@article{kuneff_rosero_paz_leiva_wilcock_heugten_elsbernd_2024, title={Evaluation of the impact of high doses of phytase and marketing strategy on performance and carcass characteristics of late finishing pigs in commercial settings}, volume={102}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skae102.100}, abstractNote={Abstract As late finishing pigs reach market weight, space allowance per unit of body weight (BW) is reduced, which negatively impacts growth performance. Supplementing high doses of phytase results in the near complete destruction of phytic acid resulting in increased levels of lower inositol esters and inositol, which have been associated with a decreased stress response as well as having insulin-like effects. This study evaluated the impacts of high doses of phytase and two marketing strategies on growth performance and carcass characteristics of late finishing pigs. Pigs (n = 2,200; initial BW = 89.64 ± 3.08 kg) were randomly distributed to 96 pens using two commercial research barns, with 18 to 24 pigs per pen, balanced for gilts and barrows. Two phytase supplementation doses (super-dosing control of 2,250 FTU/kg and hyper-dosing at 4,500 FTU/kg) and two marketing strategies (Standard or Late) were combined to create 4 treatments in a 2×2 factorial arrangement. The first marketing event occurred at an average BW of 123.3 kg on d 22 for the Standard group and at 145.3 kg on d 44 for the Late group, marketing the heaviest 1 to 5 pigs per pen (13.2% of pigs). The second group (15.4% of pigs; BW of 147.3 and 144.8 kg for Standard and Late marketing) was marketed on d 50 and marketing of all remaining pigs occurred on d 63 for both treatments. Finisher diets contained 0.74% SID lysine, 0.60% Ca, and 0.37% available P. Regardless of the dose, phytase was given the same matrix values for nutrients and metabolizable energy. No interactions were observed between marketing strategy and phytase supplementation (P > 0.22), and no effect of phytase was observed (P > 0.09). Average BW of all pigs marketed was greater (P < 0.001) for the Late compared with the Standard marketing strategy (143.8 vs. 141.7 kg/d). Days to market was greater for Late marketing (59.7 vs. 56.8 d) as a result of the extra 22 d before the first marketing compared with the Standard strategy. Thus, average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio were not impacted (P ≥ 0.486) by marketing treatments. Hot carcass weight (103.83 vs. 101.44 kg) and yield (78.10 vs. 77.73%) were greater (P < 0.001) for Late marketing. Fat cover was greater and percent lean was less (P < 0.05) for the Late marketing treatment, but loin depth and marbling were not different (P > 0.09). All primal cuts were heavier (P < 0.001), resulting in a total primal weight of 89.44 and 87.54 kg (P < 0.001) for Late and Standard marketing, respectively. Results suggest that delaying the first marketing improved final BW, yield, and weight of primal cuts and that supplementing phytase above super-dosing levels in late finishing pigs did not improve growth performance or carcass value, regardless of marketing strategy.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Kuneff, Izadora Batista and Rosero, David S. and Paz, Ximena and Leiva, Samuel F. and Wilcock, Pete and Heugten, Eric and Elsbernd, Amanda}, year={2024}, month={May}, pages={88–89} }
 @article{rubio_kuneff_soler_espinosa_koutsos_heugten_2024, title={Potential of black soldier fly (<i>Hermetia illucens</i>) larvae frass as a functional ingredient for nursery pigs}, volume={102}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skae102.415}, abstractNote={Abstract Frass is the leftover material from the production of black soldier fly larvae (BSFL), which includes chitin-containing exoskeleton shedding, small, processed larvae, leftover dietary substrate, and larvae excrement. A total of 120 nursery pigs (initial body weight of 6.85 ± 0.10 kg) weaned at 21 d of age were used in a 6-wk study to evaluate the effect of increasing dietary levels of frass on growth performance, diarrhea score, and serological indices. Pigs were randomly assigned within sex and body weight blocks to 1 of 3 dietary treatments using 30 pens (4 pigs/pen; 10 replicates/treatment). Diets were prepared from a common basal and fed in 3 dietary phases of 2 wk each and included: 1) a control diet based primarily on corn and soybean meal; 2) the control with 3% added frass; and 3) the control with 6% added frass. On d 4, 7, and 14, individual fecal samples were obtained using fecal loops and were evaluated on a scale of 1 to 5 representing hard, normal, soft, watery soft, and watery liquid feces, respectively. Blood samples were collected on d 42 from 1 median pig per pen for the analysis of serum chemistry. Data were analyzed using the mixed model procedures as a randomized complete block design using linear and quadratic contrast comparisons to determine the effects of frass. Supplementation of frass linearly increased average daily gain (ADG) from d 7 to 14 (P = 0.044; 347.9, 378.8, and 396.8 g/d for 0, 3, and 6% frass, respectively), and tended to linearly increase ADG during Phase 1 (P = 0.079; 265.1, 284.8, and 298.6 g/d). No differences were observed for final body weight (P ≥ 0.146; 29.90, 31.48, and 30.70 kg for 0, 3, and 6% frass, respectively), and overall ADG, average daily feed intake (ADFI), or gain to feed ratio (G:F). Diarrhea scores increased (P < 0.001) from d 4 (2.96) to d 7 (4.20) and then decreased (P < 0.001) on d 14 (3.69). Inclusion of frass at 6% had a decreased diarrhea score compared with 3% frass on d 7 (P = 0.029), but pigs fed 6% frass had a greater diarrhea score (P = 0.038) than pigs fed the control diet on d 14. However, scores were indicative of diarrhea for all treatments on d 7 and 14. Serum concentrations of total protein, albumin, globulin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, γ-glutamyltranspeptidase, urea N, creatinine, glucose, Ca, P, Mg, K, Na, Cl, triglycerides, amylase, cholesterol, and creatine phosphokinase measured on d 42 were not different (P > 0.093) between treatments. All serological analytical results were generally within normal expected ranges. In conclusion, these findings suggest that dietary inclusion of frass may improve growth performance of nursery pigs, especially during the early stages of the nursery period.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Rubio, Sarah and Kuneff, Izadora Batista and Soler, Fernando and Espinosa, Charmaine and Koutsos, Liz and Heugten, Eric}, year={2024}, month={May} }
 @article{kuneff_rosero_wilcock_heugten_2023, title={Evaluation of Floor Space Restriction and Hyper-Dosing of Phytase on Growth Performance, Carcass Characteristics and Serum Chemistry of Late Finishing Pigs}, volume={101}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skad341.353}, abstractNote={Abstract}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Kuneff, Izadora and Rosero, David S. and Wilcock, Pete and Heugten, Eric}, year={2023}, month={Oct}, pages={310–311} }