1. The aim of this study was to evaluate the effects of phytase and xylanase and their interaction on laying hen performance, egg quality, phosphorus (P) digestibility, phytate breakdown, volatile fatty acid (VFA) production and peptide YY concentration.2. Two hundred and forty hens were allocated to cages at 22weeks of age based on a 3x2 arrangement with phytase (0, 300 or 1500 FTU/kg) and xylanase (0 or 12 000 BXU/kg) as factors.3. Phytase increased hen-day production (P<0.05), daily egg mass (P<0.05) and P digestibility with increasing levels of phytase (P<0.001). Phytase fed at 1500 FTU/kg reduced IP6 and IP5 and increased myo-inositol concentration in gizzard digesta (P<0.05). Phytase fed at 300 FTU/kg reduced IP6 in ileal digesta (P<0.05); however, IP6 and IP5 were further reduced and myo-inositol increased when phytase was added at 1500 FTU/kg (P<0.05).4. Xylanase improved feed efficiency when phytase was fed at 300 FTU/kg (P<0.05). In the absence of phytase, xylanase reduced dry matter and Ca digestibilities (P<0.05).5. Neither phytase nor xylanase had an effect on peptide YY or caecal VFA concentrations.

Non-starch polysaccharides (NSP) present in wheat and barley can act as anti-nutrients leading to an increase in digesta viscosity and a reduction in nutrient digestibility. Xylanase, an NSP-degrading enzyme, has been shown to increase nutrient digestibility in pigs. The objectives of this study were: (1) to identify the optimum inclusion level of xylanase in grower pig diets by measuring the effect of increasing enzyme levels on growth performance, the concentration of volatile fatty acids (VFA) and peptide YY concentration in portal and peripheral blood of grower pigs and (2) to increase our understanding of the interrelationships between xylanase inclusion, VFA production and peptide YY secretion. A total of 512 grower pigs ((Large White×Landrace)×MAXGRO) were allocated to pens creating 32 replicates of four pigs per pen per treatment. Pigs were allocated to trial weighing 14.2±0.31 kg and remained on trial until ~41.5±3.31 kg. The experiment was a dose response design with four inclusion levels (0, 8000, 16 000 or 32 000 BXU/kg) of xylanase (Econase XT). Diets were cereal-based wheat, barley mix formulated to meet or exceed the nutrient requirements of grower pigs. Body weight and feed intake were recorded to calculate growth performance. Pen faecal samples were collected to estimate DM, organic matter (OM) and crude fibre (CF) apparent total-tract digestibility. At the end of the trial 16 pigs per treatment were euthanised by schedule 1 procedures. Peripheral and portal blood samples were collected for peptide YY and VFA analysis. The addition of xylanase to the diet had no effect on growth performance, DM, OM or CF total-tract digestibility; however, xylanase tended to have a quadratic effect on ileum pH with higher pH values recorded for pigs fed a diet supplemented with 8000 and 16 000 BXU/kg xylanase (P<0.1). Xylanase had no effect on peptide YY levels or VFA concentration. Total VFA concentration was higher in portal compared with peripheral blood (P<0.05). In conclusion, the addition of xylanase had no effect on grower pig performance, nutrient digestibility, VFA concentration or peptide YY concentration when fed up to 32 000 BXU/kg over a 35-day period. Pig performance was good for all treatments throughout the trial suggesting that diet quality was sufficient thus there were no beneficial effects of adding xylanase.

The aim of the current study was to evaluate the efficacy of Ronozyme HiPhos (DSM Nutritional Products Ltd.) in the immediate postweaning period and to determine the equivalency value of this phytase relative to P. A total of 568 mixed-sex pigs were weaned at 26.3 d (SD 1.01) of age and an average weight of 7.9 kg (SD 1.51). Pigs were offered 1 of 8 diets. Diets were fed from weaning for a period of 3 wk and consisted of a negative control (NC) diet containing 0.5% P, the NC diet + 0.05% P, the NC diet + 0.10% P, the NC diet + 0.15% P, the NC diet + 0.20% P, and the NC diet + 500, 1,000, or 2,000 phytase units (FYT)/kg. Increasing dietary P had no effect on ADFI or ADG; however, it did quadratically improve G:F (P < 0.05). Increasing levels of dietary phytase tended to increase ADG (linear, P = 0.056) and linearly improved G: F (P < 0.05). Increasing dietary P or adding phytase improved apparent total tract digestibility (ATTD) of P (linear, P < 0.001; quadratic, P < 0.05) and Ca (linear, P < 0.001; quadratic, P < 0.01). In conclusion, phytase was effective in improving performance and improving P and Ca ATTD of pigs during the immediate postweaning period. Based on ATTD of P, 500 FYT/kg was equivalent to the addition of 0.088% of P in weaner pig diets.

Increasing levels of phytase above commercial levels (500 FYT/kg) in pig diets have demonstrated improvements in performance beyond that of a phosphorus (P) adequate control. The aim of this study was to determine the effects of adding increasing levels of dietary phytase to diets with reduced P and calcium (Ca) levels on grower and finisher pig performance, and P and Ca digestibility. Three hundred and eighty-four pigs (Large White x Landrace dam to Hampshire boar) were allocated to trial at 35.3 (+/- 4.92) kg live weight. Pigs were fed 1 of 6 diets (8 replicates per treatment), a positive control diet (PC) containing 0.56% total P and 0.65% total Ca from 35-55 kg (grower stage) and 0.52% total P and 0.60% total Ca from 55 to 110 kg liveweight (finisher stage), a negative control diet (NC) containing 0.46% total P and 0.53% total Ca (grower stage) and 0.41% total P and 0.48% total Ca (finisher stage), NC+250, NC+500, NC+1,000, NC+2,000 phytase units FYT/kg. There was no difference in performance between the dietary treatments during the grower stage, however increasing phytase linearly improved P (P < 0.001) and Ca (P < 0.05) digestibility. Throughout the finisher stage, phytase increased feed intake (linear, P < 0.001) and ADG (quadratic, P < 0.05) and tended to improve feed efficiency (linear, P = 0.058). Pigs fed the PC diet grew faster than pigs fed the NC diet (P < 0.001). Phosphorus and Ca concentration in the metacarpal bone increased linearly with the addition of phytase (P < 0.01; P < 0.001). In conclusion, increasing levels of phytase above 250 FYT/kg in finisher pigs linearly improved performance.

The aims of this study were to determine whether Lys restriction immediately after weaning could be compensated for when pigs were switched to a high-Lys diet, and to determine whether this may be influenced by genotype. The experiment was a 2×2 factorial arrangement of diets and genotypes with 8 replicate pens per treatment and 8 or 9 mixed sex pigs per pen. Pigs received either a high- (Control; 17.5g/kg of Lys) or a low-Lys (WR; 8.0g/kg of Lys) diet during the first 3 week post-weaning followed by a high-Lys diet (15.5 and 12.0g/kg of Lys during the grower and finisher phases, respectively) to facilitate compensation until slaughter (approximately 101.2 ± 4.9kg). Two hundred and sixty four pigs [132 Hampshire sire×(Large White×Landrace) dam and 132 Large White sire×(Large White× Landrace) dam] were used and are referred to as Hampshire pigs and Large White pigs. Blood samples were collected from 2 selected pigs per pen at 6, 9, and, 15 week of age for blood urea nitrogen (BUN), non-esterified fatty acids (NEFA), and leptin analysis. Throughout the weaner phase, Control pigs gained more (105±1 g/d) than WR pigs (P<0.001). However, once pigs were switched to a high-Lys diet, WR pigs gained more (44±9 kg/d) than Control pigs and utilised their feed more efficiently (P<0.001), and thus compensatory growth was observed. Pigs of both genotypes performed similarly throughout the weaner stage when fed the low-Lys diet, however, when fed the high-Lys diet, Hampshire pigs had a greater rate of gain compared to Large White pigs (308 vs. 296±8 g/d). Throughout the experiment, Hampshire pigs ate more feed (P<0.001), gained more (P<0.001), and had a greater Lys intake (P<0.001) compared to Large White pigs. Lean meat percentage at slaughter was greater for the Large White pigs compared to Hampshire pigs (P<0.05). At 6 week of age NEFA concentrations were greater for Control pigs compared to WR pigs (P<0.05). Hampshire pigs on the WR treatment had lower BUN levels during the weaner period compared to Hampshire pigs on the Control treatment (P<0.10). In conclusion compensatory growth was observed in both genotypes. The fact that Hampshire pigs grew faster when fed a non-limiting diet but grew at a similar rate compared to Large White pigs when fed a limiting Lys diet indicates that limiting dietary Lys level rather than genotype determined growth performance.

Despite a large amount of work on compensatory growth in pigs it continues to be poorly understood with many conflicting reports. The aim of this work was to conduct four similar trials using the same genotype of pig, facilities, feed and growth restriction period to determine whether it was possible to obtain consistent results using a constant trial set-up. A total of 576 pigs (Hampshire sire×(Large White×Landrace) dam) were used. Pigs were weaned onto trial at 26.8±0.11 (mean±SE) days of age at a mean weight of 8.1±0.07kg and remained on trial until slaughter, approximately 150.9±0.66 days of age at a mean weight of 98.4±0.65kg. In each of the four trials the restriction period was for 3 weeks immediately following weaning. Pigs received either a high (Control; 17.5g/kg) or a low (weaner restrict (WR); 8.0g/kg) lysine diet during these 3 weeks, all pigs then received a high lysine diet up until slaughter, 15.5 and 12.0g/kg of lysine for the grower and finisher diets respectively. Pigs from trial 1 ate (P<0.001) and gained (P<0.001) more throughout the weaner stage than all other trials. Growth performance was successfully reduced during the weaner phase. WR pigs grew more slowly (P<0.001) and less efficiently (P<0.001) than Control pigs. WR pigs from trial 1 demonstrated compensatory gains throughout the grower stage, growing 6% faster than Control pigs from trial 1 due to an improvement in feed efficiency (P<0.001). WR pigs from trial 2 demonstrated compensatory gains during the finisher stage, increasing their rate of gain by 7.0% compared to Control pigs from trial 2 again due to an improvement in feed efficiency (P<0.1). However previous lysine restriction did not result in compensatory growth in trials 3 and 4. WR pigs from trials 3 (P<0.05) and 4 (P<0.1) had a lower feed intake compared to Control pigs during the grower stage and an overall lower lysine intake throughout the trial (P<0.05; P<0.05). Although pigs from trials 1 and 2 demonstrated compensatory growth following a reduction in performance when dietary lysine levels as low as 8.0g/kg lysine were fed for a period of 3 weeks immediately post-weaning, pigs from experiments 3 and 4 did not, thus compensatory growth was not consistently observed.

An experiment was conducted to evaluate the effects of genotype and dietary Lys concentration on the growth performance of weaner pigs. A total of 648 piglets were used. All piglets were offspring of Large White×Landrace dams sired by Hampshire (216), Pietrain (216), or Large White (216) boars. Piglets were weaned at 26.7±0.1 d of age at a mean weight of 8.3±0.1 kg and placed on trial for 20 d. Pigs were given ad libitum access to 1 of 3 diets differing in Lys concentrations: 18.2, 16.2, and 14.2 g/kg of Lys for high, medium, and low diets, respectively. Data were analysed as a 3×3 factorial arrangement with 9 replicates for each treatment with 8 piglets/replicate pen. No difference in feed intake was observed among genotypes. Genotype did not affect piglet growth rate in the first 2 wk of the trial. However, in the third week, Hampshire and Large White piglets grew faster than Pietrain piglets (454, 466, and 386 g/d, respectively; P<0.01). Pietrain piglets had a poorer feed conversion ratio (FCR) in week 3 (P<0.01) and overall (P<0.05) compared with Large White piglets. Piglets fed the medium diet were 0.6 kg heavier than piglets receiving the low diet (P<0.01) and 0.5 kg heavier than those receiving the high diet (P<0.05). Piglets ate less of the high diet in weeks 2 (P<0.05) and 3 (P<0.05) of the experiment. The FCR was greatest for piglets fed the low diet compared with piglets fed the medium and high diets (P<0.001) throughout the trial. In conclusion, this study indicated that, in the first 3 wk after weaning, Lys requirement is not substantially different among genotypes in the same environment with 16.2 g/kg being optimal across all 3 genotypes.

The projected rise in the global human population and the anticipated increase in demand for meat and animal products, albeit with a greatly reduced environmental footprint, offers a difficult set of challenges to the livestock sector. Primarily, how do we produce more, but in a way that is healthier for the animals, public, and the environment? Implementing a smart agri-systems approach, utilising multiplatform precision technologies, internet of things, data analytics, machine learning, digital twinning and other emerging technologies can support a more informed decision-making and forecasting position that will allow us to move towards greater sustainability in future. If we look to precision agronomy, there are a wide range of technologies available and examples of how digitalisation and integration of platform outputs can lead to advances in understanding the agricultural system and forecasting upcoming events and performance that have hitherto been impossible to achieve. There is much for the livestock sector and animal scientists to learn from the developments of precision technologies and smart agri-system approaches in the arable and horticultural contexts. However, there are several barriers the livestock sector must overcome: (i) the development and implementation of precision livestock farming technologies that can be easily integrated and analysed without the support of a dedicated data analyst in house; (ii) the lack of extensive validation of many developed and available precision livestock farming technologies means that reliability and accuracy are likely to be compromised when applied in commercial practice; (iii) the best smart agri-systems approaches are reliant on large quantities of data from across a wide variety of conditions, but at present the complications of data sharing, commercial sensitivities, data ownership, and permissions make it challenging to obtain or knit together data from different parts of the system into a comprehensive picture; and (iv) the high level of investment needed to develop and scale these technologies is substantial and represents significant risk for companies when a technology is emerging. Using a case study of the National Pig Centre (a flagship pig research facility in the UK) we discuss how a smart agri-systems approach can be applied in practice to investigate alternative future systems for production, and enable monitoring of these systems as a commercial demonstrator site for future pork production.