ABSTRACT This study aimed to evaluate the use of decision trees to select sows based on the production parameters of parity order (PO) 1 sows from a commercial herd. Data were collected at a piglet production unit with a capacity of housing 5,500 sows in collective pens. Piglet production and sow culling information was collected from PO1 and PO2 sows. The period from January 2017 to March 2020 was analyzed. The correlation analysis was used to identify the influence of the production parameters on sow culling after exploring the database using the graphical analysis and descriptive statistics. The ANOVA was applied to evaluate differences in the response variables between culled and unculled sows. Two models were proposed using the decision tree method: model 1 referred to sow culling, and model 2 comprised the total number of liveborn piglets (TBA). The calculated value was close to 0, although the correlations of the production parameters with culling were statistically significant. The mean number of weaned piglets was higher for unculled sows in PO1 (p < 0.05). The number of weaned piglets, total number of liveborn piglets, and weaning-service interval did not differ in the unculled and culled sows in PO2 (p > 0.05). Using a confusion matrix as a metric tool, the decision tree method used in this study provided consistent results for this database, indicating its possible use for decision-making in sow selection. PO (PO herd 5500 5 500 5,50 pens 201 202 analyzed statistics TBA. TBA . (TBA) 0 significant p 0.05. 005 0.05 05 0.05) weaningservice weaning service tool decisionmaking making selection 550 50 5,5 20 (TBA 00 0.0 55 5, 0.

Abstract This study was conducted to assess the use of dietary acidifiers and their effects on the growth performance and intestinal morphometry of challenged and non-challenged nursery piglets. A total of 18,597 piglets distributed across 1,300 experimental groups from 128 papers published between 1984 and 2020 were included in the meta-analysis. All treatments were categorized as negative control (CON), organic acid (OAC), salts of organic acids (SAL), and blends of acidifiers (BLE). The presence (+) or absence (-) of health challenges in each study was also considered. The meta-analysis was conducted sequentially via graphical, correlation, and variance-covariance analyses. Piglets weighed between 8.4 and 15.8 kg and were assessed at 29.4-48.3 days of age. The addition of OAC, BLE, and SAL to the diets improved the feed conversion ratio (FCR) of piglets (P<0.001) by 5.3%, 3.6%, and 3.6%, respectively, compared to CON. Challenged piglets consumed 7.7% less feed (P<0.05) than the non-challenged piglets. Addition of OAC to diets reduced stomach pH by 8.6% (P<0.05) compared to CON piglets. The OAC and BLE diets reduced jejunum pH by 2.7% and 2.1% (P<0.05), respectively, compared to CON piglets. Challenged piglets had a 14.8% lower (P<0.01) villus height in the ileum compared non-challenged piglets. Acidifiers reduced the crypt depth in the jejunum of piglets by 17.4% (P<0.05) compared to the CON group. Acidifiers in the diet of nursery piglets improve performance by reducing pH in the gastrointestinal tract and indirectly improving intestinal integrity. Blends improved the performance of nursery piglets. nonchallenged non 18597 18 597 18,59 1300 1 300 1,30 12 198 202 metaanalysis. metaanalysis meta analysis. analysis CON, , (CON) (OAC) SAL, (SAL) BLE. . (BLE) + (+ (- considered graphical correlation variancecovariance variance covariance analyses 84 8 4 8. 158 15 15. 29.448.3 294483 29.4 48.3 29 48 3 29.4-48. age FCR (FCR P<0.001 P0001 P 0 001 (P<0.001 53 5 5.3% 36 6 3.6% respectively 77 7 7.7 P<0.05 P005 05 (P<0.05 86 8.6 27 2 2.7 21 2.1 P<0.05, 148 14 14.8 P<0.01 P001 01 (P<0.01 174 17 17.4 group integrity 1859 59 18,5 130 30 1,3 19 20 (CON (OAC (SAL (BLE ( 448 29.448. 29448 294 29. 483 48. 29.4-48 P<0.00 P000 00 (P<0.00 5.3 3.6 7. P<0.0 P00 (P<0.0 2. 14. 17. 185 18, 13 1, 44 29.448 2944 29.4-4 5. 3. P<0. P0 (P<0. 29.44 29.4- P<0 (P<0 P< (P< (P

RESUMO: Neste estudo, o objetivo foi avaliar diferentes abordagens de sistematização e meta-análise sobre o uso de ácidos cítrico e ascórbico no desempenho de leitões de creche. O estudo incluiu 24 publicações entre 1985 e 2018 (moda 1998), totalizando 4215 leitões de creche. O índice de Higgins indicou alta heterogeneidade entre os estudos envolvendo ácido cítrico (96,9%) e ácido ascórbico (91,4%). Na análise por forest plot a adição de ácido ascórbico em dietas de leitões não melhora (P > 0.05) o ganho de peso de leitões em creche. Na abordagem de meta-análise proposta por LOVATTO et al. (2007) e SAUVANT et al. (2008) não houve efeito significativo (P > 0.05) da adição de ácidos cítrico e de ascórbico no desempenho dos leitões. Numericamente, observou-se aumento do ganho de peso (Δ > 0) relacionado aos ácidos (suplementado em relação aos tratamentos controle) observado em 59.7% (acido ascórbico) e 46.6% (ácido cítrico) das comparações do ganho de peso diário. A suplementação de ácido ascórbico em relação ao tratamento controle no período total de creche teve variação de 0,98%, 1,07% e -1,3% para ADFI, ADG e FCR, respectivamente. A adição de ácido cítrico em relação ao tratamento controle teve variação de 1,67%, 4,40% e -2,29 para ADFI, ADG e FCR. A adição de ácidos cítrico e ascórbico em dietas para leitões de creche não altera o desempenho, independentemente da abordagem de meta-análise utilizada.

ABSTRACT: This study evaluated different meta-analytical approaches tousing citric and ascorbic acids in the performance of nursery piglets. The study included 24 publications between 1985 and 2018 (mode 1998), totaling 4215 nursery piglets. The Higgins index indicated high heterogeneity (98.5%) among the studies concerning citric acid (96.9%) and ascorbic acid (91.4%). In variances and forest plot analysis, using citric and ascorbic acids and their analogs was no significant effect (P > 0.05) on piglet weight gain. In the meta-analysis approach proposed by LOVATTO et al. (2007) and SAUVANT et al. (2008), there was no significant effect (P > 0.05) of the addition of citric and ascorbic acids on piglet performance. Numerically, was observed an increased ADG (Δ > 0) related to acids (supplemented over control treatments) in 59.7% (ascorbic acid) and 46.6% (citric acid) of the ADG comparisons. The effect of ascorbic supplementation on the respective control treatment of the overall nursery period was on average 0.98%, 1.07%, and -1.3% for ADFI, ADG, and FCR, respectively. Citric acid supplementation to the respective control treatment of the overall nursery period was on average 1.67%, 4.40%, and -2.29% for ADFI, ADG, and FCR. Adding citric and ascorbic acids in diets for nursery piglets does not alter performance regardless of the meta-analysis method used.