The inclusion of beta-hydroxy beta-methyl butyrate (HMB) in sow diets can improve sow and piglet pre -weaning performance. The aim of this study was to determine whether there was a dose -dependent effect of HMB supplementation of sows in gestation on litter and piglet performance to weaning and on colostrum production. A total of 140 (Large White x Landrace [JSR Gene -packer 90, JSR, UK]) multiparous sows were allocated to one of four treatments. There was a control treatment (CT) which was supplemented with HMB at the following doses to create four treatments: 0 (CT + 0), 5 (CT + 5), 15 (CT + 15) or 45 (CT + 45) mg/kg of the sow's body weight. Sows were fed their treatments from d 100 of gestation until parturition. Feeding sows increasing doses of HMB increased total live born litter weight and average piglet 24-h weight in a quadratic manner (P < 0.001 and P = 0.004, respectively). This quadratic pattern remained significant for litter and piglet weights at week one (P = 0.021 and P = 0.021, respectively) and a trend for litter weights at weaning (P = 0.056). There were quadratic increases in colostrum intake (P = 0.005) and yield (P = 0.004) in response to increased doses of HMB. Additionally, the IgG concentration of colostrum increased linearly up to the highest dose tested (P = 0.002). Mortality within the first 24-h of farrowing was reduced in a quadratic manner (P = 0.045) and this remained a trend at weaning (P = 0.055). Overall, increasing the dose of HMB fed to sows for the last 15 days of gestation increased litter and piglet weights and colostrum yield quadratically and increased colostrum IgG level linearly which in turn contributed towards reduced mortality to weaning.

Positive effects of beta-hydroxy beta-methyl butyrate (HMB) on reproductive performance, growth rate and health have been reported in both human and animal studies. However, research into its effect on sow and litter performance is limited and the results show inconsistencies. The aim of this work was to determine the effects of HMB supplementation to sows on litter and piglet performance to weaning. A total of 279 (214 Large White x Landrace and 65 Large White x Landrace x Duroc) multiparous sows were used across four experiments. Sows received either a control diet or a diet supplemented with HMB (minimum of 15 mg/kg sow's body weight) from day 100 of gestation until parturition (ca. day 115). The number of piglets born (total, alive or dead) was not affected by maternal dietary treatments. Feeding sows HMB increased total live born litter weight by 5.0 % (P = 0.031) with tendencies for these litters to remain heavier at week one (P = 0.081) and at weaning (P = 0.084). There were tendencies for HMB to increase average piglet weights at birth (P = 0.088), week one (P = 0.088) and at weaning (P = 0.054). In addition, there was a tendency for HMB to increase piglet growth rate from week one to weaning (P = 0.079). The concentration of IgM in colostrum was increased by 9.7 % with HMB supplementation (P = 0.029). The concentration of IgG was influenced by an interaction between diet and experiment (P = 0.016) whereby HMB significantly increased the colostrum concentration of IgG in experiment 1, numerically increased IgG concentration in experiment 2, but had no effect in experiment 3. Overall HMB supplementation to sows at a minimum dose of 15 mg/kg body weight for 15 days prior to parturition significantly increased litter weight at birth with tendencies for litters and average piglet weights to remain heavier at weaning. Supplemental HMB significantly increased the concentration of IgM in colostrum with a significant interaction between diet and experiment for IgG concentration.

In studies of both humans and farm animals, the inclusion of omega-3 polyunsaturated fatty acids in the diet have been shown to have beneficial effects on many physiological processes including reproduction. The aim of this study was to examine the effects of supplementary omega-3 on sow reproductive performance and piglet survival. Salmon oil (1 %) was fed to sows throughout gestation and lactation as a source of omega-3 and sows were followed through their subsequent parity when returned to a commercial gestation and lactation diet. It was hypothesised that sows fed omega-3 would show improved piglet survivability (+2 %) and an increased litter size (one extra piglet born alive per litter) in the second experimental period compared with a soya oil supplemented control. Supplementation of 1 % salmon oil across one parity increased the body weight of sows at weaning (p = 0.01) and these sows maintained on average 4 kg +/- 2.3 more over the lactation period than soya oil supplemented controls. Sows that were followed across a second un-supplemented reproductive period were heavier at farrowing (p < 0.01) and weaning (p < 0.05), had a higher condition score at farrowing and tended to have a higher condition score (p = 0.063) and back fat at weaning (p = 0.073) when they had received salmon oil in the previous reproductive cycle. However, salmon oil increased pre-weaning mortality by 2.4 % in the first reproductive period (p < 0.05) and significantly reduced litter weight at birth (ca 600 g; p < 0.05). Pre-weaning mortality was reduced by 3.4 % in the second experimental period when supplementation of both salmon oil and the soya oil control had ceased (p < 0.001). This effect tended to be greater for sows previously supplemented with omega-3. There was no effect on litter size, or the number of piglets born alive. Supplementation of 1 % salmon oil improved sow body weight at weaning and increased maternal stores across a second, un-supplemented reproductive cycle perhaps through effects on maternal nutrient partitioning. The increased mortality in the first experimental period and reduced mortality (across both treatment groups) when returned to a commercial diet suggests a negative effect of omega 3 fatty acid supplementation on piglet survival when fed throughout gestation and lactation.

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.

The aim of the work was to assess the effects of three dietary protein regimes on pig performance and nitrogen (N) excretion, in particular, whether performance can be maintained in lean, fast growing pigs when protein levels are reduced to limit N excretion. Entire male pigs of a lean genotype (Pietrain × Large White × Landrace), 192 in total in four batches, were grown from 40 to 115 kg in pens with four pigs per pen. The diets were: (i) a high-protein control regime; (ii) a low-protein regime in which protein was reduced by ~2 percentage units in each growth stage, but with levels of five essential amino acids the same as in the control (LP1); (iii) an even lower protein regime in which levels of essential amino acids were not maintained beyond 60 kg (LP2). The LP2 regime was designed to promote intramuscular fat deposition rather than efficient growth. Excretion of N was reduced by 17% and 19% in LP1 and LP2, respectively, compared with the control. Average daily gain was lower and feed conversion ratio higher in LP2 than the other regimes, as expected. The control and LP1, which differed in protein but not essential amino acid levels, produced broadly similar results for performance, but pigs in LP1 had poorer feed conversion than control pigs, which could be due to slightly greater fat deposition. The results show the difficulty in maintaining consistently high levels of performance in fast-growing, lean pigs when dietary protein levels are reduced.

The effects on compositional changes across the growing-finishing period (40-115 kg) of feeding pig diets with different protein and amino acid levels were investigated using CT scanning (at 60, 85 and 115 kg live weight). Pigs of a lean commercial genotype were fed a commercial control regime (C), or a low protein regime with either high (LP1) or low (LP2) essential amino acid levels, all balanced for net energy. In vivo CT measurements agreed well with post-slaughter sample joint dissection results for carcass tissue weights/proportions, and CT-measured muscle density predicted intramuscular fat accurately. Pigs on C and LP1 regimes did not differ significantly in composition during growth. However, pigs on the LP2 regime had significantly more fat (in carcass, internal and intra-muscular depots) and less muscle, from 85 kg onwards. Although fat levels differed depending on diet regime (LP2>others), proportions of fat in different body depots were unaffected.

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.

Pigs with a lean genotype were fed diets differing in protein and amino acid contents between 40 and 115 kg live weight. A high protein control regime (C) was compared with one supplying 11% less total protein but the same essential amino acid levels (LP1) and one supplying 16% less protein but lower amino acid levels (LP2). Regime LP2 produced fatter pigs in terms of subcutaneous, intermuscular and intramuscular fat (IMF), the latter measured in longissimus and semimembranosus muscles. The percentage of linoleic acid was lowest and that of oleic acid highest in IMF from LP2 pigs (11.57 and 34.59% respectively in longissimus). Pigs in regime LP1 had more longissimus IMF than C but similar semimembranosus IMF although both muscles had lower percentages of linoleic acid in LP1 than C, suggesting a tendency towards greater fat deposition in LP1. The high IMF content in LP2 produced the most tender, juicy steaks.

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.

Crossbreeding is common practice in commercial pig production as one way to increase lean growth and improve meat quality (Visscher et al., 2000). Reducing disease is another way to help improve growth rate in pigs. Porcine circovirus type 2 (PCV2) has devastated the pig industry in recent years. PCV2 infection increases mortality and reduces growth rate as it acts as an immunosuppressant thereby making pigs more susceptible to co-infections (Kixmöller et al 2008). Keeping disease at low levels has been achieved by improving husbandry standards, biosecurity, minimising presence of other pathogens and use of antibiotics. However vaccines against PVC2 are now available. The aim of this study was to investigate the effects of sire genotype and PCV2 vaccine on growth performance and body composition of pigs.

The potential conflict between reproductive functions and the drive to deposit body protein may impair productive performance in modern gilts of lean genotype. To study the response of the gilt to this conflict, a choice-feeding experiment was carried out to measure the nutrient intake selected by breeding gilts and responses in reproductive and lactation performance. Using a 2×2 factorial design, gilts of two different genotypes (24 of NPD 402, expected higher body protein/lipid ratio (L) or 24 of Camborough 23, expected lower body protein/lipid ratio, (F)) were either choice-fed (C) by offering both a low (120 g crude protein (CP)/kg) and a high protein (218 g CP/kg) feed during rearing and pregnancy or fed conventionally (R) single feeds, ad libitum during rearing and restricted during pregnancy. Choice-fed gilts selected mainly the low protein feed (0.92 of total feed intake) regardless of genotype and had lower protein intakes than R gilts prior to puberty. However, in pregnancy, due to higher feed intakes, C gilts had higher dietary protein and energy intakes than R gilts. C gilts were heavier, and had greater back-fat and eye muscle depth at farrowing than R gilts, but had smaller litter sizes (P<0.01). During lactation, dietary treatments were reallocated so that gilts received either a low (LE, maintenance+45 MJ/day) or a high (HE, maintenance+67 MJ/day) digestible energy intake. Litter size was standardised within 2 days of farrowing. LE gilts had greater decreases in weight and back-fat and eye-muscle depth during lactation than HE gilts, but dietary lactation treatment had no effect on litter performance. The choice-feeding regime which resulted in heavier gilts with greater back-fat and eye-muscle depth at farrowing did not produce any advantage in terms of partitioning of nutrients towards milk production, as indicated by litter performance, irrespective of gilt genotype. F gilts had greater piglet growth rates than L gilts and also had a higher milk protein concentration. A greater number of L than F gilts failed to complete the experiment for health reasons. Treatment effects on glucose tolerance at day 13 of lactation were not significant. Choice-feeding was therefore not found to be suitable for determining nutrient requirements of modern lean-genotype gilts which would improve reproductive performance.

The effects of different energy Sources in the lactation diet on sow and piglet performance were assessed in association with effects on the metabolic state of the sow around peak lactation. Either maize starch (S) or soya-bean oil (F) was added to a basal diet to provide 0.34 of total digestible energy (DE) intake, such that the experimental diets provided the same daily intakes of DE and crude protein. Twenty-four multiparous sows were allocated between two groups at farrowing, each given one of the two dietary treatments for a lactation period of 28 days. Sow weight and backfat (P-2) as well as individual piglet weights were measured on a weekly basis. Litter sizes were standardized to 10 piglets. Milk samples were collected from sows on days 8, 12, 17, 21 and 25 of lactation to measure milk composition and prolactin concentrations. Blood samples were taken via an ear vein catheter from a subsample (7 S, 6 F) of sows on day 14 of lactation; two pre- and seven post-feeding samples were taken at 60-min intervals to measure plasma prolactin, insulin, glycerol, triglyceride, non-esterified fatty acid, urea, beta-hydroxybutyrate and glucose concentrations. There was no effect of energy source on sow weight or P2 loss or on subsequent weaning-to-oestrus interval. Sows offered starch weaned more piglets than sows offered soya-bean oil (9.4 v. 8.4. P < 0.05). Litter weight gains were higher for S than F sows in week 3 of lactation (2.2 v. 1.7 kg/day, P < 0.05), irrespective of litter size. Significantly increased plasma urea and beta-hydroxybutyrate concentrations and lower post-prandial increases in plasma glucose and insulin concentrations were observed in F sows around peak lactation. Neither milk nor plasma prolactin concentrations were significantly affected by dietary treatments. The metabolic indices indicated that the F diet was more limiting in dietary glucose availability, which was associated with impaired milk yield as indicated by poorer litter performance. In conclusion, this study suggests that starch is superior to fat as an energy source in sow lactation diets, particularly in the later stages of lactation.

Two trials were conducted to examine the influence of dietary oil type and rate of inclusion on fatty acid profiles of adipose tissue and eating qualify of griddled pork. Trial I was based on three sources high in specific fatty acids: palm oil (palmitic acid), follow (stearic acid) and linseed oil (linolenic acid) each at three rates of inclusion (palm at 44.6, 88.7 and 133.3 g/kg; tallow at 44.1, 87.6 and 131.7 g/kg; linseed oil at 40.1, 79.8 and 120.0 g/kg into a synthetic fat-free diet. Trial 2 was based on systematic replacement of soya-bean oil (incorporated at a rate of 0, 34, 69 and 104 g/kg diet) with olive oil (rate of 62, 46, 29 and 13 g/kg diet) to alter dietary concentrations of oleic acid. Diets were offered to pigs over the live-weight range 55 to 90 kg. Samples of subcutaneous fat were analysed for fatty acid composition and samples of loin assessed for meat qualify with taste panels. There were no significant effects (P > 0.05) of treatment on daily live-weight gain, food conversion ratio or gross carcass composition, with the exception of anterior loin fat for trial 1 (P < 0.05) although not in a manner that was consistent between treatments and, in trial 2, anterior loin fat, minimum loin fat and posterior loin fat (all P < 0.05) but, again, not consistently between treatments allowing no meaningful conclusions to be drawn. Fatty acid profiles of adipose tissue reflected dietary levels to a variable degree, the more so with oleic acid and the greatest for linoleic and linolenic acids. The quality of the pig meat as measured by sensory analysis was related to the fatty acid profile in the situation where the most extreme changes in fatty acid profile occurred, as was apparent for the diets based upon linseed oil. No other major influences on meat quality were obtained.

The extent to which young sows, which still have a strong drive to continue maternal growth, partition nutrients from body reserves towards milk production, may be influenced by their genetic growth target. Modern genotype sows, with a high mature body protein mass, are thus particularly challenged. It has been suggested that to optimise their metabolic state for expressing lactational potential they will have to achieve a satisfactory proportion of their mature body protein mass before farrowing. This could be constrained by current feeding and breeding regimes. To test this hypothesis, gilts of genotypes differing in their body protein:lipid content were given the choice between a low and a high protein diet during rearing and pregnancy, and their intake, subsequent performance and metabolic state in lactation were measured.

The effect of feeding different sources of dietary fibre at varying rates of inclusion on the concentrations of skatole and indole in the backfat of finishing pigs and their subsequent carcass quality was studied. Sugar-beet pulp (SBP) and straw (S) were selected because of their assumed widely differing hind-gut-fermentability characteristics. They were individually and in combination added to a diet at three rates of inclusion designed to provide concentrations of 40, 80 and 120 g non-starch polysaccharide (NSP) per kg. The digestible energy (DE) contents varied between the three levels of inclusion of NSP but were formulated to a lysine: energy ratio of 0.625 g : MJ DE with other amino acids being in the same individual proportion to lysine. The nine experimental diets were offered to 10 replicate (five entire males and five females) pigs of initial live weight 55 kg. Food intakes were adjusted between treatment to ensure that energy and nutrient intakes were common. Animals were slaughtered on reaching 85 kg live weight. Adipose tissue teas analysed for skatole and indole and meat quality characteristics assessed. No significant differences in performance were detected although carcasses from animals given sugar-beet pulp were significantly fatter There were significant correlations between the level of skatole in the backfat and the following eating quality characteristics: skatole odour intensity of the fat, abnormal odour intensity of fat, abnormal odour intensity of lean and abnormal flavour intensity of lean with correlations coefficients of 0.656, 0.709, 0.496 and 0.523 respectively (coefficients >0.276; P < 0.05). The range in skatole levels in the backfat were attributable substantially to very high levels found in three boars. No significant correlations were found between indole concentrations in the backfat and eating quality characteristics. However no effects of dietary NSP type or inclusion level on the eating quality characteristics of pig meat, with pigs given diets on the basis of equal energy and nutrient intakes, were detected.

Reproductive failure, especially in young sows, is the major contributor to the steady rise in sow culling and mortality rates in recent years. There is now considerable interest in the nutrition of the gilt and its effect on production characteristics and subsequent reproductive performance. Both fat, and more recently lean tissue, have been postulated to play singularly important roles. The objective of the current study was to use production performance criteria of both primiparous and multiparous animals to estimate the proportions of fat and lean tissue mobilised during lactation.Ninety two animals, forty five gilts and forty seven third parity sows, based at the University commercial pig unit, were used in this study. All animals were weighed and monitored for P2 backfat depth on entry to the farrowing house, during lactation and, finally, at weaning. The data for each individual animal was then used to calculate, by linear regression, the daily rate of loss of both body weight and P2 backfat depth during lactation. These responses were then utilized to calculate the weight and P2 backfat level of each animal on days 1 and 28 of lactation.

Starch and fat are the two major energy sources available for sow lactation diets. Fat is more energy dense and can be used to maximise energy intakes, particularly in sows with low appetite. However, the quantity of milk produced in sows has been associated with milk lactose production and the main precursor for lactose is glucose, for which dietary starch is the major source. It is therefore important to know the consequences of using a glucose deficient energy source, such as fat, compared to starch in lactation diets. The following experiment was designed to assess energy sources in lactation diets at an isocaloric level in determining sow and piglet performance, in association with the effects of dietary glucose availability on the metabolic state of the sow around peak lactation.

Relationships between sow nutrition, milk yield, milk composition and piglet performance during lactation have been studied in numerous experiments. However, the subsequent effects of these pre-weaning factors on post-weaning piglet performance are less well studied. Commonly a growth check in piglets in response to weaning is noted, but to date it is unknown why some piglets do better than others in this period. The present experiment explored some of the pre-weaning factors that could explain the variability in piglet post-weaning growth.The performance of piglets from 41 litters was monitored during a lactation period of 26 days. Litter size was standardised to 10 piglets, which were not offered creep food. Piglets were weighed individually on a weekly basis from farrowing to weaning at 26 days. Daily litter milk intake was estimated by a weigh-suckle-weigh technique in 24 litters on 4 occasions at 5 day intervals across lactation. On the day after each of these days, the composition of milk was determined from milk samples obtained by hand milking following oxytocin injection. Litter milk intake and composition of milk were used to calculate the mean daily piglet nutrient intakes during lactation. After weaning some piglets were sacrificed for the analysis of body composition and 310 piglets out of the 41 litters were penned in litter groups in controlled environment flat decks for two weeks to monitor daily group feed intakes and weekly individual growth rates.