The efficiency of different levels of dietary xylanase on growth performance, nutrient digestibilities and carcass and meat quality was evaluated in 128 barrows. The performance study lasted from about 27 to 110 kg of body weight with pigs allocated to 4 groups (32 animals each), fed ad libitum and kept in straw-bedded pens (4 animals each). Pigs from group I (control) received standard feeds without any enzyme added, while pigs from groups II, III and IV received the same diet including additionally xylanase at levels of 8000, 16000 or 24000 BXU (Birch Xylan Unit) per kg, respectively. The digestibility experiment was carried out with 40 barrows not involved in the first part of the experiment. Pigs were allocated to 4 groups (10 animals each) receiving the same diets as in the performance experiment. Xylanase significantly improved body weight gains of pigs receiving diets with 16000 BXU/kg (P<0.05) and 24000 BXU/kg feed (P<0.01) by 4.2% and 6.2%, respectively. Final body weights of 111-112 kg were achieved in a significantly shorter feeding period and at a lower feed conversion ratio by pigs that received highest xylanase application (24000 BXU/kg feed, P<0.05). In younger pigs xylanase mainly improved fibre digestibility which was significant for pigs receiving 24000 BXU/kg (P<0.05). In the final feeding period dry matter, fat and fibre digestibility were improved by xylanase with effects getting more pronounced with the increase of xylanase inclusion rate. No differences in carcass and meat quality were observed between any feeding groups. Based on these results it is assumed that application of xylanase (Econase XT) can improve performance of grower-finisher pigs without having any impact on the carcass quality. Performance improvements were in line with better nutrient digestibility.
Effect of Genetically Modified Feeds on Physico-Chemical Properties of Pork
The objective of this study was to evaluate the effects of genetically modified (GM), insect-resistant Bt maize (MON810) and the meal made of glyphosate-tolerant soybean (Roundup Ready MON40-3-2) used as the dietary components for pigs on the physico-chemical properties of meat. Forty-eight fatteners derived from Polish Landrace x Polish Large White sows mated to a Duroc x Pietrain boar were used. All animals received isonitrogenous and isoenergetic diets containing or not containing the genetically modified components. The design of the experiment was as follows: group I (control) - non-modified soybean meal and maize; group II - GM soybean meal and non-modified maize; group III - non-modified soybean meal and GM maize; group IV - GM soybean meal and GM maize. The examination of the pH values of loin and neck muscles indicated no statistically significant differences between pigs fed diets containing non-transgenic or transgenic feeds. No statistical differences were observed for water holding capacity (WHC) within dietary treatments. The introduction of transgenic maize and soybean meal into pig diets did not significantly affect the a* colour parameter of loin as well as neck muscles. The use of transgenic maize or soybean meal did not cause significant changes in the L* colour value of loin. Results obtained for neck muscles were more differentiated, possibly due to the natural heterogeneity of this primal cut. Pigs which had consumed the transgenic diet exhibited slightly decreased lipid stability of loin, as indicated by thiobarbituric acid reactive substances (TBARS). The decrease was statistically significant only in the case of muscles from group II. The addition of feeds derived from genetically modified crops into pig diets did not significantly affect the stability of neck muscle lipids; however, TBARS values of these muscles were twice those of loin muscles.
The effect of corn distillers dried grains with solubles (DDGS), used in grower-finisher diets with or without supplemental enzymes, on growth performance and carcass and meat quality was determined in an experiment with 48 pigs. Group I (control) received a standard grain-soybean meal mixture without DDGS and without enzymes; Group II was fed a mixture containing 15% (grower) or 20% (finisher) of corn DDGS but without the enzymes; Group III received a mixture containing 15% (grower) or 20% (finisher) of corn DDGS with NSP-hydrolyzing enzymes (200 g t-1). The feed mixtures were isonitrogenous and isoenergetic. All pigs were fattened from 30 to 112 kg. At the end of the experiment all pigs were slaughtered, right carcass sides were evaluated and samples of longissimus muscle were taken for analysis. Inclusion of corn DDGS did not significantly affect pig fattening results and meat quality. The addition of NSP-hydrolyzing enzymes to feed mixtures containing corn DDGS tended to positively influence pig performance. The carcasses of pigs receiving the diet with corn DDGS and NSP-hydrolyzing enzymes were characterized by thinner backfat and greater weight of the primal cuts.
The aim of this experiment was to examine the possibility of replacing part of soybean meal in the diets of sows, their piglets and fatteners with two varieties of high- or low-tannin faba bean seed. Twenty-four sows were allocated to 3 groups, 8 animals in each. Control group (C) received standard feed mixture containing soybean meal as the main protein source. Next groups received standard feed mixture in which part of soybean meal was replaced by high-tannin variety Bobas (group HT) or low-tannin variety Kasztelan (group LT). Faba bean was added to diets at the level of 12 and 14% for pregnant and lactating sows, 6% for piglets, and 12 and 16% for fatteners (grower and finisher, respectively). Diets for half piglets and fatteners were supplemented with the enzyme Ronozyme VP. Apparent digestibility of nutrients was evaluated in a parallel experiment, using the same feeds on 18 barrows weighing about 40 kg (grower) and 80 kg (finisher). There was almost no difference in sow reproductive rates, litter weight and body weight of piglets on the first day of life were similar. Until 35 days of age piglets receiving faba bean grew faster than control ones. Control piglets grew fastest from 35 to 84 days of age, but differences were not significant. Enzyme supplement had a positive effect on body weight only from 56 to 84 days of piglet life. Digestibility of nutrients was lower in pigs fed with faba beans, especially in the grower period. Faba bean HT had lower nutrient digestibility in both periods of fattening. Almost all carcass traits were better in control pigs than in those fed with bean variety Bobas. Meat of these pigs had also the lowest content of unsaturated fatty acids and highest atherogenic indices. In sensory evaluation this meat had also the worst smell and taste. It can be stated that faba bean seeds, in moderate amounts, can partially replace soybean meal in feed for pigs, but some lowering of body weight gain and meat quality is possible especially when high-tannin varieties are used.
The effect of Roundup Ready MON-40-3-2 soybean meal and Bt maize MON810 on sows performance and haematological indices, including parameters of erythrocytes, leukocytes, and trombocytes, as well as the piglets rearing indices were evaluated in the experiment carried out on 24 sows and their progeny. After mating sows were divided into groups: I - control, conventional soybean meal and conventional maize; II - genetically modified (GM) soybean meal and conventional maize; III - conventional soybean meal and GM maize; IV - GM soybean meal and GM maize. All used feed mixtures were isonitrogenous and isoenergetic, however differed in presence or absence of genetically modified maize MON810 (5% for pregnant and 8% for lactating sows) and/or soybean meal MON-40-3-2 (4% for pregnant and 14% for lactating sows). Born piglets were allotted to the same group as their mothers. The study showed that feeding pregnant and lactating sows with mixtures containing genetically modified RR soybean or/and meal Bt maize did not significantly affect their reproductive characteristics and offspring performance. There was no effect of dietary treatment on haematological indices. Transfer of transgenic DNA from GM feed to blood was not confirmed.
The possibility of replacing soybean meal with a mixture of legume seeds and rapeseed press cake (RPC) was evaluated on 60 pigs weighing about 30 kg at the beginning of the experiment. Pigs were allocated to 5 experimental groups. Group I (control) received standard feed mixture containing soybean meal as a main protein source. Next groups received rapeseed press cake (RPC) mixed with fodder pea (Pisum sativum var. Ramrod) - group II, field bean (Vicia faba var. Kasztelan) - group III, blue lupin (Lupinus angustifolius var. Regent) - group IV or yellow lupin (Lupinus luteus var. Mister) - group V. Soybean protein was replaced by experimental protein sources at about 30% in grower (17% legumes, 13% rapeseed press cake) and at 100% in finisher diets (experimental proteins in equal ratio accounted for about 55% of mixture protein). Limited feeding was used, water was available ad libitum. Half the animals in each group received mixtures supplemented with fibrolytic enzymes Ronozyme VP and Ronozyme WX. Apparent digestibility of feed nutrients was estimated using the balance method on 30 fatteners not used in the fattening experiment, weighing about 40 kg for grower and 70 kg for finisher diets. Gross composition of legume seeds and RPC, amino acid composition of their protein, glucosinolate content in RPC and tannin content in faba bean and alkaloids in lupins were analysed. Carcass traits and meat quality were also estimated. Legume protein content ranged from 19.6% (pea) to 39.8% (yellow lupin). RPC protein contained more sulphur amino acids than legume protein. There was no significant difference in protein and fat digestibility. Body weight gains of fatteners fed with blue lupin were comparable to controls but significantly lower than those of the remaining groups. Supplemental enzymes improved body weight gains of fatteners receiving field bean. There was no significant difference in carcass traits and meat quality except for sensory analysis. It is concluded that the mixture of RPC and legume seeds can replace soybean meal in fattener feed.
The aim of the study was to evaluate the immune effects of genetically modified (GM), insect resistant corn (MON810) expressing toxin protein of Bacillus thuringiensis, and glyphosate-tolerant soybean meal (Roundup Ready MON-40-30-2), which are used as the feed mixture components in domestic animals. The study was conducted on 60 pigs (36 fatteners and 24 sows), 20 calves, 40 broilers, and 40 laying hens. Each species was divided into four basic nutritional groups: group I (control) - conventional feed, group II - feed consisted of GM soybean meal and non-modified corn, group III - non-modified soybean meal and GM corn, group IV - GM soybean meal and GM corn. Moreover, in the experiment on fatteners two additional groups were formed: group V - animals fed both conventional soybean meal and bruised grain, and group VI - GM soybean meal and conventional bruised grain. The results of study did not reveal any significant effect of feed mixtures containing GM components on the immune response in all animals regardless of their species and technological producing groups.
In this study, we have attempted to analyse the impact of dietary fats on the liver transcriptome in pigs. Four nutritional groups were created. The animals’ diets differed among groups in terms of the presence of corn dried distillers’ grains with solubles (DDGS) (group I - no DDGS, groups II, III, IV - 20% DDGS) as well as the type of fat (rapeseed oil - groups I and II, beef tallow - group III, coconut oil - group IV) used. Using the RNA-Seq method we identified 39 differentially expressed genes (DEGs) as a result of Cuffdiff analysis of the differences among all groups. Analysis of these genes with Panther Gene Classification System revealed that among identified DEGs, genes responsible for lipid and fatty acids metabolism are overrepresented as well as the genes engaged in oxidoreductase and catalytic activity. The article presents for the first time the RNAseq analysis of the liver transcriptome in pigs fed with different sources of fats. The results may be useful for the elaboration of new therapies for cardiovascular diseases in humans as well as for the preparation of new nutrition strategies in animals.
Β-hydroxy-β-methylbutyrate (HMB) is one of the leucine metabolites with protein anabolic effects which makes it very popular among athletes. Previously, it was shown that HMB administered during the prenatal period reduced the pool of primordial follicles and increased the proportion of developing follicles in newborn piglets. This work is a further step to understand these morphological alterations. Therefore, the aim of this study was to examine the effect of prenatal HMB treatment on the expression of the Kit ligand, BMP-4, bFGF, and the IGF-1/IGF-1R system which are the main growth factors controlling follicular development. Excised ovaries from 12 newborn piglets, originated from the control (n=6) and HMB-treated (n=6) sows were used for immunohistochemical and western-blot analysis. The tested proteins were localized within egg nests and ovarian follicles. Furthermore, the western-blot assay indicated higher BMP-4, Kit ligand, and IGF-1R expression, while the level of bFGF and IGF-1 proteins decreased after HMB dietary treatment. These findings show that HMB included into sow diet can modulate the expression of growth factors and thereby alter ovarian morphology in offspring. Therefore, this study opens a discussion about the benefits and risks of the diet supplemented with HMB and its potential application in medicine and animal husbandry, and further research is necessary in this area.
Histopathological examination of liver, kidney, spleen, pancreas, duodenum, jejunum, skeletal muscle, and bursa of Fabricius samples, collected from broiler chickens, laying hens, fattening pigs, and calves fed genetically modified corn MON 810 and soybean meal MON-40-3-2 (Roundup Ready, RR), was performed The examination showed no significant differences between the control animals fed diets containing no genetically modified feeds and animals fed genetically modified feeds. In some cases, congestion of parenchyma and focal lymphoid cell infiltrations were observed in all dietary groups, including controls, and therefore, it was assumed that the lesions were not associated with the feeding transgenic feeds.