The effect of diet in late pregnancy on colostrum production and immunoglobulin absorption in sheep

1997 ◽  
Vol 64 (1) ◽  
pp. 87-96 ◽  
Author(s):  
J. V. O'Doherty ◽  
T. F. Crosby
Keyword(s):  
Birth Weight ◽  
Crude Protein ◽  
Total Yield ◽  
Late Pregnancy ◽  
Protein Supplementation ◽  
Soya Bean ◽  
Metabolizable Energy ◽  
Factors Affecting ◽  
Bean Meal ◽  
Soya Bean Meal

AbstractOne hundred and twenty-six twin-bearing ewes were given either formic acid (FA) treated grass silage or grass/ molassed sugar-beet pulp (MSBP) silage in order to investigate factors affecting colostrum yield and quality and the efficiency of immunoglobulin (IgG) absorption. The experiment commenced on day 91 of pregnancy and the diets consisted ofFA-treated silage (Tl), FA-treated silage + soya-bean meal (SB) (72), MSBP silage (T3), MSBP silage + SB (T4), FA-treated silage + MSBP (T5), FA-treated silage + MSBP + SB (T6) or FA-treated silage + 150 g/kg of a crude protein concentrate (T7). Soya-bean meal was offered only in the last 3 weeks of pregnancy aiming for a total crude protein intake of220 g per ewe per day. Blood samples were taken from lambs in order to measure serum Ig concentrations. Ewes were milked at 1 h,10h and 18 h post lambing. Daily metabolizable energy intakes of 6·8, 11·4, 9·6, 12·8, 10·5, 13·7 and 14·7 (s.e. 0·58) M] per ewe were recorded for Tl to T7 respectively over the last 3 weeks of pregnancy. Respective crude protein intakes of 72, 213, 110, 225, 109, 215 and 175 (s.e. 5·64) g per ewe per day were recorded for Tl to T7 over the last 3 weeks of pregnancy. The addition of protein increased colostrum yield at 1 h (P < 0·01), 10 h (P < 0·01) and 18 h (P < 0·01) post lambing and total yield of colostrum to 18 h (P < 0·001). There was no significant response (P > 0·05) in colostrum production during the first 18 h following protein supplementation when the basic diet was FA-treated silage. There was no difference (P > 0·05) in colostrum production during the first 18 h between ewes offered MSBP treated silage or MSBP supplemented silage. Ewes offered FA-treated silage produced less colostrum during the first 18 h compared with ewes offered either MSBP treated or supplemented silage (P < 0·05). The production of colostral IgG during the first 18 h after parturition was related to the amount of colostrum produced; the greater the colostrum production the greater the Ig production. There was a significant quadratic relationship between the total amount of IgG ingested per kg lamb birth weight during the first 18 h and lamb serum IgG at 24 h (R2 = 0·4005; P < 0·0001). Lamb serum Ig level increased linearly with increasing colostrum IgG consumption up to 15 g/kg lamb birth weight. Proportionately about 0·17 of the IgG ingested was present in the lamb's circulation at 24 h. Ewe protein supplementation pre-lambing increased the lamb's efficiency to absorb colostral IgG (P < 0·05) during the first 24 h. In conclusion, the data show positive relationships between feeding regimes, colostrum production and IgG transfer.

The effect of level of protein supplementation on the performance and carcass composition of young bulls given grass silage ad libitum

1991 ◽  
Vol 52 (3) ◽  
pp. 465-475 ◽  
Author(s):  
R. W. J. Steen
Keyword(s):  
Live Weight ◽  
Protein Supplementation ◽  
Soya Bean ◽  
Carcass Composition ◽  
Metabolizable Energy ◽  
Total N ◽  
Grass Silage ◽  
Bean Meal ◽  
Ad Libitum ◽  
Soya Bean Meal

ABSTRACTTwo experiments have been carried out to examine the effects of the level of protein supplementation given with grass silage-based diets on the performance and carcass composition of bulls, and to compare diets based on silage and dried forage. The five treatments used consisted of grass silage offered ad libitum and supplemented with 2·5 kg dry matter (DM) of barley-based concentrates containing (1) zero (2) 200 (3) 400 and (4) 600 g soya-bean meal per kg and (5) artificially dried grass and hay supplemented with 3·2 kg concentrate DM. The silages used in both experiments were well preserved, containing on average 200 g DM per kg; 140 g crude protein (CP) per kg DM; 63 g ammonia-nitrogen per kg total N and 731 g digestible organic matter per kg DM. The bulls were of late-maturing breed type and were initially 12 months old and 412 and 405 kg live weight in experiments 1 and 2 respectively. For treatments 1, 2, 4 and 5 in experiment 1 respectively (treatment 3 was not used) total DM intakes were 8·3, 8·3, 81 and 110 (s.e. 0·21) kg/day; CP intakes 1063, 1271, 1664 and 1539g/day; metabolizable energy intakes (MEI) 98, 99, 96 and 87 MJ/day; carcass weights 317, 316, 317 and 316 (s.e. 3·2) kg; carcass saleable meat concentrations 714, 712, 718 and 716 (s.e. 5·8) g/kg and carcass fat trims 73, 81, 73 and 68 (s.e. 3·9) g/kg. In experiment 2 for treatments 1 to 5 respectively total DM intakes were 8·3, 8·5, 8·3, 8·4 and 11·2 (s.e. 0·26) kg/day; CP intakes were 1090, 1329, 1504, 1720 and 1561 g/day; MEI 102, 106, 103, 103 and 94 MJ/day; carcass weights 318, 331, 330, 327 and 321 (s.e. 3·3) kg; carcass saleable meat concentrations 726, 721, 725, 721 and 732 (s.e. 60) g/kg and fat trims 71, 77, 78, 80 and 64 (s.e. 4·5) g/kg. It is concluded that protein supplementation of a silage-based diet did not affect performance or carcass fatness in experiment 1 or carcass fatness in experiment 2, but including 200 or 400 g soya-bean meal per kg concentrate increased performance in experiment 2. Animals given silage produced fatter carcasses than those given dried forage in experiment 2 but not in experiment 1.

Soya bean meal, crystalline urea, and a urea, mineral and vitamin solution as nitrogen sources for lactating ewes given whole oats

1980 ◽  
Vol 31 (3) ◽  
pp. 299-305
Author(s):  
Jean M. Bass ◽  
G. Fishwick ◽  
J. J. Parkins
Keyword(s):  
Crude Protein ◽  
Liquid Product ◽  
Live Weight ◽  
Basal Diet ◽  
Soya Bean ◽  
Metabolizable Energy ◽  
Crystalline Urea ◽  
Digestible Crude Protein ◽  
Bean Meal ◽  
Soya Bean Meal

ABSTRACTFifty-one ewes with single lambs and 87 ewes suckling twin lambs (mean ewe live weight, 67 kg) were given a basal diet of 1·0kg hay and 1·0kg whole oats, providing approximately 16·7MJ metabolizable energy and lOOg digestible crude protein per day. Three supplements (A, B and C), providing an additional 45 g digestible crude protein, were compared. Supplement A consisted of 40 g of a fully-soluble liquid product (LS) containing urea, (equivalent to 1090g crude protein per kg), minerals and vitamins; B was 16g urea with solid minerals and vitamins; and C was 125g soya bean meal given in substitution for the same amount of whole oats plus solid minerals and vitamins. The growth rate to 6 weeks for single lambs (11 kg) was unaffected by treatment. For twin lambs the growth rates were 7·5kg (LS), 7·1kg (crystalline urea), 7·8kg (soya) and 6·4k g (unsupplemented) (s.e. of mean = 0·31 kg). Ewes with twin lambs given crystalline urea or LS lost more live weight (approximately 1·04kg) than those given soya (6·6kg) over the first 6 weeks of lactation. The maintenance of normal concentrations of calcium and phosphorus in the blood of ewes suggested that the low total intakes of approximately 4·1 g calcium and 4·7 g phosphorus by the ewes were not inadequate.

The effect of source and level of dietary protein on the performance of in-lamb ewes

1967 ◽  
Vol 9 (4) ◽  
pp. 521-530 ◽  
Author(s):  
T. J. Forbes ◽  
J. J. Robinson
Keyword(s):  
Birth Weight ◽  
Dietary Protein ◽  
Crude Protein ◽  
Dry Matter ◽  
Nitrogen Retention ◽  
Specific Effect ◽  
Soya Bean ◽  
Dry Matter Digestibility ◽  
Bean Meal ◽  
Soya Bean Meal

The aim of the investigation was to evaluate the specific effect, if any, of grass protein on the birth weight of lambs born to ewes wintered indoors. Grass meal was used as a substitute for fresh grass, and soya bean meal—representing a more conventional source of protein for winter diets—was compared with it. Both sources of protein were included at two levels, providing a high (90 g or 0·2 lb/day) and a low (45 g or 0·1 lb/day) intake of digestible crude protein.The digestibility of dry matter was significantly higher for the diets containing soya bean meal (67·7%) than for those containing grass meal (58·2%). Dry-matter digestibility was not affected by level of protein intake. The digestibility of crude protein was significantly affected by protein source and level of intake.Lamb birth weights were not significantly affected by source or level of dietary protein. There was a tendency for birth weights to be higher on the diet containing grass meal at low protein intakes. Ewe weight gains during the last eight weeks of gestation were significantly affected by level of dietary protein, and net body weight change was significantly affected by both source and level of protein. Gestation treatments had no effect on the performance of ewes or lambs during the first three weeks of lactation.The retention of nitrogen during the 18th–20th weeks of gestation was affected by both source and level of dietary protein. Mean nitrogen retention was higher with diets containing soya bean meal (5·8 g per day) than with diets containing grass meal (3·6 g per day). There was no correlation between nitrogen retention and lamb birth weight.

Blood metabolite concentrations in late pregnant ewes as indicators of nutritional status

1998 ◽  
Vol 66 (3) ◽  
pp. 675-683 ◽  
Author(s):  
J. V. O'Doherty ◽  
T. F. Crosby
Keyword(s):  
Crude Protein ◽  
Late Pregnancy ◽  
Metabolizable Energy ◽  
Normal Range ◽  
Plasma Albumin ◽  
Healthy Sheep ◽  
Beet Pulp ◽  
Bean Meal ◽  
Soya Bean Meal ◽  
Dietary Treatments

AbstractIn a feeding experiment β-hydroxybutyrate (BHB), glucose, albumin, total protein, globulin and urea concentrations in the plasma of twin-bearing ewes were analysed. Mature Suffolk cross ewes were given either formic acid (FA)-treated grass silage or grasslmolassed sugar-beet pulp (MSBP) silage in late pregnancy. The experiment commenced on day 91 of pregnancy and the dietary treatments were FA-treated silage (Tl), FA-treated silage + soya-bean meal (SBM) (T2), MSBP silage (T3), MSBP silage + SBM (T4), FA-treated silage + MSBP (T5), FA-treated silage + MSBP + SBM (T6) or FA-treated silage + 150 g crude protein (CP) per kg concentrate (T7). SBM was given only in the last 22 days of pregnancy aiming for a total CP intake of 220 g per ewe per day. Blood samples were collected by jugular venipuncture from each ewe 3 h following consumption of the morning dietary allowance on days 121, 128, 135 and 142 of pregnancy. Daily metabolizable energy (ME) intakes of 6·8, 11·4, 9·6, 12·8, 10·5, 13·7 and 14·7 (s.e. 0·58) MJ per ewe were recorded for Tl to T7 respectively over the last 3 weeks of pregnancy. Respective CP intakes of 72, 213, 110, 225, 109, 215 and 175 (s.e. 5·64) g per ewe were recorded for Tl to T7 respectively over the last 3 weeks of pregnancy. BHB concentrations (mmol/l) on day 121 of pregnancy of 1·18, 1·25, 0·52, 0·52, 0·56, 0·39 and 0·45 (s.e. 0·17), on day 128 of pregnancy of 1·17, 0·94, 0·52, 0·51, 0·72, 0·62 and 0·39 (s.e. 0·20), on day 135 of pregnancy of 1·53, 0·68, 0·68, 0·66, 0·71, 0·62 and 0·46 (s.e. 0·20) and on day 142 of pregnancy of 1·43, 0·60, 0·62, 0·56, 0·62, 0·56 and 0·63 (s.e. 0·20) were recorded for Tl to T7 respectively. There was a quadratic relationship between plasma BHB concentration and ME intake on days 121 (R2 = 0·538, P < 0·001), 128 (R2 = 0·324, P < 0·001), 135 (R2 = 0·429, P < 0·001)) and 142 (R2 = 0·344, P < 0·002) of pregnancy. There was a positive relationship between plasma glucose concentration and ME intake on day 222 (R2 = 0·208, P < 0·002), 228 (R2 = 0·203, P < 0·05), and 135 (R2 = 0·160, P < 0·02) of pregnancy. Albumin concentrations (gll) on day 128 of pregnancy of 21·8, 21·7, 23·6, 22·9, 22·5, 22·9 and 24·3 (s.e. 0-75), on day 135 of 20·9, 23·6, 24·2, 24·1, 22·4, 24·1 and 23·8 (s.e. 0·75), and on day 142 of 16·9, 22·6, 20·7, 22·2, 20·4, 22·7 and 21·1 (s.e. 1·05) were recorded for Tl to T7 respectively. Plasma albumin concentrations were significantly affected by SBM supplementation (P < 0·05). Despite the lower than generally recommended energy concentrations in T2 to T7, the concentrations of plasma BHB were within the normal range for healthy sheep.

Protein supplementation of silage-based diets for calves

1985 ◽  
Vol 41 (3) ◽  
pp. 293-300 ◽  
Author(s):  
R. W. J. Steen
Keyword(s):  
Fish Meal ◽  
Live Weight ◽  
Protein Supplementation ◽  
Soya Bean ◽  
Vitamin Supplement ◽  
Total N ◽  
Concentrate Supplementation ◽  
Grass Silage ◽  
Bean Meal ◽  
Soya Bean Meal

AbstractTwo experiments were carried out to examine the effects on the intake and performance of calves of supplementing a diet, based on high-digestibility, well-preserved grass silage, with fish meal. The effects of fish-meal supplementation were examined at each of two amounts of concentrate intake (1·05 and 2·2 kg/day) in a 2 × 2 factorial design. Fish meal was offered at a rate of 75 g/kg silage dry-matter (DM) intake. Experiments 1 and 2 involved 36 and 40 castrated male calves, respectively, which were initially 7 weeks old and had a live weight of 70 kg. The treatments were imposed for 20 weeks. The silages used in the two experiments had mean concentrations of 22-8 g nitrogen (N) per kg DM; 524 g protein N per kg total N; 59 g ammonia N per kg total N; 0·4 g butyric acid per kg DM; and 712 g digestible organic matter per kg DM. The concentrate consisted of (g/kg) 800 ground barley, 125 soya bean meal, 50 molasses and 25 mineral and vitamin supplement, respectively, and contained 29 g N per kg DM. Silage DM intakes and live-weight gains for the low and high amounts of concentrate supplementation were 1·93 and 1·46 (s.e. 0·055) kg/day and 0·84 and 1·01 (s.e. 0·013) kg/day respectively. The supplement of fish meal did not affect silage DM intake or animal performance for either concentrate intake. Proportionately, only 0·21 of the difference in live weight at the end of the treatment periods between the two amounts of concentrate intake remained at slaughter at 18 months of age. It is concluded that the optimum growth rate for autumn-born calves during their first winter can be sustained by a diet of high-digestibility grass silage supplemented with a maximum of 1·0 kg cereal-soya bean meal concentrate and that no response in performance was obtained to supplementation of this diet with fish meal.

The effect of formaldehyde treatment of soya-bean meal and rapeseed meal on the amino acid profiles and acid-pepsin solubility of rumen undegraded protein

1983 ◽  
Vol 101 (3) ◽  
pp. 603-612 ◽  
Author(s):  
T. Varvikko ◽  
J. E. Lindberg ◽  
J. Setälä ◽  
Liisa Syrjälä-Qvist
Keyword(s):  
Crude Protein ◽  
Decisive Role ◽  
Rapeseed Meal ◽  
Soya Bean ◽  
Soluble Nitrogen ◽  
Nitrogenous Compounds ◽  
Formaldehyde Treatment ◽  
Methionine Concentration ◽  
Bean Meal ◽  
Soya Bean Meal

SUMMARYSoya-bean meal and rapeseed meal treated with 0, 0·4 or 0·8 g formaldehyde/100 g crude protein (N × 6·25) was incubated in the rumen in nylon bags with 10 and 40 μm aperture.Disappearance of dry matter and nitrogenous compounds was reduced with increasing formaldehyde treatment.The proportion of acid-pepsin soluble nitrogen in the undegraded residues of untreated and treated soya-bean meal was similar to the original samples. For rapeseed meal the proportion of acid-pepsin soluble nitrogen in the undegraded residues decreased with increasing rumen incubation time. This reduction decreased with increasing formaldehyde treatment.Concentration of amino acids in the undegraded residues did not generally deviate from those in the original samples. However, a distinguishable decrease in the methionine concentration was observed in all the rapeseed meal samples and in glutamic acid concentration in rapeseed meal treated with 0 and 0·4 g formaldehyde/100g- crude protein.Most of the changes due to rumen incubation were smaller using the 10 μm bags than using the 40 μm bags. However, the bag pore size did not play a decisive role in the conclusions of the results given.

Response of fast growing lambs to compound protein level

1991 ◽  
Vol 1991 ◽  
pp. 85-85
Author(s):  
J S Blake ◽  
T D A Brigstocke ◽  
P J Kenyon
Keyword(s):  
Financial Support ◽  
Crude Protein ◽  
Soya Bean ◽  
Barley Straw ◽  
Protein Levels ◽  
Development Unit ◽  
Bean Meal ◽  
Market Needs ◽  
Soya Bean Meal ◽  
Lamb Growth

Reduction of the financial support by the EC to sheep farmers has highlighted the need for lamb fattening diets which can adjust the rate of lamb growth, depending on market needs. A trial was run at BOCM SILCOCK Development Unit, Barhill using 144 Texel and Suffolk x Mule lambs, with a mean start weight of 18.6 ± 0.50 kg (mean ± SE). Lambs were divided into 24 pens and allocated one of four compound diets (Diets A, B, C or D). The diets were designed to be isoenergetic with an estimated energy of 11.4 MJ ME/kg DM and contained 138, 172, 206 and 250 g crude protein/kg DM. Protein levels were increased by increasing soya bean meal inclusion from 0 to 25% and reducing barley and wheat levels.Formulations and actual analysis are shown in Table 1. Lambs were bedded on barley straw refreshed daily, with compound diets and water available ad-lib.

scholarly journals Phosphorus studies in pigs

1993 ◽  
Vol 70 (1) ◽  
pp. 289-311 ◽  
Author(s):  
P. P. Ketaren ◽  
E. S. Batterham ◽  
E. Belinda Dettmann ◽  
D. J. Farrell
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
Live Weight ◽  
Bending Moment ◽  
Soya Bean ◽  
P Availability ◽  
Apparent Digestibility ◽  
Slope Ratio ◽  
Bean Meal ◽  
Soya Bean Meal

Two experiments were conducted (1) to determine the effects of phytase (EC 3.1.3.26) on the digestibility and availability of P in soya-bean meal for growing pigs and (2) to compare growth v. digestibility variables for assessing the availability of P. In the first experiment the effect of phytase on P availability was assessed in a growth assay using a slope–ratio design of treatments. Two different levels of either monosodium phosphate (MSP) or soya-bean meal were added to a basal sugar–soya-bean-meal diet (2·5 g P/kg) to give two levels of P (g/kg): 3·25 and 4·0 for each source. An additional five diets were supplemented with phytase. The ten diets were offered ad lib. for 35 d to female pigs initially weighing 20 kg live weight. In addition, the relative effectiveness of different variables for assessing P availability were compared: bone bending moment, ash in various bones, and ash and P in the empty body. The addition of phytase increased growth rate (g/d) (741 v. 835; P < 0·05), lowered the food conversion ratio (2·37 v. 2·16; P < 0·01), and increased protein deposition (g/d) (108 v. 123; P < 0·05), protein retention (kg/kg) (0·33 v. 0·36; P < 0·05), energy retention (MJ gross energy/MJ digestible energy) (0·36 v. 0·38; P < 0·05) and the availability of P in soya-bean meal from 0·11 to 0·69 when bone bending moment was the criterion of availability. All other criteria for assessing availability were unsuitable. In the second experiment the availability of (P) in soya-bean meal was assessed in a digestibility experiment with grower pigs using diets 1–5 as for Expt 1 arranged in a slope–ratio design of treatments. In addition, the effects of phytase supplementation on the apparent digestibility of P, dry matter, crude protein (N × 6·25) and energy were determined. The diets were offered at three times maintenance energy requirements to male pigs initially weighing approximately 30 kg live weight and total collection of faeces was conducted over a 10 d period. The availability of P in the soya-bean meal was 0·66 using digestible P intake as the criterion of response. The apparent digestibility of P in soya-bean meal was 0·42. Phytase supplementation increased the apparent digestibility of soya-bean meal P to 0·69 (P < 0·01) but had no effect on the faecal digestibility of dry matter or crude protein. Overall these experiments indicate that (1) estimates of P digestibility and availability were unlikely to be interchangeable and (2) phytase was effective in releasing much of the bound P in soya-bean meal.

DETERMINANTS OF THE SELECTION OF RAW MATERIALS USED IN ANIMAL FEED PRODUCTION

2020 ◽  
Vol XXII (2) ◽  
pp. 191-199
Author(s):  
Magdalena Śmiglak-Krajewska
Keyword(s):  
Animal Feed ◽  
Raw Materials ◽  
Soya Bean ◽  
Raw Material ◽  
Factors Affecting ◽  
Feed Production ◽  
Bean Meal ◽  
Materials Used ◽  
Soya Bean Meal ◽  
Selection Of

The main purpose of this paper was to identify the factors affecting the selection of raw materials used by feed operators in feed production. An attempt was also made to indicate the barriers to increasing the use of native protein plants by feed operators in feed production. Today, many EU countries (including Poland) primarily rely on vegetable protein derived from genetically modified soya bean meal (mainly imported from South America and the U.S.) in addressing their needs for protein raw material used in animal feed. For many years now, Poland has taken steps to increase the production and use of native protein raw material to partially replace soya bean meal imports. The use of mixes of diverse domestic protein sources derived from grain legumes (peas, field beans, lupine) can provide an advantageous alternative to compound feeding stuff based on imported post-extraction soya bean meal. To meet the objective defined above, this paper relied on the results of a 2018 survey conducted with a sample of 29 feed operators located across the country. More than half (55%) of the enterprises surveyed did not use legumes in feed production; the use of legumes was above 10% in only 3% of respondents. When asked about the key factors affecting the selection of raw materials used in production processes, the respondents declared to be interested in buying large batches of homogeneous raw materials that meet specific quality parameters (33% replied “rather yes” and 67% replied “definitely yes”). The protein content of plant seeds used in feed production was identified as another aspect of extreme importance (55% replied “rather yes” and 24% replied “definitely yes”).

Estimation of endogenous amino acid losses in growing chickens given soya-bean meal supplemented or not with DL-methionine

2002 ◽  
Vol 75 (3) ◽  
pp. 415-426 ◽  
Author(s):  
I. Fernández-Fígares ◽  
R. Nieto ◽  
the late C. Prieto ◽  
J. F. Aguilera
Keyword(s):  
Body Weight ◽  
Regression Analysis ◽  
Amino Acid ◽  
Live Weight ◽  
Soya Bean ◽  
Metabolizable Energy ◽  
Bean Meal ◽  
Soya Bean Meal ◽  
Protein Free Diet ◽  
Lower Ileum

AbstractAn experiment was carried out in growing chickens to study the effect of supplementation of a semi-synthetic diet containing soya-bean meal as the sole protein source with DL-methionine, to improve its biological value, on the excretion of endogenous protein and amino acids measured in lower ileum and total tract using traditional methods. Thirty-two White Rock male broilers (10 days old) were randomly divided into eight groups each of four birds, of similar body weight (mean live weight: 142·8 (s.e. 0·68) g), and individually housed in metabolism cages. Following a paired-feeding design based on metabolic body weight (kgM0·75), each group of birds was given, for an experimental period of 20 days, each of four levels of protein (60, 120, 180 or 240 g/kg; 5 days each) in two groups of isoenergetic (14·5 kJ metabolizable energy per g dry matter) and semi-synthetic diets based on soya-bean meal, either not supplemented or supplemented with 2 g/kg DL-methionine (diets S and SM, respectively). After 3 days of each treatment excreta were collected for 48 h, frozen and stored at –20ºC. At the end of the fourth treatment three chickens of each group were killed and their lower ileal contents collected. The remaining chick of each treatment was fasted for 24 h and given a protein-free diet for 8 days and excreta were collected for the last 4 days. Then (day 39 of age), chickens were killed and lower ileum contents removed and stored at –20ºC. Samples of excreta and lower ileum contents were subjected to nitrogen (N) analysis by Kjeldahl procedure and amino acid (AA) analysis by high-performance liquid chromatography. Supplementation with DL-methionine of the soya-bean meal-based diets halved total tract endogenous AA losses. Regression analysis produced a higher estimation of ileal and faecal endogenous AA excretion than feeding a protein-free diet. Endogenous AA excretion determined in the lower ileum was higher than in excreta no matter which estimation procedure was utilized. In conclusion, supplementation of dietary protein with the first limiting AA to improve its protein quality, causes an important drop in endogenous AA losses, that may have an important effect on the N economy and energy requirements in poultry. The use of regression analysis on excreta data where graded amounts of protein are given to growing chickens, seems a suitable method for determining endogenous AA losses provided that good quality proteins are used.

Sign in / Sign up

Export Citation Format

Share Document