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The effects of lactose inclusion and seaweed extract on performance, nutrient digestibility and microbial populations in newly weaned piglets
Livestock Science 134 (2010) 205–207
Contents lists available at ScienceDirect
Livestock Science j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / l i v s c i
The effects of lactose inclusion and seaweed extract on performance, nutrient digestibility and microbial populations in newly weaned piglets☆ S. Dillon, T. Sweeney, S. Figat, J.J. Callan, J.V. O'Doherty ⁎ School of Agriculture, Food Science & Veterinary Medicine, College of Life Sciences, Lyons Research Farm, Newcastle, Dublin, Ireland
a r t i c l e Keywords: Lactose Laminarin Fucoidan Piglet
i n f o
a b s t r a c t A 2 × 2 factorial experiment was conducted to investigate the interactions between 2 different lactose levels (150 g/kg vs 250 g/kg) and the addition of seaweed extract (2.8 g/kg, containing laminarin and fucoidan) derived from Laminaria spp. on growth performance, nutrient digestibility and faecal microbial population in the weanling pig. Two hundred and forty piglets were selected after weaning (24 days of age, 7.6 kg (s.d 0.9 kg) live weight) and blocked on the basis of live weight and within each block assigned to one of four dietary treatments. Piglets offered diets supplemented with seaweed extract had a higher average daily gain (ADG) (0.322 vs 0.281 kg, s.e. ±0.009) (P b 0.01) and gain to feed ratio (0.669 vs 0.611 kg/kg, s.e. ±0.019) (P b 0.05) during the entire experimental period (days 0–25) compared with piglets offered unsupplemented seaweed extract diets. Piglets offered high lactose diets had a higher ADG (0.319 vs 0.283 kg, s.e. ±0.009) (P b 0.05) and average daily feed intake between days 0 and 25 (0.480 vs 0.447 kg, s.e. ±0.011) (P b 0.05) compared with piglets offered the low lactose diets. The inclusion of seaweed extract increased (P b 0.001) the apparent digestibility of nitrogen (N Dig) and gross energy (GE Dig) and decreased (P b 0.05) faecal E. coli populations compared with unsupplemented seaweed extract diets. Piglets offered the high lactose diets had increased GE dig (P b 0.001), N dig (P b 0.05) and decreased (P b 0.05) faecal E. coli populations compared with piglets offered low lactose diets. In conclusion, the inclusion of either a high dietary concentration of lactose or a laminarin–fucoidan extract increased daily gain and gain to feed ratio of post weaned piglets through an increase in nutrient digestibility and decreased E. coli populations in the gut. © 2010 Elsevier B.V. All rights reserved.
1. Introduction Seaweeds and seaweed extracts have been researched as an alternative to in-feed antibiotics in piglet diets (Reilly et al., 2008; Gahan et al., 2009). Recently, Reilly et al. (2008) showed that laminarin had antimicrobial properties by working as a modulator of intestinal metabolism. Fucoidans have also been shown to have antibacterial properties (McClure et al., 1992). Thus, fucoidan and laminarin may alleviate the need for high concentrations of lactose (O'Doherty et al., 2005) in antibiotic
☆ This paper is part of the special issue entitled “11th International Symposium on Digestive Physiology of Pigs”. ⁎ Corresponding author. Tel.: +353 1 7167128; fax: +353 1 7161103. E-mail address: [email protected] (J.V. O'Doherty). 1871-1413/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.livsci.2010.06.142
free diets. The hypothesis of this study is that the inclusion of a seaweed extract containing laminarin and fucoidan from Laminaria spp. will improve intestinal health through reductions in coliforms, allowing levels of lactose to be reduced while maintaining post weaned piglet performance in growth promoter free diets. 2. Materials and methods 2.1. Experimental design and dietary treatments This experiment was designed as a 2 × 2 factorial. Two hundred and forty piglets were selected after weaning at 24 days of age and blocked on the basis of weaning weight and within each block assigned to one of four dietary
206
S. Dillon et al. / Livestock Science 134 (2010) 205–207
treatments. The piglets were offered the following diets for 25 days: T1) 150 g/kg lactose; T2) 150 g/kg lactose plus seaweed extract; T3) 250 g/kg lactose T4) 250 g/kg lactose plus seaweed extract. The seaweed extract was included at 2.8 g/kg and contained laminarin (112 g/kg), fucoidan (89 g/kg) and ash (799 g/kg) and sourced from Bioatlantis Ltd (Tralee, County Kerry, Ireland). The composition and chemical analysis of the experimental diets are presented in Table 1. Pigs were housed in groups of four (15 replicates per treatment) on fully slatted pens (1.68 m × 1.22 m). Fresh faecal samples were collected once daily from all pens on days 10 to 15 for the determination of nutrient digestibility. Chromium III oxide was added to the diets at a concentration of 150 ppm in order to determine nutrient digestibility. Fresh faecal samples were collected from all pens on day 10, for the enumeration of E. coli and Lactobacilli according to the method described by O'Connell et al. (2005).
2.2. Laboratory and microbial analysis The dry matter of faeces and feed were determined after drying over night at 103 °C. Ash was determined after ignition of a known weight of concentrates or faeces in a muffle furnace at 500 °C. The nitrogen content of both feed and faeces was determined using the LECO FP 528 instrument (Leco Instruments, Cheshire, UK). The gross energy of the feed and faeces was determined using a Parr 1201 oxygen bomb calorimeter. Chromium concentration was determined according to the method of Williams et al. (1962). The total laminarin and fucoidan content in the diets and faecal Lactobacilli and E. coli populations were determined using the methods described by Reilly et al. (2008).
Table 1 Diet composition and chemical analysis of experimental starter diets (g/kg as fed). 2
3
1
Lactose (g/kg) Seaweed extract (g/kg)
150 0
Composition (g/kg) Whey permeate Wheat Soya bean meal Whey protein isolate Full fat Soya oil Lysine HCL DL methionine L threonine Minerals and vitamins
107.5 445.2 160 130 80 65 4.5 1.6 2.2 4
107.5 445.2 160 130 80 65 4.5 1.6 2.2 4
215 349 160 130 80 55 3.7 1.6 1.8 4
215 349 160 130 80 55 3.7 1.6 1.8 4
Feed analysis (g/kg) Dry matter Lactose Crude protein (N*6.25) Neutral detergent fibre Ash Gross energy (MJ/kg) Laminarin (ppm) Fucoidan (ppm)
902.3 147.9 204.5 859.4 43.4 17.7 0 0
898.6 153.3 201.3 962.0 44.6 17.8 300 236
913.3 247.2 197.9 855.8 50.2 17.5 0 0
903.5 249.0 195.8 784.7 50.2 17.3 300 236
250 0
The experimental data was analysed as a 2 × 2 factorial using the General Linear Model procedure of Statistical Analysis Systems Institute (1985). The models for both performance and digestibility analysis included the main effects of lactose level, seaweed extract inclusion and the interaction between lactose and seaweed extract. Both the performance and digestibility data were adjusted for initial live weight by covariance analysis. 3. Results 3.1. Performance Piglets offered diets containing seaweed extracts gained more weight than piglets offered un-supplemented seaweed extract diets on days 0–25 (0.322 vs 0.281 kg; s.e. ±0.009) (P b 0.01). Piglets offered high lactose diets had a higher ADG throughout the experimental period (0.319 vs 0.283 kg; s.e. ±0.009) (P b 0.05) than piglets offered low lactose diets. Piglets offered the high lactose diets had a higher average daily feed intake throughout the experimental period (0.480 vs 0.447 kg; s.e. ±0.011) (P b 0.05) compared to piglets offered the low lactose diets. Dietary inclusion of seaweed extract increased the gain: feed ratio throughout the experimental period (0.669 vs 0.611 kg; s.e. ±0.019) (Pb 0.05). 3.2. Coefficient of total tract apparent digestibility (CTTAD) The supplementation of seaweed extracts increased (P b 0.001) the CTTAD of nitrogen (N) (90.96 vs 85.27 s.e. ± 0.730) and gross energy (GE) (92.69 vs 88.07 s.e. ±0.490) compared with the un-supplemented seaweed extract diets. The inclusion of high lactose in the diet increased (P b 0.001) the CTTAD of GE (92.33 vs 88.43 s.e. ±0.490) (P b 0.0001) and N (89.60 vs 86.63 s.e. ±0.730) (P b 0.05) compared with piglets offered low lactose diets. 3.3. Microbiology
Treatment
2.8
2.3. Statistical analysis
4 2.8
The inclusion of seaweed extract decreased (P b 0.05) faecal E. coli populations compared with un-supplemented seaweed extract diets (5.1 vs 6.05 Log10 CFU/g; s.e. ±0.25). High lactose diets decreased the faecal E. coli population (6.0 vs 5.1 Log10 CFU/g; s.e. ±0.25) (P b 0.05) compared with low lactose diets. There was a significant interaction between lactose × seaweed extract on the Lactobacilli population (P b 0.05). Dietary inclusion of seaweed extracts increased the population of Lactobacilli in piglets fed the high lactose diets; however there was no effect of seaweed extracts inclusion at the low lactose concentration (Table 2). 4. Discussion The inclusion of the laminarin and fucoidan extract in the current experiment increased both ADG and gain:feed ratio of the pigs throughout the duration of the experiment. This positive response to seaweed extracts maybe due to a number of reasons. Firstly, the improved performance may be attributable to the improved nutrient digestibility of the
S. Dillon et al. / Livestock Science 134 (2010) 205–207
207
Table 2 The effect of dietary treatment on Lactobacilli and Escherichia coli populations (L.S.M ± S.E.M). Treatment
1
Lactose (g/kg) Seaweed extract
150 −
2
3
+
250 −
+
8.19 5.70
8.84 4.50
Bacterial populations (log10 CFU./g faeces) Lactobacilli 8.46 8.63 Escherichia coli 6.30 5.80
4
SEM
0.12 0.42
Significance Lactose
Seaweed extract
Lactose × seaweed extract
ns *
*** *
* ns
Probability of significance; * P b 0.05; ***P b 0.001, ns P N 0.05.
diets and secondly, the improved performance may be attributable to a reduction in E. coli populations in the gut of the laminarin and fucoidan extract fed pigs. Similar results were reported by Reilly et al. (2008) who showed that the inclusion of a laminarin and fucoidan extract, similar to the one used in the current experiment, resulted in a significant reduction in coliform populations in the caecum and colon of piglets post weaning. The increased nutrient digestibility maybe due to the increase in the lactobacilli population which was particularly evident with high lactose inclusion. These bacteria have an ability to produce a wide range of cellassociated polysaccharide depolymerases which may aid in nutrient digestion. The results of this experiment also indicate the beneficial effects of using high lactose levels in weaned piglet diets. This may be attributed to a number of reasons. Firstly, this improved performance may be attributable to an observed increase in nutrient digestibility and feed intake. Secondly, lactose increased the Lactobacilli populations and decreased the population of E. coli in the current experiment. Lactose is a substrate for Lactobacilli spp., which are in abundance post weaning rapidly converting lactose to lactic acid (Pierce et al., 2006) through fermentation in the hindgut. This further causes a reduced intestinal pH and thereby unfavorable conditions for coliform bacteria.
5. Conclusion In conclusion, the inclusion of either a high dietary concentration of lactose or a laminarin–fucoidan extract increased daily gain and gain to feed ratio of post weaned piglets mainly through an increase in nutrient digestibility and decreased E. coli populations in the gut. However, the inclusion of a laminarin–fucoidan extract did not substitute for high levels of lactose in the post weaned piglet diet.
Conflict of interest None of the authors had any conflict of interest in this work. Acknowledgements Funding for this research was provided under the National Development Plan, through the Research Stimulus Fund, administered by the Department of Agriculture, Fisheries & Food. References Gahan, D.A., Lynch, M.B., Callan, J.J., O'Sullivan, J.T., O'Doherty, J.V., 2009. Performance of weanling piglets offered low-, medium- or high-lactose diets supplemented with a seaweed extract from Laminaria spp. Animal 3, 24–31. McClure, M.O., Moore, J.P., Blanc, D.F., Scotting, P., Cook, G.M., Keynes, R.J., Weber, J.N., Davies, D., Weiss, R.A., 1992. Investigations into the mechanism by which sulfated polysaccharides inhibit HIV infection in vitro. AIDS Res. Hum. Retroviruses 8, 19–26. O'Connell, J.M., Sweeny, T., Callan, J.J., O'Doherty, J.V., 2005. 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. Anim. Sci. 81, 357–364. O'Doherty, J.V., Nolan, C.S., McCarthy, P.C., 2005. Interaction between lactose levels and antimicrobial growth promoters on growth performance of weanling pigs. J. Sci. Food Agric. 85, 371–380. Pierce, K.M., Sweeny, T., Brophy, P.O., Callan, J.J., Fitzpatrick, E., McCarthy, P., O'Doherty, J.V., 2006. 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. Anim. Sci. 82, 311–318. Reilly, P., O'Doherty, J.V., Pierce, K.M., Callan, J.J., O'Sullivan, J.T., Sweeney, T., 2008. The effects of seaweed extract inclusion on gut morphology, selected intestinal microbiota, nutrient digestibility, volatile fatty acid concentrations and the immune status of the weaned pig. Animal 2 (10), 1465–1473. Statistical Analysis Systems Institute, 1985. Statistical analysis systems, version 6.12. SAS Institute Inc., Cary, NC. Williams, C.H., David, D.J., Iismaa, O., 1962. The determination of chromium oxide in faecal samples by atomic absorbtion spectrophotometry. J. Anim. Sci. 63, 381–385.
Contents lists available at ScienceDirect
Livestock Science j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / l i v s c i
The effects of lactose inclusion and seaweed extract on performance, nutrient digestibility and microbial populations in newly weaned piglets☆ S. Dillon, T. Sweeney, S. Figat, J.J. Callan, J.V. O'Doherty ⁎ School of Agriculture, Food Science & Veterinary Medicine, College of Life Sciences, Lyons Research Farm, Newcastle, Dublin, Ireland
a r t i c l e Keywords: Lactose Laminarin Fucoidan Piglet
i n f o
a b s t r a c t A 2 × 2 factorial experiment was conducted to investigate the interactions between 2 different lactose levels (150 g/kg vs 250 g/kg) and the addition of seaweed extract (2.8 g/kg, containing laminarin and fucoidan) derived from Laminaria spp. on growth performance, nutrient digestibility and faecal microbial population in the weanling pig. Two hundred and forty piglets were selected after weaning (24 days of age, 7.6 kg (s.d 0.9 kg) live weight) and blocked on the basis of live weight and within each block assigned to one of four dietary treatments. Piglets offered diets supplemented with seaweed extract had a higher average daily gain (ADG) (0.322 vs 0.281 kg, s.e. ±0.009) (P b 0.01) and gain to feed ratio (0.669 vs 0.611 kg/kg, s.e. ±0.019) (P b 0.05) during the entire experimental period (days 0–25) compared with piglets offered unsupplemented seaweed extract diets. Piglets offered high lactose diets had a higher ADG (0.319 vs 0.283 kg, s.e. ±0.009) (P b 0.05) and average daily feed intake between days 0 and 25 (0.480 vs 0.447 kg, s.e. ±0.011) (P b 0.05) compared with piglets offered the low lactose diets. The inclusion of seaweed extract increased (P b 0.001) the apparent digestibility of nitrogen (N Dig) and gross energy (GE Dig) and decreased (P b 0.05) faecal E. coli populations compared with unsupplemented seaweed extract diets. Piglets offered the high lactose diets had increased GE dig (P b 0.001), N dig (P b 0.05) and decreased (P b 0.05) faecal E. coli populations compared with piglets offered low lactose diets. In conclusion, the inclusion of either a high dietary concentration of lactose or a laminarin–fucoidan extract increased daily gain and gain to feed ratio of post weaned piglets through an increase in nutrient digestibility and decreased E. coli populations in the gut. © 2010 Elsevier B.V. All rights reserved.
1. Introduction Seaweeds and seaweed extracts have been researched as an alternative to in-feed antibiotics in piglet diets (Reilly et al., 2008; Gahan et al., 2009). Recently, Reilly et al. (2008) showed that laminarin had antimicrobial properties by working as a modulator of intestinal metabolism. Fucoidans have also been shown to have antibacterial properties (McClure et al., 1992). Thus, fucoidan and laminarin may alleviate the need for high concentrations of lactose (O'Doherty et al., 2005) in antibiotic
☆ This paper is part of the special issue entitled “11th International Symposium on Digestive Physiology of Pigs”. ⁎ Corresponding author. Tel.: +353 1 7167128; fax: +353 1 7161103. E-mail address: [email protected] (J.V. O'Doherty). 1871-1413/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.livsci.2010.06.142
free diets. The hypothesis of this study is that the inclusion of a seaweed extract containing laminarin and fucoidan from Laminaria spp. will improve intestinal health through reductions in coliforms, allowing levels of lactose to be reduced while maintaining post weaned piglet performance in growth promoter free diets. 2. Materials and methods 2.1. Experimental design and dietary treatments This experiment was designed as a 2 × 2 factorial. Two hundred and forty piglets were selected after weaning at 24 days of age and blocked on the basis of weaning weight and within each block assigned to one of four dietary
206
S. Dillon et al. / Livestock Science 134 (2010) 205–207
treatments. The piglets were offered the following diets for 25 days: T1) 150 g/kg lactose; T2) 150 g/kg lactose plus seaweed extract; T3) 250 g/kg lactose T4) 250 g/kg lactose plus seaweed extract. The seaweed extract was included at 2.8 g/kg and contained laminarin (112 g/kg), fucoidan (89 g/kg) and ash (799 g/kg) and sourced from Bioatlantis Ltd (Tralee, County Kerry, Ireland). The composition and chemical analysis of the experimental diets are presented in Table 1. Pigs were housed in groups of four (15 replicates per treatment) on fully slatted pens (1.68 m × 1.22 m). Fresh faecal samples were collected once daily from all pens on days 10 to 15 for the determination of nutrient digestibility. Chromium III oxide was added to the diets at a concentration of 150 ppm in order to determine nutrient digestibility. Fresh faecal samples were collected from all pens on day 10, for the enumeration of E. coli and Lactobacilli according to the method described by O'Connell et al. (2005).
2.2. Laboratory and microbial analysis The dry matter of faeces and feed were determined after drying over night at 103 °C. Ash was determined after ignition of a known weight of concentrates or faeces in a muffle furnace at 500 °C. The nitrogen content of both feed and faeces was determined using the LECO FP 528 instrument (Leco Instruments, Cheshire, UK). The gross energy of the feed and faeces was determined using a Parr 1201 oxygen bomb calorimeter. Chromium concentration was determined according to the method of Williams et al. (1962). The total laminarin and fucoidan content in the diets and faecal Lactobacilli and E. coli populations were determined using the methods described by Reilly et al. (2008).
Table 1 Diet composition and chemical analysis of experimental starter diets (g/kg as fed). 2
3
1
Lactose (g/kg) Seaweed extract (g/kg)
150 0
Composition (g/kg) Whey permeate Wheat Soya bean meal Whey protein isolate Full fat Soya oil Lysine HCL DL methionine L threonine Minerals and vitamins
107.5 445.2 160 130 80 65 4.5 1.6 2.2 4
107.5 445.2 160 130 80 65 4.5 1.6 2.2 4
215 349 160 130 80 55 3.7 1.6 1.8 4
215 349 160 130 80 55 3.7 1.6 1.8 4
Feed analysis (g/kg) Dry matter Lactose Crude protein (N*6.25) Neutral detergent fibre Ash Gross energy (MJ/kg) Laminarin (ppm) Fucoidan (ppm)
902.3 147.9 204.5 859.4 43.4 17.7 0 0
898.6 153.3 201.3 962.0 44.6 17.8 300 236
913.3 247.2 197.9 855.8 50.2 17.5 0 0
903.5 249.0 195.8 784.7 50.2 17.3 300 236
250 0
The experimental data was analysed as a 2 × 2 factorial using the General Linear Model procedure of Statistical Analysis Systems Institute (1985). The models for both performance and digestibility analysis included the main effects of lactose level, seaweed extract inclusion and the interaction between lactose and seaweed extract. Both the performance and digestibility data were adjusted for initial live weight by covariance analysis. 3. Results 3.1. Performance Piglets offered diets containing seaweed extracts gained more weight than piglets offered un-supplemented seaweed extract diets on days 0–25 (0.322 vs 0.281 kg; s.e. ±0.009) (P b 0.01). Piglets offered high lactose diets had a higher ADG throughout the experimental period (0.319 vs 0.283 kg; s.e. ±0.009) (P b 0.05) than piglets offered low lactose diets. Piglets offered the high lactose diets had a higher average daily feed intake throughout the experimental period (0.480 vs 0.447 kg; s.e. ±0.011) (P b 0.05) compared to piglets offered the low lactose diets. Dietary inclusion of seaweed extract increased the gain: feed ratio throughout the experimental period (0.669 vs 0.611 kg; s.e. ±0.019) (Pb 0.05). 3.2. Coefficient of total tract apparent digestibility (CTTAD) The supplementation of seaweed extracts increased (P b 0.001) the CTTAD of nitrogen (N) (90.96 vs 85.27 s.e. ± 0.730) and gross energy (GE) (92.69 vs 88.07 s.e. ±0.490) compared with the un-supplemented seaweed extract diets. The inclusion of high lactose in the diet increased (P b 0.001) the CTTAD of GE (92.33 vs 88.43 s.e. ±0.490) (P b 0.0001) and N (89.60 vs 86.63 s.e. ±0.730) (P b 0.05) compared with piglets offered low lactose diets. 3.3. Microbiology
Treatment
2.8
2.3. Statistical analysis
4 2.8
The inclusion of seaweed extract decreased (P b 0.05) faecal E. coli populations compared with un-supplemented seaweed extract diets (5.1 vs 6.05 Log10 CFU/g; s.e. ±0.25). High lactose diets decreased the faecal E. coli population (6.0 vs 5.1 Log10 CFU/g; s.e. ±0.25) (P b 0.05) compared with low lactose diets. There was a significant interaction between lactose × seaweed extract on the Lactobacilli population (P b 0.05). Dietary inclusion of seaweed extracts increased the population of Lactobacilli in piglets fed the high lactose diets; however there was no effect of seaweed extracts inclusion at the low lactose concentration (Table 2). 4. Discussion The inclusion of the laminarin and fucoidan extract in the current experiment increased both ADG and gain:feed ratio of the pigs throughout the duration of the experiment. This positive response to seaweed extracts maybe due to a number of reasons. Firstly, the improved performance may be attributable to the improved nutrient digestibility of the
S. Dillon et al. / Livestock Science 134 (2010) 205–207
207
Table 2 The effect of dietary treatment on Lactobacilli and Escherichia coli populations (L.S.M ± S.E.M). Treatment
1
Lactose (g/kg) Seaweed extract
150 −
2
3
+
250 −
+
8.19 5.70
8.84 4.50
Bacterial populations (log10 CFU./g faeces) Lactobacilli 8.46 8.63 Escherichia coli 6.30 5.80
4
SEM
0.12 0.42
Significance Lactose
Seaweed extract
Lactose × seaweed extract
ns *
*** *
* ns
Probability of significance; * P b 0.05; ***P b 0.001, ns P N 0.05.
diets and secondly, the improved performance may be attributable to a reduction in E. coli populations in the gut of the laminarin and fucoidan extract fed pigs. Similar results were reported by Reilly et al. (2008) who showed that the inclusion of a laminarin and fucoidan extract, similar to the one used in the current experiment, resulted in a significant reduction in coliform populations in the caecum and colon of piglets post weaning. The increased nutrient digestibility maybe due to the increase in the lactobacilli population which was particularly evident with high lactose inclusion. These bacteria have an ability to produce a wide range of cellassociated polysaccharide depolymerases which may aid in nutrient digestion. The results of this experiment also indicate the beneficial effects of using high lactose levels in weaned piglet diets. This may be attributed to a number of reasons. Firstly, this improved performance may be attributable to an observed increase in nutrient digestibility and feed intake. Secondly, lactose increased the Lactobacilli populations and decreased the population of E. coli in the current experiment. Lactose is a substrate for Lactobacilli spp., which are in abundance post weaning rapidly converting lactose to lactic acid (Pierce et al., 2006) through fermentation in the hindgut. This further causes a reduced intestinal pH and thereby unfavorable conditions for coliform bacteria.
5. Conclusion In conclusion, the inclusion of either a high dietary concentration of lactose or a laminarin–fucoidan extract increased daily gain and gain to feed ratio of post weaned piglets mainly through an increase in nutrient digestibility and decreased E. coli populations in the gut. However, the inclusion of a laminarin–fucoidan extract did not substitute for high levels of lactose in the post weaned piglet diet.
Conflict of interest None of the authors had any conflict of interest in this work. Acknowledgements Funding for this research was provided under the National Development Plan, through the Research Stimulus Fund, administered by the Department of Agriculture, Fisheries & Food. References Gahan, D.A., Lynch, M.B., Callan, J.J., O'Sullivan, J.T., O'Doherty, J.V., 2009. Performance of weanling piglets offered low-, medium- or high-lactose diets supplemented with a seaweed extract from Laminaria spp. Animal 3, 24–31. McClure, M.O., Moore, J.P., Blanc, D.F., Scotting, P., Cook, G.M., Keynes, R.J., Weber, J.N., Davies, D., Weiss, R.A., 1992. Investigations into the mechanism by which sulfated polysaccharides inhibit HIV infection in vitro. AIDS Res. Hum. Retroviruses 8, 19–26. O'Connell, J.M., Sweeny, T., Callan, J.J., O'Doherty, J.V., 2005. 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. Anim. Sci. 81, 357–364. O'Doherty, J.V., Nolan, C.S., McCarthy, P.C., 2005. Interaction between lactose levels and antimicrobial growth promoters on growth performance of weanling pigs. J. Sci. Food Agric. 85, 371–380. Pierce, K.M., Sweeny, T., Brophy, P.O., Callan, J.J., Fitzpatrick, E., McCarthy, P., O'Doherty, J.V., 2006. 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. Anim. Sci. 82, 311–318. Reilly, P., O'Doherty, J.V., Pierce, K.M., Callan, J.J., O'Sullivan, J.T., Sweeney, T., 2008. The effects of seaweed extract inclusion on gut morphology, selected intestinal microbiota, nutrient digestibility, volatile fatty acid concentrations and the immune status of the weaned pig. Animal 2 (10), 1465–1473. Statistical Analysis Systems Institute, 1985. Statistical analysis systems, version 6.12. SAS Institute Inc., Cary, NC. Williams, C.H., David, D.J., Iismaa, O., 1962. The determination of chromium oxide in faecal samples by atomic absorbtion spectrophotometry. J. Anim. Sci. 63, 381–385.