Maternal and progeny diets supplemented with 2 sources of trace mineral (TM) were evaluated for effects on the size and severity of osteochondrosis (OC) lesions in progeny produced by 64 Landrace × Large White sows. At breeding, sows were randomly assigned to maternal diets (gestation and lactation) consisting 1 of 2 TM treatments. One treatment consisted of inorganic TM (ITM) with ZnO, MnSO, and CuSO at concentrations to provide 150, 50, and 16.5 mg/kg diet of Zn, Mn, and Cu, respectively. The other treatment consisted of the same ITM concentrations plus an additional 50, 20, and 10 mg/kg diet of Zn, Mn, and Cu, respectively, supplied by a blend of AA-complexed TM (CTM) using Availa Sow. Within maternal dietary treatment groups, selected progeny ( = 280) were fed either ITM- or CTM-supplemented diets. The humerus and femur (1 each) from progeny euthanized at 12 ( = 80) or 24 wk ( = 200) were collected for microscopic (12 wk) or gross (24 wk) assessment of OC lesions. Microscopic OC lesions were present in all pigs at 12 wk. Dietary treatments had limited effects on OC prevalence or severity. A maternal × progeny diet interaction ( = 0.044) revealed femoral OC latens lesions that were approximately twice the size in progeny fed CTM that were produced by sows fed CTM compared with those found in pigs in the other 3 dietary treatment groups. At 24 wk, the sum of gross OC scores at predilection sites of the thoracic (elbow joint) and pelvic (stifle and hock joints) limbs remained similar among treatments, despite greater ( = 0.004) gross OC scores of the medial femoral condyle in progeny from sows fed CTM diets than in progeny from sows fed ITM diets, regardless of progeny diet. Progeny produced by sows fed CTM vs. ITM had increased ADG (0.71 vs. 0.68 ± 0.01 kg/d), regardless of the diet fed to progeny during the growth phases. Covariant analysis using ADG did not alter inferences about maternal or progeny diet effects on OC responses. Although 100% of progeny at 12 wk had histologically apparent OC lesions, only 3 of the 200 pigs examined at 24 wk had gross lesions of sufficient severity to potentially result in clinically apparent disease. Therefore, although some results imply that maternal and progeny CTM diets increased the size (12 wk) and severity (24 wk) of OC in 1 site (the femur), on the whole animal level, no evidence of lameness was noted.

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The potential relation between body condition of gilts in late-pregnancy and litter BW gain as well as mammary development was studied using 2 sets of data. Gilts either from a commercial herd (Part 1, n = 182) or from a series of trials looking at mammary development (Part 2, n = 172) were separated in 3 groups according to backfat thickness (BF) on d 110 of gestation. Group categorization was similar for Parts 1 and 2 of the study and was: low (LOW), 13.6 ± 1.6 mm (mean ± SD); medium (MED), 17.6 ± 1.0 mm (mean ± SD); and high BF (HIGH), 21.8 ± 1.8 mm (mean ± SD) for Part 1, and LOW, 14.2 ± 1.3 mm (mean ± SD); MED, 18.1 ± 1.0 mm (mean ± SD), and HIGH 23.4 ± 2.6 mm (mean ± SD) for Part 2. The effects of BF group on piglet BW gain (Part 1) or on various mammary gland characteristics (Part 2) were determined using ANOVA. Litters from HIGH sows tended to have a greater lactation BW gain than those from LOW sows (P < 0.10). Sows with HIGH BF had more mammary parenchymal tissue and more total protein and total DNA than MED and LOW sows (P < 0.05), which led to greater total protein and total DNA contents (P < 0.05). There were strong positive correlations (P < 0.0001) between parenchymal weight and total protein, total DNA, and total RNA. Results suggest that it is beneficial for primiparous sows to have greater BF (i.e., 20 to 26 mm) at the end of gestation to achieve optimal mammary development and greater litter BW gain in the subsequent lactation.

Precision feeding (PF) aims to provide the right amount of nutrients at the right time for each animal. Lactating sows generally receive the same diet, which either results in insufficient supply and body reserve mobilization, or excessive supply and high nutrient excretion. With the help of online measuring devices, computational methods, and smart feeders, we introduced the first PF decision support system (DSS) for lactating sows. Precision (PRE) and conventional (STD) feeding strategies were compared in commercial conditions. Every day each PRE sow received a tailored ration that had been computed by the DSS. This ration was obtained by blending a diet with a high AA and mineral content (13.00 g/kg SID Lys, 4.50 g/kg digestible P) and a diet low in AAs and minerals (6.50 g/kg SID Lys, 2.90 g/kg digestible P). All STD sows received a conventional diet (10.08 g/kg SID Lys, 3.78 g/kg digestible P). Before the trial, the DSS was fitted to farm performance for the prediction of piglet average daily gain (PADG) and sow daily feed intake (DFI), with data from 1,691 and 3,712 lactations, respectively. Sow and litter performance were analyzed for the effect of feeding strategy with ANOVA, with results considered statistically significant when P<0.05. The experiment involved 239 PRE and 240 STD sows. DFI was similarly high in both treatments (PRE: 6.59, STD: 6.45 kg/d; P=0.11). Litter growth was high (PRE: 2.96, STD: 3.06 kg/d), although it decreased slightly by about 3% in PRE compared to STD treatments (P<0.05). Sow body weight loss was low, although it was slightly higher in PRE sows (7.7 versus 2.1 kg, P<0.001), which might be due to insufficient AA supply in some sows. Weaning to estrus interval (5.6 d) did not differ. In PRE sows SID Lys intake (PRE: 7.7, STD: 10.0 g/kg; P<0.001) and digestible P intake (PRE: 3.2, STD: 3.8 g/kg; P<0.001) declined by 23% and 14%, respectively, and feed cost decreased by 12%. For PRE sows, excretion of N and P decreased by 28% and 42%, respectively. According to these results, PF appears to be a very promising strategy for lactating sows.

Imbalances between calcium (Ca) and phosphorus (P) impair growth performance and bone mineralization. However, reducing dietary limestone may change the buffering capacity of feed in early nursery piglets, which may help prevent post-weaning diarrhea. An experiment was conducted to evaluate the impact of reducing Ca post weaning compared to recommendations outlined by NRC (2012) or a low P diet. Dietary treatments consisted of 1) Low Ca (LCa; Phase 1, 0.51% Ca and 0.47% STTD P), 2) NRC recommendations (NRC; Phase 1, 0.85% Ca and 0.42% STTD P), and 3) a recommendation lower in phosphorus (LP; Phase 1, 0.65% Ca and 0.36% STTD P). Each diet was fed over 4 phases. Piglets (n = 953; 276/275 Fast X PIC 800 genetics) were blocked by room, sex, and initial BW (6 kg). Feed intake and pig weights were recorded weekly. At 12 d and 41 d, blood was collected and Dual-X ray (DXA) measurements were taken using 8 piglets per treatment. Fecal scores were evaluated during wk 4 and 5. Data were analyzed using MIXED procedure of SAS (SAS Inst. Inc., Cary, NC). There were no differences observed in mortality, overall growth performance, plasma Ca and P, and scour scores at either time point. At 12 d, the bone mineral content was reduced (P = 0.001) in LP pigs compared to LCa and NRC. At 41 d, bone mineral content was reduced in NRC in comparison to LCa while LP was intermediate (P = 0.001). Plasma parameters showed an increased magnesium (Mg) and Ca:Mg in LCa (P < 0.01) that can be related to bone resorption to face Ca hypocalcemia. Pigs were healthy with no enteric challenges, limiting the ability to observe a benefit in fecal scores. In conclusion, piglets can maintain growth and bone mineralization through a short-term limestone removal program.