Impact of nutrition on lameness and claw health in sows

Wheatgrass extract has chondroprotective and anti-inflammatory effects on porcine cartilage

Lameness is a commonly observed disorder in sows and negatively impacts both animal welfare and the profitability of the pig sector. The purpose of this study was to determine anti-inflammatory and/or chondroprotective effects of wheatgrass (WG) on porcine cartilage explants stimulated with lipopolysaccharide (LPS). Explants were aseptically prepared from the intercarpal joints of nine market-weight pigs and placed in culture at 37°C for a total of 120 hours. For the final 96 hours, explants were conditioned with an aqueous extract of WG (0, 5 or 15 μg/mL), and for the final 48 hours explants were stimulated with LPS (0 or 10 µg/mL). Media was removed and replaced every 24 hours. Samples from the final 48 hours were analyzed for biomarkers of cartilage inflammation [prostaglandin E2 (PGE2) and nitric oxide (NO)] and cartilage structure [glycosaminoglycan (GAG)], and cartilage explants were stained for an estimate of cell viability. Stimulation of explants with LPS significantly increased media concentrations of PGE2, GAG and NO compared with that from unstimulated explants. LPS stimulation did not significantly affect cell viability. Conditioning of explants with WG (5 μg/mL) significantly reduced LPS-stimulated cartilage release of PGE2, NO, and GAG (5 and 15 μg/mL), without impairing chondrocyte viability. These data provide evidence for a non-cytotoxic chondroprotective and anti-inflammatory effect of WG extract in cartilage and suggest a role of WG in protection against cartilage breakdown, inflammation, and pain associated with osteoarthritis.

Dietary supplementation of 25-hydroxycholecalciferol as an alternative to cholecalciferol in swine diets: A review

25-hydroxycholecalciferol (25-OHD₃ ) formed via hepatic hydroxylation from vitamin D, cholecalciferol, represents the precursor of the biologically active vitamin D hormone, 1,25-dihydroxyvitamin D. Due to a higher absorption rate and the omission of one hydroxylation, dietary supplementation of 25-OHD₃ instead of vitamin D₃ is considered to be more efficient as plasma concentrations of 25-OHD₃ are increased more pronounced. The present review summarises studies investigating potential beneficial effects on mineral homeostasis, bone metabolism, health status and performance in sows, piglets and fattening pigs. Results are inconsistent. While most studies could not demonstrate any or only a slight impact of partial or total replacement of vitamin D₃ by 25-OHD₃ , some experiments indicated that 25-OHD₃ might alter physiological processes when animals are challenged, for example, by a restricted mineral supply.

The Influence of Nesfatin-1 on Bone Metabolism Markers Concentration, Densitometric, Tomographic and Mechanical Parameters of Skeletal System of Rats in the Conditions of Established Osteopenia

Simple Summary

Nesfatin-1 is an adipokine with little known effect on the skeletal system. In this study, we examined the effect of 8-wk administration of nesfatin-1 on densitometric, tomographic, and mechanical parameters of bones, as well as the concentration of bone metabolism markers in rats with experimentally induced established osteopenia.

Abstract

Our study aimed to evaluate the impact of nesfatin-1 administration on bone metabolism and properties in established osteopenia in ovariectomized female rats. In total, 21 female Wistar rats were assigned to two groups: sham-operated (SHAM, n = 7) and ovariectomized (OVA, n = 14). After 12 weeks of osteopenia induction in the OVA females, the animals were given i.p. physiological saline (OVA, n = 7) or 2 µg/kg body weight of nesfatin-1(NES, n = 7) for the next 8 weeks. The SHAM animals received physiological saline at the same time. Final body weight, total bone mineral density and content of the skeleton were estimated. Then, isolated femora and tibias were subjected to densitometric, tomographic, and mechanical tests. Bone metabolism markers, i.e., osteocalcin, bone specific alkaline phosphatase (bALP), and crosslinked N-terminal telopeptide of type I collagen (NTx) were determined in serum using an ELISA kit. Ovariectomy led to negative changes in bone metabolism associated with increased resorption, thus diminishing the densitometric, tomographic, and mechanical parameters. In turn, the administration of nesfatin-1 led to an increase in the value of the majority of the tested parameters of bones. The lowest bALP concentration and the highest NTx concentration were found in the OVA females. The bALP concentration was significantly higher after nesfatin-1 administration in comparison to the OVA rats. In conclusion, the results indicate that nesfatin-1 treatment limits bone loss, preserves bone architecture, and increases bone strength in condition of established osteopenia.

Dynamic Changes of Metabolite Profiles in Maternal Biofluids During Gestation Period in Huanjiang Mini-Pigs

The biochemical parameters related to nitrogenous metabolism in maternal biofluids may be linked and even reflect the fetal metabolism and growth. The present study have measured the concentrations of various parameters related to amino acid (AA) and lipid metabolism, as well as different metabolites including the free AAs in maternal plasma and amniotic and allantoic fluid corresponding to fetuses with different body weight (BW) during different gestation periods, in order to identify the possible relationships between biochemical parameters and fetal growth. A total of 24 primiparous Huanjiang mini-pigs were fed with a standard diet. Data showed that, from day 45 to day 110 of gestation, the maternal plasma levels of alanine aminotransferase (ALT), albumin (ALB), Ile, Orn, Car, α-ABA, and β-AiBA increased (P < 0.05); while the levels of ammonia (AMM), choline esterase (CHE), high density lipoprotein-cholesterol (HDL-C), Leu, Glu, Cys, Asp, and Hypro decreased (P < 0.05). From day 45 to 110 of gestation, the amniotic fluid levels of aspartate transaminase (AST), CHE, total protein (TP), and urea nitrogen (UN) increased (P < 0.05), as well as the level of CHE and TP and concentration of Pro in allantoic fluid; while the amniotic fluid concentrations of Arg, Glu, Orn, Pro, and Tau decreased (P < 0.05), as well as allantoic fluid concentrations of Arg and Glu. At day 45 of gestation, the amniotic fluid concentrations of Arg, Orn, and Tau corresponding to the highest BW (HBW) fetuses were higher (P < 0.05), whereas the allantoic fluid concentrations of His and Pro were lower (P < 0.05) when compared with the lowest BW (LBW) fetuses. At day 110 of gestation, the amniotic fluid concentration of Tau corresponding to the HBW fetuses was higher (P < 0.05) than the LBW fetuses. These findings show that the sows display increased protein utilization and decreased lipid metabolism and deposition from day 75 to 110 of gestation. In addition, our data are indicative of a likely stronger ability of HBW fetuses to metabolize protein; and finally of a possible key role of Arg, Gln, Glu, Pro, Tau, and His for the fetal growth and development.

Claw Characteristics of Culled Sows from Three Farrow-to-Finish Greek Farms. Part 1: Claw Length Measurements, Lesion Scores and Their Association

The aim of the study was to investigate variations in lengths and lesions in claws of culled sows and to evaluate their association. All four feet of 185 sows from three Greek farrow-to-finish farms (Farm A: 57 sows; Farm B: 64 sows; Farm C: 64 sows) were examined for lesions and their lengths were measured. All claw lengths were lower in sows of farm C compared to those from sows of B and A. Claw lengths in sows of farm B were lower compared to those from A for all lateral toes of front feet and for all medial and four out of three lateral toes of rear feet. Sum of length measurements of the main toes of the front feet (SLF) associated with lesions on sole, white line and heel of front feet, while sum of length measurements of the main toes of the rear feet (SLR) associated with all lesions of the rear feet. The lengths of the main toes were correlated with the length of dew claws on front and rear feet. Overall, sows’ claw lesion severity and claw lengths may differ between farms and frequency of lesions is higher in longer claws.

Evaluation of serum parameters to predict the dietary intake of calcium and available phosphorus in growing pigs

Adequate provision of calcium (Ca) and phosphorus (P) is essential for bone formation and high growth performance in pigs. Nevertheless, reliable serum biomarkers for pig's Ca and P intake are still missing. Here, we used phytase supplementation to alter the dietary available P (aP) level in order to investigate the effect of differences in dietary aP levels on serum parameters related to the Ca and P homeostasis in pigs. Moreover, we assessed whether serum parameters can be used to predict the Ca, total P (tP), and aP intake in barrows and gilts throughout the fattening period. In total, 216 pigs (115 gilts and 101 barrows) were randomly allotted to one of the two diets in three replicate batches, each lasting 56 d (n = 108/diet). Pigs had free access to the diets without (Con) or with phytase (Phy; 650 phytase units/kg) via a transponder-based feeding system. Blood samples were collected on days 2, 23, and 52, and serum parameters were correlated with the daily Ca, tP, and aP intake. The intake of tP, aP, and Ca was overall 14.2%, 13.8%, and 14.2% higher in barrows compared with gilts, respectively (P < 0.001). Concurrently, phytase decreased the intake of tP and Ca by 8.4% and 6.7%, respectively, whereas it raised the intake of aP by 16.3% compared with the Con diet (P < 0.001). Serum levels of fibroblast growth factor 23, alkaline phosphatase (ALP), vitamin D (VitD), and osteocalcin (OCN) decreased with age (P < 0.05). The higher aP intake of pigs fed the Phy diet increased serum P on days 2 and 23 but decreased it on day 52 compared with the Con diet (P = 0.004). Pigs fed the Phy diet had higher serum ALP compared with pigs fed the Con diet on days 23 and 52 (P < 0.05). Correlation analysis between serum parameters and Ca, tP, and aP intake showed age- and sex-related associations. With 12 wk of age, serum P in both sexes, serum VitD in barrows, and serum OCN and ALP in gilts correlated with aP intake (|r| > 0.38), whereas serum OCN correlated with Ca in both sexes' intake (r > 0.50). At 20 wk, serum Ca and ALP in gilts correlated with aP intake, whereas serum P, Ca, and VitD correlated with Ca intake in both sexes (|r| > 0.39). In conclusion, the present results showed that the daily Ca and aP intake could be most reliably estimated from serum parameters for an approximate age of 12 and 20 wk. Serum P and the Ca:P ratio at 12 wk of age and serum VitD at 20 wk of age may be used to predict pig's daily aP intake in both sexes.

Concentração de minerais no tecido queratinizado podal de equinos jovens da raça Crioula em diferentes fases de crescimento

RESUMO O presente estudo avaliou o perfil mineral de Cálcio (Ca), Cobre (Cu) e Zinco (Zn) no estojo córneo pré e pós-desmame e sua associação com pigmentação, gênero e idade de potros da raça Crioula criados em pastagens nativas no Rio Grande do Sul. Foram coletadas amostras do casco de potros da raça Crioula 41 dias pré e 28 dias pós-desmame. Os teores de Ca, Cu e Zn variaram no casco fetal (571,0±39,4; 14,5±7,6 e 130,0±30,5mg/kg, respectivamente; P<0,05) e no definitivo (653,0±169,2; 33,8±11,5 e 69,3±36,8mg/kg, respectivamente; P<0,05), no pré (620,0±184; 17,2±21,2 e 103,0±75,5mg/kg, respectivamente; P<0,05) e no pós-desmame (517,5±181; 0 e 79,0±41,7mg/kg, respectivamente; P<0,05). Houve associação positiva (P<0,05) com a faixa etária no pré-desmame para Ca (r=0,5) e Cu (r=0,57), e negativa para Zn (r=-0,69; P<0,05). No pós-desmame, houve associação positiva (P<0,05) para Ca (r=0,36) e Zn (r=0,64) e negativa para Cu (r=-0,39; P<0,05). Tanto a pigmentação quanto o gênero não afetaram o perfil mineral. Conclui-se que há diferenças nas concentrações de Ca, Cu e Zn na epiderme do casco de potros da raça Crioula no pré e pós-desmame, independentemente da pigmentação e do gênero, onde as concentrações de Ca e Cu aumentam com a idade, enquanto as de Zn diminuem.

Dietary fatty acid content and thickness of plantar pads in gilts

The objective of this study was to test a diet enriched in the most abundant components of foot fat pads (oleic and palmitic acid) to increase its thickness in gilts. We evaluated the effects of two oleic and palmitic acid dietary concentrations (control and test) and three treatment durations (35, 45, and 65 d) on 116 gilts (Landrace × Large White), all 180-d-old and slaughtered at the end of the study. Both test and control diets contained 5.9% total fat. The control diet contained 0.9% oleic acid and 0.6% palmitic acid; the test diet contained 1.9% and 1.2%, respectively. Body weight (BW), backfat (BF), lateral, and medial plantar pad thickness from the left rear leg were measured. No significant differences were detected for BW or BF between the test and control groups. The lateral pad was always thicker than the medial one (P < 0.001). No significant difference for plantar pad thickness was detected for the 35 d treatment. For the other treatments, thickness increased with respect to the control group (P < 0.01); the percentage of increase ranged from 20.8% (lateral side, 45 d treatment) to 37.8% (lateral side, 65 d treatment). Its effects on foot health must still be demonstrated.

The effect of group composition and mineral supplementation during rearing on the behavior and welfare of replacement gilts

Sow longevity supported by good health and reproductive performance is necessary to optimize sow lifetime performance. In some countries, replacement gilts are reared with finisher pigs destined for slaughter, so they are exposed to sexual and aggressive behaviors performed by males. This is associated with stress and injury. Moreover, diets formulated for finishers are not designed to meet the needs of replacement gilts and may not supply the necessary minerals to promote limb health, optimal reproduction, and, thus, sow longevity. In this 2 × 2 factorial design experiment with 384 animals (32 pens [12 animals per pen]), we investigated the effect of female-only (FEM) or mixed-sex (MIX) rearing, with (SUPP) or without (CON) supplementary minerals (copper, zinc, and manganese) on locomotion, salivary cortisol levels, behavior, body lesions (BL), and hoof health of gilts. The experimental period began at transfer to the finisher stage (day 81.3 ± 0.5 of age; day 0) until breeding age (day 196 ± 0.5 of age; day 115). Locomotion was scored (0-5) biweekly from day 0 until slaughter day 67 or breeding age day 115 for the remaining gilts. Saliva samples were taken monthly from four focal gilts per pen. All counts of aggressive, harmful, sexual, and play behavior were recorded by direct observation 1 d biweekly (5- × 5-min observations/pen/d). BL scores were recorded on focal pigs biweekly from day 1 until day 99 on the back, neck, shoulder, flank, and hind quarter on each side of the body. Hind hooves were scored for eight disorders (heel erosion [HE], heel sole separation [HSS], and white line separation [WLS], dew claw length and dew claw cracks, toe length and both vertical and horizontal toe cracks) by severity, and a total hoof lesion score was calculated by summing individual scores. General linear mixed models were used to analyze cortisol, behavior, BL, and total hoof scores. Generalized linear mixed models were used for locomotion, bursitis and individual hoof disorders. There was less aggression (P < 0.05) and sexual behavior in the FEM compared to the MIX groups with more play behavior in MIX compared to FEM groups (P < 0.01). Gilts in the MIX groups had higher BL scores than gilts in the FEM groups (P < 0.001). Total hoof scores were higher in MIX (8.01 ± 0.15) than FEM (7.70 ± 0.12; P < 0.02) gilts. CON diet gilts had higher HE scores than SUPP gilts (P < 0.05). HSS (P < 0.05) and WLS (P < 0.05) scores were higher in MIX than FEM gilts. Rearing gilts in FEM groups had benefits for hoof health likely mediated through lower levels of activity due to male absence, and minerals helped reduce HE.

Factors influencing claw lesion scoring in sows

Claw lesions have a multifactorial origin and may affect sow welfare and farm profitability. However, estimating the precise impact is hampered by several factors that interfere with the accuracy of claw lesion assessment. The objective of this study was to determine the impact of observer, scoring condition and claw cleanliness on claw lesion scoring in sows. The first experiment evaluated the impact of observer by calculating the inter- and intra-observer reliability during three test sessions using photographs. The second experiment evaluated the impact of observer, scoring condition (Feet First© chute of Zinpro Corp., "sow chute" vs. Mobile Claw Scoring Device, "MCSD"), and claw cleanliness (clean or soiled claws) on claw lesion scoring. For this experiment, 20 hybrid mid-gestating sows were hoisted up using the sow chute in which the MCSD was positioned. Lateral and medial claw digits of both hind claws were scored for heel horn erosion and separations along the heel/sole junction and white line. Scores were given by drawing a vertical bar on a 160 mm tagged visual analogue scale (tVAS); the severity of a claw lesion type was determined by measuring the distance from 0 mm. Four scores per sow were collected and analysed: clean claws × MCSD video recordings, soiled claws × MCSD video recordings, clean claws × visual scoring in a sow chute, and soiled claws × visual scoring in a sow chute. In both experiments, observer had an impact on the claw lesion scores. The inter-observer reliability was highest for overgrown dewclaws and lowest for the horizontal wall cracks (0.84 and 0.35, resp.). The highest intra-observer reliability was found for overgrown dewclaws and heel horn erosion (0.89) and lowest for vertical wall cracks (0.64). Furthermore, scoring condition and claw cleanliness influenced the scores in the second experiment and the limits of agreements were high (23.5-58.9 mm). The improved concordance correlation coefficient (iCCC) was highest for the heel horn erosion scores. In conclusion, the impact of observer seemed less relevant for claw lesion scoring; however, claw cleanliness and scoring condition were important and cannot be used interchangeably.

The Effect of Group Composition and Mineral Supplementation during Rearing on Measures of Cartilage Condition and Bone Mineral Density in Replacement Gilts

Lameness is a major cause of poor longevity and poor welfare in replacement gilts. The problem is exacerbated by inappropriate housing and diet during the rearing period. Replacement gilts are often reared with male finisher pigs destined for slaughter. If they are not castrated, they perform high levels of potentially injurious sexual and aggressive behaviour. Furthermore, finisher pig diets are not designed to meet the needs of developing gilts and may not supply the necessary minerals to support good limb health. The objective of this study was to evaluate the effect of supplementing the diet of replacement gilts with copper, zinc and manganese and separating them from males during the rearing period on locomotory ability, bone mineral density and cartilage lesion scores. A 2 × 2 factorial design experiment investigated the effect of female-only or mixed-sex rearing, with or without supplementary minerals (Copper, Zinc and Manganese). In total, 384 maternal line gilts were assigned to 32 pens of 12 and were locomotion scored during the rearing period. A sub-sample (n = 102) of gilts were culled at breeding age and the front right limb was removed at slaughter. Areal bone mineral density (aBMD) was measured using dual energy X-ray absorptiometry, after which the limb was dissected to score the condition of the cartilage. The addition of trace minerals to the diet resulted in increased aBMD in the humerus (P < 0.05) compared to the control diet. Rearing gilts in female-only groups reduced the number of cartilage lesions overall (P < 0.05), and on the humeral condyle (P < 0.05). Rearing replacement gilts in female-only groups and with mineral supplementation had benefits for limb health.

Effects of supplementing organic microminerals and methionine with or without limiting growth during the rearing phase of replacement gilts on lameness, growth, and body composition

Previous research suggested that lameness in growing pigs could be reduced using feeding strategies, such as limiting growth rate and supplementing trace minerals (TM) and (or) methionine (Met). The present study evaluates effects of 1) TM and Met and 2) limiting total lysine (Lys) during the rearing phase (90 d) of gilts (as a means to limit growth rate) on lameness, performance, and sow claw health and productivity (to first parity). Gilts (n = 240; 58.0 ± 11.1 kg body weight [BW]) were blocked, distributed into pens of 10 gilts, and pens were allocated to a 2 × 2 factorial arrangement. Factors were: 1) control or TM plus Met, which provided additional 10, 20, and 50 mg/kg of chelated copper, manganese, and zinc, respectively (0.1%, Aplomotec Plus, Tecnología & Vitaminas, S.L.; Alforja, Spain), and a 1.01 Met:Lys ratio and 2) standard Lys was formulated to meet growth requirements or low Lys to 19% below growth requirements. Feeding was provided through two phases, first between 119 and 163 d of age (phase I) and the second between 163 and 209 d of age (phase II). Diets had 2.43 and 2.31 Mcal net energy/kg for phases I and II, respectively, and were offered ad libitum. Low Lys did not affect feed intake but rather reduced average daily gain (ADG) by 6.35% and the final BW by 3.80% compared with standard Lys (P < 0.001). Low Lys reduced ADG (P < 0.001) and gain:feed (P = 0.012) during phase I but not during phase II. Lameness prevalence was 7.92% during rearing and increased with time (P < 0.001). Final BW (151 kg) and ADG (989 g) were similar (P > 0.05) whether gilts displayed lameness or not. Lameness was low in severity and not affected by dietary factors. However, TM- plus Met-fed gilts were 19.2 kg heavier (P = 0.016) than were control at lameness detection. On the sow farm, there was no evidence for differences in lameness or claw lesions among previous dietary treatments. In conclusion, lameness prevalence during the rearing phase was similar, independent of TM plus Met supplement, low Lys, or the interaction. Insufficient reduction of ADG and low severity in lameness may have limited the potential of dietary treatments. Moreover, a greater deficiency of Lys would be needed to achieve the degree of growth reduction previously reported to lessen lameness through feed restriction.

Effects of supplementing organic microminerals and methionine during the rearing phase of replacement gilts on lameness, growth, and body composition

Lameness is a primary reason for culling and mortality within a sow herd. This study evaluated the impact of feeding organic trace minerals and methionine (Met) to growing gilts (134 d) on lameness, performance, body composition and claw health (to first parity), productivity (to second parity), and reproductive performance through 2 parities. Young gilts (28.8 ± 8.8 kg of body weight [BW], n = 360) were BW blocked (10 gilts/pen) and randomly allotted to 1 of 4 dietary treatments: control (CON, basal diet); CON plus organic minerals (MIN, at 10, 20, and 50 mg/kg of Cu, Mn, and Zn, respectively; Aplomotec Plus, Tecnología & Vitaminas, S.L, Alforja, Spain); additional Met (MET, at 102% Met: Lys); and MET plus MIN (MM). Feed was provided ad libitum. Lameness, BW, and body composition were measured 7 times during rearing, at gilt service, day 109 of gestation, and first weaning. Gilts fed the MM diet had lower average daily feed intake (5.1%) and final BW (2.1%) than CON gilts (P < 0.05), whereas MIN and MET were intermediate and not different from each other. Similarly, final backfat (BF) was greatest in CON (P < 0.05), whereas CON and MIN increased final loin depth compared with MM (P < 0.05) with MET not being different. During rearing, 7.7% of all gilts presented lameness, which appeared between 106.8 and 129.7 kg BW confidence interval. Gilts that had been or were lame had reduced BW and average daily gain compared with never lame gilts (P < 0.05). Lameness during rearing was highest (P < 0.01) in gilts fed CON diet (14.8%), with no differences amongst MIN (2.0%), MET (5.3%), or MM (6.5%). In the sow herd, 21% of sows showed lameness and 24% of those were associated with claw lesions. At weaning, gilts fed CON diet had highest (P < 0.01) prevalence of lameness (20.8%) with no differences amongst MIN (6.5%), MET (11.1%), or MM (7.6%). Over the first 2 parities, 27.3% of gilts were culled. On farm, lameness was associated with 0.7 more stillborn piglets (P < 0.10), 1 mm more BF loss in first lactation (P < 0.05), and increased weaning-to-estrus by 3 d (P < 0.05). In conclusion, lameness during rearing was decreased by supplementing organic trace minerals, methionine, and their combination, which also reduced lameness during lactation.

Locomotion Disorders and Skin and Claw Lesions in Gestating Sows Housed in Dynamic versus Static Groups

Lameness and lesions to the skin and claws of sows in group housing are commonly occurring indicators of reduced welfare. Typically, these problems are more common in group housing than in individual housing systems. Group management type (dynamic versus static) and stage of gestation influence the behavior of the animals, which in turn influences the occurrence of these problems. The present study compared prevalence, incidence and mean scores of lameness and skin and claw lesions in static versus dynamic group housed sows at different stages of gestation during three consecutive reproductive cycles. A total of 10 Belgian sow herds were monitored; 5 in which dynamic groups and 5 in which static groups were utilized. All sows were visually assessed for lameness and skin lesions three times per cycle and the claws of the hind limbs were assessed once per cycle. Lameness and claw lesions were assessed using visual analogue scales. Static groups, in comparison with dynamic groups, demonstrated lower lameness scores (P<0.05) and decreased skin lesion prevalence (24.9 vs. 47.3%, P<0.05) at the end of gestation. There was no difference between treatment group regarding claw lesion prevalence with 75.5% of sows demonstrating claw lesions regardless of group management. Prevalences of lameness (22.4 vs. 8.9%, P<0.05) and skin lesions (46.6 vs. 4.4%, P<0.05) were highest during the group-housed phase compared to the individually housed phases. Although the prevalence of lameness and skin lesions did not differ three days after grouping versus at the end of the group-housing phase, their incidence peaked during the first three days after moving from the insemination stalls to the group. In conclusion, the first three days after grouping was the most risky period for lameness incidence, but there was no significant difference between static or dynamic group management.

Partial substitution, with their chelated complexes, of the inorganic zinc, copper and manganese in sow diets reduced the laminitic lesions in the claws and improved the morphometric characteristics of the hoof horn of sows from three Greek herds

BACKGROUND

Hoof 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.

RESULTS

Clinically, 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.

CONCLUSIONS

Partial 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.

Effect of diet supplementation with chelated zinc, copper and manganese on hoof lesions of loose housed sows

Background

Hoof 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.

Results

A 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.

Conclusions

Within 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.

Marginal dietary zinc concentration affects claw conformation measurements but not histological claw characteristics in weaned pigs

The aim of the present study was to explore whether marginal dietary zinc (Zn) concentrations affect claw quality measurements in weaned pigs. Twenty-four weaned pigs were randomly assigned to two dietary treatment groups: (1) 42 mg Zn/kg diet from ingredients only (unsupplemented, marginal dietary Zn concentration below Zn requirements of 80 mg Zn/kg feed); and (2) 106 mg Zn/kg diet, where Zn was added as ZnO (common commercial dietary Zn concentration). Claw conformation characteristics were measured at the start (day 0, 4 weeks of age) and at the end (day 36) of the study, and the histological claw characteristics of horn wall and heel horn were examined on samples collected at 9 weeks of age. Non-supplemented pigs had narrower claw widths (P= 0.028) and lower toe heights (P= 0.010) at 9 weeks. The length of the dorsal border tended to be lower for the non-supplemented piglets (P= 0.092). Claw volume and claw horn size were lower (P= 0.003 and P < 0.001, respectively) for the non-supplemented pigs at 9 weeks of age. Horn growth and wear were lower for the non-supplemented pigs (P= 0.044 and P < 0.001, respectively), but net horn growth (horn growth minus wear) was not different (P= 0.406). No changes in the histological claw characteristics were observed. Differences in claw quality measurements were found between lateral and medial claw digits and between fore and hind claws. It was concluded that marginal dietary Zn concentration affected various claw quality measurements. Marginal dietary Zn concentrations may not be sufficient to maintain claw quality in pigs.

Fluctuation of potential zinc status biomarkers throughout a reproductive cycle of primiparous and multiparous sows

Fluctuations in Zn metabolism throughout gestation and lactation might affect Zn requirements. However, scientific data on Zn requirements for breeding sows are limited. The objective of the present study was to assess the Zn status of primiparous and multiparous sows using different Zn status biomarkers, to identify periods of critical Zn status throughout the reproductive cycle at different parities. Blood samples were taken after overnight fasting before feeding in the morning from five primiparous and ten multiparous sows at fixed time intervals during gestation (days - 5, 0 (insemination), 21, 42, 63 and 84), around parturition (days 108, 112, 115 (parturition) and 118) and during lactation (days 122, 129 and 143 (weaning)). At parturition, blood samples were collected from two randomly selected piglets per sow before colostrum intake. Plasma was analysed for Zn and Cu contents, whereas serum was analysed for alkaline phosphatase, metallothionein and albumin concentrations. Independently of parity, all biomarkers fluctuated differently during gestation and lactation (P< 0·050). This reflects their different roles in Zn metabolism, and suggests that the choice of a Zn status biomarker necessitates careful consideration. Low average plasma Zn concentration at the end of gestation and throughout lactation seem to be replenished towards weaning.

Field study of hind limb claw lesions and claw measures in sows

We investigated the associations of hind limb claw lesions with claw measures and reproductive performance of sows on a commercial breeding farm. We used a five-point scale (score of 0-4) for each hind limb claw region to generate a claw lesion score (CLS). Of 110 sows, 1.8% had no hind claw lesions, and the remaining 98.2% had at least one. The proportions of sows with a CLS of 2 and 3 were 49.1% and 3.6%, respectively. The junction region had the highest frequency of a CLS of ≥ 2 (P < 0.05). The mean toe length was 45.0 ± 0.4 to 46.4 ± 0.4 mm. Sows with the highest CLS of ≥ 2 in the lateral claw had longer sole dimensions than did sows with the highest CLS of ≤ 1 (P < 0.05). There were no significant differences in claw width or height between sows with the highest CLS of ≥ 2 and ≤ 1. There was also no difference in reproductive performance between sows with the highest CLS of ≥ 2 and ≤ 1. In conclusion, most sows had hind claw lesions. The association between CLS and claw measures indicates that the sole length can be used as an indicator of claw lesions.