Mechanisms of Growth Promoters in Single-Stomach Animals

O’Connor, John J.

doi:10.1016/b978-0-408-10638-2.50015-x

Cited by 14 publications

(3 citation statements)

References 139 publications

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“…However, in the work of Rowan & Lawrence (1986c) the ileal apparent digestibilities of amino acids were increased in diets containing some varieties of RSM, but not in diets containing TRSM. O'Connor (1980) suggested that there were considerable differences in the gut microflora of individual pigs and that these could account, at least in part, for the equivocal growth responses to antimicrobial substances, including Cu, found both within and between experiments as noted by Braude (1965) and Cooke et al (1979). Relative to this, another possible explanation for the protein supplement (SBM and TRSM) x Cu concentration interaction found in this work could be that the higher concentrations of Cu affected the gut microflorae in such a way as to reduce the production of growth depressant factors from the hydrolysis of the glucosinolates found in RSMs (Rowan, 1983).…”

Section: Discussionmentioning

confidence: 96%

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

Rowan

Lawrence

1986

J. Agric. Sci.

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In 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 < 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 54mg/kg air-dry diet significantly improved growth rate (P < 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.

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Section: Discussionmentioning

confidence: 96%

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

Rowan

Lawrence

1986

J. Agric. Sci.

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“…However, other intestinal microorganisms not only compete with the host for the same nutrients but may alter the nutrients entering the intestine and, hence, interfere with the nutrient supply to the host animal (Wallace, 1970;Coates, 1980;O'Connor, 1980;Visek, 1978). It is well recognized that the intestinal microorganisms synthesize nutrients such as amino acids and vitamins that are essential for the host.…”

Section: Non-ionophore Antibioticsmentioning

confidence: 99%

The Rumen Microbial Ecosystem

Hobson¹,

Stewart²

1997

348

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“…The mechanisms by which copper acts as a growth promoter remain controversial. The more favoured suggestions include suppression of the gut microfiora and improved absorption of nutrients (Braude, 1965;O'Connor, 1980) and Castell & Bowland (1968) found increased faecal apparent digestibilities of nitrogen and increased nitrogen retentions in pigs given diets containing copper sulphate (approximately 250mg copper/kg air-dry diet). Dierick et al (1986) found in vitro that copper sulphate decreased the rate of amino acid degradation by the porcine small intestinal microfiora.…”

Section: Amino Acid Studiesmentioning

confidence: 99%

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

Rowan

Lawrence

1986

J. Agric. Sci.

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A 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 (P 2 ) were similar. There were no significant differences between protein levels in the killing-out proportions, the proportions of fat in carcasses and backfat thicknesses (P 2 ) 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. riTrnnnnnnmrnw results would be obtained with near minimal concentrations of that element. The results from other studies (Rowan & Law-The literature reviewed by the Agricultural rence, 1986a, b) indicated that when differences in Research Council (1981) suggested that differing digestible energy, crude protein and total lysine dietary crude-protein concentrations and protein contents were accounted for, low glucosinolate sources (amino acid composition) influence carcass rapeseed meals gave similar responses to soya-bean composition. In an extensive review of the germane meal (SBM) when used as major protein sources in literature Rowan (1983) noted that there was no diets based on barley. At the same time the results evidence of how rapeseed meals (RSM) affected the suggested that a low glucosinolate rapeseed meal, deposition of carcass tissues as indicated by comcv. Tower (TRSM), was goitrogenic, having induced plete carcass dissection. Ov...

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Mechanisms of Growth Promoters in Single-Stomach Animals

Cited by 14 publications

References 139 publications

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

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

The Rumen Microbial Ecosystem

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

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