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.

RESUMO: O objetivo do estudo foi avaliar o efeito de extrato de tanino condensado de acácia-negra (Acacia mearnsii) no desempenho, consistência fecal e concentração sérica de haptoglobina em leitões na fase de creche. Foram utilizados 88 leitões desmamados aos 28±3 dias, com peso vivo médio inicial 8,02 ± 1,21 kg, alojados em duplas de mesmo sexo, e distribuídos em quatro tratamentos em um delineamento de blocos inteiramente ao acaso, em esquema fatorial 2 x 2. Os tratamentos experimentais foram: dieta simples (SD); dieta simples + tanino (SD+T); dieta complexa (CD) e dieta complexa + tanino (CD+T). As dietas simples foram formuladas com menores concentrações de derivados de leite, inclusão de cevada e sem adição de óxido de zinco, palatabilizante e levedura. As dietas com inclusão de tanino foram suplementadas com 1850 mg kg-1 de extrato concentrado de tanino de acácia negra. O programa alimentar foi constituído de três dietas: Pré-inicial I (0 a 7 dias), Pré-inicial II (8 a 21 dias) e Inicial (22 a 28 dias). Ração e água ficaram disponíveis ad libitum. O peso e o consumo de ração dos leitões foram mensurados semanalmente, para calcular a média diária de consumo, o ganho de peso diário e a conversão alimentar. O índice de consistência fecal foi medido diariamente para calcular a porcentagem de ocorrência de diarreia. Amostras de sangue para concentração sérica de haptoglobina foram coletadas aos sete e 14 dias após o desmame. A adição de tanino condensado não teve efeito (P > 0,05) no desempenho de leitões desmamados. O tipo de dieta também não afetou o desempenho dos leitões (P > 0,05). A inclusão do tanino condensado de acácia-negra (Acacia mearnsii) não afetou desempenho, reduziu a incidência de diarreia na primeira semana após o desmame, e diminuiu a resposta inflamatória da haptoglobina. RESUMO acácianegra negra Acacia mearnsii creche 8 283 3 28± 802 02 8,0 121 1 1,2 kg sexo acaso SD (SD) SD+T SDT T (SD+T) CD (CD CD+T. CDT CD+T . (CD+T) leite zinco levedura 185 kg1 kg- Préinicial Pré 0 ( , 22 (2 dias. libitum semanalmente desmame P 0,05 005 05 0,05. 80 8, 12 1, (SD (SD+T (CD+T 18 0,0 00 0,

ABSTRACT: This study evaluated the effect of black wattle (Acacia mearnsii) condensed tannin extract in simple and complex diets for weaned piglets on performance, faecal consistency and serum haptoglobin concentrations. Eighty-eight female and castrated male piglets were used, weaned at 28 ± 3 days old, with an initial body weight of 8.02 ± 1.21 kg, housed in same-sex pairs and distributed in four treatments in a 2 x 2 factorial experiment in a randomised complete block design. The experimental treatments were simple diet (SD), simple diet + tannin (SD+T), complex diet (CD) and complex diet + tannin (CD+T). The simple diets contained lower concentrations of dairy ingredients, inclusion of barley and no addition of zinc oxide, palatant, acidifier and yeast. The diets with tannin were supplemented with 1,850 mg kg-1 of black wattle condensed tannin extract. The feed programme consisted of three diets: Pre-starter I (0-7 days), Pre-starter II (8-21 days) and Starter (22-28 days). Feed and water were available ad libitum. Body weight and feed intake were measured weekly to calculate the average daily feed intake, daily weight gain and feed conversion ratio. The faecal consistency score was measured daily to calculate the diarrhoea occurrence percentage. Blood samples for serum haptoglobin concentration were collected at 7 and 14 days after weaning. The addition of condensed tannin had no effect (P > 0.05) on evaluated performance variables for weaned piglets. The diet type also did not affect the piglets’ performance (P > 0.05). The inclusion of black wattle (Acacia mearnsii) condensed tannin does not affect piglet performance, reduces the incidence of diarrhoea in the first week after weaning and decreases the haptoglobin inflammatory response. ABSTRACT Acacia mearnsii Eightyeight Eighty eight used old 802 8 02 8.0 121 1 21 1.2 kg samesex same sex design SD, SD , (SD) SD+T, SDT SD+T T (SD+T) CD (CD CD+T. CDT CD+T . (CD+T) ingredients oxide palatant yeast 1850 850 1,85 kg1 kg- Prestarter Pre starter 07 0 (0- days, 821 (8-2 2228 22 (22-2 days. libitum ratio percentage P 0.05 005 05 0.05. response 80 8. 12 1. (SD (SD+T (CD+T 185 85 1,8 (0 82 (8- 222 (22- 0.0 00 18 1, ( (8 (22 0. (2

To evaluate the effects of glutamine (Gln) supplementation on sow performance during late gestation and lactation and their offspring, eighty pregnant, multiparous sows of a commercial hybrid line were used in a completely randomized, 2 χ 2 experimental design at the end of gestation and lactation, respectively. Females were subjected to a control diet or a Gln-supplemented diet (1% of L-glutamine) from 85 d of gestation until farrowing. During lactation, the dietary treatment groups were CON_C: without Gln supplementation; CON_G: Gln only during lactation; GLN_C: Gln only during gestation; GLN_ GLN: Gln during gestation and lactation. At 105 d of gestation, there was no statistical difference regarding the body weight of the sows, however, sows fed the Gln-supplemented diet had greater backfat thickness at P1 and loin depth at P2 than control sows. Placental weight and efficiency showed no effect between treatments. Litters born from Gln-supplemented sows tended to be heavier at birth compared to control litters, reducing the probability of piglets weighing less than 1.5 kg. In addition, litters from supplemented sows had a lower standard deviation of BW at birth. There were no effects of dietary treatments on the performance of sows and offspring during the lactation period. Maternal Gln supplementation during late gestation improved piglet weight and litter uniformity at birth without affecting sow body composition after farrowing.

ABSTRACT A meta-analysis was employed to assess the effects of phytogenic feed additives and antibiotics on the performance and intestinal morphometry of unchallenged weanling pigs. The database included 41 articles published between 2004 and 2017, comprising 5,197 unchallenged nursery piglets. Piglets had 7.7 to 13.8 kg body weight and were assessed at 27.3 to 47.8 days of age, distributed into 156 experimental groups. All treatments were categorized into negative control, phytogenic additive (PA), and antibiotics (ATB) groups. The meta-analysis followed two sequential analyses: graphical and variance-covariance. Age and body weight were the factors that highly influenced the model. Piglets that received antibiotics had a higher (12.2%) daily weight gain than piglets in the control group. Phytogenic additives in diets enhanced intestinal morphometry in unchallenged piglets. Antibiotics increased (by 12.7%) the crypt depth of jejunum in comparison to the control treatment. Animals on PA had an 11.1% increment in villus height:crypt depth ratio than those on antibiotics. Phytogenic additives and antibiotics boost nursery piglet performance. Antibiotics advances the performance of unchallenged nursery piglets, but increases crypt depth in the jejunum. Performance of nursery piglets is better with combined phytogenic additives than with the isolated use of plant extracts. metaanalysis meta analysis pigs 4 200 2017 5197 5 197 5,19 77 7 7. 138 13 8 13. 273 27 3 27. 478 47 47. age 15 groups PA, , (PA) ATB (ATB analyses variancecovariance. variancecovariance variance covariance. covariance variance-covariance model 12.2% 122 12 2 (12.2% group by 12.7% 127 treatment 111 11 1 11.1 heightcrypt height extracts 20 201 519 19 5,1 (PA 12.2 (12.2 12.7 11. 51 5, 12. (12. (12 (1 (

The aim of this study was to evaluate the effects of seven different types of additives on the production performance and economic benefits of piglets at the nursery stage. A total of 2806 piglets, at ~21 days of age, were selected and divided into a high-bodyweight (H) group (> 6.5 kg) and a low-bodyweight (L) group (<6.0 kg) based on the weaned bodyweight (BW). Each group was further subdivided into seven additive groups and a control group. The control group was provided with basal diet, while the additive groups received the corresponding functional additives for either 15 or 30 d. Data collection continued until the end of the nursery stage (on the 45th day of the trial, at 70 d of age). Any single additive did not substantially improve the gained BW in nursery piglets. Overall, sex did not result in any BW differences at any time points. Supplementing feed with additives for 30 d led to better results in terms of production performance and economics for both H and L groups compared to 15 d, particularly with the fermented traditional Chinese medicine (additive VI). In comparison to the control group, the beneficial differences in the H group was more than double that observed in the L group. In summary, supplementing with functional additives for 30 d has potential to improve the production performance and economic benefits of nursery piglets, especially high-bodyweight piglets.

The study tested a 10% dietary inclusion of Macadamia nut oil cake (MOC) fortified with exogenous enzymes on nutrient digestibility and nitrogen balance in growing pigs. The diets included a commercial maize-soybean pig grower control and a 10% MOC diluted iso-nutrient mix, each with a duplicate supplemented with 500 g/tonne of an enzyme cocktail containing 3000 FTU g-1 6-phytase (IUB 3e1.3.26), 7270 U g-1 endo-1,4-beta-xylanase (EC-3.2.1.8), 300 U g-1 alpha amylase (EC-3.2.1.1), 6000 g-1 subtilisin protease (EC-3.4.21.62), and 532 U g-1 endo-1,4-beta-glucanase (IUB 3.2.1.6). Eight male Large White × Landrace 28-day-old weaned piglets were randomly assigned to the four diets in a 2×2 factorial experiment within two balanced 4 × 4 Latin squares for cross-over feeding over 8-day periods (3-d adaptation + 5-d feed intake) and total faecal and urine measurement. The digestibility of proximate and detergent fibre components, the nitrogen intake, faecal and urinary excretion; and the calculated total excretion, apparent digestibility, absorption, retention, utilization, and biological value of the dietary protein were evaluated. The 10% inclusion reduced dietary crude protein digestibility and the scaled live (g.kg-1 live weight) and metabolic (g/day/kg LW0.75) nitrogen retention. Scaled on live weight, the 10% MOC diet reduced nitrogen retention only when the diets contained exogenous enzymes. Further research is recommended to test the enzymes at a higher dosage or evaluate different enzyme activities.

ABSTRACT. This study aimed to correlate the physical characteristics of ground corn, at different crushing intensities, with the zootechnical performance of piglets in the nursery phase. Forty piglets (20 castrated males and 20 females) with an initial average weight of 15.7±1.98 kg and final weight of 32.5±3.27 kg were used. They were subjected to the same type of experimental diet (4% of commercial premix for the phase, 29% of soybean meal, and 67% of ground corn), with the only difference being the corn grinding process. The corn used was fractionated into five portions, and each one of them was crushed in a hammermill equipped with a different screen hole diameter (2; 2.5; 3; 3.5 and 4 mm). Which resulted in ground corn with the following particle sizes (PS): 518, 580, 628, 706 and 740 μm, and the following corn geometric standard deviations (GSD): 1.72, 1.71, 1.75, 1.80 and 1.90, respectively. The piglets were distributed in a completely randomized design with five treatments and four replications, with the experimental units being formed by pens with two piglets each. There was no effect (p > 0.10) from grinding intensities on daily feed intake (DFI) and daily weight gain (DWG). Conversely, there was an effect (p < 0.10) from different grinding intensities on feed conversion (FC). The PS and GSD of both the corn and diet, as well as the corn fractions retained on the 4-, 2- and 1.2-mm test sieves showed positive correlations with FC (p < 0.05). On the other hand, the corn fractions retained on the 0.6-, 0.3- and 0.15-mm teste sieves showed negative correlations with FC (p < 0.05). The linear model was the one that fitted the estimated data into the data observed for FC. A corn PS reduction from 740 to 580 μm promoted a linear improvement in FC. The use of corn fractions, retained on the 1-, 2- and 0.3-mm test sieves, and the use of corn GSD and diet GSD as independent variables showed a higher R² than that obtained with the use of corn PS as an independent variable in linear equations for estimating FC. ABSTRACT phase (2 2 females 157198 15 7 1 98 15.7±1.9 325327 32 5 3 27 32.5±3.2 4% (4 29 meal 67 , corn) process portions 2.5 25 35 3. mm. mm . mm) (PS) 518 628 70 74 (GSD) 172 72 1.72 171 71 1.71 175 75 1.75 180 80 1.8 190 90 1.90 respectively replications p 0.10 010 0 10 DFI (DFI DWG. DWG (DWG) Conversely (FC) 4, 4- 1.2mm 12mm 1.2 0.05. 005 0.05 05 0.05) hand 0.6, 06 0.6 6 0.6- 0.3 03 0.15mm 015mm 0.15 58 1, 1- 0.3mm 03mm R ( 15719 9 15.7±1. 32532 32.5±3. 2. (PS 51 62 (GSD 17 1.7 18 8 1. 19 1.9 0.1 01 (DWG (FC 2mm 12 00 0.0 0. 15mm 015 3mm 1571 15.7±1 3253 32.5±3 157 15.7± 325 32.5± 15.7 32.5 15. 32.

ABSTRACT. The aim of the present study was to evaluate the dietary effect of an enzymatic complex on the growth performance variables, blood parameters, and economic viability of piglets. To achieve this, we used 80 piglets (40 castrated males and 40 females) in a 2 × 2 factorial design following a randomized block experimental distribution, with two levels of metabolizable energy (adequate: 3206.09 and low: 3005.45 kcal kg-1) and two enzyme levels (0 and 50 g ton-1). The results showed no significant difference between treatments in the growth performance variables or blood parameters of piglets. The economic viability, economic efficiency index, and cost index were improved when we used a diet with a low energy supplemented with the enzyme complex as compared to other experimental diets. Thus, we concluded that enzyme complex supplementation can maintain growth performance and blood parameters in piglets even when they are fed low energy diets. Moreover, this could reduce production costs. ABSTRACT 8 (4 4 females distribution adequate (adequate 320609 3206 09 3206.0 300545 3005 45 3005.4 kg1 kg 1 kg-1 0 ( 5 ton1. ton1 ton . ton-1) diets Thus Moreover costs 32060 320 3206. 30054 300 3005. kg- ton-1 32 30 ton- 3

Resumo Com a seleção e progresso genético, o perfil das fêmeas foi modificado e a prolificidade tornou-se a principal característica. Como consequência, o desenvolvimento fetal foi afetado pelo aumento do número de leitões, o que resultou em maior competição uterina por nutrientes e espaço. O objetivo deste estudo foi analisar os efeitos da suplementação de glutamina e vitamina A na sobrevivência embrionária e fetal e sua influência no desempenho reprodutivo e produtivo de fêmeas. Foram selecionadas 71 fêmeas, oriundas dos cruzamentos Large White X Landrace X Meishan X Jianjing, de diferentes ordens de parto (OP) para a distribuição uniforme entre os tratamentos divididos em dois grupos. A suplementação de glutamina e vitamina A em períodos considerados críticos para a gestação mostrou-se efetiva neste estudo, em termos de coloração placentária, resultando em placentas mais escuras, o que poderia significar maior vascularização. A inclusão de glutamina e vitamina A influenciou em menos variabilidade em Natimortos por Leitegada (NL) e no Peso ao Nascer intra-leitegada dos Leitões Nascidos Vivos (PNLNV). Embora o tratamento não tenha influenciado o Peso Médio ao Nascer dos Leitões (PMNL), a suplementação reduziu a porcentagem de leitões leves (≤ 1000 g) em fêmeas de alta e baixa prolificidade. genético tornouse tornou se característica consequência espaço 7 Jianjing OP (OP grupos mostrouse mostrou placentária escuras vascularização NL (NL intraleitegada intra leitegada PNLNV. PNLNV . (PNLNV) PMNL, PMNL , (PMNL) ≤ ( 100 g (PNLNV (PMNL 10 1

Abstract Selection and genetic progress have led to the modification of the female profile, and prolificacy has become the main trait. Consequently, fetal development was affected by the increased number of piglets, resulting in higher uterine competition for nutrients and space. This study aimed to analyze the effects of glutamine and vitamin A supplementation on embryonic and fetal survival and their influence on the reproductive and productive performance of females. We selected 71 females from Large White X Landrace X Meishan X Jianjing crosses from different orders of parturition for uniform distribution between treatments, divided into two groups. Glutamine and vitamin A supplementation during periods considered critical for gestation was effective in terms of placental color, resulting in darker placentas, which could mean higher vascularization. The inclusion of glutamine and vitamin A influenced less variability in stillborn per litter and intra-litter birth weight of liveborn piglets. The treatment did not influence the mean birth weight of piglets but supplementation reduced the percentage of light piglets (≤ 1000 g) in high and low prolificacy females. profile trait Consequently space 7 treatments groups color placentas vascularization intralitter intra ≤ ( 100 g 10 1

RESUMO Avaliou-se o desempenho e morfometria das vilosidades intestinais em leitões alimentados com dietas líquidas com diferentes níveis de água comparando com dieta seca durante a primeira semana pós desmame. Foram usados 48 leitões de +/- 7 kg, desmamados aos 25 dias de idade, alojados em 24 baias durante sete dias. Adotou-se um delineamento inteiramente casualizado com seis tratamentos: ração seca (controle) fornecida no comedouro e água fornecida em bebedouro, dieta de controle umedecida com água na proporção 1:1 (ração/água) e acesso à agua no bebdouro (dieta 1:1+água); dieta controle umedecida com água na proporção de 1:2 (ração/água) e acesso ao bebedouro (dieta 1:2+água); dieta controle umedecida com água na proporção de 1:3 (ração/água) e acesso ao bebedouro (dieta 1:3+água); dieta controle umedecida com água na proporção de 1:2 (ração/água) sem acesso ao bebedouro (dieta 1:2/sem água); dieta controle umedecida com água na proporção de 1:3 (ração/água) sem acesso ao bebedouro (dieta 1:3/sem água). Nas dietas 1:2+água e 1:3+água observou-se melhora no desempenho dos leitões em comparação com a dieta seca. A dieta 1:2+água melhorou a proporção vilo/cripta do duodeno e dietas 1:2+água e 1:3+água melhoraram a relação vilo/cripta no jejuno em relação a dieta seca. Avaliouse Avaliou se desmame 4 +/ kg 2 idade Adotouse Adotou tratamentos (controle 11 1 1: ração/água raçãoágua (ração/água 11+água 11água 1+água 1:1+água) 12 12+água 12água 2+água 1:2+água) 13 3 13+água 13água 3+água 1:3+água) 12/sem 12sem 2/sem água) 13/sem 13sem 3/sem água. . observouse observou vilocripta vilo cripta + 1água 1:1+água 2água 3água 2sem 3sem

ABSTRACT The performance and morphometry of intestinal villi were evaluated in piglets fed liquid diets with different water levels compared to dry diets during the first week after weaning. The experiments were using 48 piglets around 7 kg, weaned at 25 days of age, and housed in 24 bays for seven days. A completely randomized design was adopted with six treatments: dry feed (control) provided in the feeder and water provided in the drinker; control diet moistened with water in a 1:1 ratio (feed/water) and access to the drinker (1:1+water); control diet moistened with water in a 1:2 ratio (feed/water) and access to the drinker (1:2+water); control diet moistened with water in a 1:3 ratio (feed/water) and access to the drinker (1:3+water); control diet moistened with water in a ratio of 1:2 (feed/water) without access to the drinker (diet 1:2/no water); control diet moistened with water in a ratio of 1:3 (feed/water) without access to the drinker (diet 1:3/no water). In the 1:2+water and 1:3+water diets, there was an improvement in piglet performance compared to the dry diet. The 1:2+water diet improved the duodenal villus/crypt ratio and the 1:2+water and 1:3+water diets improved the jejunal villus/crypt ratio compared to the dry diet. weaning 4 kg 2 age treatments (control 11 1 1: feed/water feedwater (feed/water 11+water 11water 1+water (1:1+water) 12 12+water 12water 2+water (1:2+water) 13 3 13+water 13water 3+water (1:3+water) 12/no 12no no 2/no water) 13/no 13no 3/no water. . villuscrypt villus crypt 1water (1:1+water 2water (1:2+water 3water (1:3+water 2no 3no

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

ABSTRACT This study aimed to develop and assess a deterministic mathematical model for predicting the impacts of varying sow replacement rates on the performance of farms producing weaned piglets. Initially, the influence of replacement rate on herd structure was examined using two equations, which accounted for the percentage of sows replaced (55, 45, and 35%), retention rates between parities (13, 9, and 5%), and number of last parities in the herd (6, 7, and 8). The model then estimated sow development throughout the reproductive cycle, starting with an initial weight of 140 kg at first mating and adjusting for weight gains during gestation and losses during lactation, influenced by the varying number of live-born piglets across parities. Energy requirements were calculated using the factorial method, which included maintenance, protein and fat gains, and milk production. The generated data formed various scenarios to derive productive values. These scenarios were analyzed using analysis of variance with the general linear model procedure, treating each scenario as a separate treatment. Early parities (up to P3) contributed 42% in SC-35, 51% in SC-45, and 60% in SC-55. Significant differences were noted in variables such as average parity, birth weight, feed intake during gestation, and average piglet weight gain. The developed model, incorporating replacement gilt modules, gestation, and lactation, can effectively predict herd structure by parity and assess the impact of annual sow replacement rates on the productivity of farms rearing weaned piglets. Initially equations 55, 55 (55 45 35%, 35 35% , 35%) 13, 13 (13 9 5%, 5 5% 5%) 6, 6 (6 7 8. 8 . 8) cycle 14 lactation liveborn live born method maintenance production values procedure treatment up P3 P 42 SC35, SC35 SC 35, SC-35 51 SC45, SC45 SC-45 60 SC55. SC55 55. SC-55 gain modules (5 4 3 1 (1 ( SC3 SC-3 SC4 SC-4 SC5 SC-5 SC-

Abstract The aim of this study was to classify the sows for longevity based on the total number of piglets born alive in the first parities. Data comprising the period from January 2017 to March 2020 were obtained from a commercial farm with 5,500 sows. A total of 8,869 sows were used in the analyses. The animals were divided into three parity groups according to the 1st and 3rd quartiles of the total number of piglets born alive in the first and second farrowing: parity 1 - 1L (low): <12 piglets, 1M (medium): 12 to 16 piglets, and 1H (high): >16 piglets; parity 2 - 2L: <12 piglets; 2M: 12 to 16 piglets, and 2H: >16 piglets. Sows exhibiting high performance in the first parity continued to do so up to the sixth parity. Regarding parity 1 classification, 1H sows (>16 piglets) produced more piglets than the other classes up to the fifth parity. When the parity 2 classification was added, 1H2H and 1H2M sows produced more piglets up to the fourth parity. Comparison of the length of stay of sows in the herd showed a longer mean stay of the 1H2M class. The main reasons for culling were cystitis, uterine prolapse, hoof problems, and physical condition. In general, the results demonstrated that it is possible to use the number of piglets born alive in the first two parities of sows to predict the productivity of subsequent parities. The method is able may therefore help to maintenance of the sow in the herd or culling of sows. 201 202 5500 5 500 5,50 8869 8 869 8,86 analyses st rd farrowing L low (low) <1 M medium (medium) H (high) >1 2L 2M 2H (>1 added HH HM class cystitis prolapse problems condition general 20 550 50 5,5 886 86 8,8 (low < (medium (high > (> 55 5, 88 8, (

Abstract Objective: To analize the contribution of women to the family’s economy through their experiences and agricultural sales strategies at Pedernal, San Cristóbal de Las Casas, Chiapas. Methodology: Qualitative research of ethnographic nature was carried out by applying semistructured interviews to women and participant observation. Results: Family agriculture in Pedernal provides food for self-consumption and monetary income through the sale of surplus mainly obtained from backyards managed by women. They sell different products at a regional scale of which we highlight avocado fruits and pigs (piglets); for both products they have got contrasting and complementary sales strategies inside and outside the locality, addressed to obtain the highest possible profit and to minimize the risk of loss. However, prices neither meet production costs nor consider women’s care work. Limitations: The exploratory and qualitative nature of this research does not allow to deepen aspects such as the quantification of investments, returns, and the value of care work. Conclusions: The sale of women's agricultural and livestock production generates an additional income to meet daily subsistence needs, and contributes to diversity of regional creole varieties.

Resumen Objetivo: Analizar la contribución de las mujeres a la economía familiar a través de sus experiencias y estrategias de venta agropecuaria en Pedernal, San Cristóbal de Las Casas, Chiapas. Metodología: investigación cualitativa, de corte etnográfico, a través de la aplicación de entrevistas semiestructuradas a mujeres y observación participante. Metodología: Investigación cualitativa, de corte etnográfico, a través de la aplicación de entrevistas semiestructuradas a mujeres y observación participante. Resultados: La agricultura familiar de Pedernal provee alimentos de autoconsumo y un ingreso económico mediante la venta de excedentes, donde es relevante el traspatio, manejado por las mujeres. Ellas comercializan distintos productos en la región, de los que destacamos los frutos del aguacate y los cerdos (lechones); para ambos productos tienen estrategias de venta contrastantes y complementarias dentro y fuera la localidad, tratando de obtener la mayor ganancia posible y minimizar los riesgos de pérdida. Aun así, los precios de venta no alcanzan a cubrir los costos de producción y del trabajo de cuidado realizado por las mujeres. Limitaciones: El énfasis exploratorio y cualitativo del trabajo no permitió profundizar en aspectos importantes como la cuantificación de inversión e ingresos monetarios de la producción y venta agropecuaria, incluyendo el valor del trabajo de cuidados. Conclusiones: La venta de productos agropecuarios permite a las mujeres generar un ingreso económico complementario para solventar necesidades de subsistencia cotidiana, y contribuye a la diversidad alimentaria regional con productos criollos.

Abstract 19. In the last decades, infections by several serovars of Salmonella have become relevant worldwide, not only due to their impact on veterinary health and animal production, but also because they may serve as a source of infection for the human population. Pigs can be infected by several Salmonella serovars, being S. Typhimurium one of the most frequently isolated worldwide. In this context, the evaluation of strategies to control Salmonella in farms demands the understanding of the pathogenesis of the microorganism. Thus, the objective of this work was to carry out an experimental infection in 50-day-old pigs using a field strain of S. Typhimurium to evaluate the excretion of the microorganism, organs colonization and the development of histological injuries over the 13-day trial period. Disease was successfully reproduced in eight animals, and two clinical patterns were identified. In four animals, a primarily enteric pattern was observed, where the infection was limited to the gastrointestinal tract, while in another four pigs, enteric and systemic infection with variable fecal excretion and invasion of internal organs was observed. These two infectious patterns were accompanied by changes in fecal consistency and reduced daily weight gain or weight loss in the animals. The observation of two different infectious patterns highlights the need to consider the complexity of the pathogenicity of Salmonella Typhimurium infection in pigs.

Resumen. 23. En las últimas décadas las infecciones por diferentes serovariedades de Salmonella han adquirido importancia a nivel mundial, no solo por su impacto en la sanidad y en la producción de los animales, sino también porque estos constituyen una fuente de infección para los humanos. Los cerdos pueden estar infectados o ser portadores de distintas serovariedades con potencial zoonótico, siendo S. Typhimurium una de las más frecuentemente aisladas a nivel mundial. En este contexto, la evaluación de estrategias para el control de Salmonella en granjas exige el conocimiento de la patogenia del microorganismo. El objetivo de este trabajo fue realizar una infección experimental en cerdos de 50 días de edad utilizando una cepa de campo de S. Typhimurium para evaluar la excreción del microorganismo, la colonización de órganos y el desarrollo de lesiones histológicas durante los 13 días del ensayo. Se logró reproducir la enfermedad en ocho animales y se pudo identificar dos cuadros clínicos. En cuatro animales se observó un cuadro principalmente entérico, en el que la infección estuvo limitada al tracto gastrointestinal; mientras que en otros cuatro cerdos se observó infección entérica y sistémica con excreción fecal variable e invasión de órganos internos. Estos dos cuadros infecciosos estuvieron acompañados de cambios en la consistencia de la materia fecal y menor ganancia diaria de peso o adelgazamiento de los animales. La observación de dos cuadros infecciosos diferentes muestra la necesidad de considerar la complejidad de la patogenicidad de la infección por Salmonella Typhimurium en cerdos.