The objective of this study was to determine the effect of dietary manganese on the reproductive performance of sows. Sows (n = 39; 231 ± 8 kg) were randomly assigned to one of three dietary levels of supplemented Mn (CON: 0 ppm Mn; PRO20: 20 ppm Mn; PRO40: 40 ppm Mn). The experimental treatments were initiated at breeding and continued through two parities. The sows were blocked by parity within each farrowing group. The data were analyzed as a randomized complete block design using the MIXED procedure of SAS with diet as a fixed effect and block as a random effect. The lactation feed intake increased in the PRO20 sows compared to the CON and PRO40 sows (p < 0.05). The PRO20 and PRO40 sows farrowed piglets with improved average daily gain from birth to weaning (CON 214 g/day; PRO20 237 g/day; 220 g/day; p < 0.05) compared to the CON sows. The milk fat content was lower in the PRO20 (5.5%) and PRO40 sows (6.1%; p < 0.05) compared to the CON sows (7.8%), possibly due to increased milk demand. Supplementary dietary Mn throughout two gestation and lactation cycles led to improved birth weights and pre-weaning growth of piglets.

The objective of this study was to determine the effect of dietary manganese (ProPath Mn, Zinpro Corporation) on the reproductive performance of sows. Sows (N = 39; 231 ± 8 kg) were randomly assigned to 1 of three dietary levels of Mn (CON: 0 ppm Mn; PRO20: 20 ppm Mn; PRO40: 40 ppm Mn). Experimental treatments were initiated at breeding and continued through 2 parities. Sows were blocked by parity within each farrowing group and dietary treatments were represented within each block. Data were analyzed as a randomized complete block design using the MIXED procedure of SAS with diet as a fixed effect and block as a random effect. Dietary treatment did not affect sow body weights (P > 0.10). Lactation feed intake was increased in PRO20 sows compared with CON and PRO40 sows (P < 0.05). PRO20 and PRO40 sows farrowed heavier piglets (CON 1.23 kg; PRO20 1.57 kg; PRO40 1.40 kg; P = 0.001) with improved average daily gain to weaning (CON 213 g/day; PRO20 237 g/day; 220 g/day; P < 0.05), compared with CON sows. Milk fat content (average from d 7 and 14 of lactation) was reduced in PRO20 (5.5%) and PRO40 sows (6.1%; P < 0.05) compared with CON sows (7.8%), possibly due to increased milk demand from the piglets. There were no significant differences in milk mineral concentrations during lactation or piglet tissue Mn-superoxide dismutase (MnSOD) activity at weaning (P > 0.10). On day 3 of lactation, prolactin concentrations were similar across treatments (P > 0.10), whereas progesterone concentrations tended to differ in response to Mn level (CON 23.70 ng/mL; PRO20 26.15 ng/mL; PRO40 22.10 ng/ml; P = 0.09). Supplementary dietary Mn throughout 2 gestation and lactation cycles led to increased birth weights and pre-weaning growth of piglets.

Research findings for supplementing boar stud diets with fish oils are inconsistent.This study was designed to address three possible causes of performance variation of boars to fish oil supplementation: stability of the fatty acid source, level of inclusion and breed of boars tested.Three groups of 87 boars each, from two genetic lines (PIC 337 and PIC 800), were assigned to treatment based on age, mean sperm production (previous 12 weeks), and body condition score.All boars received a corn-soybean meal diet with a commercial fish oil supplement providing 1.83 g/boar/day of docosahexaenoic acid (DHA) as a preconditioning diet.On 10-Aug., 2020, the DHA source was changed to a stabilized starch imbedded source of refined fish oil (Salmate®), providing 1.83 g/b/d for the test diet.Two additional levels providing 2.38 and 2.94 g/b/d of DHA were fed for a 9 week pretreatment period and during the test period.Salmate® fed at 2.38 g/b/d of DHA resulted in a reduction in the number of rejected ejaculates (P < 0.045) by 7.5% and 6.4% compared to the lowest and highest inclusion rates, respectively.There were no treatments by genetic line interactions.A retrospective study of semen production and quality of 77 boars on the Salmate® diet containing 1.83 g/b/d DHA was done to compare to the original source of DHA at the same inclusion level.There were no differences in semen quality parameters between the 2 lipid sources.Ejaculate volume increased from 177.9 ml to 233.4 ml (P < 0.001) and total sperm cells per ejaculate increased from 69.7 × 10 9 to 82.0 × 10 9 (P < 0.001) due to substitution of Salmate®.Adding Salmate® at 2.38 g/b/d resulted in a lower number of rejected ejaculates per boar by 7.5% and 6.4% vs. 1.83 and 2.94 g/b/d, respectively, and boars fed Salmate® at 1.83 g/b/d produced 17% more doses than the competing product.

Abstract Porcine pregnancy establishment and maintenance are dependent on the formation of functional corpora lutea (CL). Manganese (Mn) is critical for CL function as it is a cofactor for Mn superoxide dismutase and enzymes involved in cholesterol synthesis. Previously, we have shown that luteal Mn content increased and luteal progesterone (P4) concentration decreased in the CL of gilts fed diets supplemented with an Mn–amino acid complex (Availa-Mn; Zinpro Corporation) compared with controls fed Mn sulfate. Importantly, serum P4 increased from 0 (estrus onset) to 12 d post estrus (dpe), as expected, but P4 abundance in circulation was not affected by dietary Mn source (P = 0.15). We hypothesized that a more bioavailable Mn source (which results in increased luteal Mn content) would alter the luteal proteome and abundance of mRNA associated with steroid biogenesis during the mid-luteal phase of the estrous cycle. Postpubertal gilts (n = 32) were assigned to one of the four gestation diets. The control diet (CON) contained 20 ppm of supplemental Mn in the form of Mn sulfate. Three additional diets included 20 (TRT1), 40 (TRT2), or 60 (TRT3) ppm of supplemental Mn in the form of a Mn–amino acid complex instead of Mn sulfate. Dietary treatment began at estrus synchronization (approximately 20 d before estrus) and continued through 12 dpe when gilts were euthanized and tissues were collected. Protein and total RNA extracts from the CL were used for proteomic analysis via label-free liquid chromatography with tandem mass spectrometry to assess global protein abundance and quantitative real-time polymerase chain reaction (qRT-PCR) to assess specific mRNA abundance, respectively. Compared with CON, 188, 382, and 401 proteins were differentially abundant (P < 0.10) in TRT1, TRT2, and TRT3, respectively. Gene Ontology enrichment software revealed that proteins involved in P4 signaling and cholesterol synthesis were downregulated in CL of gilts fed Mn–amino acid complex compared with controls. Quantitative RT-PCR showed that relative transcript abundance of genes encoding steroidogenic enzymes (CYP11A1 and StAR) in CL tissue was decreased in gilts from TRT2 compared with CON (P = 0.02), but TRT1 and TRT3 were not affected (P ≥ 0.30). Collectively, these data support our hypothesis that a more bioavailable dietary Mn source may influence luteal function by altering the abundance of protein and mRNA involved in steroidogenesis.

Boars are a source of genetic improvement and influence farrowing rate and litter size. Overfeeding boars increases incidence of feet and leg problems and reduces libido, whereas underfeeding boars may decrease semen output and libido. To help boar stud personnel estimate the energy requirements and base feeding levels, an interactive web application named PIC Optimum Boar Feeding Tool has been developed. The application encompasses three components, including an input interface using dynamic models to estimate energy requirement, an output interface displaying recommended feeding program, and functional modules facilitating the ease of use. The input interface requests users to provide the start and final weight of boars in isolation, isolation length, boar stud room temperature, number of collections per week, and dietary energy level. The daily energy requirement (Mcal of ME/day) is calculated using the following energy-demanding factors: 1) maintenance, 0.1823 × (body weight, kg)0.665; 2) weight gain, 0.00489 × (average daily gain, kg/d); 3) each degree below 17°C for individually penned boars on slatted floors, 0.00382 × (body weight, kg)0.75; 4) mating activity, 0.0043 × (body weight, kg)0.75; and 5) sperm production, 0.1. These factors and the user-defined inputs including dietary energy, are used to calculate a daily feeding amount. The users also have the option to calculate the recommended feeding level for boars of specified body weight. Other functional modules include a flank-to-flank measurement tool that estimates boar body weight and customized downloadable nutrient specifications. This web application incorporates a spectrum of biological, nutritional, and management aspects to allow boar stud personnel to easily make boar feeding decisions.

Functional corpora lutea (CL) are required for pregnancy establishment and gestational maintenance in swine, and CL function is susceptible to environmental influences. Manganese (Mn) could be critical in regulating CL function since it is a component of the antioxidant enzyme Mn superoxide dismutase (MnSOD) as well as enzymes involved in cholesterol and steroid hormone synthesis. We hypothesized that a more bioavailable dietary Mn source would increase Mn content in the CL thereby influencing luteal function during the mid-luteal phase of the estrous cycle. Postpubertal gilts (n = 32) were assigned to one of four gestation diets. The control diet (CON) met or exceeded National Research Council (2012) requirements and was formulated to contain 20 parts per million (ppm) of added Mn in the form of Mn sulfate. Three additional diets included 20 (treatment [TRT]1), 40 (TRT2), or 60 (TRT3) ppm of added Mn from a Mn-amino acid complex (Availa-Mn; Zinpro Corporation) instead of Mn sulfate. Dietary treatment began at estrus synchronization onset and continued through 12 days post estrus (dpe) of the ensuing estrous cycle. Blood samples were collected at estrus onset, which was assigned as 0 dpe, as well as 4, 8, and 12 dpe. Gilts were euthanized and tissues were collected at 12 dpe. Serum progesterone (P4) increased (P < 0.01) from 0 to 12 dpe but was unaffected by dietary treatment (P = 0.15) and there was no effect of the interaction between day and treatment (P = 0.85). Luteal Mn content increased (P ≤ 0.05) by 19%, 21%, and 24% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Luteal P4 concentrations decreased (P = 0.03) 25%, 26%, and 32% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Relative to CON gilts, CL calcium content decreased (P = 0.02) by 36%, 24%, and 34% for TRT1, TRT2, and TRT3 gilts, respectively. Collectively, these data support the hypothesis that feeding a more bioavailable Mn source increases Mn accumulation in CL tissue. If and how this influences CL function may be related to altered luteal P4 concentrations.

Abstract Functional corpora lutea (CL) are required for pregnancy establishment and gestational maintenance in swine. Manganese (Mn) could be critical in regulating CL function since it is a cofactor for the enzyme Mn superoxide dismutase (Mn-SOD) as well as enzymes involved in progesterone (P4) synthesis. We hypothesized a more bioavailable dietary Mn source would increase CL Mn content thereby influencing luteal function during the mid-luteal phase of the estrous cycle. Post-pubertal gilts (n = 32) were assigned to one of four gestation diets. The control diet (CON) met or exceeded NRC requirements and was formulated to contain 20 ppm added Mn in the form of Mn sulfate. Three additional diets included 20 (TRT1), 40 (TRT2) or 60 (TRT3) ppm Mn from a Mn-amino acid complex (Availa-Mn; Zinpro Corporation) in place of Mn sulfate. Dietary treatment began at estrus synchronization onset and continued through D12 of the ensuing estrous cycle when gilts were euthanized. Mn content increased (P ≤ 0.06) 19, 21 and 24% in CLs of gilts fed TRT1, TRT2, and TRT3, respectively, and luteal P4 concentration decreased (P ≤ 0.03) 25, 26, and 32% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Total CL protein was extracted and liquid chromatography with tandem mass spectrometry (LC-MS/MS) was performed to assess global protein abundance. Compared to CON, 29, 105, and 118 proteins were differentially abundant (P < 0.01) in TRT1, TRT2, and TRT3, respectively. KEGG pathway analysis revealed proteins involved in P4 signaling (membrane-associated P4 receptor component 2) and cholesterol synthesis and transport (mevalonate kinase, diphosphomevalonate decarboxylase, low density lipoprotein receptor) were downregulated in response to Availa-Mn. Collectively, these data support the posit that dietary Mn source affects Mn accumulation and P4 concentration in CL tissue and influences protein abundance which may affect CL function.

Early lesions of osteochondrosis (OC) are exhibited by regions of cartilage retention along the growth plate and articular cartilage. Progression of OC lesions may impair locomotion and necessitate euthanasia in adherence to animal welfare guides. Little is known about the role of nutrition in the initiation and early stages of OC. However, dietary components are commonly implicated as predisposing factors. In this study, diets were altered as an attempt to induce early stage OC lesions under controlled conditions. At 8 wk of age, 96 crossbred gilts (body weight [BW] = 17.4 ± 0.18 kg) were randomly assigned to one of four corn-soybean meal-based diets (four pens per diet, six pigs per pen) to assess diet effects on the number and volume of OC lesions in the distal femur. Diets included a non-pelleted control diet (Ctl); Ctl plus 20% glucose (Glc); the Ctl with increased concentrations of lysine, Ca, and P (+CaP); and the +CaP diet in a pelleted form (PEL). Femurs were collected from pigs euthanized at either 14-wk (Wk 14) or 24-wk (Wk 14) of age for assessments of OC lesions. Based on a mixed model analysis with pen as the experimental unit, dietary treatments did not affect final BW (129.3 ± 3.8 kg) or average daily gain (ADG) (1.00 ± 0.03 kg/d) over the trial. As expected, pigs fed PEL and Glc diets were more efficient (P < 0.05) in feed conversion compared with Ctl and +CaP. Using femurs as the experimental unit at Wk 14 (collected from two of the six pigs per pen), bone mineral content, determined by dual-energy x-ray absorptiometry scans, was greater (P < 0.05) in pigs fed +CaP and PEL than Ctl or Glc diets; however, only +CaP group differed (P < 0.05) at Wk 24 (collected from four pigs per pen). Computed tomography (CT) scans of femurs were reconstructed as three-dimensional images to allow detection of the number, volume, and surface area of lesions in distal growth plates. At Wk 14, pigs fed Ctl had fewer number of lesions (P < 0.05); however, no differences were detected among dietary treatments in lesion volume or lesion surface area. Pigs had fewer lesions at Wk 24 than Wk 14; however, differences were not detected among dietary treatments. At Wk 24, pigs fed Ctl diets had the greatest lesion volume among dietary treatments (P < 0.05). In conclusion, none of the pigs exhibited symptoms of lameness regardless of dietary treatment or OC lesion traits. Diet modifications due to pelleting or inclusion of rapidly digestible ingredients, such as glucose, did not increase prevalence or size of OC lesions. Image analysis of CT scans was a reliable method to quantify the number, size, and location of OC lesions.

Objective: To determine the effect of functional claw trimming versus blunt claw trimming on the gait of sows. Materials and methods: Nineteen sows (PIC C29) were transported to the research center and claws were trimmed 3 times over an 8-day period. Dewclaws were trimmed even with the coronary band of the hoof on day 1. Claws were blunt trimmed on day 4 and functional trimming occurred on day 8. The gait of each sow was recorded prior to each trimming to compare the effect of the previous trimming. A final gait recording was taken on day 12. The gait data collected from the sows was compared across days to determine if any changes occurred. Results: Positive improvements in gait data were noted after dewclaw trimming. Changes were seen in velocity (P = .03), stride length (P = .02), stride duration (P = .04), stance (P = .04), and rear percent stance (P = .03). Blunt trimming offset the improvement gained by trimming dewclaws, seen in the changes to rear percent stance (P = .02) and front swing (P = .04). Functional trimming increased the improvement observed by trimming dewclaws. Changes were seen in the stance (P < .001), percent stance (P < .001), stride duration (P = .003), stride length (P = .008), and velocity (P = .003). Implications: Trimming dewclaws and functionally trimming claws improved the sow’s gait. Blunt trimming did not provide the same benefits observed by trimming dewclaws or functionally trimming the claws.

Study objectives were to determine the effects of zinc (Zn) amino acid complex (Availa Zn, Zinpro Corporation, Eden Prairie, MN) on metabolism, biomarkers of leaky gut, and inflammation during and following heat stress (HS) and nutrient restriction. Crossbred gilts (n = 50; 50 +/- 2 kg BW) were blocked by initial BW and randomly assigned to one of five treatments: 1) thermoneutral (TN) and ad libitum fed a control diet (TNCtl), 2) TN and pair-fed a control diet (PFCtl), 3) TN and pair-fed a Zn-supplemented diet (PFZn), 4) HS and ad libitum fed a control diet (HSCtl), and 5) HS and ad libitum fed a Zn-supplemented diet (HSZn). The study consisted of 3 experimental periods (P): during P1 (7 d), all pigs were fed their respective diets ad libitum and housed in TN conditions (20.84 +/- 0.03 degrees C, 47.11 +/- 0.42% relative humidity). During P2 (7 d), HSCtl and HSZn pigs were exposed to progressive cyclical HS conditions (27 to 30 degrees C, 41.9 +/- 0.5% relative humidity), while TNCtl, PFCtl, and PFZn pigs remained in TN conditions and were fed ad libitum or pair-fed to their respective HSCtl and HSZn counterparts. During P3 (5 d; "recovery phase"), all pigs were housed in TN conditions and fed ad libitum. Pigs exposed to HS had overall increased rectal temperature, skin temperature, and respiration rate (0.33 degrees C, 3.76 degrees C, and 27 bpm, respectively; P < 0.01). Relative to TN controls, HS decreased ADFI and ADG (28 and 35%, respectively; P < 0.05), but these variables were unaffected by dietary treatment. Additionally, circulating insulin did not differ between HS and TN pigs (P = 0.41), but was decreased in PF relative to TN pigs (P < 0.01). During recovery, no differences were observed in rectal temperature or respiration rate across treatments, but HSZn pigs had decreased skin temperature relative to TN, PF, and HSCtl pigs (P < 0.01). During P3, no Zn effects were observed in production parameters; however, PF pigs had increased ADFI and ADG relative to TN and HS treatments (P < 0.01). During P3, circulating insulin was increased in pigs that were HS relative to TN and PF pigs (75%, P < 0.05). Interestingly, tumor necrosis factor alpha (TNF alpha) levels were decreased during P3 (P = 0.04) in Zn relative to Ctl-fed pigs. Circulating lipopolysaccharide-binding protein was not different among periods (P > 0.10). In summary, Zn reduced TNF alpha (regardless of HS), and the stimulatory effect of HS on insulin secretion is amplified during HS recovery.

Heat stress (HS) dramatically disrupts the events in energy and nutrient metabolism, many of which requires zinc (Zn) as a cofactor. In this study, metabolic effects of HS and Zn supplementation were evaluated by examining growth performance, blood chemistry, and metabolomes of crossbred gilts fed with ZnNeg (no Zn supplementation), ZnIO (120 ppm ZnSO4), or ZnAA (60 ppm ZnSO4 + 60 ppm zinc amino acid complex) diets under diurnal HS or thermal-neutral (TN) condition. The results showed that growth performance was reduced by HS but not by Zn supplementation. Among measured serum biochemicals, HS was found to increase creatinine but decrease blood urea nitrogen (BUN) level. Metabolomic analysis indicated that HS greatly affected diverse metabolites associated with amino acid, lipid, and microbial metabolism, including urea cycle metabolites, essential amino acids, phospholipids, medium-chain dicarboxylic acids, fatty acid amides, and secondary bile acids. More importantly, many changes in these metabolite markers were correlated with both acute and adaptive responses to HS. Relative to HS-induced metabolic effects, Zn supplementation-associated effects were much more limited. A prominent observation was that ZnIO diet, potentially through its influences on microbial metabolism, yielded different responses to HS compared with two other diets, which included higher levels of short-chain fatty acids (SCFAs) in cecal fluid and higher levels of lysine in the liver and feces. Overall, comprehensive metabolomic analysis identified novel metabolite markers associated with HS and Zn supplementation, which could guide further investigation on the mechanisms of these metabolic effects.

Objective: To characterize histologic lesions in pigs with and without claw overgrowth.Materials and methods: Hindlimb claws from a subset of 24 sows that were part of a larger field study were selected because of claw deformities associated with overgrowth and change in gait. Length measurements were available for 72 lateral or medial rear claws. Claws were examined histologically and the lesions categorized. Overgrowth was defined as a toe growth measuring > 50 mm in length.Results: Lateral rear claws were most consistently overgrown. However, the distribution and severity of lesions failed to suggest a common etiology for overgrowth. Inflammation, arteriosclerosis, lamellar epithelial changes, phalanx rotation, or combinations of these were not prominent gross or histologic changes.Implications: The pathogenesis of overgrowth in this collection of claws is unknown, but does not appear to represent primary laminitis in this species. As lameness continues to prompt a significant economic loss due to culling, further studies on claw overgrowth, its effect on motion, and its pathogenesis are warranted.