Introduction
The first international and national provisions for the safety assessment and regulation of genetically modified organisms (GMO), including genetically modified crops and derived foods were drawn up by scientific experts in the mid-1980s (OECD, 1986; US OSTP, 1986). Then, the first successful transformation experiment in plants (tobacco) in 1988 and the International Food Biotechnology Council (IFBC) published the first report on the issue of safety assessment of these new varieties after two years (IFBC, 1990). Other organizations, such as the Organization for Economic Cooperation and Development (OECD), the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) and the International Life Sciences Institute (ILSI) have developed further guidelines for safety (Kuiper et al., 2001). However, many people question the potential benefits and risks of genetically modified crops (Fernandez-Cornejo et al., 2014). If without direct tangible benefits to the consumer, the foods produced with GMO ingredients may be perceived as being inferior to their non-GM counterparts (Chern and Rickertsen, 2001). Moreover, some food industry non-GMO by-products can be used as feed ingredient substitutes to reduce feed costs.
Sugar-beet pulp (SBP) is a botanically diverse by-product of the food industry, which contains substantial amounts of non-starch polysaccharide (NSP) (600 to 700 g NSP per kg dry matter [DM]) (Yan et al., 1995). It can be used as bulking materials in a diet for pregnant sows since the daily allowance for concentrated grain diets is much lower than the potential appetite of sows (Kay et al., 1990; Gill et al., 1992). Canola meal (CM) is a good source of available calcium, iron, manganese, selenium, and many of the B vitamins (Newkirk, 2009). Although high in phytate, CM is also one of the richest sources of non phytate (available) phosphorus (Khajali and Slominski, 2012).
Consumers concern about the increase of GMO has been increasing. We try to use non-GMO by-products from the food industry to replace GMO dietary ingredients to avoid potential risks and reduce costs. Consequently, the objectives of this experiment were to compare the effect of dietary supplementation of non-GMO SBP and CM with GMO basal diets on reproduction performance in gestation-lactation sows.
Materials and Methods
The experiment was conducted at the swine experimental unit of Dankook University (Cheonan, Korea). The protocol for the current experiment was approved by the Animal Care and Use Committee of Dankook University.
Test and control sugar-beet pulp and canola meal
Non-GMO SBP and CM sample were sent to independent laboratory Kogenebiotech Co., Ltd. (Seoul, Korea) for GMO Analysis. GMO qualitative analysis of SBP was performed by PCR with the specific primer pairs of H7-1 gene respectively. GMO qualitative analysis of CM was performed by PCR with the specific primer pairs of T45, GT73, Ms8, Rf3, and MON88302 gene respectively. The results are shown in Table 1. The results confirmed that the SBP and CM were non-GMO.
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Table 1. GMO qualitative analysis results of beet pulp. 
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zIndependent laboratory Kogenebiotech (2017). |
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Experimental design, animals and housing
A total of 16 lactating sows (Landrace × Yorkshire), were randomly allotted to 1 of 2 treatments with 8 sows per treatment. Treatments consisted of GMO basal diet (CON) and GMO basal diet supplemented with Non-GMO SBP and CM (NO). Gestating sows were housed on a slat floor, in an environmentally regulated building. The experiment lasted from 4 weeks prior to farrowing, to day 21 of lactation. The ambient environments in the dry sow accommodation and the farrowing house were kept at a fairly constant temperature of 19 - 21℃, and 60% relative humidity. A nursery box equipped with an infrared spotlight and heating mat was provided to meet the requirements of piglets. Sows were individually fed, using specially installed troughs and nipple drinkers. The diets were formulated to meet or exceed NRC (2012) recommendations for all nutrients (Table 2). The temperature in the farrowing house was maintained at a minimum of 20℃. Supplemental heat was provided for piglets using heat lamps. All diets of sows were provided in meal form, and sows and piglets were provided with free access to water throughout the experimental period. Piglets were treated according to routine management practices that included teeth clipping, tail docking, and ear notching.
Sampling and measurements
The backfat thickness of sows was measured 6 cm off the midline at the 10th rib using a real-time ultrasound instrument (Piglet 105, SFK Technology, Herlev, Denmark) 4 day before farrowing, 1 day after farrowing, and during weaning. Values from the two measurements were averaged to obtain a single backfat measurement. The measurement of backfat was done as per the method described by Song et al. (2012). The amount of feed consumed during the lactation periods was recorded and used to calculate the average daily feed intake (ADFI). Detection of estrus was conducted twice per day from weaning onwards, at 8 am and 4 pm every day. A sow was considered to return to estrus when exhibiting a standing response induced by a back pressure test when in the presence of a boar. Number of piglets borne and weaned pigs was also recorded to calculate the survival rate. Individual piglet body weight (BW) and litter weights were assessed on days 0, and 26 to calculate average daily gain (ADG).
Statistical analysis
All data were subjected to the GLM procedures of SAS (2013) as a randomized complete block design (SAS Inst. Inc., Cary, USA). The individual sow or litter of piglets was used as the experimental unit. Differences among all treatments were separated by using the Tukey’s test. The variability in the data was expressed as standard error (SE). A probability level of p < 0.05 was considered to be statistically significant.
Results
GMO qualitative analysis
The GMO qualitative analysis results are presented in Table 1 and 2. H7-1 gene was not detected non-GMO SBP. T45, GT73, Ms8, Rf3, MON88302 gene were not detected in non-GMO CM. Those results confirmed that the SBP and CM, which applied in non-GMO meal, were non-GMOs.
Reproduction performance of lactation sows
The replacement of feed ingredients with feed by-product SBP and CM on reproduction performance in sows fed non-GMO diets compared with CON diets (Table 3).
Growth performance of sucking piglets
No significant difference effects (p > 0.05) were detected on growth performance in piglets fed non-GMO diets compared with CON diets (Table 4).
Discussion
Dried SBP contains a large quantity of NSP, of which 15% to 30% is pectin (Pilnik and Voragen, 1992). Sugar-beet pectin has been shown to be extensively degraded in the caecum (Robertson et al., 1987). Therefore if sugar-beet pectin is available for fermentation in the caecum, it may replace protein fermentation and associated harmful by-products will be reduced. Longland et al. (1994) has also demonstrated that the incorporation of SBP into the diet enhances the fermentation of the cell wall carbohydrates in pigs. Although piglets (Longland et al., 1994) and growing pigs (Longland et al., 1993) have been reported to be able to digest and utilize the NSP fraction of SBP, pig studies on dietary ingredients rich in NSP are mainly focused on finishing and breeding animals. Because of their ability to digest and ferment fiber is thought to be greater than that of the newly weaned piglet (Gill et al., 2000) and it has been demonstrated that digestibility of the dietary fiber fraction increases with BW of the pig with a particularly important difference between growing pigs and adult sows (Noblet and Shi, 1994). In consistent with our research, the gestating mature sow has the ability to utilize fibrous feeds because of a larger digestive tract capacity, particularly the hindgut, and lower nutrient requirements compared with the lactating sow or the growing pig. Pond (1981) suggested that feeding fibrous feeds to sows could be greatly increased.
Canola meal is known for its lower and less consistent amino acid digestibility than soya-bean meal (SBM) (Khajali and Slominski, 2012). The results of a series of experiments indicated that when growing pigs are allowed feed ad libitum, the substitution of the major part of SBM by CM significantly reduced feed intake and had a slightly negative effect on daily weight gain (McKinnon and Bowland, 1977; Bell and Shires, 1980). Nevertheless, contradictory reports are available in the literature regarding the CM were used in the sows. Clowes et al. (2003) reported that 8.1% CM did not have any adverse effect on maternal growth, piglet birth weight, and litter growth in lactation, wean-to-breeding interval, or subsequent litter size. King et al. (2001) evaluated the effect of diets containing up to 20% of solvent-extracted canola meal on sow performance; results indicated that average sow performance and piglet weight were not affected by the different levels of CM in the diets. Quiniou et al. (2012) studied the effects of feeding 10% of low-glucosinolate rapeseed meal (B. napus) during gestation and lactation, over three reproductive cycles, on the performance of hyper prolific sows and their litters and found no differences when compared to diets containing no rapeseed meal. These reports are consistent with our research results. In addition, these contradictory reports convince us that the stage of pig growth may be an important factor that must be considered.
Conclusion
In conclusion, the results of the current study indicate the supplementation of non-GMO beet pulp, and canola meal do not have any adverse effect on reproduction performance in gestation-lactation sows. In this experiment, non-GMO ingredients can be added to the feed as an alternative ingredient.
