Consequences of timing of organic enrichment provision on pig performance, health and stress resilience after weaning and regrouping

Publication history: Accepted - 20 August 2022; Published online - 29 September 2022Most pigs in slatted systems are provided with enrichment meeting only minimum legal requirements. We aimed to explore the effects of a novel enrichment treatment consisting of daily provided fodder beet and jute bags for pigs in slatted systems, and investigate the timing of enrichment provision on performance, health and stress resilience. We used 280 weaners allocated into standard (S, meeting only legal requirements consisting of a plastic toy and softwood) or enriched (E) treatment (n = 14 groups/treatment). At regrouping during the grower to finisher transition, pigs were either kept in the same treatment (EE, SS) or switched from enriched to standard (ES) and vice versa (SE); each treatment was replicated on five groups. Pigs were weighted at the start and end of weaner, and finisher stage, and feed intake was recorded. Occurrence of scouring, respiratory problems, locomotor disorders, tail, ear, and body lesions were recorded twice a week. Ten males per treatment were sampled for saliva on days 1, 2 and 4, either postweaning or after the housing switch. Saliva samples were analysed for cortisol, alpha-amylase, haptoglobin (Hp), and adenosine deaminase. Additionally, these pigs were sampled for hair at the start and end of weaner, and end of finisher stage to analyse for hair cortisol and cortisone. We found that E weaners consumed less feed (P = 0.04), had better FCR (feed conversion ratio, P = 0.03) and less ear lesions for two weeks postweaning (P = 0.04), and tended to have lower occurrence of scouring (P = 0.07) and higher salivary cortisol concentrations (P = 0.09) than S weaners. Effects of enrichment treatment during weaner stage on performance were carried through to finisher stage, with EE and ES pigs having better FCR (P = 0.0009) and higher BW (P = 0.0001) compared to SS and SE pigs. E treatment during finisher stage decreased feed intake (P = 0.04) and tended to decrease Hp levels (P = 0.07). There was a significant interaction between enrichment treatments during weaner and finisher stages on finisher body lesions: EE finishers had less lesions than SS, ES, and SE finishers (P = 0.04). There were no other significant differences caused either by enrichment treatment during weaner/finisher stage or their interaction. We conclude that the novel enrichment applied at weaner stage had positive effects on ear lesions and performance, which were carried through to finisher stage. Body lesions were affected by its application during both stages, with finishers receiving the enrichment treatment throughout (EE) having reduced body lesions than the rest of the finishers.This research was part of the EU-China HealthyLivestock project. The authors wish to acknowledge that HealthyLivestock is funded by the European Union H2020 research and innovation programme under grant agreement number 773436. The European Commission’s support for the production of this publication does not constitute an endorsement of the contents, which reflect the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein

Effects of the feed : Water mixing proportion on diet digestibility of growing pigs

Funding: This research was funded by Spanish Ministry of Science and Innovation (CDTI project IDI-20110003), and TEM 2010 research grant form "Comissionat per a Universitats I Recerca del Departament d'Innovació, Universitats I empresa form Generalitat de Catalunya (AGAUR).The effect of different water-to-feed ratios on apparent total tract digestibility of energy and nutrients were evaluated in growing-finishing pigs. In trial 1 (26 d), 16 female pigs (46.7 ± 1.98 kg of body weight, BW) were individually assigned to four treatments (n = 4). In trial 1, pigs were fed a control diet in dry form (CON) and in blend form with water-to-feed ratios of 0.6:1, 2.1:1 and 2.7:1. In trial 2 (26 d), rearranged animals (65.4 ± 3.14 kg of BW) were assigned a control diet in dry form (CON) and ratios of 1.35:1, 2.7:1 and 3.5:1. In trial 1, pigs fed on ratios of 2.1:1 and 2.7:1 had a higher organic matter digestibility (OMd) and gross energy digestibility (GEd) than CON. In trial 2, pigs fed on ratios of 1.35:1, 2.7:1, and 3.5:1 had a higher OMd and GEd than CON. Quadratic regressions showed the maximum dilution rate to reach higher digestibility coefficients at 1.83:1 and at 2.7:1 for trials 1 and 2, respectively. During trial 1, pigs on the 0.6:1 dilution rate had higher weight gain than those on CON. The water-to-feed ratio that optimized OM and GE digestibility may increase with the age of the pigs

Impact of feeding low and average birthweight pigs on a weight basis post-weaning on growth performance and body composition

Publication history: Accepted - 28 August 2020; Published online - 29 August 2020This study aimed to investigate the effectiveness of employing a targeted nutritional regime until slaughter to maintain performance in animals recording high weaning weights. Low birthweight (Low BW; <1 kg) and average birthweight (Av BW; 1.3kg-1.7 kg) pigs were reared on sows exhibiting a high lactation feed intake and, as a result, weaning weights were 7.9 kg and 8.9 kg respectively. Pens containing either Low BW or Av BW animals were then offered either a ‘standard’ (STAND) or ‘feed-to-weight’ (FTW) regime from weaning until slaughter. The STAND regime was reflective of commercial production, where diet transitions were implemented after pre-determined feed levels or time intervals had been reached. In contrast, diet transitions in the FTW regime were carried out when target pen average weights of 12 kg, 18 kg, 22 kg, 45 kg and 75 kg respectively were met. Animal growth, feeding performance and body composition were monitored from weaning until slaughter. As expected, Av BW pigs were heavier than Low BW animals throughout (P<0.001), recording a superior average daily gain (ADG) (P<0.01) and average daily feed intake (ADFI) (P<0.001) at each stage of growth. This resulted in Av BW animals recording a greater carcass weight (P<0.001) and kill-out percentage (P<0.01). DEXA scan analysis showed Low BW animals to exhibit a greater percentage fat (P<0.001) and lower percentage lean (P0.05). Feeding regime did not affect age or weight at diet transition for Av BW animals for most transitions (P>0.05). However Low BW animals offered the FTW regime were significantly older and heavier than those offered the STAND regime at each transition (P<0.05). The FTW regime increased animal ADG and ADFI compared to STAND pigs from weeks 4 to 10 of age (P<0.05), whilst providing a greater average daily intake of energy and lysine from week 4 to 10 (P<0.05) and week 10 to 17 (P<0.05). This facilitated a greater liveweight in FTW animals from 7 weeks of age through to slaughter (P<0.05). Feeding regime had no effect on kill-out percentage or back-fat depth (P>0.05). Furthermore, DEXA scan results showed total or percentage lean and fat did not differ for FTW or STAND pigs at 10 or 21 weeks of age (P>0.05). In conclusion, feeding Low BW animals on a ‘feed to weight’ basis improved nutrient intake and animal liveweight, likely due to a greater time allowance for digestive development between diet transitions. As such, this approach should be considered for commercial adoption.DAER

Effect of Phase Feeding, Space Allowance and Mixing on Productive Performance of Grower-Finisher Pigs

Publication history: Accepted - 2 February 2022; Published online - 7 February 2022This study investigates the effects of space allowance (SA), mixing and phase feeding (PF) on performance of grower-finisher pigs. Three trials (T) were conducted. In T1 and T2, 345 pigs/trial were moved to finisher stage at 11 weeks of age and assigned to two SAs: 0.96 (n = 15 pens; 10 pigs/pen) and 0.78 (n = 15; 13 pigs/pen) m2/pig. Mixing was applied to 5 pens of each SA leading to a 2 × 2 factorial arrangement (SA × Mixing). For PF, 2 diets with 0.95 and 0.82 g SID Lys/MJ NE were applied to 5 pens of each SA (not mixed) leading to another 2 × 2 factorial arrangement (SA × PF). In T3, 230 pigs were moved to the grower-finisher stage at 11 weeks of age, mixed, and assigned to 4 treatments (SA × PF; n = 5 pens). Data were analyzed using general linear mixed models. SA did not affect performance (p > 0.05). Non-mixed pigs were 5.40 (T1) and 5.25 (T2) kg heavier than mixed pigs at 21 weeks of age (p < 0.001). PF reduced performance of pigs by 3.45 (T1) and 4.05 (T2) kg at 21 weeks of age (p < 0.001). In conclusion, mixing and reducing SID Lys:NE ratio from 0.95 to 0.82 g/MJ at 15–16 weeks of age, have a more marked impact on performance than reducing SA from 0.96 to 0.78 m2/pig.Jordi Camp Montoro and Joana Pessoa were supported by the Teagasc Walsh Scholarship Scheme grant-in-aid projects Introducing new feeding programs and facilities for Irish finishing pigs ref 0415 and Optimizing feedback of computerized meat inspection findings and Precision Livestock Farming monitors on farm to improve pig health, welfare and carcass quality ref 0165, respectively

Blood and faecal biomarkers to assess dietary energy, protein and amino acid efficiency of utilization by growing and finishing pigs.

Publication history: Accepted - 20 June 2022; Published online - 4 July 2022Background: Diet evaluation and optimization is a slow and expensive process and it is not possible to do it at a farm level. This study aimed to use the blood serum metabolite (BSM) and faecal volatile fatty acid (VFA) profles as potential biomarkers to identify changes in protein, amino acid and energy dietary content in growing and fnishing pig diets at farm level. Results: Two studies were conducted. The frst study (S1) included 20 pens of 11 pigs (87.0±4.10 kg; 18 weeks old) assigned to 5 diets: control (C1), high or low crude protein (HP1 and LP1, respectively), and high or low net energy (HE1 and LE1, respectively). The second study (S2) included 28 pens of 11 pigs (41.3±2.60 kg; 12 weeks old) assigned to 7 diets: control (C2), high or low crude protein (HP2 and LP2, respectively), high or low amino acid (HA2 and LA2, respectively), and high or low net energy (HE2 and LE2, respectively). Pigs were followed for 10 (S1) and 20 (S2) days, and blood and faecal samples were collected at 20 (S1) and 14 (S2) weeks of age. Data were analysed using gen‑ eral linear models and receiver operating characteristic curve analysis. Urea nitrogen showed the best results as a biomarker. Urea nitrogen was higher in pigs fed high protein diets, HP1 (13.6±0.95 mg/dL) and HP2 (11.6±0.61), compared to those fed low protein diets, LP1 (6.0±0.95) and LP2 (5.2±0.61; P<0.001), showing good discrimination ability (Area under the curve (AUC)=98.4 and 100%, respectively). These diferences were not observed between diets LA2 (6.5±0.61) and HA2 (8.7±0.61; P>0.05; AUC=71.9%), which were formulated based on the ideal protein profle but with no excess of protein. Creatinine, triglycerides, branched-chain fatty acids, albumin, propionic acid, and cholesterol showed diferences between at least 2 diets but only in one of the studies. Conclusions: Urea nitrogen showed high accuracy to detect excess of crude protein in growing and fnishing pig diets. Other biomarkers like BCFA showed promising results and need to be further studied.Jordi Camp Montoro was supported by the Teagasc Walsh Scholarship Scheme grant-in-aid project Introducing new feeding programs and facilities for Irish finishing pigs ref 0415. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

Parturition in mammals: animal models, pain, and distres

Publication history: Accepted - 12 October 2021; Published online - 14 October 2021.Parturition is a complex physiological process and involves many hormonal, morphological, physiological, and behavioural changes. Labour is a crucial moment for numerous species and is usually the most painful experience in females. Contrary to the extensive research in humans, there are limited pain studies associated with the birth process in domestic animals. Nonetheless, awareness of parturition has increased among the public, owners, and the scientific community during recent years. Dystocia is a significant factor that increases the level of parturition pain. It is considered less common in polytocous species because newborns’ number and small size might lead to the belief that the parturition process is less painful than in monotocous animal species and humans. This review aims to provide elements of the current knowledge about human labour pain (monotocous species), the relevant contribution of the rat model to human labour pain, and the current clinical and experimental knowledge of parturition pain mechanisms in domestic animals that support the fact that domestic polytocous species also experience pain. Moreover, both for women and domestic animal species, parturition’s pain represents a potential welfare concern, and information on pain indicators and the appropriate analgesic therapy are discusse

Improving vitamin D content in pork meat by UVB biofortification

Publication history: Accepted - 11 January 2023; Published online - 14 January 2023Vitamin D deficiency is prevalent worldwide and identification of alternative food-based strategies are urgently warranted. In two studies, 12-week old crossbred pigs (Duroc x (Large White x Landrace)) were exposed daily to narrowband UVB radiation for ∼10 weeks or control (no UVB exposure) until slaughter. In Study 1 (n = 48), pigs were exposed to UVB for 2 min and in Study 2 (n = 20), this duration was tripled to 6 min. All pigs were fed the maximum permitted 2000 IU vitamin D3/kg feed. Loin meat was cooked prior to vitamin D LC-MS/MS analysis. In Study 1, pork loin vitamin D3 did not differ between groups. Study 2 provided longer UVB exposure time and resulted in significantly higher loin vitamin D3 (11.97 vs. 6.03 μg/kg), 25(OH)D3 (2.09 vs. 1.65 μg/kg) and total vitamin D activity (22.88 vs. 14.50 μg/kg) concentrations, compared to control (P < 0.05). Pigs remained healthy during both studies and developed no signs of erythema. Biofortification by UVB radiation provides an effective strategy to further safely increase the naturally occurring vitamin D content of pork loin, alongside feed supplementationThis work was funded as part of a Department for the Economy (DfE) Co-operative Awards in Science and Technology (CAST) PhD studentship, supported by Devenish Nutrition Limited and Agri-Food Quest Competence Centre (AFQCC)

Welfare and management strategies to reduce pre-weaning mortality in piglets

La mortalitat durant la lactació és probablement el major problema econòmic i de benestar a afrontar per les explotacions porcines. Davant aquesta problemàtica, el principal objectiu d’aquesta tesis doctoral és intentar identificar els principals aspectes que poden contribuir a incrementar la supervivència dels garrins durant la lactació i, al mateix temps, identificar i jerarquitzar les tasques de maneig més efectives realitzades al voltant del part. Quatre estudis s’han dissenyat per assolir els nostres objectius (chapter 4, 5, 6 and 7): Al primer estudi, es van portar a terme dos experiments per estudiar l’efecte sobre truges primípares i les seves garrinades que s’observa després d’allotjar les truges en grup durant la gestació i mantenir-les lleugerament sobrealimentades (PEN, n = 27 per Exp. 1; n = 10 per Exp. 2) en comparació a tenir-les en gàbies convencionals (STALL, n = 24 per Exp. 1, n = 9 per Exp. 2). Es va mesurar la grassa dorsal (BF) al inici i final de la lactació i es va registrar la mortalitat. Els garrins es van pesar i es va registrar la seva temperatura rectal (RT). Per l’Exp. 1 es va enregistrar el comportament d’un subgrup de truges. Per l’Exp. 2 es van analitzar cortisol salivar de les truges i la concentració en sang de TSH i T4 dels garrins. Les truges del grup PEN van mostrar major BF a l’inici de la lactació (P < 0.001). Es va observar una tendència a major concentració de cortisol en les truges del grup PEN a les 24 h d’estar a les gàbies de part (P = 0.070) i una tendència a passar-se més temps assegudes o dempeus la jornada anterior al part (P = 0.057). Els garrins nascuts al grup PEN van tenir nivells menors de T4 (P = 0.078). No obstant, els garrins del grup STALL tingueren major RT als 60 min de vida (P < 0.05) i van sobreviure en més nombre després de les primeres 48 h de vida fins al final de la lactació (P < 0.05). A l’Exp. 2, els garrins del grup STALL pesaven més (P < 0.05) i van tenir un guany mig diari durant lactació més elevat (P < 0.05). Les truges nul·lípares allotjades en grup i lleugerament sobrealimentades durant la gestació es veuen sotmeses a un major estrès al ser introduïdes a les gàbies de maternitat que les truges allotjades en gàbies convencionals durant la gestació. Aquest estrès matern pot comprometre la capacitat de termoregulació dels seus garrins. L’objectiu del segon experiment va ser el de desenvolupar, a partir del seu comportament, un sistema d’avaluació de la vitalitat dels garrins que guardés relació amb el seu posterior creixament i supervivència. Es van emprar 287 garrins provinents de 21 truges multípares. Els garrins es van pesar acabat el part i es van avaluar 4 paràmetres comportamentals en un petit tancat circular de 55 cm de diàmetre: capacitat de moviment (U), estimulació del braguer (U), nombre de voltes completes dins el tancat (N), i capacitat de cridar (S). A dia 1, 2, 3 i 17 es van pesar els garrins, i a dia 1, 2 i 3 se’ls hi va mesurar la RT. Es van realitzar anàlisis de regressió múltiple per la supervivència i creixement dels garrins fins el deslletament. El guany de pes dels garrins durant la lactació va estar influenciat pel pes al naixement (P < 0.001), el número de part de al truja (P = 0.024), el número de nascuts vius al part (P < 0.001), i pel sumatori dels paràmetres U i N (UN; P = 0.023). La capacitat de sobreviure dels garrins va ser influenciada pel pes al naixement (P = 0.015), pel paràmetre UN (P = 0.026), i per la RT a dia 3 (P = 0.085). El sumatori de la valoració als paràmetres U i N, combinats amb el pes al naixement i la informació de la truja, són útils per ajudar a predir el potencial de creixement i la viabilitat del garrí durant la lactació, convertint-se en una possible eina per millorar el maneig durant els primers dies de vida dels garrins. Resumint, el paràmetre UN és fàcil d’obtenir i pot ser d’utilitat per avaluar els garrins tant per criteris científics com productius. El tercer estudi està centrat en estudiar diferents mesures de maneig orientades a maximitzar la presa de calostre per part dels garrins. Es van utilitzar 39 truges primípares (507 garrins) i 100 multípares (1375 garrins). Els garrins es van classificar en: nascuts amb un pes de 1.30 kg o inferior (SP) i nascuts amb un pes superior a 1.30 kg (BP). Les garrinades es va distribuir a un dels 4 tractaments: grup control (CON); deixar que els SP mamin durant 2 h separant els BP (SPLIT); subministrar oralment 15 ml de calostre de truja als SP (COL); i subministrar 3 ml d’un producte energetic (Calostrene®) als SP (EN). Es van fer el mínim d’adopcions, ajustant les garrinades a 12 garrins (mantenint 4 o 5 SP a cada garrinada). Els garrins es van pesar al dia 1 i 18 de vida, i es va registrar la mortaitat. En les garrinades de primípares, els SP del grup COL van pesar més que els de CON, SPLIT i EN a les 24 h de vida (dia 1) (P = 0.020, P = 0.022, and P = 0.046, respectivament). Malauradament, aquesta diferència no es va observar a dia 18. En les garrinades de multípares no es van observar diferències de pes durant la lactació entre els diferents grups. Tot i que entre les garrinades de primípares i multípares els SP no diferien en pes al naixement, a dia 1, els SP de primípares eren més pesats (P = 0.020). Malgrat aquestes circumstàncies, no es va reduir la mortalitat a les garrinades del grup COL (ni en primípares ni en multípares). La complementació oral millora el guany de pes durant el primer dia de vida dels garrins SP nascuts de primípares, però no ajuda a reduir la mortalitat durant la lactació. En el quart i últim experiment es va estudiar l’efecte d’aportar calostre als garrins nascuts amb un pes igual o inferior a 1.35 kg (SP) (CON: grup control; COL:subministrar oralment 15 ml de calostre de truja), i l’efecte de realitzar adopcions a les 24 h (HL: ajustar garrinades a 12 garrins amb 4 o 5 essent SP; o LL: majoria dels garrins de al garrinada essent SP). Combinant els dos factors s’obtingueren 4 tractaments: CON-HL, CON-LL, COL-HL, COL-LL. Els garrins de 46 garrinades es van pesar també a dia 1 i 19, i la mortalitat es va registrar. Al dia 4 de vida, es va extreure sang de 79 garrins SP per analitzar la concentració d’IgG, i també de 8 garrins SP separats de la truja durant 12 h i alimentats artificialment que es van utilitzar com a control negatiu. Les garrinades LL tenien un CV del pes a dia 1 menor comparat amb el grup HL (16.2 vs. 21.9 ± 0.91%, P = 0.003), però no diferien pel mateix paràmetre a dia 19 (23.2 vs. 23.4 ± 1.72%; P > 0.10). A dia 19, les truges HL van tenir menys garrins morts per garrinada que les truges LL (0.80 vs. 1.69 ± 0.307; P = 0.022) i les truges del grup COL-HL van tenir menys garrins morts per garrinada que les CON-HL (0.47 vs. 1.14 ± 0.160; P = 0.062). Les adopcions dels SP per formar garrinades LL no va aconseguir reduir el CV de pes de al garrinada al deslletament. Els garrins del grup COL van tenir major concentració de IgG que els del grup CON (P = 0.001); mentre que el grup control negatiu va tenir nivells de IgG inferiors a COL i CON (5.4 ± 2.32 mg/ml vs. 30.6 ± 1.58 mg/ml and 21.5 ± 0.95 mg/ml. respectively; P < 0.001 ambdós casos). Fer ‘garrinades de petits’ no va reduir la mortalitat ni va reduir el CV del pes de la garrinada. Donar calostre als garrins SP millora el seu estatus immunitari a dia 4. A més a més, en garrinades no homogeneïtzades, aportar calostre als garrins SP és una bona estratègia per millorar el seu rendiment.Pre-weaning mortality in breeding herds remains as one of the most important welfare and economic problems in swine production. Therefore, the principal objective of the present thesis was to identify the main aspects that may help to reduce on-farm piglet pre-weaning mortality and to establish a management hierarchy identifying the most effective tasks around farrowing. To achieve our objective, four studies were performed (chapter 4, 5, 6 and 7): In the first study, two experiments were carried out to observe the effect of two gestation management systems (STALL: gilts housed in stalls with no changes in management, and PEN: slightly overfed gilts loose-housed in pens) on gilt and piglet performance. A total of 27 PEN and 24 STALL gilts and 10 PEN and 9 STALL gilts were used in Exp. 1 and Exp. 2, respectively. Backfat (BF) at the beginning and at the end of lactation, and litter pre-weaning mortality were recorded in gilts. Weight and rectal temperature (RT) was recorded in piglets. In Exp. 1 the behaviour of a subsample of gilts was continuously videotaped during lactation. In Exp. 2 cortisol in gilt saliva, and TSH and T4 in piglet blood were measured. In both experiments, PEN gilts had more BF than STALL gilts when moved to the farrowing stalls (P < 0.001). PEN gilts tended to have higher cortisol concentration 24 h after entering the farrowing stall (P = 0.070) and to spend more time sitting or standing up 1 day before parturition (P = 0.057) than STALL gilts. Piglets from PEN gilts had lower T4 (P = 0.078) than those from STALL gilts. However, piglets from STALL gilts showed higher RT 60 min after birth (P < 0.05) and lower mortality from 48 h after of birth until weaning (P < 0.05). In Exp. 2, piglets from STALL group also had higher BW (P < 0.05) and average daily gain (P < 0.05) at the end of lactation. During lactation, PEN gilts lost more BF than STALL gilts (P < 0.001). Gilts that are loose-housed and slightly overfed in pens during gestation may be more stressed when housed in farrowing stalls than those that have been kept in stalls during gestation, thus compromising their offspring thermoregulatory capacity and growth. For the second study, the aim was to develop a vitality scoring method based on piglet behavior and relate it to piglet growth and survival. From 21 sows, 287 piglets were used. After farrowing (day 0), piglets were weighed and tested for 4 behavioural parameters in a circular enclosure (55 cm diameter): movement capacity (M), udder stimulation (U), number of completed circles around the enclosure (N), and screaming (S). Piglets were weighed again on day 1, 2, 3 and 17. Piglet RT was recorded on day 0, 1, 2 and 3. Sow’s farrowing information was recorded. Multiple regression analyses for survival and BW gain at weaning as dependent variables was performed. Piglet BW gain at weaning was influenced by BW at birth (P < 0.001), sow parity (P = 0.024), total number of piglets born alive per sow (P < 0.001), and the sum of U and N parameters (UN; P = 0.023). Piglet survival during lactation was influenced by BW at birth (P = 0.015), UN parameter (P = 0.026), and RT on day 3 (P = 0.085). The sum of U and N parameters, in combination with BW at birth and information of the sow might be useful to predict piglet growth and survival during lactation, thus becoming a useful tool to improve piglet management during the first days of lactation. In conclusion, UN parameter seems to be an easy and useful way to assess piglet vitality for both scientific and commercial purposes. The third study focused on early management towards newborn piglets and its effect on piglet’s growth and survival. For the experiment, 39 primiparous sows and their litters (507 piglets) and 100 multiparous sows and their litters (1375 piglets) were used. Piglets were classified according to their BW at birth: SP, piglets born weighing 1.30 kg or less; and BP, piglets born weighing more than 1.30 kg of BW. Litters were allocated to one of the 4 treatments: control group (CON); split nursing of the BP piglets of the litter for 2 h allowing SP piglets free access to teats (SPLIT); orally supplementation with 15 ml of sow colostrum to the SP piglets of the litter (COL); and orally supplementation with 3 ml of an energetic product (Calostrene®) to the SP of the litter (EN). Cross-fostering was performed at a minimum level, fixing litters at 12 piglets (all the litters had 4 or 5 SP piglets). Piglets were weighed again on day 1 and 18 post-partum. Mortality was recorded. For primiparous sows oral supplementation with COL enhanced SP BW at day 1 compared to CON, SPLIT, and EN (P = 0.020, P = 0.022, and P = 0.046, respectively). However no differences were observed at day 18. For multiparous sows, no differences among treatment groups were observed for SP BW at day 1 and at day 18. Although there were no differences between gilts and multiparous sows for SP birth weight, gilt’s SP had higher BW at day 1 than sows’ SP (P = 0.020). Despite its effect on SP piglets’ BW at day 1, COL did not reduced pre-weaning mortality within gilt’s litters or within multiparous sows. Colostrum supplementation of low birth weight piglets enhanced their colostrum intake improving weight gain in piglets born from gilts. But it did not affect piglet’s weaning BW or pre-weaning mortality. The fourth experiment studied the effect of oral supplementation of piglets born weighing 1.35 kg or less (SP) (CON: control group; COL: 15 ml of sow colostrum fed within 4 h after birth), and the effect of cross-fostering 24 h after farrowing on litter performance (HL: litters fixed at 12 piglets, with less than 50% of the piglets being SP, aiming to as minimum movements of piglets as possible; LL: litter fixed with most of the piglets being SP) on litter performance. The combination of the 2 management strategies described above resulted in a 2 x 2 factorial model. Forty six litters were used. Litters were allocated to 1 of the 4 treatments: CON-HL, CON-LL, COL-HL, COL-LL. Piglets were weighed on day 1 and 19 post-partum. Mortality was recorded. On day 4 post-partum, a 2 ml blood sample was obtained from 79 SP piglets born from multiparous sows included in the experiment. To obtain a negative control group, blood samples were obtained on day 4 post-partum from 8 extra SP piglets that were separated from their mothers at birth and bottle fed with milk replacement for 12 h. LL sows had lower within litter CV of BW at day 1 than HL sows (16.2 vs. 21.9 ± 0.91%, P = 0.003) but they did not differ for litter CV of BW at day 19 (23.2 vs. 23.4 ± 1.72%; P > 0.10). At day 19, HL sows had lower number of dead piglets per litter than LL sows (0.80 vs. 1.69 ± 0.307; P = 0.022) and COL-HL sows had lower number of dead piglets per litter than CON-HL (0.47 vs. 1.14 ± 0.160; P = 0.062). Cross-fostering SP at the same litter did not prevent from increasing litter’s CV of BW at weaning. Piglets from COL group had higher IgG concentration than piglets from CON group (P = 0.001). While piglets from the negative control group had lower IgG concentration than COL and CON groups (5.4 ± 2.32 mg/ml vs. 30.6 ± 1.58 mg/ml and 21.5 ± 0.95 mg/ml. respectively; P < 0.001 in both cases). Allocating small piglets to the same litter through cross-fostering had a negative effect on mortality and did not improve litter CV of BW at weaning. Colostrum supplementation of SP piglets improves immune status at day 4. Besides, in non homogenized litters, coslostrum supplementation of SP piglets might be a good management strategy to improve litter performance

Welfare and management strategies to reduce pre-weaning mortality in piglets

La mortalitat durant la lactació és probablement el major problema econòmic i de benestar a afrontar per les explotacions porcines. Davant aquesta problemàtica, el principal objectiu d'aquesta tesis doctoral és intentar identificar els principals aspectes que poden contribuir a incrementar la supervivència dels garrins durant la lactació i, al mateix temps, identificar i jerarquitzar les tasques de maneig més efectives realitzades al voltant del part. Quatre estudis s'han dissenyat per assolir els nostres objectius (chapter 4, 5, 6 and 7): Al primer estudi, es van portar a terme dos experiments per estudiar l'efecte sobre truges primípares i les seves garrinades que s'observa després d'allotjar les truges en grup durant la gestació i mantenir-les lleugerament sobrealimentades (PEN, n = 27 per Exp. 1; n = 10 per Exp. 2) en comparació a tenir-les en gàbies convencionals (STALL, n = 24 per Exp. 1, n = 9 per Exp. 2). Es va mesurar la grassa dorsal (BF) al inici i final de la lactació i es va registrar la mortalitat. Els garrins es van pesar i es va registrar la seva temperatura rectal (RT). Per l'Exp. 1 es va enregistrar el comportament d'un subgrup de truges. Per l'Exp. 2 es van analitzar cortisol salivar de les truges i la concentració en sang de TSH i T4 dels garrins. Les truges del grup PEN van mostrar major BF a l'inici de la lactació (P 0.001). Es va observar una tendència a major concentració de cortisol en les truges del grup PEN a les 24 h d'estar a les gàbies de part (P = 0.070) i una tendència a passar-se més temps assegudes o dempeus la jornada anterior al part (P = 0.057). Els garrins nascuts al grup PEN van tenir nivells menors de T4 (P = 0.078). No obstant, els garrins del grup STALL tingueren major RT als 60 min de vida (P 0.05) i van sobreviure en més nombre després de les primeres 48 h de vida fins al final de la lactació (P 0.05). A l'Exp. 2, els garrins del grup STALL pesaven més (P 0.05) i van tenir un guany mig diari durant lactació més elevat (P 0.05). Les truges nul·lípares allotjades en grup i lleugerament sobrealimentades durant la gestació es veuen sotmeses a un major estrès al ser introduïdes a les gàbies de maternitat que les truges allotjades en gàbies convencionals durant la gestació. Aquest estrès matern pot comprometre la capacitat de termoregulació dels seus garrins. L'objectiu del segon experiment va ser el de desenvolupar, a partir del seu comportament, un sistema d'avaluació de la vitalitat dels garrins que guardés relació amb el seu posterior creixament i supervivència. Es van emprar 287 garrins provinents de 21 truges multípares. Els garrins es van pesar acabat el part i es van avaluar 4 paràmetres comportamentals en un petit tancat circular de 55 cm de diàmetre: capacitat de moviment (U), estimulació del braguer (U), nombre de voltes completes dins el tancat (N), i capacitat de cridar (S). A dia 1, 2, 3 i 17 es van pesar els garrins, i a dia 1, 2 i 3 se'ls hi va mesurar la RT. Es van realitzar anàlisis de regressió múltiple per la supervivència i creixement dels garrins fins el deslletament. El guany de pes dels garrins durant la lactació va estar influenciat pel pes al naixement (P 0.001), el número de part de al truja (P = 0.024), el número de nascuts vius al part (P 0.10). A dia 19, les truges HL van tenir menys garrins morts per garrinada que les truges LL (0.80 vs. 1.69 ± 0.307; P = 0.022) i les truges del grup COL-HL van tenir menys garrins morts per garrinada que les CON-HL (0.47 vs. 1.14 ± 0.160; P = 0.062). Les adopcions dels SP per formar garrinades LL no va aconseguir reduir el CV de pes de al garrinada al deslletament. Els garrins del grup COL van tenir major concentració de IgG que els del grup CON (P = 0.001); mentre que el grup control negatiu va tenir nivells de IgG inferiors a COL i CON (5.4 ± 2.32 mg/ml vs. 30.6 ± 1.58 mg/ml and 21.5 ± 0.95 mg/ml. respectively; P 0.001 ambdós casos). Fer 'garrinades de petits' no va reduir la mortalitat ni va reduir el CV del pes de la garrinada. Donar calostre als garrins SP millora el seu estatus immunitari a dia 4. A més a més, en garrinades no homogeneïtzades, aportar calostre als garrins SP és una bona estratègia per millorar el seu rendiment.Pre-weaning mortality in breeding herds remains as one of the most important welfare and economic problems in swine production. Therefore, the principal objective of the present thesis was to identify the main aspects that may help to reduce on-farm piglet pre-weaning mortality and to establish a management hierarchy identifying the most effective tasks around farrowing. To achieve our objective, four studies were performed (chapter 4, 5, 6 and 7): In the first study, two experiments were carried out to observe the effect of two gestation management systems (STALL: gilts housed in stalls with no changes in management, and PEN: slightly overfed gilts loose-housed in pens) on gilt and piglet performance. A total of 27 PEN and 24 STALL gilts and 10 PEN and 9 STALL gilts were used in Exp. 1 and Exp. 2, respectively. Backfat (BF) at the beginning and at the end of lactation, and litter pre-weaning mortality were recorded in gilts. Weight and rectal temperature (RT) was recorded in piglets. In Exp. 1 the behaviour of a subsample of gilts was continuously videotaped during lactation. In Exp. 2 cortisol in gilt saliva, and TSH and T4 in piglet blood were measured. In both experiments, PEN gilts had more BF than STALL gilts when moved to the farrowing stalls (P 0.001). PEN gilts tended to have higher cortisol concentration 24 h after entering the farrowing stall (P = 0.070) and to spend more time sitting or standing up 1 day before parturition (P = 0.057) than STALL gilts. Piglets from PEN gilts had lower T4 (P = 0.078) than those from STALL gilts. However, piglets from STALL gilts showed higher RT 60 min after birth (P 0.05) and lower mortality from 48 h after of birth until weaning (P 0.05). In Exp. 2, piglets from STALL group also had higher BW (P 0.05) and average daily gain (P 0.05) at the end of lactation. During lactation, PEN gilts lost more BF than STALL gilts (P 0.001). Gilts that are loose-housed and slightly overfed in pens during gestation may be more stressed when housed in farrowing stalls than those that have been kept in stalls during gestation, thus compromising their offspring thermoregulatory capacity and growth. For the second study, the aim was to develop a vitality scoring method based on piglet behavior and relate it to piglet growth and survival. From 21 sows, 287 piglets were used. After farrowing (day 0), piglets were weighed and tested for 4 behavioural parameters in a circular enclosure (55 cm diameter): movement capacity (M), udder stimulation (U), number of completed circles around the enclosure (N), and screaming (S). Piglets were weighed again on day 1, 2, 3 and 17. Piglet RT was recorded on day 0, 1, 2 and 3. Sow's farrowing information was recorded. Multiple regression analyses for survival and BW gain at weaning as dependent variables was performed. Piglet BW gain at weaning was influenced by BW at birth (P 0.001), sow parity (P = 0.024), total number of piglets born alive per sow (P 0.10). At day 19, HL sows had lower number of dead piglets per litter than LL sows (0.80 vs. 1.69 ± 0.307; P = 0.022) and COL-HL sows had lower number of dead piglets per litter than CON-HL (0.47 vs. 1.14 ± 0.160; P = 0.062). Cross-fostering SP at the same litter did not prevent from increasing litter's CV of BW at weaning. Piglets from COL group had higher IgG concentration than piglets from CON group (P = 0.001). While piglets from the negative control group had lower IgG concentration than COL and CON groups (5.4 ± 2.32 mg/ml vs. 30.6 ± 1.58 mg/ml and 21.5 ± 0.95 mg/ml. respectively; P 0.001 in both cases). Allocating small piglets to the same litter through cross-fostering had a negative effect on mortality and did not improve litter CV of BW at weaning. Colostrum supplementation of SP piglets improves immune status at day 4. Besides, in non homogenized litters, coslostrum supplementation of SP piglets might be a good management strategy to improve litter performance

Effects of the feed : Water mixing proportion on diet digestibility of growing pigs

Funding: This research was funded by Spanish Ministry of Science and Innovation (CDTI project IDI-20110003), and TEM 2010 research grant form "Comissionat per a Universitats I Recerca del Departament d'Innovació, Universitats I empresa form Generalitat de Catalunya (AGAUR).The effect of different water-to-feed ratios on apparent total tract digestibility of energy and nutrients were evaluated in growing-finishing pigs. In trial 1 (26 d), 16 female pigs (46.7 ± 1.98 kg of body weight, BW) were individually assigned to four treatments (n = 4). In trial 1, pigs were fed a control diet in dry form (CON) and in blend form with water-to-feed ratios of 0.6:1, 2.1:1 and 2.7:1. In trial 2 (26 d), rearranged animals (65.4 ± 3.14 kg of BW) were assigned a control diet in dry form (CON) and ratios of 1.35:1, 2.7:1 and 3.5:1. In trial 1, pigs fed on ratios of 2.1:1 and 2.7:1 had a higher organic matter digestibility (OMd) and gross energy digestibility (GEd) than CON. In trial 2, pigs fed on ratios of 1.35:1, 2.7:1, and 3.5:1 had a higher OMd and GEd than CON. Quadratic regressions showed the maximum dilution rate to reach higher digestibility coefficients at 1.83:1 and at 2.7:1 for trials 1 and 2, respectively. During trial 1, pigs on the 0.6:1 dilution rate had higher weight gain than those on CON. The water-to-feed ratio that optimized OM and GE digestibility may increase with the age of the pigs