J. V. O'Doherty

The influence of diet crude protein level on odour and ammonia emissions from finishing pig houses

Feed trials were carried out to assess the influence of crude protein content in finishing pig diets on odour and ammonia emissions. Eight pigs (4 boars and 4 gilts), average initial weight 70.8 kg (s.e. 3.167) were housed in two pens that were isolated from the rest of a pig house at University College Dublin Research Farm, Newcastle, Dublin, Ireland. Four diets containing 130, 160, 190 and 220 g x kg(-1) crude protein were fed during six four-week feeding periods (one treatment per room). The first week of the feeding periods served to allow odour build up in the pens and as a dietary adjustment period. The pens had partially slatted floors that were cleaned and had all the manure removed after each four-week period. Odour and ammonia concentrations were measured on days 9, 14, 16, 21 and 23 of each trial period. Odour samples were collected in Nalophan bags and analysed for odour concentration using an ECOMA Yes/No olfactometer. The odour threshold concentration was calculated according to the response of the olfactometry panel members and was displayed in Ou(E)m(-3), which referred to the physiological response from the panel equivalent to that elicited by 40 ppbv(-1) n-butanol evaporated in 1 m(3) of neutral gas. Ammonia concentrations in the ventilation air were measured using Dräger tubes. The odour emission rates per animal for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 12.1, 13.2, 19.6 and 17.6 Ou(E)s(-1)animal(-1), respectively (P<0.01). The odour emission rate per livestock unit (500 kg) for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 77.6, 80.0, 115.8 and 102.9 Ou(E)s(-1)LU(-1), respectively (P<0.01). The ammonia emission rates per animal for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 3.11, 3.89, 5.89 and 8.27 g x d(-1)animal(-1), respectively (P<or=0.001). There was no significant difference in the average daily intake and the average daily gain for the four diets (P>0.05). Manipulation of dietary crude protein levels would appear to offer a low cost alternative, in relation to end-of-pipe treatments, for the abatement of odour and ammonia emissions from finishing pig houses.

The effect of cereal type and exogenous enzyme supplementation in pig diets on nutrient digestibility, intestinal microflora, volatile fatty acid concentration and manure ammonia emissions from finisher pigs

A 2 × 2 factorial experiment was conducted to investigate the interaction between cereal type (wheat v . barley) and an exogenous enzyme supplement (with or without) on nutrient digestibility, large intestinal microflora, volatile fatty acid profile and in vitro manure ammonia emissions from finisher pigs. The enzyme supplement used contained endo-1, 3-β-glucanase (EC 3·2·1·6) and endo-1, 4-β-xylanase (EC 3·2·1·8). The diets were formulated to contain similar concentrations of net energy (9·8 MJ/kg) and lysine (10·0 g/kg). Urine and faeces were collected over seven consecutive days from 16 boars (four boars per treatment, 80·0 kg live weight) that were housed in metabolism crates. After collections, the pigs were slaughtered and the contents of the intestinal tracts were removed for analysis. There was a significant interaction between cereal type and enzyme inclusion in the apparent total tract digestibility of dry matter (DMD), organic matter (OMD) and nitrogen. The inclusion of an enzyme supplement in barley-based diets increased ( P P in vitro ammonia emissions. In the absence of an enzyme supplement, barley-based diets reduced the proportion of isovaleric acid ( P P P

Postoperative pain following epi-LASIK, LASEK, and PRK for myopia.

PURPOSE To compare mechanical epithelial separation using the epi-LASIK technique with alcohol assisted separation (LASEK). METHODS Patients deemed suitable for surface ablation were randomized to receive epi-LASIK in one eye and LASEK in the other eye. If epi-LASIK failed, the procedure was converted to photorefractive keratectomy (PRK), forming the third comparison group. The outcome measures were postoperative pain, vision, refraction, and haze. Patients were followed for 3 months. RESULTS Fifty-seven patients (95 eyes) were included in this study (38 epi-LASIK, 19 PRK, and 38 LASEK eyes). There was a 33% rate of conversion from intended epi-LASIK to PRK. Epi-LASIK patients were found to have significantly less pain in the first few hours after surgery but at 4 hours all patients had the same levels of pain, which improved to minimal or no pain at 24 hours. No significant difference was noted among groups for vision, refractive error, and haze; however, epi-LASIK patients had the best day 1 visual acuity. CONCLUSIONS Epi-LASIK offers comparable visual and refractive results to other surface ablation techniques with lower levels of postoperative pain only for the first 2 hours. However, there was a high rate of flap failure and conversion to PRK.

The effect of lactose and inulin on intestinal morphology, selected microbial populations and volatile fatty acid concentrations in the gastro-intestinal tract of the weanling pig

Twenty piglets (21 days, 7·8 kg live weight (LW)) were used in a 2×2 factorial to investigate interactions between lactose and inulin on intestinal morphology, microbiology and volatile fatty acid (VFA) production of the weanling pig. The piglets were offered the following diets for 6 days and then sacrificed: (T1) 150 g/kg lactose, (T2) 150 g/kg lactose +15 g/kg inulin, ( T3) 330 g/kg lactose, and ( T4) 330 g/kg lactose +15 g/kg inulin. Tissue samples were taken from the duodenum, jejunum and ileum for morphological measurements. Digesta samples were taken from the ileum, caecum and colon. There was an interaction ( P P 2 =0·45) and the jejunum ( P 2 =0·25). The inclusion of 330 g/kg lactose increased ( P P P

The effect of dietary Laminaria-derived laminarin and fucoidan on nutrient digestibility, nitrogen utilisation, intestinal microflora and volatile fatty acid concentration in pigs.

BACKGROUND In experiment 1, 30 boars were assigned to one of five treatments (n = 6): T1, 0 g kg(-1) seaweed extract (SWE); T2, 0.7 g kg(-1) SWE; T3, 1.4 g kg(-1) SWE; T4, 2.8 g kg(-1) SWE and T5, 5.6 g kg(-1) SWE. The extract contained laminarin and fucoidan only and was extracted from Laminaria spp. In experiment 2, 28 boars were assigned, in a 2 x 2 factorial to one of four treatments (n = 7): T1, control; T2, control plus 300 mg laminarin; T3, control plus 240 mg fucoidan; T4, control plus 300 mg laminarin and 240 mg fucoidan kg(-1) diet. RESULTS In experiment 1 there was a response to SWE on colonic Bifidobacterium spp. (P < 0.01 quadratic), Enterobacterium spp. (quadratic P < 0.05) and on caecal Enterobacterium spp. (quadratic P < 0.05). In experiment 2 there was an interaction (P < 0.05) between laminarin and fucoidan supplementation on Enterobacterium spp. in the proximal and distal colon. Pigs offered laminarin had reduced Enterobacterium spp. compared with pigs offered the control diet. However, the combination of laminarin and fucoidan had increased Enterobacterium spp. compared with alone. Pigs offered diets containing fucoidan had increased Lactobacilli spp. in the proximal colon (P < 0.05) and distal colon (P < 0.001) compared with non-fucoidan diets. CONCLUSION Overall, the reductions in intestinal Enterobacterium spp. and increases in Lactobacilli spp. obtained suggest that laminarin and fucoidan may provide a dietary means to improve gut health in pigs.

Performance of weanling piglets offered low-, medium- or high-lactose diets supplemented with a seaweed extract from Laminaria spp.

An experiment (3 × 4 factorial arrangement) was conducted to investigate the interaction between different levels of lactose (60 v. 150 v. 250 g/kg) and seaweed extract (0 v. 1 v. 2 v. 4 g/kg) containing both laminarin and fucoidan derived from Laminaria spp. on growth performance and nutrient digestibility of weanling pigs. In all, 384 piglets (24 days of age, 7.5 kg (s.d. 1 kg) live weight) were blocked on the basis of live weight and were assigned to one of 12 dietary treatments (eight replicates per treatment). Piglets were offered diets containing either low (60 g/kg), medium (150 g/kg) or high (250 g/kg) lactose levels with one of the following levels of seaweed extract additive: (1) 0 g/kg, (2) 1 g/kg, (3) 2 g/kg or (4) 4 g/kg seaweed extract. The pigs were offered the diets ad libitum for 21 days post weaning. There was a significant lactose × seaweed extract interaction (P < 0.05) in average daily gain (ADG) during the experimental period (days 0 to 21). At the low and medium levels of lactose, there was an increase in ADG as the level of seaweed extract increased to 2 g/kg (P < 0.05). However, at the high level of lactose there was no further response in ADG as the level of seaweed extract increased above 1 g/kg. There was a significant lactose × seaweed extract interaction during the experimental period (days 0 to 21) (P < 0.05) on the food conversion ratio (FCR). At the low level of lactose, there was a significant improvement in FCR as the levels of seaweed extract increased to 4 g/kg (P < 0.01). At the medium level of lactose, there was a significant improvement in FCR as seaweed extract increased to 2 g/kg. However, there was no significant effect of seaweed extract on FCR at the high levels of lactose (P > 0.05). There was a linear increase in average daily feed intake (ADFI) during the experimental period (days 0 to 21) (P < 0.05) as levels of seaweed extract increased. There was a linear increase in ash digestibility (P < 0.01) during the experimental period (days 0 to 21) as the level of lactose increased. There was a quadratic decrease (P < 0.01) in nitrogen (N) and neutral detergent fibre digestibility as the levels of lactose increased. In conclusion, pigs responded differently to the inclusion levels of seaweed extract at each level of lactose supplementation. The inclusion of a laminarin-fucoidan extract in piglet diets may alleviate the use for high-lactose diets (>60 g/kg) and would also alleviate some of the common problems that occur post weaning.

Effect of maternal fish oil and seaweed extract supplementation on colostrum and milk composition, humoral immune response, and performance of suckled piglets

An experiment with a 2 x 2 factorial arrangement of treatments (n = 10 sows/treatment) was conducted to investigate the effect of maternal dietary supplementation with seaweed extract (SWE: 0 vs. 10.0 g/d) and fish oil (FO) inclusion (0 vs. 100 g/d) from d 109 of gestation until weaning (d 26) on sow colostrum and milk composition, humoral immune response on d 5 and 12 of lactation, and suckling piglet performance. Furthermore, the influence of dietary treatment on the phagocytic activity of whole blood white cells at weaning was examined. The SWE (10 g) contained laminarin (1 g), fucoidan (0.8 g), and ash (8.2 g) and was extracted from a Laminaria spp. The FO contained approximately 40% eicosapentaenoic acid and 25% docosahexaenoic acid. The SWE-supplemented sows had greater colostrum IgG (P < 0.01) and milk protein (P < 0.05) concentrations on d 12 of lactation compared with non-SWE-supplemented sows. Piglets suckling SWE-supplemented sows had greater serum IgG (P < 0.01) and IgA (P < 0.05) concentrations on d 5 and IgG concentrations on d 12 (P < 0.05) of lactation compared with those suckling non SWE-supplemented sows. In contrast, FO supplementation exerted a suppressive effect on piglet serum IgA concentrations on d 5 of lactation (P < 0.05) compared with non-FO-supplemented diets. Dietary FO supplementation enhanced the n-3 PUFA proportion of sow milk (P < 0.001) and piglet serum at weaning (P < 0.001). Piglets suckling SWE-supplemented sows had a greater percentage of Escherichia coli phagocytizing leukocytes (P < 0.05) and a reduced percentage of E. coli phagocytizing lymphocytes (P < 0.01) compared with non-SWE-supplemented sows. Piglets suckling FO-supplemented sows had a greater percentage of leukocytes (P < 0.05) and lymphocytes (P < 0.05) phagocytizing E. coli compared with non-FO-supplemented sows. However, total leukocyte, lymphocyte, monocyte, and neutrophil numbers were not influenced by sow dietary treatment. Average piglet weaning weight and ADG between birth and weaning were not influenced by sow dietary treatment. In conclusion, the current study demonstrates that SWE supplementation from d 109 of gestation until weaning enhanced colostral IgG concentrations and circulatory IgG concentrations in suckled piglets on d 5 and 12 of lactation. Furthermore, the percentage of leukocytes and lymphocytes phagocytizing E. coli at weaning increased in piglets suckling FO-supplemented sows, indicating an enhancement of immune function against presenting pathogens. However, the combination of SWE and FO bestowed no positive effect on immune responses investigated in the current study.

The effect of diet in late pregnancy on colostrum production and immunoglobulin absorption in sheep

One hundred and twenty-six twin-bearing ewes were given either formic acid (FA) treated grass silage or grass/ molassed sugar-beet pulp (MSBP) silage in order to investigate factors affecting colostrum yield and quality and the efficiency of immunoglobulin (IgG) absorption. The experiment commenced on day 91 of pregnancy and the diets consisted ofFA-treated silage (Tl), FA-treated silage + soya-bean meal (SB) (72), MSBP silage (T3), MSBP silage + SB (T4), FA-treated silage + MSBP (T5), FA-treated silage + MSBP + SB (T6) or FA-treated silage + 150 g/kg of a crude protein concentrate (T7). Soya-bean meal was offered only in the last 3 weeks of pregnancy aiming for a total crude protein intake of220 g per ewe per day. Blood samples were taken from lambs in order to measure serum Ig concentrations. Ewes were milked at 1 h,10h and 18 h post lambing. Daily metabolizable energy intakes of 6·8, 11·4, 9·6, 12·8, 10·5, 13·7 and 14·7 (s.e. 0·58) M] per ewe were recorded for Tl to T7 respectively over the last 3 weeks of pregnancy. Respective crude protein intakes of 72, 213, 110, 225, 109, 215 and 175 (s.e. 5·64) g per ewe per day were recorded for Tl to T7 over the last 3 weeks of pregnancy. The addition of protein increased colostrum yield at 1 h (P 0·05) in colostrum production during the first 18 h following protein supplementation when the basic diet was FA-treated silage. There was no difference (P > 0·05) in colostrum production during the first 18 h between ewes offered MSBP treated silage or MSBP supplemented silage. Ewes offered FA-treated silage produced less colostrum during the first 18 h compared with ewes offered either MSBP treated or supplemented silage (P 2 = 0·4005; P

Effect of purified β-glucans derived from Laminaria digitata, Laminaria hyperborea and Saccharomyces cerevisiae on piglet performance, selected bacterial populations, volatile fatty acids and pro-inflammatory cytokines in the gastrointestinal tract of pigs.

β-Glucans have been identified as natural biomolecules with immunomodulatory activity. The first objective of the present study was to compare the effects of purified β-glucans derived from Laminaria digitata, L. hyperborea and Saccharomyces cerevisiae on piglet performance, selected bacterial populations and intestinal volatile fatty acid (VFA) production. The second aim was to compare the gene expression profiles of the markers of pro- and anti-inflammation in both unchallenged and lipopolysaccharide (LPS)-challenged ileal and colonic tissues. β-Glucans were included at 250 mg/kg in the diets. The β-glucans derived from L. hyperborea, L. digitata and S. cerevisiae all reduced the Enterobacteriaceae population (P<0·05) without influencing the lactobacilli and bifidobacteria populations (P>0·05) in the ileum and colon. There was a significant interaction between gastrointestinal region and β-glucan source in the expression of cytokine markers, IL-1α (<0·001), IL-10 (P<0·05), TNF-α (P<0·05) and IL-17A (P<0·001). β-Glucans did not stimulate any pro- or anti-inflammatory cytokine markers in the ileal epithelial cells. In contrast, the expression of a panel of pro- and anti-inflammatory cytokines (IL-1α, IL-10, TNF-α and IL-17A) was down-regulated in the colon following exposure to β-glucans from all the three sources. However, the data suggest that the soluble β-glucans derived from L. digitata may be acting via a different mechanism from the insoluble β-glucans derived from L. hyperborea and S. cerevisiae, as the VFA profile was different in the L. digitata-treated animals. There was an increase in IL-8 gene expression (P<0·05) in the gastrointestinal tract from the animals exposed to L. digitata following an LPS ex vivo challenge that was not evident in the other two treatment groups. In conclusion, β-glucans from both seaweed and yeast sources reduce Enterobacteriaceae counts and pro-inflammatory markers in the colon, though the mechanisms of action may be different between the soluble and insoluble fibre sources.

Performance of weanling pigs offered low or high lactose diets supplemented with avilamycin or inulin

One hundred and eighty piglets (24 days old, 6·0 kg live weight) were used to investigate interactions between lactose, avilamycin and inulin on growth performance and nutrient digestibility in weaned piglets. The piglets were blocked on the basis of live weight and within each block assigned to one of six dietary treatments (six replicates (pens) per treatment). The piglets were offered diets containing either a low (175 g/kg) or high (295 g/kg) lactose levels with one of the following food additives (1) 0 supplementation (2) avilamycin (60 mg/kg) or (3) inulin (15 g/kg) in a 2 × 3 factorial arrangement. The starter diets were offered for 21 days and all diets contained chromium III oxide at 150 p. p. m. There was an interaction ( P P