” diet. Histologically, lamellar hyperplasia was the most frequently recorded change in the epidermis of the sows’ claws regardless of the diet’s mineral source. The claws of the sows which received the organic diet were more likely to have none or less histologic changes than at least one or more, respectively, compared to those of the sows on the “inorganic” diet. Morphometrically, the density and vertical and horizontal diameters of the horn tubules was significantly higher and smaller, respectively, in the hoof horn of sows which received the “organic” compared to those which received the “inorganic” source diet.ConclusionsPartial substitution of the inorganic zinc, copper and manganese in sows’ diet with their chelated complexes, provided a comparative advantage against a conventional, inorganic mineral source diet, at least under the conditions examined in the current study, in terms of macroscopic, histologic and morphometric criteria, characterizing the health and horn quality status of sows’ hooves.

Swine influenza A virus (swIAV), which plays a major role in the porcine respiratory disease complex (PRDC), is eliminated from the respiratory tract within 7–9 days after infection. Therefore, diagnosis is complicated in endemically infected swine herds presenting no obvious clinical signs. This study aimed to investigate the right time point for sampling to detect swIAV. A cross-sectional study was performed in 131 farms from 12 European countries. The sampling protocol included suckling piglets, weaners, and nursery pigs. In each age group, 10 nasal swabs were collected and further examined in pools of 5 for swIAV by Matrix rRT-PCR, followed by a multiplex RT-PCR to determine the influenza subtype. SwIAV was detected in 284 (37.9%) of the samples and on 103 (78.6%) farms. Despite the highest number of animals with clinical signs being found in the nursery, the weaners were significantly more often virus-positive compared to nursery pigs (p = 0.048). Overall, the swIAV detection rate did not significantly differ between diseased or non-diseased suckling and nursery piglets, respectively; however, diseased weaners had significantly more positive pools than the non-diseased animals. Interestingly, in 9 farms, different subtypes were detected in different age groups. Our findings indicate that to detect all circulating swIAV subtypes on a farm, different age groups should be sampled. Additionally, the sampling strategy should also aim to include non-diseased animals, especially in the suckling period.

ABSTRACT. Trace minerals are constituents of proteins and enzymes that are involved in a variety of metabolic processes, having functional implications in growth, development, reproduction and health. Chelated minerals, are minerals bound to organic ligands, usually amino acids, providing higher levels of bioavailability compared to conventional inorganic mineral sources. In the present study, we investigated the effect of partial substitution of inorganic mineral sources with chelated minerals in sows' diets, on three important reproductive parameters, the number of liveborn and weaned piglets and the wean-to-first service interval, in three Greek farrow-to-finish herds. Before initiation of the study the sows were on diets supplemented with 15 mg/kg feed Cu (from CuSO4), 125 mg/kg Zn (from ZnO) and 40 mg/kg Mn (from MnO). After exiting the farrowing facilities they were offered diets in which 93.3%, 36.0% and 62.5% of the supplemented Cu, Zn and Mn, respectively, originated from commercially available chelated minerals. For the last farrowing on inorganic minerals diet and the subsequent one or two (for 35.0% and 65.0% of the studied sows, respectively) on chelated minerals, each sow's reproductive data (total number of parities, number of liveborn and weaned piglets and wean-to-first service interval) were recorded. The reproductive parameters, before and after the supplementation with chelated minerals, were compared in two mixed-effect linear regression models, for the number of liveborn and weaned piglets, and in a zero inflated negative binomial model for the weaning-to-first service interval. There was an improvement of the mean number of liveborn piglets after partial substitution of inorganic source of minerals with chelated minerals by almost half a piglet (P=0.015), whereas there was no effect on the total number of weaned piglets (P=0.15) and the wean-to-first service interval (P=0.65). The increase in the number of liveborn piglets may be directly attributed to improved embryo survival due to increased bioavailability of the organic minerals or indirectly to the beneficial effect of chelated minerals on sows' hoof health, locomotor ability, feed intake and body condition.