Abstract Phytate-bound phosphorus (P) in plant-based feed ingredients limits mineral availability in swine diets, often requiring supplemental inorganic P to meet nursery pig requirements. Exogenous microbial phytase can increase P release from phytate, thereby improving P utilization and decreasing P excretion. The present study evaluated the effects of graded levels of a novel phytase on growth performance, apparent total tract digestibility (ATTD) of minerals, and bone mineralization in nursery pigs. A total of 150 Pietrain × (Landrace × Large White) pigs (8.25 ± 0.42 kg body weight (BW)) were used in a 35-d experiment. Pigs were blocked by sex and initial BW and housed 3 pigs/pen across 50 pens. Within block, pens were randomly assigned to one of five dietary treatments: a positive control (PC; 0.35% digestible P), a negative control without inorganic P (NC; 0.12% digestible P), or the NC supplemented with 250, 500, or 1,000 FTU/kg of a novel phytase. Diets were based on wheat–barley–rice by-product meal and soybean meal, pelleted, and offered ad libitum. Wheat and barley were pre-heated (>85 °C) prior to feed manufacture to inactivate endogenous phytase. Titanium dioxide (0.4%) was included as an indigestible marker. During the final week, fecal samples were collected from each pen, freeze-dried, and analyzed for crude protein (CP) and P to determine ATTD. One pig per pen was euthanized on d 35 to collect metacarpals (III and IV) for bone weight and ash analysis. Data were analyzed using the GLM procedure of SAS, and means were separated using Tukey’s test. Significance was observed when P ≤ 0.05. Pen served as the experimental unit. Feed efficiency and average daily gain (ADG) were reduced (P < 0.001) in NC compared with the PC. Supplementation of phytase at any inclusion level restored ADG and feed efficiency to values comparable with the PC. The ATTD of CP of pigs supplemented the 500 FTU/kg diet exceeded the PC, with all remaining treatments intermediate (P = 0.047). The ATTD of P increased in a dose-dependent matter with phytase supplementation, matching the PC at 250 FTU/kg and exceeding it by 15% at 1,000 FTU/kg (P < 0.001). Bone weight was reduced in pigs fed the NC, and phytase supplementation restored to levels comparable with the PC (P ≤ 0.003). Bone ash percentage followed the same pattern, increasing from NC (10.85%) to the highest phytase inclusion (16.21%; P < 0.001), demonstrating improved bone mineralization with increasing phytase dose. Overall, the novel phytase improved growth performance and mineral utilization in nursery pigs fed diets limited in inorganic P. Higher phytase activity (1,000 FTU/kg) produced the greatest improvements in ATTD of P and bone mineralization, suggesting potential to reduce inorganic P supplementation and P excretion while maintaining productive performance

Abstract Gilt development is essential for optimizing sow productivity and longevity, while reducing culling rate. It was hypothesized that lowering SID Lysine content in the diet during the rearing would reduce lean growth, promote fat deposition, and therefore improve gilt body condition at farrowing. The aim of this study was to evaluate how this nutritional strategy affected growth, body composition, and reproductive performance at first farrowing. The study was conducted with 72 gilts (age: 79 ± 4 d) with an initial body weight (BW) of 24.95 ± 3.48 kg at arrival. Until approximately 50.5 ± 5.29 kg BW, gilts were fed a common diet (10.4 MJ/kg NE, 9.8 g SID Lys/kg). Thereafter, animals were weighed, distributed into two groups according to BW, and assigned to one of two dietary treatments until detection of the third estrus. A 4-phase feeding strategy was used and gilts were fed ad libitum. Treatments consisted of a control diet formulated according to standard recommendations for growing gilts (50–65 kg: 9.83 MJ/kg NE, 8.80 g SID Lys/kg; 65–85 kg: 9.75 MJ/kg NE, 8.20 g SID Lys/kg; 85–105 kg: 9.91 MJ/kg NE, 7.60 g SID Lys/kg; 105-120 kg: 9.92 MJ/kg NE, 7.00 g SID Lys/kg) and an experimental slow-growth diet applying a 30% reduction in SID Lysine and amino acids (50–65 kg: 9.91 MJ/kg NE, 6.16 g SID Lys/kg; 65–85 kg: 9.88 MJ/kg NE, 5.74 g SID Lys/kg; 85–105 kg: 9.85 MJ/kg NE, 5.32 g SID Lys/kg; 105-120 kg: 9.86 MJ/kg NE, 5.00 g SID Lys/kg). Gilts were individually monitored (days 1, 24, 38, 66, 79, 94, and 123) for BW, backfat thickness, and loin muscle depth. After detection of the third estrus, gilts were inseminated and subsequently fed approximately 2.6 kg/day of a common gestation diet until farrowing. During the rearing period, gilts fed diets with reduced SID Lysine exhibited lower growth rate, gaining 70 g/day less than controls (ADG: 0.95 vs. 0.88 kg/day; P < 0.01). Although average daily feed intake did not differ overall, gilts in the reduced SID Lys treatment showed a higher feed conversion ratio (2.81 vs. 3.03; P < 0.01). No significant differences between treatments were observed in backfat thickness or loin muscle depth. At farrowing, the number of total born, liveborn, and piglets weaned per litter did not differ between treatments. In conclusion, feeding diets with a 30% reduction in SID Lysine compared with standard recommendation during the rearing period decreased growth rate but did not affect body composition (backfat thickness, loin depth) or reproductive performance at first parity.

Iberian sow productivity is characterised by a low number of weaned piglets with higher within-litter variation in piglet birth BW compared with conventional breeds. To overcome this, nutritional strategies, such as the dietary addition of n-3 fatty acids (FAs), are being studied to improve sow performance, as well as colostrum and milk composition. In addition, n-3 FAs and their derived oxylipins could also be beneficial for the offspring due to their anti-inflammatory roles. The present study was conducted in an outdoor production system where sows were group-fed during the mating and gestation periods, while feed intake was provided individually during lactation. The study aimed to evaluate the effects of including fish oil rich in eicosapentaenoic and docosahexaenoic acids (EPA and DHA, respectively) in Iberian sow diets on litter size, piglet growth during lactation, and the concentrations of anti-inflammatory molecules in colostrum and milk. Forty sows were randomly assigned to either a control or fish oil diet during pregnancy and lactation. Sow performance and litter traits were monitored until weaning. Colostrum and milk were collected after the birth of the first piglet and at weaning, respectively. Their FA composition, oxylipin profile, and immune indicators were analysed. Despite the piglets from the control group having greater average birth BW than those from the fish oil litters (P = 0.016), the fish oil piglets were heavier at weaning (P < 0.028). Total n-3 FA concentration was increased in the colostrum and milk of fish oil-fed sows (all P < 0.001), mainly due to increases in EPA and DHA concentrations (all P < 0.001). In the same way, most of their oxygenated derivatives were also increased in both colostrum and milk (P <= 0.045). The colostrum from fish oil-fed sows also presented higher concentrations of immunoglobulins (Ig) G and A than that from control sows (P = 0.025 and P = 0.026, respectively). In conclusion, the inclusion of fish oil in sow diets increased the levels of IgG and IgA in colostrum, n-3 FAs and their derived oxylipins in colostrum and milk, and piglet BW at weaning. (c) 2025 The Author(s). Published by Elsevier B.V. on behalf of The animal Consortium. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Data from 8 datasets generated from 5 independent experiments that determined the effects of a consensus bacterial 6-phytase variant (PhyG) on apparent ileal digestibility (AID) of amino acids (AA) in growing pigs (~21 to 45 kg body weight) were combined and modeled to test the hypothesis that the phytase results in significant improvements in ileal AA digestibility. The aim was to generate accurate and robust dose-related predictions of the digestible AA contributions of the phytase. The 5 experiments were conducted in Spain, Australia, USA, and Brazil and incorporated variation in diet composition (ingredient composition, phytate-phosphorus (PP) content, limestone solubility), diet form, animal breed and sex. A total of 325 datapoints (observations) were analyzed. First, the relationship between the percentage AID of AA and log-transformed phytase dose (range 0 to 4,000 phytase units (FTU)/kg, analyzed values) was modeled by log-linear regression across all datasets without adjustment for variation in the response to the negative control (NC) diet. The model predicted that the mean AID of total AA in the NC diets was 68.6% (range 43.3% [Cys] to 81.7% [Arg]). This was increased linearly by PhyG supplementation (P < 0.05), by 3.7 percentage units when dosed at 1,000 FTU/kg and by 4.5 percentage units at 4,000 FTU/kg. Second, the percentage unit change in the AID of AA at each phytase dose from baseline (NC without added phytase) was calculated separately for each dataset and the data then combined and modeled together by log-linear regression, against analyzed and log-transformed phytase dose. By this analysis, increases were evident for the AID of all individual (and total) AA. Increases (vs. baseline) at 1,000 and 2,000 FTU/kg were greatest for Trp (+ 6.1 and + 6.8 percentage units), Thr (+ 3.4 and + 3.8 percentage units after correction for synthetic Thr), Gly (+ 7.5 and + 8.3 percentage units) and Cys (+ 5.6 and + 6.2 percentage units). In conclusion, combined data from 5 separate experiments indicate that the bacterial phytase-6 variant will improve ileal digestibility of AA if included in diets fed to growing pigs. The data will allow diet-specific AA matrix recommendations to be made in commercial feed formulations containing PhyG.

Weaning is a decisive event in piglets' life. This study aimed to evaluate whether the inclusion of fish oil, rich in eicosapentaenoic and docosahexaenoic acids (EPA and DHA), in sow and piglet diets, increased the concentration of anti-inflammatory molecules in the blood of weaned piglets and whether the effect was dependent on the pigs being born with either low or a high birth BW (bBW). Thirty-six sows in four consecutive batches were randomly distributed between a control diet with animal fat (15 g/kg in gestation and 30 g/kg in lactation) or a n-3 long-chain fatty acid diet (LCFA; totally or half replacing animal fat by fish oil during gestation and lactation, respectively) from service until weaning (ca. 28 days). At birth, the two lightest (LBW) and the two heaviest (HBW) piglets in each litter were identified and, at weaning, grouped in pens by pairs prioritising their bBW. Pens were further distributed into a control (30 g/kg animal fat) or n-3 LCFA diet (totally replacing animal fat by fish oil) for 28 days. At the end of the trial, blood was collected from piglets in the first batch (n = 48). Serum fatty acids (FAs) were quantified by GC, plasma oxylipins by ultra-HPLC-MS, and plasma immune indicators by ELISA. An interaction between piglet diet and bBW for average daily gain (P = 0.020) and average daily feed intake (P = 0.014) during the whole postweaning indicated that dietary n-3 LCFA-promoted LBW piglets to have a similar growth and intake than HBW piglets reaching 1.5 kg average BW more at the end of the postweaning period than LBW control piglets. Fish oil in piglet diets also increased the concentrations of total n-3 FA, EPA and DHA (all P < 0.001), their resultant oxylipins, particularly their hydroxy derivatives from lipoxygenase enzymatic pathway (all P < 0.001) and tended to increase immunoglobulin M (P = 0.067) in blood. Regarding the bBW category, LBW piglets tend to increase tumour necrosis factor alpha in plasma (P = 0.083) compared to HBW. It is concluded that fish oil in postweaning diets could enhance the daily gain and feed intake of LBW piglets, increasing the concentration of serum n-3 FAs and their derived oxylipins in plasma.

The post-weaning period is a stressful process for piglets with compromised gut health, increasing susceptibility to diarrhea and infection. Oxygen concentration in the gut affects microbiome and fermentation profile. Live yeasts have been used to promote gut health and performance of young animals. An experiment was carried out to determine the influence of live yeast on gut conditions including redox potential, microbial composition, and short chain fatty acid (SCFA) production of piglets. Sixteen Pietrain *(Landrace*Large White) piglets were distributed into blocks by live weight and allocated at 4 per pen for a 28-d trial. Each block was composed by a combination of the 2 dietary treatments corresponding to a control diet and a diet supplemented with live yeast (1 kg/tonne Vistacell, AB Vista). At the end of trial, piglets were euthanized to measure kinetics of redox potential (Eh) and pH from caecum until 35 min post-mortem. Then, digesta samples from stomach, duodenum, jejunum, ileum, caecum, and rectum were collected for microbial composition and SCFA production. Data were analyzed using GLM procedure of SAS 9.4 and means compared with a Student-Newman-Keuls test. Redox potential decreased with time (P < 0.001) until stabilizing after 20 min, and a clear difference was observed between treatments (P < 0.001). Supplemented live yeast survives throughout gastrointestinal tract and modifies microbial populations enhancing lactic acid bacteria (P < 0.001) while reducing enterobacteria (P < 0.001) or eliminating fungi (P < 0.001). The production of SCFA from caecum digesta was 3-fold higher than in ileum with significantly different molar proportion of individual SCFA. Lactic, formic, and acetic acids predominate on ileum (> 93%) whereas acetic, propionic, and butyric dominate on caecum digesta (> 90%). Nevertheless, no differences were observed due to dietary treatments. In conclusion, live yeast supplementation of diets modifies redox conditions prevailing in the gut modifying microbial populations and helping piglets to overcome post-weaning growth check.

The study determined efficacy of different phytases in diets without inorganic phosphorus (P) in piglets. Piglets (initial body weight 9.7 ± 1.2 kg) were randomly assigned (2 piglets/pen), based on sex and body weight over 6 diets. Positive control (PC) corn-wheat based diet was formulated to meet NRC specification. Negative control (NC) diet was formulated without inorganic P (-0.16% STTD P), with reduced calcium (Ca; -0.15%), net energy (-33 kcal/kg), and standardized ileal digestible amino acids (average -0.02% unit). The NC diets were supplemented with 4 different phytases at 1,500 FTU/kg feed including a novel consensus bacterial 6-phytase variant expressed in Trichoderma reesei (PhyG), a Citrobacter braakii phytase expressed in Aspergillus oryzae (PhyC), a hybrid phytase (Hafnia sp., Yersinia sp. and Buttiauxella sp.) expressed in Aspergillus niger (PhyH) and an Escherichia coli phytase expressed in Pichia pastoris (PhyE). Piglets were fed ad libitum for 42 d. Fecal samples were collected during last 3 d. On d 42, 1 piglet per pen was euthanized and metacarpi collected for bone strength and ash analysis. Data were analysed by one-way ANOVA and treatment mean comparison by Tukey test using JMP 14. Pigs fed NC diets showed reduced (P < 0.05) growth, P digestibility, bone ash and bone strength vs PC and all phytases treatments. Overall feed conversion ratio (FCR) was less (P < 0.05) with PhyG (-22 points) and PhyE (-8 points) vs NC, while PhyC and PhyH showed intermediate FCR between PhyG and PhyE. PhyG improved (P < 0.05) bone strength and P digestibility vs PhyC, PhyE and PC. Based on FCR and bone strength, ranking of the phytases are: PhyG >PhyC >PhyH >PhyE. In conclusion, all phytases improved growth, nutrient digestibility and bone strength vs NC; however, only PhyG fully compensated nutrients and energy reduction, fully recovered performance to the level of PC and resulted in improved bone strength compared with PC.

Over the last decades, genetic selection has increased sows’ litter size. Consequently, there is a high proportion of piglets born with low weight which are vulnerable. Their viability may potentially be enhanced through early nutrition. The aim of the current study was to evaluate whether including a fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the diets of the sow and piglets was able to increase concentrations of anti-inflammatory molecules in their blood. Thirty-six sows, in four consecutive batches, were randomly assigned to either a control diet with animal fat (15 g/kg in gestation and 30 g/kg in lactation) or an n-3 long-chain fatty acid (n-3 LCFA) diet from insemination until the end of lactation. From day 11 of lactation, piglets were also offered a diet containing 30 g/kg of animal fat or n-3 LCFA. To prepare the n-3 LCFA diet, 15 g/kg or 30 g/kg of animal fat in the control diet were replaced by an equivalent amount of solid fish oil for sows and piglets, respectively. All the sows were sampled for serum and plasma at day 108 of gestation and at weaning. Additionally, only for the first batch of sows, blood samples were also obtained at weaning from the two lightest (>800 g) and the two heaviest birth weight piglets in each litter. Serum fatty acids (FAs) were quantified by gas chromatography, plasma oxylipins by ultra-HPLC-MS and plasma immunoglobulins (Ig) and cytokines by ELISA. The n-3 LCFA diet increased the concentrations of n-3 FAs in gestating and lactating sows and in piglets (P < 0.001, P < 0.001 and P = 0.011, respectively), particularly EPA (P < 0.001, P < 0.001 and P < 0.001, respectively) and DHA (P < 0.001, P < 0.001 and P < 0.001, respectively), and also their oxygenated derivatives. In addition, fish oil increased plasma IgM in gestating and lactating sows (P = 0.014 and P = 0.008, respectively), interleukin (IL) 6 in sows at weaning (P = 0.012), and IL1β in piglets (P = 0.018). Birth BW of piglets, regardless of diet, slightly influenced some of the n-6-derived oxylipins. In conclusion, fish oil addition in diets increased the blood concentrations of n-3 FAs and their oxygenated derivatives, some of which have anti-inflammatory activity, in gestating and lactating sows and piglets, IgM in gestating and lactating sows, IL6 in lactating sows and IL1β in piglets.

Introduction:Very little is known about the impact of n-3 long-chain fatty acids (n-3 LCFAs) on the microbiota of sows and their piglets. The aim of this study was to evaluate the effect of n-3 LCFA in sow diets on the microbiota composition of sows' feces, colostrum, and milk as well as that of piglets' feces.Methods:Twenty-two sows were randomly assigned to either a control or an n-3 LCFA diet from service to weaning. Sows' and piglets' performance was monitored. The gestating and lactating sows' microbiomes in feces, colostrum, and milk were characterized by 16s ribosomal RNA gene sequencing. The fecal microbiome from the two lowest (>800 g) and the two highest birth weight piglets per litter was also characterized, and the LPS levels in plasma were analyzed at weaning.Results and Discussion:n-3 LCFA increased microbiota alpha diversity in suckling piglets' and gestating sows' feces. However, no effects were observed in colostrum, milk, or lactating sows' feces. Dietary n-3 LCFA modified the microbiota composition of gestating sows' feces, milk, and suckling piglets' feces, without affecting lactating sows' feces or colostrum. In gestating sows' feces and milk, the decrease in genus Succinivibrio and the increase of Proteobacteria phylum, due to the increased genera Brenneria and Escherichia, respectively, stand out. In the feces of suckling piglets, the higher abundance of the beneficial genus Akkermansia and Bacteroides, and different species of Lactobacillus are highlighted. In addition, positive correlations for families and genera were found between lactating sows' feces and milk, milk and suckling piglets' feces, and lactating sows' feces and suckling piglets' feces. To conclude, dietary n-3 LCFA had a positive impact on the microbiome of suckling piglet's feces by increasing microbial diversity and some beneficial bacteria populations, had a few minor modifications on the microbiome of milk and gestating sows' feces and did not change the microbiome in lactating sows' feces or colostrum. Therefore, this study shows the effect of dietary n-3 LCFA on the microbiota of sows, colostrum, milk, and suckling piglets during the lactation period providing crucial information on the microbiota status at the early stages of life, which have an impact on the post-weaning.

[This corrects the article DOI: 10.1016/j.aninu.2019.11.003.].

Colostrum and milk are the first nutrient sources for newborn piglets. In addition, n-3 fatty acids (FAs) and their oxygenated derivatives (oxylipins) have the capacity to modulate immune components. The aim of the current study was to include a fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in sow diets to promote an increase of anti-inflammatory molecules in colostrum and milk to benefit piglets. Thirty-six sows were randomly assigned from insemination to the end of lactation to either a control diet with animal fat (15 g/kg in gestation and 30 g/kg in lactation) or an n-3 diet in which animal fat was totally (gestation) or half (lactation) replaced by an equivalent amount of solid fish oil. Performance of sows and piglets was monitored during the study. Colostrum and milk samples were obtained after the birth of the first piglet and at weaning, respectively. From all samples (n = 18 per treatment), FAs were quantified by gas chromatography and immunoglobulins and cytokines by ELISA. Three samples per treatment were randomly selected to analyse oxylipin composition by liquid chromatography-tandem mass spectrometry. In colostrum and in milk, the n-3 FA (P = 0.020 and P < 0.001), particularly EPA (P < 0.001 and P < 0.001) and DHA (P < 0.001 and P < 0.001), and also their oxygenated derivatives were increased in samples from sows fed n-3 diet. Fish oil had no effect on immunoglobulin concentrations, but reduced tumour necrosis factor α (TNFα) (P = 0.011) and a tendency to reduce interleukin 10 (IL10) (P = 0.059) were observed in milk. In conclusion, fish oil in sow diets increased n-3 FA, particularly EPA and DHA, and their oxygenated derivatives in colostrum and milk, reducing TNFα and IL10 in milk.

Restricted feed can affect the body composition of pigs. Body composition can be studied non-destructively in live pigs using computed tomography (CT). The objective was to investigate the effect of different feeding restriction strategies on the productive and carcass quality parameters of gilts during growth via CT images and the effects of such strategies on meat quality, sensory properties and consumer preferences. Moreover, we sought to determine whether CT is a suitable tool for this purpose in this type of study. Thus, 36 Pietrain x (Large White x Landrace) gilts were assigned to the following three feeding strategies: 1) ad libitum feeding (AL) during all fattening periods (AL-AL); 2) AL feeding between 30 and 70 kg target body weight (TBW) followed by restriction (84% of AL) until 120 kg TBW (AL-RV); and 3) restriction feeding (78% of AL) between 30 and 70 kg TBW followed by AL until 120 kg TBW (RV-AL). When the pigs reached 30, 70, 100 and 120 kg, they were CT scanned to obtain the carcass composition parameters. At 120 kg TBW, the pigs were slaughtered, and the carcass and meat quality was determined. The loins were collected for trained panel evaluation and consumer tests. The panellists evaluated the odour, flavour and texture attributes of cooked loins. A total of 120 consumers scored the overall acceptability, tenderness, odour and flavour. The results showed a decrease of 76% and 80% in the average daily gain and average daily feed intake during the restriction period compared with the ad libitum in the growth phase, respectively, and a decrease of 89% and 87% in these parameters during the fattening phase, respectively. A restriction reduces the body fat content during the period of the restriction. Differences in the carcass and cut composition and meat quality were not observed at the end of the experiment among the treatments. Regarding sensory quality, meat from the animals in the AL-AL treatment was tougher than that from animals in the RV-AL and AL-RV treatments. Nevertheless, these differences were not detected by consumers, who did not provide significantly different scores for acceptability. Thus, when preparing feeding strategies, these results should be considered to optimize costs and increase benefits. Furthermore, computed tomography represents a non-destructive technology suitable for determining carcass composition before slaughter.

The present study investigated the replacement of 5% of starch (ST) by 5% of sunflower oil (SO), with or without feed restriction, in the diet of growing-finishing Iberian x Duroc pigs exposed to heat stress conditions. The effects of these strategies on the welfare, performance and meat quality of the animals were evaluated. Seventytwo crossbred males [51.00 +/- 6.29 kg body weight (BW)] were housed in collective pens and randomly distributed according to their initial BW in climate-controlled rooms under heat stress conditions (30-32 degrees C; 35%-50% humidity). The experiment was carried out in a randomized block design, in a 2 x 2 factorial design composed of two diets (control or oil) and two feed management (ad-libitum and restriction) types. The investigated treatments were: 1) control diet (5% ST x 0% SO) with ad-libitum feed intake, 2) oil diet (replacement of 5% of ST by 5% SO) with ad-libitum feed intake, 3) control diet with restriction feed intake, and 4) oil diet with restriction feed intake. The pigs' behavior and dirtiness score were observed daily, and their performance was assessed weekly. Furthermore, three blood samples were collected from each animal for hemogram analysis during the period of study. The analysis of meat and carcass quality was performed 24 h post-mortem once the animals had reached an average BW of 130-140 kg. Statistical analyses were performed using the PROC MIXED and PROC GENMOD procedures of the Statistical Analysis System (SAS). The diet-regimen interaction produced no effects (P > 0.05) on the analyzed variables, except for behavior. Animals on the control diet associated with ad-libitum feed management spent more time in the lateral decubitus position and showed reduced activity. In addition, pigs fed ad-libitum and those that received the control diet displayed the highest level of dirtiness during the experiment. Evaluation of performance revealed that pigs receiving the oil diet showed reduced feed intake (P < 0.05) with no difference in average daily gain and consequently presented better feed conversion values compared to animals on the control diet. Furthermore, the oil diet resulted in a higher (P < 0.05) carcass yield as well as a higher oleic fat content in the meat. Pigs on restricted feeding management with lower body and carcass weights produced higher values of leanness percentage and carcass compared to animals in the adlibitum group. In conclusion, the replacement of 5% of starch by 5% of sunflower oil in the pigs' diet during high ambient temperatures improved the animals' welfare, feed efficiency, and carcass characteristics.

The utility of a next generation biosynthetic bacterial 6-phytase (PhyG) in restoring bone ash, bone phosphorus (P) content and performance in piglets depleted in P was evaluated. A total of 9 treatments were tested as follows. Treatment 1, a negative control (NC) diet; treatments 2, 3, 4, NC supplemented with 250, 500 or 1,000 FTU/kg of PhyG; treatments 5, 6, NC supplemented with 500 or 1,000 FTU/kg of a commercial Buttiauxella sp phytase (PhyB); treatments 7, 8, 9, NC supplemented with monocalcium phosphate (MCP) to provide 0.7, 1.4 and 1.8 g/kg digestible P, equating to a digestible P content of 1.8, 2.5 and 2.9 g/kg. The latter constituting the positive control (PC) diet with adequate P and calcium (Ca). The NC was formulated without inorganic P (1.1 g digestible P/kg) and reduced in Ca (5.0 g/kg). Additional limestone was added to treatments 7 to 9 to maintain Ca-to-P ratio between 1.2 and 1.3. A total of 162 crossed Pietrain × (Large White × Landrace) 21-d-old piglets (50% males and 50% females) were fed adaptation diets until 42 d old and then assigned to pens with 2 pigs/pen and 9 pens/treatment in a completely randomized block design. Piglets were fed mash diets based on corn and soybean meal ad libitum for 28 d. At the end of the study, one piglet perpen was euthanized and the right feet collected for determination of bone strength, bone ash and mineral content. Compared with the PC, the NC group had reduced average daily gain (ADG) and increased feed conversion ratio (FCR) during all growth phases and overall, and at d 28 (70 d old) NC pigs had bones with reduced ash, Ca and P content (P < 0.05). The PhyG at 250 FTU/kg improved bone ash vs. NC. Increasing PhyG dose linearly or quadratically improved bone ash, ADG and FCR (P < 0.05). At ≥ 500 FTU/kg, both PhyG and PhyB maintained ADG and FCR equivalent to PC. Linear regression analysis was done to compare the measured response parameters to increasing digestible P from MCP. Based on this analysis it was shown that PhyG and PhyB at 1,000 FTU/kg could replace 1.83 and 1.66 g/kg digestible P from MCP in the diet, respectively, on average across metacarpi bone ash, ADG or FCR. These findings suggest that the biosynthetic phytase is highly effective in the tested dietary setting.

Abstract The effect of a Buttiauxella sp. phytase on performance and bone ash in piglets was evaluated. A negative control (NC) diet was formulated without inorganic phosphate [0.11% digestible phosphorus (P)] and lower in calcium (Ca, 0.5%). NC was supplemented with the phytase at 0, 500 and 1,000 FTU/kg diet or with mono-calcium phosphate (MCP) at 4 levels to add 0, 0.7, 0.14 and 0.18% digestible P and with additional limestone to maintain Ca to P ratio (1.2 to 1.3). The latter was the positive control (PC) and contained 0.7% Ca and 0.29% digestible P, meeting NRC requirement. A total of 108 Pietrain × (Landrace × Yorkshire) piglets were fed adaptation diets from 21 (weaned) to 42 d of age. Then, they were divided into 9 blocks according to body weight (BW) (9 replicates/treatment, mean initial BW 10.2 kg, mixed sex) and allocated at 2 piglets per pen. Piglets were fed mash test diets (based on corn, soybean meal with broken rice, rice bran and sugar beet pulp) ad lib for 28 d. At the end, 1 piglet per pen was euthanized and the right foot collected to determine metacarpal ash, Ca and P content. Data were analyzed using JMP 14.0. The NC reduced (P < 0.05) average daily gain (ADG), average daily feed intake (ADFI), bone ash, Ca and P, and increased feed conversion ratio (FCR) vs PC (Table 1). Increasing phytase and MCP linearly increased (P < 0.05) ADG, bone ash, Ca and P and reduced FCR. Linear regression analysis using increasing digestible P from MCP as reference indicated that phytase at 1,000 FTU/kg can replace 0.16, 0.18 or 0.16% digestible P from MCP, using bone ash, ADG or FCR as response parameter, respectively. In conclusion, Buttiauxella phytase improved performance and bone ash in piglets fed diet without added inorganic phosphate.

The present study was divided in two different trials. The aim of the first trial was to determine if the thresholds of detection of skatole and indole are achieved in females and in males vaccinated against the GnRF housed in two different type of floors and subject to control or high environmental temperatures. The aim of the second trial was to assess the effect of sire (Duroc crossbreed and Pietrain crossbreed) and heat stress on the concentration of skatole and indole in entire males. In the first trial, the animals subjected to heat stress on a concrete floor were found to be dirtier and to present higher skatole and indole concentrations than did animals from the control treatment in 100% slatted floors. In the second trial, although the animals were dirtier when subjected to high temperatures, no effect of the temperature was found in skatole/indole concentrations. The Duroc pigs were dirtier and had higher skatole and indole concentrations than did Pietrain pigs. It is concluded that even females or vaccinated males can reach values of skatole/indole close to the thresholds of sensory detection under conditions of dirtiness and heat stress. However, the relationship between heat, dirtiness and skatole/indole concentrations in fat were not confirmed in trial 2 using entire males.