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peer-reviewed An experiment was conducted to assess the effect of a combination of carbohydrolase (from Talaromyces Versatilis) and 6-phytase (from Schizosaccharomyces Pombe) multi enzyme complex (mec; Rovabio Max®, Adisseo, France) on the growth and bone mineralization of pigs fed maize-wheat-soybean meal diets. Pigs (n = 384) were selected at 28 days of age, penned in same gender pairs and fed a common acclimatization diet meeting animal requirements for 14 days. Four experimental diets were formulated for each of 4 growth stages from 42 days of age to slaughter at 147 days: 1) Positive control (PC), formulated to meet nutritional requirements; 2) Negative control 1 (NC1; DE × 0.985, CP × 0.985, −1.0 g Ca/kg and −1.2 g dig P/kg), 3) Negative control 2 (NC2; DE × 0.975, CP × 0.975, −1.0 g Ca/kg and −1.2 g dig P/kg) and 4) Negative control 3 (NC3; DE × 0.975, CP × 0.975, −1.5 g Ca /kg and −1.7 g dig P/kg). Negative control diets were also supplemented with mec resulting in 7 experimental treatments. Feed disappearance, wastage and individual pig live weight (LW) were recorded at the beginning and end of each growth phase. Reducing in dietary constituents (CP, DE, P and Ca) compared to PC reduced LW (P < 0.001), average daily feed intake (ADFI; P < 0.01), and average daily gain (ADG; P < 0.001) throughout the trial. Addition of mec to NC diets increased LW (P < 0.001), ADFI (P < 0.001) and ADG (P < 0.001) up to slaughter and improved feed conversion ratio (FCR; P < 0.001) to day 112 of the trial. There were increases in area bone mineral density (aBMD) of the foot from day 77 onwards (P < 0.01) and metacarpal aBMD (P < 0.01) from day 112 onwards when mec was added to NC diets although no effect (P > 0.05) on metacarpal Ca or P percentages was found. It was concluded that supplementing carbohydrolase and phytase to low nutrient density diets can return the growth and FCR of the pigs as well as metacarpal and foot aBMD to the levels reached by pigs fed diets meeting nutrient recommendations.

This study aimed to determine the effects of weaning age and postweaning feeding programme on pig performance and health. In experiment 1, 96 same gender pairs of pigs weaned at 3, 4 and 5 weeks of age were used in a 3 (weaning age)×4 (dietary programme) factorial design experiment. Pigs received different amounts of a phase 1 diet (16.2 MJ/kg digestible energy (DE) and 16.2 g/kg lysine) and phase 2 diet (15.3 MJ/kg DE and 15.0 g/kg lysine): (A) very low (VL, 1 kg phase 1 and 3 kg phase 2 diet per pig); (B) low (L, 2 kg phase 1 and 6 kg phase 2 diet per pig); (C) medium (M, 3 kg phase 1 and 9 kg phase 2 diet per pig) or (D) high (H, 4 kg phase 1 and 12 kg phase 2 diet per pig), followed by a cereal based phase 3 diet (15.0 MJ/kg DE and 13.8 g/kg lysine) to 10 weeks of age. In experiment 2, faecal samples from 60 pigs weaned at 3, 4 and 5 weeks of age were collected at 10 days postweaning and analysed for Escherichia coli and lactic acid bacteria counts. In experiment 1, there were no interaction effects of age×dietary programme on growth performance. Dietary programme did not affect growth performance from weaning to 10 weeks of age. From weaning to 10 weeks of age, increasing weaning age increased average daily gain (ADG; 363, 402, and 476 g for 3, 4 and 5 weeks respectively; s.e. 17.6; P 0.05) on pig weight at 10 weeks of age. In experiment 2, 3 week weaned pigs had higher faecal counts of E. coli (P 0.01) than 5 week weaned pigs at 10 days postweaning. In conclusion, feeding higher amounts of phases 1 and 2 diets did not affect performance at any of the weaning ages tested. Increasing weaning age increased growth performance between weaning and 10 weeks of age, but had no effect on the resulting body weight. Pigs weaned at 3 weeks of age had increased counts of selected faecal bacteria compared to those weaned later.

Two experiments were conducted using nursery and grower–finisher pigs and dual energy X-ray absorptiometry to monitor the ability of pigs to compensate in area bone mineral density (aBMD; g/cm2) in response to the levels of dietary digestible P following a period of P insufficiency. In experiment 1, 48 female pigs were selected at 8.1 ± 1.0 kg and individually allocated to one of four treatments. The treatments were: high–high (HH) digestible P (3.7 g digestible P/kg for 28 days followed by 3.5 g digestible P/kg for 28 days); high–low (HL) digestible P (3.7 g digestible P/kg for 28 days followed by 2.5 g digestible P/kg for 28 days); low–high (LH) digestible P (3.0 g digestible P/kg for 28 days followed by 3.5 g digestible P/kg for 28 days); and low–low (LL) digestible P (3.0 g digestible P/kg for 28 days followed by 2.5 g digestible P/kg for 28 days). The aBMD was measured at days 0, 28 and 56. In experiment 2, 32 female pigs were selected at 34.0 ± 2.0 and individually allocated to one of four treatments until slaughter at about 102 ± 2 kg live weight. The treatments were: HH digestible P (2.8 g digestible P/kg fed for 35 days followed by 2.3 g digestible P/kg fed to slaughter); HL digestible P (2.8 g digestible P/kg diet fed for 35 days followed by 1.6 g digestible P/kg fed to slaughter); LH digestible P (1.6 g digestible P/kg fed for 35 days followed by 2.3 g digestible P/kg fed to slaughter); and LL digestible P (1.6 g digestible P/kg fed for 35 days followed by 1.6 g digestible P/kg fed to slaughter). The pigs were scanned at days 0, 35 and 70, and a third metacarpal was collected at slaughter for analysis. At day 56 in experiment 1 the left and right hind aBMD was higher (P

Two experiments were performed in weaner, grower and finisher pigs in order to monitor the changes in skeletal area bone mineral density (aBMD, g/cm2) and dietary phosphorus (P) concentrations using dual energy X-ray absorptiometry (DXA) scan data. In experiment 1, 24 female pigs were selected at 8 kg (SD ± 1.04 kg) and individually fed either high (3.7 g/kg) or low (3.0 g/kg) digestible P diets for 8 weeks (with reductions of 0.5 g/kg digestible P at 4 weeks) until they reached ca. 30 kg body weight. The pigs were anaesthetised and scanned at the start of the study (day 0) and after 28 and 56 days. In experiment 2, 30 female pigs were selected at 34 kg (SD ± 2.3 kg) and individually fed high (2.8 g/kg), medium (2.2 g/kg) or low (1.6 g/kg) digestible P until slaughter at 100 kg (SD ± 4.3 kg). These pigs were scanned at the start of the experiment (day 0) and after 35 and 70 days. One foot from each pig in experiment 2 was collected at slaughter for analysis of metacarpal cross section area, moment of inertia, dry matter, apparent density, aBMD, and ash percentage. In both experiments, there were significant diet × time interactions (P

The effect of 3 slaughter weights (85, 95 or 105 kg) on performance and carcass traits of 481 pigs in single-gender groups of 13 (18 groups of gilts and 19 groups of intact males) was evaluated. Pigs (39.5 ± 3.3 kg) were fed a liquid diet 3 times daily in a long trough. The behaviour of pigs slaughtered at 105 kg was recorded at 50, 60 and 70 days after the start of the experiment (5 groups of gilts and 4 groups of intact males). Behaviour (active, inactive, feeding) and posture (standing, lying, dog-sitting) of all pigs was recorded at 5-min intervals for 30 min prior to and 1 h after each feeding event. Slaughtering pigs at 95 kg and 105 kg delayed production by 7 and 16 days, respectively, compared to slaughtering at 85 kg (P 0.05). Muscle depth increased with increasing slaughter weight (P

peer-reviewed Variations in maternal nutrition during gestation can influence foetal growth, foetal development and permanently ‘programme’ offspring for postnatal life. The objective of this study was to analyse the effect of increased maternal nutrition during different gestation time windows on offspring growth, carcass quality, meat quality and gene expression in skeletal muscle. A total of 64 sows were assigned to the following feeding treatments: a standard control diet at a feed allocation of 2.3 kg/day throughout gestation, increased feed allowance of 4.6 kg/day from 25 to 50 days of gestation (dg), from 50 to 80 dg and from 25 to 80 dg. At weaning, Light, Medium and Heavy pigs of the same gender, within litter, were selected based on birth weight, individually penned and monitored until slaughter at 130 days post weaning. Carcass and meat quality traits of the semimembranosus (SM) muscle were recorded post mortem. A cross section of the semitendinosus (ST) muscle encompassing the deep and superficial regions were harvested from pigs (n518 per treatment) for RNA extraction and quantification of gene expression by real-time PCR. The results showed that doubling the feed intake from 25 to 50 dg reduced offspring growth, carcass weight, intramuscular fat content and increased drip loss of the SM muscle. Interestingly, protein phosphatase 3 catalytic subunit – a-isoform, which codes for the transcription factor calcineurin, was upregulated in the ST muscle of offspring whose mothers received increased feed allowance from 25 to 50 dg. This may provide an explanation for the previous observed increases in Type IIa muscle fibres of these offspring. Increasing the maternal feed intake from 50 to 80 dg negatively impacted pig growth and carcass weight, but produced leaner male pigs. Extending the increased maternal feed intake from 25 to 80 dg had no effect on offspring over the standard control gestation diet. Although intra-litter variation in pig weight is a problem for pig producers, increased maternal feeding offered no improvement throughout life to the lighter birth weight littermates in our study. Indeed, increased maternal nutrition at the three-gestation time windows selected provided no major benefits to the offspring. Teagasc, under the National Development Plan; Teagasc Walsh Fellowship; Short Term Scientific Mission (STSM) fund, COST925.

Pain and discomfort provoked by surgical castration of male pigs causes behavioural alterations that are particularly evident in the immediate days following this procedure. Less information is available in relation to whether the physiological consequences of surgical castration also persist with time. The objective of this study was to assess the behavioural response to this procedure; and evaluate its effects on levels of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β), as well as cortisol [Exp. 1]; and the acute phase proteins C-reactive protein (CRP), serum amyloid A (SAA) and haptoglobin (Hp) [Exp. 2]. Forty male piglets were used in each experiment. At 5 days-of-age, pigs were randomly assigned to undergo surgical castration or to being handled identically but not castrated (treatments were imposed in the morning period). Behaviour was assessed by scan sampling every 3 min for 3 h in the afternoon period on the day of castration [Exp. 1]; and for intervals of 2.5 h on the day of castration (morning and afternoon periods) and 2 h-intervals on three consecutive days thereafter (afternoon period) [Exp. 2]. Pigs were assigned to one of five sampling times, where blood was collected by venipuncture before (0 h), 1, 2, 3 or 4 h [Exp. 1] and 0, 12, 24, 48 or 72 h after treatments [Exp. 2]. Castration provoked specific pain-related behaviours ( P P P P P P P P > 0.1). Castrated piglets tended to have higher cortisol levels than handled pigs ( P

The effects of an extract of the brown seaweed Ascophyllum nodosum (AN) in grower–finisher pigs are reported. In Experiment 1, the effect of dietary supplementation with increasing levels of AN extract (ANE) on growth performance, carcass characteristics and gastrointestinal microflora was investigated. A total of 360 pigs were randomly allocated, based on initial live-weight and sex, to one of four experimental treatments as follows; control diet (no ANE), control diet plus 3 g ANE/kg, control diet plus 6 g ANE/kg and control diet plus 9 g ANE/kg. These diets were fed ad libitum up to slaughter. In Experiment 2, eight male pigs were allocated to a control diet (no ANE) or the control diet plus 2.5 g ANE/kg to determine effects of ANE on coefficient of total tract apparent digestibility (CTTAD) of nutrients and nitrogen (N) balance. Supplementation with increasing levels of ANE in Experiment 1 resulted in reduced daily gain, carcass weight and kill-out yield during the combined grower–finisher period (P 0.05). In Experiment 2, the CTTAD was unaffected by the inclusion of ANE (P>0.05). Overall, the intestinal coliform reductions obtained suggest that ANE may provide a dietary means to improve gut health and potentially reduce pathogen carriage in finishing pigs. However, the negative effects on growth performance observed in healthy animals will most likely limit the commercial use of dietary ANE as a feed additive.

Changes in physical body size during gestation were monitored using 529 sets of sow measurements. All sows were from the same herd and production system with a range in parity from 1 to 8. Sows were individually weighed, P2 backfat thickness was determined by ultrasound and morphometric measurements of body size were taken five times during gestation: day 0 (at service), day 25, day 50, day 80 and day 110. The morphometric measurements included sow height (from floor to last rib at the midline, from floor to ventral surface and from floor to hip), heart girth, depth of last rib, length (from snout to tail and from anterior scapula to tail) and width (at ham, at last rib and at shoulder). Regression analyses were used to model the relationship between day of gestation or parity number and morphometric measurements of body size. Regression equations were also developed to estimate sow weight from physical measurements, day of gestation and parity. As expected, sow dimensions, in general, increased as pregnancy progressed and also with increasing parity number. The relationships between day of gestation and body dimensions were described by linear and quadratic regression models, which had a range of adjusted R2 values up to 0.99. Similar relationships to parity number had a range of R2 values between 0.51 and 0.96. Sow depth, which can be used as an estimate of the width of the sow when lying, equalled the maximum width of the gestation stall (650 mm) at day 103 of gestation. However, by day 40 of gestation, predicted mean sow depth (570 mm) equalled the width at the rear of the crate. The implication of this is that after day 40 of gestation, the average sow was too wide for the rear of the crate when lying in a recumbent position. On day 110 of gestation, 95% of the mean sow body depths would be accommodated in stalls that were 674 mm wide; however, the range in body sizes with increasing parity number suggests the use of more than one stall width would be appropriate. Sow weight could be estimated with an adjusted R2 value of 0.81 and with a residual standard deviation (r.s.d.) of 16.5 kg using heart girth alone, or more accurately using a model with parity, day of gestation, P2 backfat depth and heart girth as the parameters (R2 = 0.89, r.s.d. 12.4 kg).

The objective of this study was to establish the pro-inflammatory cytokine and acute phase protein responses to low-dose lipopolysaccharide (LPS) challenge in pigs and to determine whether these immune parameters could also be measured in saliva. Possible gender differences in the acute phase reaction were also assessed. At 6 weeks of age, 24 male and 24 female pigs were injected intraperitoneally with a single dose of 0 or 5 μg/kg live weight (LW) of LPS fromEscherichia coli(treatment). Matched saliva and blood samples were taken at 0, 2, 4, 8, 12 or 24 h after treatment administration. Samples were analysed for concentrations of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β), the acute phase proteins C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin (Hp), and cortisol. Low-dose LPS administration increased plasma levels of TNF-α (PPPP>0·1). Treatment by time interactions showed that plasma levels of TNF-α and CRP in LPS-treated pigs peaked at 2 h (PPP=0·056) and the response to LPS differed between genders (PPPP

Two experiments (exp.) were conducted to determine the effect of dietary lysine restriction during the grower phase and subsequent dietary lysine concentration during realimentation on the performance, carcass characteristics and nitrogen (N) balance of growing–finishing pigs. Seventy-two pairs of crossbred [meatline sires × (Large White × Landrace) dams] pigs (36 pairs entire male, 36 pairs female) were used in a 2 × 4 factorial performance study (exp. 1, 35 to 96 kg). The two factors were Diet1 (two lysine levels: LO or HI, day (d) 0 to 35) and Diet2 (four lysine levels: LO, M1, M2 and HI, d36 to slaughter). A further 30 boars were used in a 2 × 3 factorial N-balance study (exp. 2, 31 to 42 kg; Diet1: LO or HI; Diet2: LO, M3 and HI). The crude protein (CP) and lysine contents of the five isoenergetic (14.0 MJ DE/kg) diets were: LO (139 g/kg CP, 8.1 g lysine/kg), M1 (162 g/kg CP, 9.7 g lysine/kg), M2 (190 g/kg CP, 11.4 g lysine/kg), M3 (180 g/kg CP, 10.7 g lysine/kg) and HI (217 g/kg CP, 13.1 g lysine/kg). Diets were based on barley, wheat and soyabean meal with added vitamins, minerals and amino acids. Ratios of amino acids relative to lysine were similar for all diets. From d0 to 35 in exp. 1, pigs fed LO had lower daily gains (ADG: 785 vs. 939 g/day; P

Three trials were conducted to determine the optimum dietary lysine concentration for maximum growth rate (ADG) or minimum food conversion ratio (FCR) of boars and gilts from 60 to 90 kg (in pairs) and 80 to 100 kg (in pairs or groups). Ninety pairs of pigs and six treatments (dietary lysine concentrations) were used in experiment 1 (60 to 90 kg), 144 pairs and eight treatments in experiment 2 (80 to 100 kg) and groups of 13 pigs (no.=42 groups) and six treatments in experiment 3 (80 to 100 kg). Experiments were arranged as randomized-block designs, blocked on the basis of sex and start weight. Isoenergetic diets (13·8 MJ digestible energy per kg) were based on barley, wheat, soya-bean meal, with added vitamins, minerals and amino acids. Dietary lysine concentrations were: 7·9, 8·8, 9·7, 10·7, 11·7 and 12·5 g/kg in experiment 1; 7·0, 7·9, 8·8, 9·7, 10·7, 11·7, 12·5 and 13·5 g/kg in experiment 2; and 7·0, 7·9, 8·8, 9·7, 10·7 and 11·7 g/kg in experiment 3. In experiment 1 (60 to 90 kg pairs), ADG increased (quadratic, P

The objective of this study was to evaluate the effect of providing paper or rope, alternative enriching substrates to straw, to piglets in farrowing crates on piglet and sow welfare. Sixty multiparous sows and their litters were housed in crates that were either barren (BARREN), enriched with shredded paper (PAPER) or natural fibre rope (ROPE). Enriching substrates were introduced when piglets were 10 days old. The proportion of sows with udder and teat lesions before parturition and at weaning was recorded. Piglet facial lesions were scored according to severity on days 11, 18 and 27. Sow and piglet behaviour was recorded using scan sampling on days 14, 18, 22 and 26. Furthermore, the behaviour of one male and one female focal piglet per litter was recorded continuously for 10 min twice per day on days 14, 18, 22 and 26. On day 27 post-partum, focal piglets were observed for 5 min in a novel arena and for a further 5 min after a novel object was introduced. On day 27, there was a tendency for more BARREN sows to have teat lesions ( P = 0.07). PAPER litters tended to have a smaller proportion of piglets with facial lesions ( P = 0.06). ROPE piglets were active in the enriched area of the crate in more observations than BARREN and PAPER piglets ( P P P P P = 0.05). In conclusion, shredded paper improved piglet welfare and was easily incorporated into the farrowing crates.

A study consisting of 3 trials was designed to assess the relative biological efficacy of DL-methionine (DL-Met) in comparison to liquid methionine hydroxy analogue (MHA-FA) in growing pigs. In trial I a basal diet was supplemented with three graded levels of DL-methionine (0.25, 0.50 and 0.75 g/kg) or liquid MHA-FA (0.0285, 0.0570 and 0.0855 g/kg) on equimolar basis. The basal diet contained 18.3% CP, 0.22% Met and 0.51% Met+Cys, which is below the methionine requirement for weaned pigs between 10 and 20 kg BW according to NRC (1998) but adequate in all other essential nutrients and energy. Using an exponential model, the efficacy of the two methionine sources was estimated from nitrogen retention data obtained in 42 piglets with an initial BW between 11.0 kg (Exp. 1) and 11.7 kg (Exp. 2). In trials II and III, with a total of 192 and 96 pigs, and with an initial BW of 10.6 and 21 kg, respectively, growth response criteria were assessed to determine if in agreement with previous studies in pigs and poultry a biological effectiveness of about 65% on average could be confirmed for liquid MHA-FA in comparison to DL-met. Based on N-retention (trial I) the biological efficacy of liquid MHA-FA on a weight-to-weight basis was calculated to be 62% relative to DL-met. Basically, these results were confirmed using growth response criteria as measures; the results of trial II and III revealed no significant differences in growth performance and feed conversion between treatments indicating that 100 parts of liquid MHA-FA can be replaced by 65 parts of DL-met.

A study was designed to determine if pig performance and lysine conversion ratio would be improved by phase feeding a series of diets with either the same, or with reduced overall mean crude protein (lysine) content, compared with providing a single diet throughout the growing-finishing period. Four hundred and forty-eight group-penned pigs (no. = 32 groups) were assigned at random to one of four treatments: single diet (SD: 11·1 g lysine per kg), high lysine (HL: 12·2, 11·6, 11·1, 10·5 and 10·0 g lysine per kg), medium lysine (ML: 11·1, 10·5, 10·0, 9·5 and 8·9 g lysine per kg) and low lysine series of diets (LL: 10·0, 9·5, 8·9, 8·4 and 7·8 g lysine per kg). The mean lysine contents of the treatments were 11·1, 11·1, 10·0 and 8·9 g/kg for SD, HL, ML and LL respectively. There were five 2-week phases from 38·3 kg to slaughter at 97·3 kg live weight. LL pigs had lower carcass average daily gain (709 v. 742 g/day;P< 0·05) and poorer carcass FCR (P< 0·05: 2·95 v. 2·84 kg/kg) than SD pigs. Daily lysine intake was lower for pigs on HL (P< 0·05: 22·5 g/day), ML (P< 0·001: 20·9 g/day) and LL (P< 0·001: 18·2 g/day) compared with SD (23·4 g/day). Live weight lysine conversion ratio was better for HL (P< 0·05: 26·9 g/kg), ML (P< 0·001: 24·5 g/kg) and LL (P< 0·001: 22·6 g/kg) pigs compared with SD pigs (27·6 g/kg), but carcass lysine conversion ratio was only better for pigs on the ML (P< 0·001: 27·9 g/kg) and LL (P< 0·001: 25·7 g/kg) treatments compared with SD (31·6 g/kg). Nitrogen intake was lower for LL pigs than SD pigs (P< 0·001: 3·45 v. 4·03 kg). Estimated nitrogen excretion was lower for ML (P< 0·01: 2·16 kg) and LL (P< 0·001: 1·85 kg) pigs than SD pigs (2·47 kg). Nitrogen deposition rate was lower for pigs on the LL compared with the SD treatment (P< 0·05: 22·3 v. 23·2 g/day). Although phase feeding diets with the same mean lysine content (11·1 g/kg) as a single diet over the growing-finishing period resulted in similar pig performance, reduced overall daily lysine intake and improved lysine conversion ratio, there was no effect on carcass characteristics or carcass lysine conversion ratio. Reducing the overall mean lysine content to either 10·0 or 8·9 g/kg improved lysine conversion ratio and reduced nitrogen excretion. However, reducing the overall mean lysine content of the diet to 8·9 g/kg had a negative effect on pig growth performance.

Three 28-day trials were carried out to determine the optimum dietary lysine concentration for growing pigs between 20 and 68 kg. There were 96 pairs of pigs in experiment 1 (20 to 41 kg), 72 pairs in experiment 2 (40 to 68 kg) and 42 groups (14 per group) in exp. 3 (40 to 62 kg). All experiments were arranged as randomized complete block designs, blocked on the basis of sex and start weight. Treatments consisted of isoenergetic (13·8 MJ digestible energy per kg) diets with increasing lysine concentrations. Dietary lysine concentrations were 9·7, 10·7, 11·6, 12·5, 13·5 and 14·4 g/kg (experiment 1) and 9·0, 9·9, 11·0, 12·1, 13·1 and 14·1 g/kg (experiments 2 and 3). Response curves were fitted to the data to determine the optimum dietary lysine concentration for maximum average daily gain (ADG) and minimum food conversion ratio (FCR). In experiment 1, ADG and FCR responded quadratically to dietary lysine content (P < 0·01 and P < 0·05). Male pigs had better FCR and lysine conversion ratio (LCR) than female pigs (P < 0·05). In experiment 2, there was a quadratic effect of increasing dietary lysine concentration on FCR (P < 0·05). Male pigs had lower daily food intake (DFI, P < 0·01) and daily lysine intake (DLYIN, P < 0·01) and had better FCR (P < 0·01) and LCR (P < 0·01) than female pigs. In experiment 3, there was a quadratic effect of increasing lysine concentration on FCR (P < 0·05). Male pigs had better FCR and LCR (P < 0·05) than female pigs. In all experiments, increasing dietary lysine concentration resulted in an increase in DLYIN and a deterioration in LCR (all linear, P < 0·001). Regression analysis predicted optimum dietary lysine concentrations for maximum ADG at 13·1 and 12·7 g lysine per kg in experiments 1 and 2, and minimum FCR at lysine concentrations of 14·6, 12·2 and 12·7 g/kg for experiments 1, 2 and 3 respectively. In conclusion, the optimum dietary lysine concentration for maximum ADG and minimum FCR could be predicted using quadratic models and although males had better FCR than females, optimum dietary lysine concentrations were similar for both sexes.

Two experiments were completed with grower-finisher pigs to determine if pigmeat output, as measured by carcass gain per m2 per year, could be increased, by 1: increasing group size or 2: split-marketing pen groups. In experiment 1, 390 pigs (mean initial live weight 36·7 (s.d. 1·99) kg) were assigned to one of three treatments each with 10 replicates: 11, 13 or 15 pigs per single-sex group in pens measuring 11·04 m2. Space allowance was 1·00, 0·85 and 0·74 m2 per pig, respectively. Pelleted food was provided ad libitum. There were no differences (P > 0·05) between group sizes in growth rate, food intake, food conversion ratio, carcass growth and carcass food conversion ratio, backfat and muscle depth or carcass lean content. Pigmeat output per unit area increased with each increase in group size (234, 279 and 314 kg/m2 per year for 11, 13 and 15 pigs: P < 0·001). In experiment 2, 26 groups of 13 pigs (mean initial live weight 38·3 (s.d. 2·15) kg) were assigned to one of three treatments: 1D - group sold on 1 day (no. = 9), 2D - group sold over 2 days (14 days apart, no. = 10), or 3D - group sold over 3 days (each 7 days apart, no. = 7). Pigs were given a standard liquid diet three times daily. No differences (P > 0·05) were observed between treatments for overall growth rate, food intake, food conversion ratio, carcass weight, carcass lean content, backfat and muscle depth, carcass growth and carcass food conversion ratio or killing-out proportion of pigs. Split-marketing increased cycle length (67·7, 75·9 and 76·8 days for 1D, 2D and 3D, respectively; P < 0·001). Live and carcass daily growth rates per pig place decreased with increase in number of sale days (live: 772, 680, 670 g/day and carcass: 658, 575, 571 g/day; P < 0·001). Carcass gain per unit area decreased in split-marketed groups (358, 318, 312 kg/m2 per year for 1D, 2D and 3D, respectively: P < 0·05). Carcass weight variation (s.d.) within pen decreased with each increase in number of sale days (s. d. 5·28, 3·81 and 1·74, respectively; P < 0·001). In conclusion, pigmeat output, as measured by carcass gains per m2 per year, was improved with increase in group size and by marketing all pigs in a group on a single day.

Teeth resection is a method of controlling the injurious effects of the aggression displayed when newborn piglets fight to establish a teat order. Recent European legislation discourages the practice. The objective of this study was to assess the effect of clipping and grinding piglets’ needle teeth, compared to leaving them intact, on the welfare of piglets in farrowing crates. Six days pre-partum, 60 sows were assigned to one of three treatments. Litters had their teeth clipped (C), ground (G) or left intact (I) at birth. The time taken to carry out each procedure was recorded. Piglet weights and facial lesions, which were scored according to severity, were recorded on days 1, 4, 11, 18 and 27. Piglet weights were also recorded at birth. Mouth lesions were recorded on days 1, 4 and 27. Instantaneous scan samples of piglet behaviour were carried out for 30 min post-teeth resection procedure (1 min intervals), and for 6 h on days 1, 4, 8, 14, 21 and 26 (5 min intervals). One male and one female piglet per litter were chosen as focal animals and observed for 5 min each post-procedure and for 10 min each twice per day on days 1, 5, 12, 20 and 26. Mortalities were recorded throughout lactation. Grinding took significantly longer than clipping the teeth or leaving them intact (F = 638.87, P In conclusion, although all three options were associated with welfare problems, grinding can be recommended in preference to clipping or leaving the teeth intact.

Recent EU legislation discourages the practice of resecting piglets’ needle teeth. However, the effect of leaving piglets’ teeth intact on the welfare of sows in farrowing crates is poorly understood. Therefore, the aim of the study was to compare the effects of clipping and grinding piglets’ needle teeth, compared to leaving them intact, on the welfare of sows in farrowing crates. Six days pre-partum 60 multiparous sows were assigned to one of three treatments. Litters had their teeth clipped (C), ground (G) or left intact (I) at birth. Sows’ teats were inspected for lesions pre-partum (day −3) and on days 1, 4, 11, 18 and 27 post-partum. Instantaneous scan samples (5 min intervals) of sow behaviour were carried out during three 2 h periods on days 1, 4, 8, 14, 21 and 26. On days 1, 4 and 11 all piglets were removed from the crate for 60 min. On re-introduction of the piglets, sow maternal behaviour was recorded continuously for 20 min. The number of sows with teat lesions tended to differ between treatments on days 11 (P = 0.06) and 18 (P = 0.10). There was an interactive effect between treatment and day on sow dog-sitting behaviour throughout lactation (P There were indications that leaving the teeth intact and to a lesser extent grinding caused injury and disturbance to sows. In farrowing crates, leaving piglets’ teeth intact cannot be recommended.

Nuggets were manufactured from equal portions of breast and thigh chicken meat from chickens fed either a basal (control) or a supplemented level of α-tocopheryl acetate (vitamin E). Rosemary (0.10%) (R), sage (0.10%) (S) and tea catechins (0.01%) (TC), which were chosen from previous screening trials, were added to both control and vitamin E meat from which chicken nuggets were manufactured. The trial was repeated twice more where in addition to antioxidant addition to meat prior to nugget manufacture, 0.75% salt and 0.75% salt and 0.25% sodium tripolyphosphate (STPP) were also incorporated into both control and supplemented minced meat. Nuggets were tested for oxidative (TBARS) stability, colour (Hunter 'L, a, b' values) stability and percentage cook loss. There was a synergism between vitamin E and added antioxidants as nuggets containing vitamin E with R, S or TC had lower TBARS values than those containing vitamin E alone. Control nuggets containing R, S and TC had lower (p

The effect of different oil combinations: olive oil (20 g/kg), sunflower oil (20 g/kg), linseed oil (5 g/kg) and either olive (15 g/kg) or sunflower oil (15 g/kg) and α-tocopheryl acetate supplementation (200 mg/kg feed) on fatty acid composition and lipid oxidation of pig muscle and muscle microsomes was investigated. The proportions of α-linolenic acid (P

Post-weaning growth rate in pigs is frequently poor and variable. Choice feeding may offer the opportunity to rectify this. In experiment 1, 24 mixed sex groups of 16 pigs weaned with an average weight of 6·8 kg were blocked on weaning weight and assigned at random to the following treatments: (A) starter diet (18·3 g/kg lysine and 16·6 MJ digestible energy (DE) per kg) for 11 days followed by link diet (15·0 g/kg lysine and 15·3 MJ DE per kg) to 27 days; (B) starter diet and link diet offered in a free choice to 27 days; and (C) starter diet and weaner diet (13·0 g/kg lysine and 14·3 MJ DE per kg) offered in a free choice to 27 days. In experiment 2, 66 pigs were weaned at 6·3 kg, blocked as individuals on sex and weight and were randomly assigned to treatments as in experiment 1. In experiment 3, 24 single sex groups of 16 pigs were formed from pigs weaned at 7·8 kg. The groups were blocked on the basis of weaning weight and randomly assigned to the following treatments: (A) starter diet for 11 days followed by link diet to 26 days, (B) starter diet and link diet offered in a free choice to 26 days and (C) starter diet and link diet offered in a free choice to 26 days with feeder position rotated twice weekly. In experiments 1 and 3 pigs were offered a common weaner diet (14·1 g/kg lysine and 14·4 MJ DE per kg) following the experimental period. In experiment 1, daily gain was 406, 410 and 397 g/day (s.e. 6·6; P > 0·05) and food coversion efficiency (FCE) was 1·24, 1·21 and 1·27 g/g (s.e. 0·01; P < 0·01) during the period from day 0 to 27 for treatments A, B and C, respectively. The proportion of the diet selected as starter diet was 0·20, 0·50 and 0·47 (s.e. 0·023; P < 0·001) for treatments A, B and C, respectively. Within-pen variation in pig weight was similar for all treatments at day 14, 27 and 56 (P > 0·05), respectively. In experiment 2, daily gain was 403, 436 and 394 g/day (s.e. 13·0; P = 0·07) and FCE was 1·19, 1·16 and 1·24 g/g (s.e. 0·02; P < 0·05) during the period from day 0 to 26 for treatments A, B and C, respectively. The proportion of the diet selected as starter diet was 0·20, 0·57 and 0·53 (s.e. 0·024; P < 0·001) for treatments A, B and C, respectively. In experiment 3, daily gain was 465, 486 and 488 g/day (s.e.9·4; P > 0·05) and FCE was 1·14, 1·11 and 1·07 g/g (s.e. 0·015; P < 0·01) during the period from day 0 to 26 for treatments A, B and C, respectively. The proportion of the diet selected as starter diet was 0·21, 0·49 and 0·55 (s.e. 0·022; P < 0·001) for treatments A, B and C, respectively. Pig weight at day 49 was 36·4, 37·1 and 37·3 kg (s.e. 0·27; P = 0·09). It was concluded from these experiments that choice feeding did improve pig performance when a choice of starter and link diet was offered.

The objective of this study was to assess the effect of feeding steam flaked wheat and maize in diets with high and low levels of dairy products and to examine the effect of sequence of feeding the processed cereals in diets for newly weaned pigs. In experiment 1, 96 pigs were weaned at 27 days of age, blocked on sex and weight and assigned as individually penned pigs to four dietary treatments as follows: (a) high dairy product diet (6 kg of starter diet containing 230 g/kg milk powder followed by a link diet containing 125 g/kg milk powder to 26 days) with uncooked cereal (HDP), (b) high dairy product diet with steam flaked cereal (HDPC), (c) low dairy product diet (6 kg of starter diet containing 125 g/kg milk powder followed by a link diet containing no milk powder to 26 days) with uncooked cereal (LDP) and (d) low dairy product diet with steam flaked cereal (LDPC). In experiment 2, 96 pigs were weaned at 19 to 24 days of age, blocked on sex and weight and assigned as individually penned pigs to four dietary treatments containing: (a) uncooked cereal for 26 days, (b) uncooked cereal for 14 days followed by cooked cereal to 26 days post weaning, (c) cooked cereal for 26 days and (d) cooked cereal for 14 days followed by uncooked cereal to 26 days post weaning. Steaming and flaking of wheat and maize did not significantly affect pig performance during the experimental period or at any subsequent period up to slaughter. Daily gain from day 0 to 26 post weaning was 415 and 453 g/day (s.e.13•5; P < 0•05) for low and high dairy product diets, respectively. Food conversion efficiency (FCE) from day 0 to 14 post weaning on the low and high dairy product diets was 1•86 and 1•33 g/g (s.e. 0•14; P < 0•05), respectively. Pigs given the high dairy product diets during the experimental post-weaning period reached final carcass weight 5 days earlier than pigs given the low dairy product post-weaning diets (P < 0•05). In experiment 2, treatment did not affect food intake (mean = 450 s.e. 13•2 g; P > 0•05), daily gain (mean = 382 s.e. 12•5 g; P > 0•05) or FCE (mean = 1•19 s.e. 0•02 g/g; P > 0•05). In conclusion, feeding steamed flaked wheat and maize in post-weaning diets failed to improve pig performance irrespective of dairy product or sequence of feeding cooked cereals.

The objective of this study was to determine if weight and age at weaning affect the response of pigs to inclusion of cooked cereal in their post-weaning diet. In experiment 1, pigs (no. = 116) weaned at 17 to 28 days of age and weighing between 4 and 10 kg were individually given for 28 days post weaning, diets based on: (1) uncooked cereal or (2) cooked cereal (steamed and flaked wheat and maize). The gelatinized starch proportion was 0•265, 0•838, 0•203 and 0•745 for uncooked maize, steam flaked maize, uncooked wheat and steam flaked wheat, respectively. Pigs were offered 2•5 kg of starter diet (16•1 MJ digestible energy (DE) per kg and 17•4 g/kg of lysine). This was followed in each case by link diet (15•2 MJ DE per kg and 16•2 g/kg of lysine) to 28 days post weaning. Thereafter, pigs were grouped and given a common weaner diet and a common finisher diet to slaughter. In experiment 2, pigs (no. = 408) were weaned at between 20 and 28 days of age. Pigs were allocated by weight to heavy (7 to 8 kg), medium (6 to 7 kg) and light (5 to 6 kg) groups (24 groups of 17 pigs) and assigned to treatments as in experiment 1 for 26 days. A common weaner diet was offered between day 26 and day 56. In experiment 1, pig weight, food intake, daily gain, food conversion efficiency and carcass measurements were not affected by cooking (P > 0•05). Regression analysis indicated that weight and age at weaning had a significant association with weight at 28 days post weaning for uncooked (R2 = 0•628; P < 0•001) and cooked (R2 = 0•579; P < 0•001) cereal diets. In experiment 2, there was no interaction between weaning weight and cooking (P > 0•05) and no performance benefit resulted from cooking (P > 0•05). In conclusion, steam flaking did not improve pig performance during the treatment period or at any subsequent period.

The aim of this study was to assess the effect of weaning weight and post-weaning diet on the performance of weaned pigs. In experiment 1, 30 litters with more than 10 pigs born alive per litter were selected. At 11 days of age, pigs of average weight for the litter were removed from 15 litters so that eight pigs remained per sow. These litters were given access to creep food (16·5 MJ digestible energy (DE) per kg and 18·7 g/kg lysine). The remaining litters were left complete and were not given creep food. Pigs were weaned at 28 days of age and pairs of pigs (a male and a female littermate of similar weight) were formed from each litter (no. = 54 pairs). Pairs were blocked on the basis of litter origin and weight and assigned at random to one of the following treatments: (1) 10 kg starter diet (16·1 MJ DE per kg and 17·4 g/kg lysine) followed by link diet (15·3 MJ DE per kg and 15·0 g/kg lysine) to 27 days (high dietary regimen; HDR); or (2) 4 kg starter diet, 10 kg link diet and weaner diet to 27 days (low dietary regimen; LDR). Thereafter pigs were given common diets to slaughter at about 95·6 kg live weight. On experiment 2, four pigs (two light and two heavy) were taken from each of 32 litters (no. = 128 pigs; age = 22 days), blocked on sex, litter origin, and weaning weight and within weight category individually assigned at random to two dietary treatments: (1) high density diet (16·1 MJ DE per kg and 17·4 g/kg lysine); and (2) low density diet (15·1 MJ DE per kg and 15·7 g/kg lysine). The duration of the experiment was 26 days. In experiment 1, reducing litter size and creep feeding increased weaning weight by 0·6 kg (P 0·05). This weight advantage at weaning was lost by day 14 post weaning (P > 0·05). From day 0 to day 27 post weaning daily gain was 472 and 427 g/day (s.e.12·8; P 0·05) and food conversion efficiency was 1·26 and 1·36 g/g (s.e. 0·026; P 0·05) for HDR and LDR, respectively. In experiment 2, weaning weight was 7·1 and 5·8 kg (s.e. 0·08; P 0·01) and pig weight at day 26 post weaning was 17·5 and 15·4 kg (s.e.0·23; P 0·01) for heavy and light weight categories, respectively. In the period from day 0 to 26, food intake was 440 and 396 g/day (s.e. 8·0; P 0·01) and daily gain was 389 and 355 g/day (s.e. 8·0; P < i 0·01) for heavy and light weight categories, respectively. Weaning weight was found to be a good determinant of weight at day 26 when terms for litter origin were included (R2 = 0·67; P 0·001 for the high density diet and R2 = 0·77; P 0·001 for the low density diet). It is concluded that weaning weight can be increased by pre-weaning management but that this weight advantage is lost in the early post-weaning period. Where weaning weight was naturally higher the weight advantage was still evident at day 26 post weaning.

Four experiments were undertaken to examine the effect of feeding postweaning diets as dry pelleted feed, fresh liquid feed, acidified liquid feed, and fermented liquid feed on pig performance from weaning (26 d) to harvest. In Exp. 1 (n = 12 replicates) and 2 (n = 10 replicates), the treatments were 1) dry pelleted feed and 2) fresh liquid feed. In Exp. 1, 2 kg of starter diet (16.7 MJ of DE/kg and 1.6% lysine) per pig and 5 kg of transition diet (16.7 MJ of DE/kg and 1.5% lysine) per pig followed by a weaner diet (14.0 MJ of DE/kg and 1.36% lysine) were offered to 27 d after weaning. In Exp. 3 (n = 8 replicates), the treatments were 1) dry pelleted feed, 2) fresh liquid feed, and 3) acidified liquid feed. In Exp. 4 (n = 8 replicates), the treatments were 1) dry pelleted feed, 2) acidified liquid feed, and 3) fermented liquid feed. In Exp. 2, 3, and 4, 3 kg of starter diet (16.1 MJ of DE/kg and 1.74% lysine) per pig and 6 kg of transition diet (15.3 MJ of DE/kg and 1.5% lysine) per pig followed by a weaner diet (14.0 MJ of DE/kg and 1.36% lysine) was offered to 27 d after weaning. All treatments were balanced for boars and gilts and diets were offered for ad libitum consumption. Acidified liquid feed was produced by adding lactic acid to the liquid feed so that its pH was decreased to 4.0. Fermented liquid feed was produced by adding an inoculum of Lactococcus lactis subsp. cremoris 303 (1.3%, vol/wt) to the first mix. In Exp. 1, ADG from weaning to d 27 after weaning was 338 and 286 g/d (SEM = 10; P 0.05) and DM gain/feed was 865, 755, and 789 g/ kg (SEM = 14.5; P < 0.001) for dry pelleted feed, fresh liquid feed, and acidified liquid feed, respectively. In Exp. 4, ADG was 361, 389, and 347 g/d (SEM = 13.2; P = 0.11) and DM gain/feed was 888, 749, and 733 g/ kg (SEM = 15.8; P < 0.001) for dry pelleted feed, acidified liquid feed, and fermented liquid feed, respectively, during the period from weaning to d 27 after weaning. It is concluded that although feeding acidified liquid feed may have some merit in the first 27 d after weaning, this benefit is lost in the subsequent period. No benefit arose from feeding fresh liquid feed or fermented liquid feed. Growth performance from d 28 after weaning to harvest was not improved by any liquid feed treatment.

Group housing systems for pregnant sows are set to become more popular, but there is evidence that this development could influence the welfare of sows in farrowing crates. A study was designed to assess the effect of gestation accommodation on behaviour, welfare and farrowing performance of sows in farrowing crates. Multiparous sows were housed loose [L] in groups of four with feeding stalls ( n =24) or individually in gestation stalls [S] ( n =24) from 1 month post-service. On day 110 of pregnancy, sows were moved to farrowing crates where they remained until 28 days post-partum. Behaviour was recorded on the first day in the crate and on day 10 of lactation. Posture changing frequency was recorded for 2 h prior to and for the duration of farrowing. Skin lesions were scored from 0 to 6 at 34 locations on the body the day before and the day after entry to the crate, post-farrowing, during weeks 2 and 3 of lactation and at weaning. On the first day in the crate S sows made significantly more attempts to lie down per lie down event than L sows ( P P P P P P

An experiment (complete randomised design) was conducted to investigate the linear and quadratic effects of an exogenous phytase inclusion level (0, 500, 1000 and 1500 FTU/kg) to a low phosphorus ( P ) diet (4.2 g/kg) on weaner pig performance (7.8 kg in body weight, 12 replicates/treatment × 2 pigs/replicate = 96 pigs) and bone characteristics at both 30 kg and 100 kg body weight pigs. Bone samples were collected from 32 pigs (8/treatment) at the end of the weaner performance study (33 kg body weight). The remaining 64 pigs were then offered a commercial grower and finisher diet with 6 and 5.5 g total P /kg until slaughter at 100 kg. There was a linear improvement in overall feed conversion ratio (P P (P P concentration (P P diet improved feed efficiency and bone mineral concentration during the weaner stage (33 kg) which subsequently affected the bone mineral content at slaughter.

There is some evidence to show that loose housing during gestation has a negative influence on the welfare of sows subsequently in farrowing crates. However, little is known about the effects of the gestation housing on the initial responses of gilts to the farrowing crate or of the effects on gilt welfare throughout lactation. The objective of this experiment was to evaluate three gestation housing systems (1) stalls (ST); (2) loose-bedded (LB) and (3) loose-unbedded (LU) pens for their effect on behaviour, heart rate and skin lesion scores of gilts in farrowing crates. During the 1st h in the farrowing crate, LB gilts were more active, while ST gilts were more vocal. Although heart rates during the 1st h did not differ significantly between treatments, LB and LU gilts had significantly higher mean heart rates during the first 5 min in the crate, compared with 35 min later. Posture changes during the first 24 h did not differ between treatments. However, there was a significant reduction in the number of posture changes made by ST gilts but not LB or LU gilts by day 8. Increases in the skin lesion score of gilts in all three treatments were observed after 24 h in the crate, further increases were observed post farrowing in both loose treatments. Although no significant differences in the skin lesion score were observed during lactation, LB gilts were weaned with lower lesion scores than LU or ST gilts. Gilts from both loose treatments experienced greater distress at first introduction to the farrowing crate. However, the change in environment also had an adverse affect on the welfare of ST gilts. Skin damage and continuing discomfort of the loose-housed gilts post farrowing suggests that they experienced more stress at parturition. Bedding during gestation had a beneficial effect on skin health in the farrowing crate that persisted until weaning.

The objective of this study was to investigate the effect of low food intake on post-weaning fertility and hormone concentrations in primiparous sows. One hundred and forty primiparous sows (Landrace × Large White) were randomly assigned to one of four treatment groups: (A) restricted to 3 kg food per day during lactation and 2 kg food per day post weaning (no. = 36); (B) restricted to 3 kg food per day during lactation andad libitumfeeding post weaning (no. = 33); (C)ad libitumfeeding throughout with a mean voluntary food intake of 3·7 kg/day during lactation (no. = 36); and (D)ad libitumfeeding throughout with a mean voluntary food intake of 4·9 kg/ day during lactation (no. = 35). Litters were standardized at eight to 10 pigs at 2 days post partum and were weaned at 27·2 (s.e. 0·5) days post partum. After weaning, sows were observed twice daily for signs of oestrus and were mated on the day(s) of standing oestrus. Six sows from each group were fitted with indwelling jugular cannulae 2 days before weaning. Blood samples were collected 1 day before weaning (W−l), 1 day after weaning (W+l) and 4 days after weaning (W+4), and these sows were slaughtered on W+4. Ovaries were recovered, follicles and corpora lutea were counted, and folUcular fluid collected. Sows given food at a restricted level (groups A and B) lost more backfat during lactation than sows given foodad libitum(groups C and D) (P < 0·01). Piglet weaning weights, weaning to conception intervals and the proportion of sows ovulating by W+4 were not significantly different among groups. In sows that did not ovulate, numbers of large follicles were not significantly different among groups but the low food intake (groups A, B and C) sows had more medium-sized follicles than high food intake (group D) sows (P < 0·01). FolUcular fluid concentrations of oestradiol, progesterone and insulin-like growth factor-1 (IGF-1) did not differ among groups (P > 0·05). Plasma non-esterified fatty acids concentrations were greater in groups C and D than in groups A and B on W−l, W+l and W+4. Serum insulin and plasma glucose concentrations were lower in groups C and D than in groups A and B on W−l and W+l, but were similar among groups on W+4. Serum growth hormone concentrations were lower in group D than group A and B on W−l and W+l but not W+4. Concentrations of IGF-1 in serum were greater in groups C and D than groups A and B on W−l and W+l but not W+4. It is concluded that low food intakes during lactation and post weaning affected body condition, serum hormones and metabolites and ovarian function of primiparous sows without dramatically affecting ovarian hormones or reproductive performance.

The effect of n−3 fatty acid-enriched diets (in the form of 0.5% linseed oil with either 1.5% sunflower oil or 1.5% olive oil) and α-tocopheryl acetate supplementation (200 mg/kg feed) on lipid oxidation (thiobarbituric acid-reactive substances, TBARS) and cholesterol oxide products (COPS) in cooked pork was investigated. Longissimus muscle was studied. Meat from pigs fed 0.5% linseed oil-enriched diets had a higher proportion of n−3 fatty acid than meat from pigs in other dietary groups in neutral (P < 0.0001) and polar lipids (P < 0.0001), and a 20% reduction in the n-6:n- 3 ratio was observed. α-Tocopheryl acetate supplemen- tation increased (P < 0.05) monounsaturated fatty acids in polar lipids and increased (P = 0.0001) α-tocopherol levels in muscle. α-Tocopherol concentration in muscle was affected by dietary fat (P < 0.05). Groups receiving diets enriched with sunflower oil had significantly higher α-tocopherol levels (P < 0.05) in muscle than those groups receiving olive oil-enriched diets. Num- bers of TBARS were significantly (P < 0.05) lower in the group fed supplemental olive oil than in those fed sunflower oil. Dietary linseed oil increased (P < 0.05) lipid oxidation principally at the initial period of storage in cooked pork. Overall, dietary α-tocopheryl acetate supplementation significantly increased (P < 0.001) lipid stability and decreased (P < 0.05) total COP pro- duction across the dietary groups. α-Tocopherol was a more effective antioxidant for decreasing TBARS val- ues in cooked meat when adding sunflower oil to the diets instead of olive oil.

Data from 3559 lactations in the Moorepark herd over a seven-year period were analysed. An increase in intake was associated with increasing litter size, increasing parity and lower pregnancy weight gain. Higher farrowing house temperatures were associated with lower intakes resulting in sows farrowing in July eating 10% less than sows farrowing in mid-winter. Higher weaning age was also associated with increased consumption. Review of the literature shows a number of other factors to be associated with variation in intake including breed of sow, system of feeding and system of sow management. Intake of higher energy diets is sometimes depressed but energy consumed may be increased. Sows fed low protein diets in pregnancy consume more of high protein diets in lactation but this is not so when a high protein pregnancy diet is fed.

Results of a trial on yellow-grey earth which compared the effects of eight annual top-dressings of superphosphate, basic slag, and Gafsa (rock) phosphate on limed and unlimed ground were summarised in this Journal by Doak (1942a) and Elliott and Lynch (1942). Residual effects on pasture production, botanical composition, herbage chemical analyses, and soil analyses were measured for 18 years subsequently. About four years after top-dressing ceased pasture production fell on all treatments to about two-thirds, of the original level. Retop-dressing after 10 years without fertiliser did not restore production to the original level. Responses to the three forms of phosphate differed on un limed compared with limed ground and their relative effectiveness in the “residual” period differed from that of the “top-dressing” period. Lime responses (in the presence of P) lasted for about eight years after regular liming ceased, but subsequently limed plots were inferior to unlimed on the superphosphate plot...

Results are presented of two multi-factorial field experiments on permanent pasture with six fertilisers and ground limestone. The trials were carried out at Marton Experimental Area and at Invermay Research Station, Mosgiel. Treatments were:—high versus low rates of ground limestone, muriate of potash, and double superphosphate; and some against nil rates of elemental sulphur, magnesium carbonate, borax, and sodium molybdate. All treatments except limestone and sodium molybdate were applied annually by top-dressing.

The main effects and interactions of lime, mono-calcium phosphate, sulphur, potassium chloride, sodium molybdate, copper carbonate, magnesium carbonate, and borax on irrigated lucerne cut for hay were studied on Lismore shallow stony silt loam over a period of 10 years. In most years greatest responses in total annual yields were to sulphur (S), followed by high lime (HL), potassium chloride (K), high mono-calcium phosphate (HP), and sodium molybdate (Mo), in that order. The relative importance of K increased in later years. A significant response to copper carbonate (Cu) was found only in the first year, and to magnesium carbonate (Mg) and borax (B) only in a few cuts. In the last two years HL, S, K, and Mo increased, and HP decreased, the percentage of lucerne in the mown herbage. All treatments significantly increased levels of the applied nutrients in plant tissues. Significant main effects of treatments on other nutrient levels in the herbage, noted in more than one cut, were as follows: (a)...

Summary A description is given of a series of experiments at the Rukuhia Soil Research Station where the responses of pasture to a number of fertilisers were measured by several different techniques. The techniques are compared as follows: 1. 1. As measures of total pasture production. 2. 2. As measures of responses to fertiliser treatments. 3. 3. Errors of estimation attached to each technique. 4. 4. Effects of techniques on the species composition of the sward. 5. 5. Effects of techniques on the chemical status of the soil. 6. 6. Labour and land requirements of each technique. For trials where stock production data are required in addition to pasture production data and where it is considered essential that treatments be compared under normal grazing management by stock, the “cage” technique as operated by the Extension Division is considered to be the most useful and reliable method. For small-plot trials where the primary aim is an estimation of fertiliser response by pastures, and where an accurate m...

This investigation was designed to evaluate the effects of the dietary inclusion of vegetable oil and its composition on fatty acid composition and lipid oxidation in pig muscle. Pigs were given the following diets from 50 kg to slaughter (90 kg): a control diet with no added fat (NF) or diets containing 20 g/kg of sunflower (SUN), olive (OL) or sunflower + linseed (SUN + LIN) oils. Meat from pigs given the SUN + LIN diet showed the highest thiobarbituric acid reactive substances (TBARS) from day 3 of refrigerated storage to the end of the experiment (P< 0·05). The OL group showed the lowest TBARS after 9 days of storage (P< 0·05). Pigs on NF showed intermediate values that were generally closer to those recorded for pigs given the SUN + LIN than the OL diet. By day 9, there was no statistical difference between the NF and the SUN + LIN group. The SUN group also showed intermediate TBARS throughout storage, with no statistical differences compared with the NF group. After 9 days of storage the lowest CIELAB a* value, corresponded to the SUN + LIN group and the highest to the OL group. These results indicate similar behaviour to that of lipid oxidation. Meat samples from pigs given the diet not enriched with fat showed greater drip loss than those given the remaining diets (P< 0·05) while there was no significant effect of dietary fat source on water-holding capacity. The inclusion of oils rich in linoleic fatty acids in pig diets modifies muscle fatty acid composition but susceptibility to lipid oxidation does not appear to be increased with respect to that occurring in pigs given diets with no added fat.