Air-dry Matter Research Articles

Competitividade relativa de soja com arroz-vermelho

Para reduzir a infestação de plantas daninhas, especialmente arroz-vermelho, áreas tradicionalmente cultivadas com arroz irrigado no Rio Grande do Sul estão sendo utilizadas para o cultivo da soja, em sistema de rotação de culturas. Objetivou-se neste trabalho quantificar as habilidades competitivas entre a cultura da soja e biótipo de arroz-vermelho. Os tratamentos foram arranjados em série de substituição, utilizando-se cinco proporções (0:16, 4:12, 8:8, 12:4 e 16:0) de soja e arroz-vermelho em delineamento de blocos casualizados, com quatro repetições. As variáveis estudadas foram massa seca da parte aérea e área foliar das plantas. A análise da competitividade foi efetuada por meio de diagramas aplicados a experimentos substitutivos e índices de competitividade. A soja apresentou maior habilidade competitiva pelos recursos do meio do que o arroz-vermelho. A cultura da soja produziu mais tendo em sua proximidade uma planta de arroz-vermelho que uma outra planta de soja.

Flavonoid Content and Antioxidant Activity of Caraway Roots (Carum Carvi L.)

Flavonoid Content and Antioxidant Activity of Caraway Roots (Carum Carvi L.) Zdolność znoszenia rodnika DPPH przez ekstrakty z korzeni kminku zwyczajnego wzrastała wprost proporcjonalnie do długości okresu wegetacji, zawartości flawonoidów i stężenia ekstraktów.

Kiełkowanie zbóż w warunkach sąsiedztwa ziarniaków Avena fatua L. i Festuca rubra L. – aspekt allelopatyczny

The present studies were aimed at determining the allopathic interspecies interactions of weed grains from wild oats (Avena fatua L.) and red fescue (Festuca rubra L.) on winter wheat and winter rye germination and seedling growth. Preliminary studies on inter-crop influences were done in a laboratory using developing dishes. Those tests allowed us to determine the allelopathic effect of the tested grain weed species on the germinating ability of seeds of other grain crop species as well as on the length of root, coleoptiles length, fresh and air dry matter of roots and coleoptiles. The results showed that the neighborhood of wild oats (Avena fatua L.) and red fescue (Festuca rubra L.) decrease germinating ability of winter wheat by about 4% as compared to the pure stand. There was no inhibiting influence of the neighboring red fescue on wheat germinating ability. There was observed a negative influence of the tested weed species on winter rye germinating ability but a significant difference was only observed between control dishes and treatment with red fescue. The research showed that the neighbourhood of wild oats inhibited the length of coleoptile and root seeds of winter wheat and their fresh and air dry matter stronger than red fescue. Winter rye was more sensitive to the neighbourhood of red fescue than wild oats.

Quantifying the damage of red deer (Cervus elaphus) grazing on grassland production in southeastern Slovenia

The influence of red deer (Cervus elaphus) grazing on grassland production for forage conservation at the forest border during the vegetation period was studied on three locations (Mala gora, Cvislerji, and Mackovec) in the Kocevje region (SE Slovenia). The experiment lasted from the 25th of March until the 8th of October 2002. Portable cages were used to exclude red deer from grazing the herbage. At four sampling dates in the season, herbage air dry matter (DM) yield was measured at three different observations (cage-protected plot, cage-protected plot only two to three weeks before sampling date, otherwise freely grazed (removed), and unprotected plot). The results from the experiment showed that red deer grazed on grassland through the entire season and that the regeneration capability of sward was the highest in summer, middle in spring and smallest in autumn. On unprotected plots, an average reduction of 50% of herbage DM yield was found with the most damaged sites also up to 80% reduction.

A műtrágyázás és a csapadék változékonyságának hatása a kukorica (Zea mays L.) termésére

The effect of natural rainfall and N, P and K nutrients on the yield of maize was investigated in 16 years of a long-term fertilization experiment set up at the Experimental Station of the Institute in Nagyhörcsök. The soil was a calcareous chernozem, having the following characteristics: pH (KCl): 7.3, CaCO 3 : 5%, humus: 3%, clay: 20-22%, AL-soluble P 2 O 5 : 60-80, AL-soluble K 2 O: 180-200, KCl-soluble Mg: 150-180; KCl+ EDTA-soluble Mn, Cu and Zn content: 80-150, 2-3 and 1-2 mg·kg -1 . The experiment had a split-split-plot design with 20 treatments in 4 replications, giving a total of 80 plots. The treatments involved three levels each of N and P and two levels of K in all possible combinations (3×3×2=18), together with an untreated control and one treatment with a higher rate of NPK, not included in the factorial system. The main results can be summarized as follows: An analysis of the weather in the 16 experimental years revealed that there were no average years, as two years were moderately dry (1981, 1982), eight were very dry (1973, 1978, 1986, 1989, 1990, 1993, 1997, 2002) and six were very wet (1969, 1974, 1977, 1994, 1998, 2001). In dry years the N, NP and NK treatments led to a yield increment of over 3.0 t·ha -1 (3.2 t·ha -1 ) (81%) compared with the unfertilized control, while the full NPK treatment caused hardly any increase in the maize yield (7.2 t·ha -1 ). In the case of drought there was a 4.0% yield loss in the N, NP and NK treatments compared to the same treatments in the dry years. This loss was only 1.0% in the NPK treatment. In very wet years the positive effects of a favourable water supply could be seen even in the N, NP and NK treatments (with yields of around 7.4 t·ha -1 ). The yield increment in these treatments compared with the droughty years averaged 8%, while balanced NPK fertilization led to a further 2% increase (10%). Significant quadratic correlations were found between the rainfall quantity during the vegetation period and the yield, depending on the nutrient supplies (Ø: R = 0.7787***, N: R = 0.8997***, NP: R = 0.9338***, NK: R = 0.9574***, NPK: R = 0.8906***). The optimum rainfall quantity and the corresponding grain yield ranged from 328-349 mm and 5.0-7.7 t·ha -1 , respectively, depending on the fertilizer rate. The grain yield increment obtained per mm rainfall in the case of optimum rainfall supplies was found to be 14.3-23.2 kg·ha -1 , while the quantity of rainfall utilized during the vegetation period for the production of 1 kg air-dry matter in the case of maximum yield amounted to 698, 449, 480, 466 and 431 litres in the control, N, NP, NK and NPK treatments, respectively. It was clear from the 43-year meteorological database for the experimental station (1961-2003) that over the last 23 years (1981-2003) the weather has become substantially drier. Compared with the data for the previous 20 years (1961-1980) there was an increase of 20, 500 and 50% in the number of average, dry and droughty years, no change in the number of wet years and a 71% drop in the number of very wet years.

Estimation of roughage intake in sheep using a known daily intake of a labelled supplement

AbstractA feeding trial with growing sheep was conducted on mixed roughage-supplement diets, to test whether roughage intake could be estimated from a known intake of a supplement and an alkane-based estimate of the supplement and roughage proportions in the diet (diet composition) without the need for separate dosing with external marker alkanes. Diets consisted of chaffed Trifolium subterraneum hay (SC), or a mix of SC and beeswax-labelled cottonseed meal (CSM) in the proportions of 7: 1, 6: 2, 5: 3 and 4: 4 (air-dry matter basis). Six sheep were given the pure SC diet and three sheep were given each of the mixed diets. Additionally, the CSM was also labelled with octatriacontane (C38) to investigate its use for labelling supplements. Due to unexpectedly low recoveries, C38 was not included in any estimation of diet composition or digestibility.The inclusion of beeswax-labelled CSM in a SC diet resulted in lower faecal alkane recoveries (as proportions of alkane ingested; P ≤ 0·05). Within mixed diets, recoveries decreased significantly with increasing proportion of CSM, but this effect was significant (P < 0·05) only for alkanes consisting of 25, 26, 27 and 29 carbon-atoms. Estimates of diet composition were close to measured values. Daily SC intake and organic matter digestibility (OMD) differed by −3·7 to 7·2% and −2·0 to 5·7% from measured values if a mean faecal recovery, across diets, was applied for each alkane. Accuracy increased greatly if estimates were based upon faecal alkane recoveries for individual diets, instead of mean recoveries across diets (−0·3 to 0·9% and −0·2 to 0·0% for SC intake and OMD, respectively).The results indicate that roughage intake can be estimated from a combination of known supplement intake and an estimate of diet composition, which obviates the need for separate alkane dosing to estimate intake. The method should be applicable in situations in which animals either normally receive supplements (e.g., dairy cows) or could readily be given supplements.

The effect of the combination of microbial phytase and amino acid supplementation of diets for finishing pigs on p and n excretion and carcass quality

The objective of this study was to evaluate the effect of a combined low-protein, low-phosphorus diet supplemented with limiting amino acids and microbial phytase on performance, nutrient utilization and carcass characteristics of late-finishing barrows. 4 × 8 crossbreed barrows were continuously housed in metabolism cages from 70 – 110 kg BW and were fed diets, either conventional (A) or protein reduced (B) or protein and phosphorus reduced diets (C) based on barley, maize and soybean meal. Diet A (positive control) contained in air dry matter 13% and 10% CP as well as 0.49% and 0.42% P at growth phases I (70 – 100 kg BW) or II (100 – 110 kg BW), respectively. Diet B was low in CP (11.3%, 8.4%), diet C low in CP and low in P (CP: as B, P: 0.36%, 0.30%). To diet B the limiting amino acids lysine, methionine, threonine and trypthophan were added to meet the levels in diet A. To diet C the limiting amino acids and 800 FTU/kg Aspergillus-phytase were supplemented. At the end of the balance periods the barrows were slaughtered, the carcasses scored and loin chops, ham and Phalanx prima IV were analysed for nutrients and minerals. The CP or P reduction in diets B and C did not generally negatively affect growth, feed efficiency, absolute nitrogen retention or overall carcass performances of the pigs. With the low CP diets B and C, N excretion per unit BWG was decreased by about 23%. The addition of microbial phytase (diet C) increased apparent total tract digestibility of P by about 20%. In spite of 30% reduction of P intake (diet C), the absolute P retention related to 1 kg BW did not differ between treatments. Thus, phytase supplementation in diet C reduced P excretion per unit BWG by about 33%. Phytase raised apparent digestibility of Zn by about 20% but not Ca digestibility. Generally the carcass traits and meat characteristics were not affected by any of the diet strategies. Mineralization of the Phalanx prima IV was also similar in all treatment groups. However, phytase supplementation led to significantly increased zinc concentration in bones (25%). In contrast, Fe incorporation into the Phalanx prima IV was not affected. In general, the feeding regimen introduced in this experiment offers substantial benefits in maintaining a sustainable environmental-friendly pork production even at the stage of late-finishing barrows.

Influence of feeding a milk replacer deficient in α-linolenic acid on fatty acid composition of various tissues in goat kids

Goat kids were fed for 5 weeks milk replacers with or without α-linolenic acid (C18:3 n-3, ALA) and growth performance, plasma lipids and fatty acid composition of red blood cells, adipose tissue, liver, kidney, lymph node and spleen were examined. Ten animals were either given a milk replacer with 1.3% (% of total fatty acids) linoleic acid (C18:2 n-6, LA) and 0.6% ALA or a milk replacer (ALA-free) with 1.2% LA and no ALA. The diets did not contain eicosapentaenoic (C20:5 n-3) or docosahexaenoic acid (C22:6 n-3). Both experimental milk replacers contained 224 g crude protein and 17 MJ metabolizable energy per kg air-dry matter. Crude fat contents were 131 and 124 g/kg air-dry matter in the control and ALA-free milk replacer, respectively. Growth performance of the goat kids was not affected by dietary treatment. The ALA-free milk replacer decreased the concentrations of plasma total and LDL cholesterol. After feeding the ALA-free diet, ALA was not detectable in any of the tissues and the erythrocytes. Except for adipose tissue and red blood cells, there was still eicosapentaenoic acid in the tissues of the goat kids fed the diet deficient in ALA, but the levels were markedly reduced. The present study shows that dietary ALA is not essential for growth in goat kids for a period of up to 5 weeks after birth. It is suggested that at birth the goat kids had sufficiently large stores of n-3 polyunsaturated fatty acids to prevent deficiency when fed the ALA-free milk replacer.

RESPONSE OF GROUNDNUTS DEPENDENT ON SYMBIOTIC AND INORGANIC NITROGEN TO HIGH AIR AND SOIL TEMPERATURES

Groundnuts (Arachis hypogaea L.) are frequently exposed to high temperatures in the semi-arid tropics. The objectives of the present research were: (i) to determine the response of groundnuts to different nitrogen sources; (ii) to quantify the effects of high air and soil temperatures on nodulation, dry matter production, partitioning and pod yields; and (iii) to discover whether plants dependent on symbiotic dinitrogen are more sensitive to heat stress than those dependent on inorganic nitrogen (N). Plants were grown at optimum air and ambient soil temperatures from sowing until the first flowering. Thereafter, plants were exposed to a factorial combination of two air temperatures [optimum: 28°/22°C (day/night) and high: 38°/22°C], two soil temperatures (ambient: 26°/24°C and high: 37°/30°C) and three N-sources [inoculated with Bradyrhizobium strain NC 92 (symbiotic N2); inoculated and supplied with 20 ppm inorganic N (symbiotic N2 plus 20 N); or not inoculated and supplied with 100 ppm inorganic N (inorganic N)]. At optimum air and ambient soil temperature dry matter and pod yields were greatest in plants dependent on inorganic N, intermediate in symbiotic N2 plus 20 N and least in symbiotic N2. High air or high soil temperatures significantly (P < 0.001) reduced pod yield to a similar extent and their effects were additive and without interaction. High soil, but not high air temperature, significantly (P < 0.001) reduced nodule numbers, nodule dry weight and 100 seed weight. High air and/or high soil temperature had no effect on pod yield in plants dependent on symbiotic N2 or symbiotic N2 plus 20 N, but significantly (P < 0.05) reduced pod yield in plants dependent on inorganic N. This suggest that effectively nodulated plants with small quantities of inorganic N are potentially more adaptable to hot environments than those relying on large quantities of inorganic N.

High intake of calcium formiate depresses macronutrient digestibility in veal calves fed milk replacers containing either dairy proteins or whey protein plus soya protein concentrate

A study to determine whether calcium intake and the type of dietary protein would show an interaction with regard to macronutrient digestibility in veal calves was carried out. Eighty four male calves, about 8 weeks of age, were fed four experimental milk replacers in a 2 × 2 factorial design. The diets contained either dairy protein as a sole source of protein or whey protein (76% of total protein) plus soya protein concentrate (24% of total protein) and either a low or high concentration of calcium. Calcium was added to the high-calcium diets in the form of calcium formiate. The concentration of calcium was on average 0.64% of air-dry matter in the low-calcium rations and 1.25% in the calcium-rich rations. After the experimental diets had been fed for 10 weeks, body-weight gain was significantly lower (on average 5.5 kg) in the calves that had been fed on the diets containing soya protein concentrate and whey protein. Calcium intake did not significantly influence weight gain. In the calves that were fed soya proteins, digestibility of protein and carbohydrates was significantly lower than in those fed dairy protein only, but fat digestion was unaffected. High calcium intake significantly reduced the digestibility of protein, fat and carbohydrates. With regard to carbohydrate digestibility there was an interaction between the amount of calcium and type of protein in the diet such that the effect of calcium was greater when the diet contained 24% of protein in the form of soya protein instead of dairy protein only.

The effect of processing of Chlorellavulgaris: K-5 on in vitro and in vivo digestibility in rats

Two experiments were done to clarify whether or not cell rupture is necessary to improve the digestibility of major components of Chlorella vulgaris: K-5. Chlorella was treated with or without high pressure homogenization (1×10 8 N/m 2 at less than −20°C) after a heating process (100–120°C). Chlorella (air-dry matter) contained 934 g dry matter and 244 g essential amino acids (total)/kg. Chemical composition was hardly altered irrespective of the treatment. In the first experiment, pepsin digestibility of chlorella protein was determined in vitro. The cell rupture by high pressure homogenization caused a small but significant improvement in pepsin digestibility of chlorella protein compared with the control. In the second experiment, total tract apparent digestibilities of chlorella were determined in the rat. Digestibility of chlorella protein was significantly enhanced by high pressure homogenization, but the difference (88.6% vs. 87.4%, P<0.01) due to treatment was small and similar to that observed in the in vitro experiment. These results suggested that Chlorella strain vulgaris: K-5 may be an efficient protein source even without cell rupture.

大豆粕の発酵処理による成長中ブタの亜鉛利用性向上

The efficacy of fermentation on zinc bioavailability in soybean meal was studied in growing pigs. Fifteen growing pigs, average initial body weight and age of 20kg and 8 weeks, were fed a soybean meal based-diet (SBM diet), a soybean meal based diet added with monosodium phosphate at 7.5g/kg of air dry matter (SBM+P diet), or a fermented soybean meal-based diet (FSBM diet) for 30 days. Zinc concentration in each diet was almost the lower limit of its requirement in the growing pigs. The FSBM group showed higher zinc concentrations in the femoral cortex and serum than did the other groups. These results suggested that fermentation of soybean meal improved zinc bioavailability in growing pigs.

Level of nutrition and age at weaning: effects on humoral immunity in young calves

Thirty-two calves were studied to determine the effects of level of nutrition (400 and 1000 g (air-dry matter) milk substitute per d) and age at weaning (5, 9 and 13 weeks) on humoral immune responses measured in serum and bronchoalveolar washings (BAW). All calves were immunized with Keyhole limpet haemocyanin (KLH) at 3 weeks of age, and with horse erythrocytes (HRBC) 1 d after weaning. Feeding the higher level of nutrition compared with the lower level decreased anti-HRBC titres and serum IgG2 and IgA responses to KLH (P < 0.05). Weaning at 5 compared with 9 weeks of age decreased serum anti-HRBC responses (P < 0.05), but weaning age had no effect on anti-KLH responses (P > 0.05). Feeding the higher level of nutrition increased total protein (P < 0.05) and IgG2 concentrations (P < 0.01) in BAW. The results showed that variation in husbandry conditions that is within conventional limits affects humoral immune responses in young, artificially-reared calves.

Alteration of cellular immune responses by nutrition and weaning in calves

The effects of two levels of nutrition (400 g and 1000 g air dry matter milk substitute powder per day) and three ages of weaning (rive, nine and 13 weeks) on cellular immune responses were determined in 32 calves. The lower level of nutrition was found to increase skin sensitivity responses to keyhole limpet haemocyanin (KLH) and decrease lymphocyte blastogenesis test (LBT) responses to ConA and pokewood mitogen (P<0·05). Weaning at five weeks old resulted in increased KLH skin responses at nine weeks old compared with unweaned calves and decreased LBT responses to ConA and phyto-haemagglutinin at 10 weeks old compared with calves weaned at nine weeks old (P<0·05). Weaning at five weeks old also increased peripheral blood concentrations of BoCD2+ and BoCD8+ lymphocytes (P<0·05). The results show that the choice of husbandry conditions alters cellular immune responses in young calves and suggest that early weaning effects are essentially nutritional.

Urinary excretions of purine derivatives and nitrogen in sheep given straw supplemented with different sources of carbohydrates

AbstractEstimations of purine derivatives excretion and urinary-nitrogen loss were used to test the response of rumen fermentation to supplementation of straw with different sources of carbohydrate. Two groups of Rasa Aragonesa ewes (44 (s.e. 0·75) kg live weight were givenad libitumbasal diets of either ammonia-treated (ATS) or urea-supplemented (USS) barley straw, with 12 animals per basal diet group. Three supplements, barley grain, sugar-beet pulp or grass hay, respectively, were given to each basal diet group, giving a total of six dietary treatments with four animals per treatment group. Four levels of supplementation were studied (150, 300, 450 and 600 g air dry matter per day), one in each of four experimental periods. Each 45-day experimental period comprised 38 days of adjustment followed by a 7-day measurement period. Digestible organic matter (DOM) intake was higher in animals receiving ATS than in animals receiving USS (504v.474 (s.e. 21·1) g/day,P&lt; 0·005) and higher in animals receiving barley grain and sugar-beet pulp than in those receiving grass hay (512 and 496v.370 (s.e. 25·9) g/day,P&lt; 0·005). DOM intake also increased with the level of supplementation and this increase was greater with barley grain (504 to 634 and 314 to 554 g/day for ATS and USS) and sugar-beet pulp (440 to 582 and 315 to 522 g/day) than with grass hay (430 to 407 and 267 to 370 for ATS and USS). Urinary excretions of hypoxanthine, xanthine and uric acid were not affected by the experimental treatment whereas allantoin excretion (y, mmol) increased in response to DOM intake (x, kg) (y = 13·72 × − 0·26; r = 0·79;P&lt; 0·001; no. = 96). The response in allantoin excretion was mainly explained by the increase in DOM intake. However when data were expressed per unit of DOM intake significant differences were still evident. Allantoin/DOM intake (mmol·kg) ratio and calculated microbial nitrogen (g·kg DOM intake) supply were lower with USS diets and sugar-beet pulp supplemented diets (P&lt; 0·05) and increased significantly with level of supplementation (P&lt; 0·001).

Yield, composition and nutritive value of leaf protein concentrates from mixed forages of cereals and legumes

Leaf protein concentrates (LPC) were produced from high- and low-legume (high-cereal) mixtures of forage. The forages were obtained by sowing seed mixtures containing either 60% legume and 40% cereal or 60% cereal and 40% legume (air dry matter). The legumes used were vetch and pea, and the cereals were wheat, triticale and barley. Average green- and dry-matter yield was highest for high-legume mixtures containing vetch. Barley-containing mixtures gave higher yields than those containing wheat or triticale. The LPC were analysed for their gross composition and amino-acid content. Biological value and true digestibility of LPC protein were estimated in rats using the Thomas-Mitchell balance method. Protein content of LPC was low (32.3–46.7% dry matter basis). All concentrates were poor in sulphur amino acids and their content of basic amino acids was unexpectedly low. Protein extracted from low-legume forages was higher in biological value than that from high-legume forages, while true digestibility did not differ significantly. It can be concluded that increasing the proportion of legume in mixed (legume-cereal) forages increases the yield of green and dry matter per unit area, but significantly decreases nutritive value of extracted protein.

Approaches to KL a measurements in solid state fermentation

A convenient method for measuring KL a in a solid state medium is proposed. Due to the particular nature of the substrate used in solid state fermentation, different modifications of the sulfite oxidation method have been necessary. This first approach allows to study the influence of air inflow rate and dry matter percentage of the medium on the oxygen volumetric mass transfer coefficient.

Growth, tissue deposition and metabolism studies in growing pigs given low glucosinolate rapeseed meal diets containing different amounts of copper and polyethylene glycol

SummaryIn three factorial growth experiments and a metabolism experiment pigs of approximately 25 kg initial live weight were given on a restricted scale of feeding simple diets, based on barley, a vitamin and mineral supplement and either soya-bean meal (SBM) or a low glucosinolate rapeseed meal (cv. Tower; TRSM). Variations in these two basic diets were produced by adding different quantities of tannic acid, polyethylene glycol (PEG) and copper (Cu).Diets based on soya-bean meal were used in the first experiment. There were no significant interactions. Tannic acid added at 3·75 and 7·50 g/kg air-dry matter was without significant effect on performance compared with no tannic acid addition, but PEG at 17 g/kg air-dry matter significantly improved growth rate compared with no PEG addition to the diet (P &lt; 0·05). In the second experiment TRSM-based diets were used. There were no significant interactions and no significant effects on performance from adding 0, 8·5 and 17·0 g PEG/kg air-dry matter. Increasing Cu from 17 to 54 mg/kg air-dry diet significantly improved growth rate (P &lt; 0·05). In the third experiment TRSM and SBM based diets, of similar digestible energy (DE), crude protein and lysine content, and containing either 19 or 202 mg Cu/kg air-dry matter, were used. Pigs were slaughtered at 87·5 kg live weight and hand joints dissected. Pigs given the TRSM diet containing 19 mg Cu/kg grew significantly more slowly than pigs given the three other diets between which there were no significant differences. There were no other significant interactions and no significant differences between Cu concentrations for the growth, carcass and efficiency of conversion results. Compared with TRSM diets, SBM diets at similar slaughter weights gave significantly greater carcass weights, killingout proportions and backfat thicknesses. Also the efficiencies with which dietary protein and DE were used to promote units of carcass growth were significantly better for the SBM diets, but there were no significant differences in the estimated weights of lean in carcasses.In the metabolism experiments the effects of adding PEG to diets similar to those used in the growth experiments were examined. The apparent digestibilities of dry matter, gross energy and nitrogen and the nitrogen retentions were significantly greater for the SBM diets than for the TRSM diets. The addition of PEG to the SBM and TRSM diets significantly decreased the apparent digestibilities of dry matter and gross energy, and significantly increased the apparent digestibility of nitrogen in the SBM diet but not in the TRSM diet.

Ileal apparent digestibilities of amino acids, growth and tissue deposition in growing pigs fed low glucosinolate rapeseed meals

SUMMARYA factorially designed growth and carcass dissection experiment was made in which a low glucosinolate rapeseed meal (cv. Tower, TRSM) was compared with soya-bean meal (SBM) as the sole protein supplement in simple diets, containing barley and a vitamin and mineral supplement (to give 18 mg copper/kg air-dry diet) only, which were fed individually on a restricted scale of feeding to 72 pigs. The diets were of similar digestible energy (DE) content and were formulated to contain in each kg of air-dry matter 150, 170 and 190 g crude protein. In each crude-protein level the total lysine content was similar. Also experiments using 35 pigs were made to determine the ileal apparent digestibilities of amino acids in barley-based diets containing SBM, the low glucosinolate rapeseed meals Erglu (ERSM) and TRSM and a high glucosinolate British rapeseed meal (BRSM) and either 20 mg or 200 mg copper/kg air-dry diet.In the growth experiments there were no significant interactions for the variables considered. Pigs given TRSM diets, compared with those given SBM diets, had significantly poorer growth rates, conversion efficiencies and killing-out proportions but the proportions of lean and fat in carcasses and the backfat thicknesses (P2) were similar. There were no significant differences between protein levels in the killing-out proportions, the proportions of fat in carcasses and backfat thicknesses (P2) but pigs given diets containing 150 g, compared with 170 and 190 g, crude protein/kg air-dry diet had significantly lower growth rates and proportions of lean in the carcass and significantly poorer efficiencies of food conversion. The quantities of dietary crude protein used to produce units of live-weight gain, carcass weight and lean tissue increased progressively from the diets containing 150 to 170 to 190 g crude protein in each kg air-dry diet.In the ileal digestibility studies the results indicated that amino acids were of a lower digestibility in the rapeseed meal diets than in those based on SBM and that the copper content of the diet may have been important in this context.

Cassava and tallow in diets for growing pigs

ABSTRACTIn two experiments 480 and 360 pigs were housed in groups of 10 and given diets containing different proportions of cassava between 35 and 87 kg live weight. The cassava contained 672, 34, 57 and 39 g/kg air dry matter of starch, crude fibre, total ash and insoluble ash respectively. The diets in the first experiment contained 0, 238, 475 or 713 kg cassava per t. In the second experiment the different levels of dietary cassava (0, 150, 300 or 450 kg cassava per t) were combined in a factorial design with different levels of tallow (0, 50 or 100 kg tallow per t). The pigs were given quantities of food calculated to give isoenergy intakes on the assumption that air-dry cassava contained 14·2 MJ digestible energy (DE) per kg. The feeding scale increased with time to give a maximum daily allowance of DE of 31·8 MJ per pig. Relative to each MJ of DE the calculated levels of lysine and of methionine plus cystine in the diets were 0·64 g and 0·39 g respectively.In both experiments, increasing levels of cassava resulted in significant reductions in growth rate but had no effect on the conversion of food to live weight or on carcass weight. In both experiments, the diets with the highest inclusions of cassava produced pigs with the thickest backfat. The effect was not significant in the second experiment but in the first experiment the differences were significant between diets with the highest and intermediate levels of cassava. There was a significant interaction between cassava and tallow on growth rate with the depression due to high levels of cassava being reduced when 100 kg tallow per t was included in the diet.The results of these growth experiments suggested that cassava of the type used here was of similar value to barley on an energy basis when used in diets based on barley and soya bean meals.