The effects of low levels of dietary phosphorus upon the dry matter intake and metabolism of lambs

1990 ◽  
Vol 41 (1) ◽  
pp. 175 ◽  
Author(s):  
JH Ternouth ◽  
CC Sevilla

The effects of feeding roughage-based diets deficient in phosphorus (P) were investigated in two 20- week experiments in young sheep. In Experiment 1, six-month-old lambs were offered diets containing low concentrations of either calcium (LCa HP) or phosphorus (HCa LP) or both minerals (LCa LP) ad libitum for 20 weeks. In Experiment 2,4-month-old lambs were offered the HCa HP, HCa LP and LCa LP diets ad libitum with a further group pair-fed the HCa HP diet at the same dry matter rate as the lambs offered the LCa LP diet. The semi-synthetic diet, based on barley straw, contained adequate quantities of energy and nitrogen. The major effect of the deficiencies was to reduce the dry matter intakes of the lambs. The lambs offered the LCa HP, HCa LP and LCa LP diets had 15,41 and 40% lower dry matter intakes than the HCa HP lambs in Experiment 1, whilst lambs offered the HCa LP and LCa LP diets consumed 34 and 3 1% less in Experiment 2. The dry matter intakes of the lambs were closely related to their plasma inorganic P concentrations in both experiments. In both experiments, the lambs offered the low P diets had lower dry matter digestibility coefficients than those offered the high P diets. This was considered to be due to changes in caeco-colic rather than rumeno-reticular digestion. There was no difference in liveweight gain of lambs pair-fed on the LCa LP and HCa HP diets. The diets, particularly the low P diets, caused significant changes in plasma Ca and P concentrations and demineralization of the bones as measured by rib biopsy and neutron activation analysis. Lambs offered the low P diets had lower faecal endogenous P losses, but the coefficients of absorption of P were similar. Lambs offered the low P diets had smaller slowly exchangeable-pool sizes and lower rates of recycling and irreversible losses of P.

Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 232
Author(s):  
Antonio Gallo ◽  
Francesca Ghilardelli ◽  
Alberto Stanislao Atzori ◽  
Severino Zara ◽  
Barbara Novak ◽  
...  

Sixty-four corn silages were characterized for chemicals, bacterial community, and concentrations of several fungal metabolites. Silages were grouped in five clusters, based on detected mycotoxins, and they were characterized for being contaminated by (1) low levels of Aspergillus- and Penicillium-mycotoxins; (2) low levels of fumonisins and other Fusarium-mycotoxins; (3) high levels of Aspergillus-mycotoxins; (4) high levels of non-regulated Fusarium-mycotoxins; (5) high levels of fumonisins and their metabolites. Altersetin was detected in clusters 1, 3, and 5. Rugulusovin or brevianamide F were detected in several samples, with the highest concentration in cluster 3. Emodin was detected in more than 50.0% of samples of clusters 1, 3 and 5, respectively. Kojic acid occurred mainly in clusters 1 and 2 at very low concentrations. Regarding Fusarium mycotoxins, high occurrences were observed for FB3, FB4, FA1, whereas the average concentrations of FB6 and FA2 were lower than 12.4 µg/kg dry matter. Emerging Fusarium-produced mycotoxins, such as siccanol, moniliformin, equisetin, epiequisetin and bikaverin were detected in the majority of analyzed corn silages. Pestalotin, oxaline, phenopirrozin and questiomycin A were detected at high incidences. Concluding, this work highlighted that corn silages could be contaminated by a high number of regulated and emerging mycotoxins.


1973 ◽  
Vol 53 (2) ◽  
pp. 257-263 ◽  
Author(s):  
G. PELLETIER ◽  
E. DONEFER

Three yearling Cheviot × Suffolk ewes and three Columbia wethers were confined in metabolic cages and fed ad libitum fresh and dried marrow-stem kale (Brassica oleracea var. acephala D.C.) harvested in mid- and late October. Chemical analyses of the forages indicated no marked effects on any of the plant constituents due to drying or advancing maturity. Digestibility measurements demonstrated that marrow-stem kale (MSK) was a highly digestible material with an average dry matter digestibility of 78%. The fresh forages had higher (P < 0.05) dry matter and gross energy digestibility values than the dried form. Dry matter digestibility coefficients were higher (P < 0.05) for late October as compared with the earlier harvest. A trend toward higher (P > 0.05) voluntary intake values due to drying maturity was observed with an average relative intake of 80%. The nutritive value index averaged 65, thus indicating a digestible energy intake similar to a high-quality (legume) forage.


1988 ◽  
Vol 47 (1) ◽  
pp. 105-110 ◽  
Author(s):  
P. K. Bhargava ◽  
E. R. Ørskov ◽  
T. K. Walli

AbstractExperiments were made to study the proportion, chemical composition, and rumen degradability of the morphological components of barley straw (Corgi variety) and to study the selection of these components by sheep. The proportions in the harvested straw dry matter (DM) as leaf blade, leaf sheath, stem and chaff were 128, 314, 500 and 58 g/kg DM, respectively. The different components of straw on analysis proved to have very different concentrations of nitrogen and neutral-detergent cellulase digestibility. The leaf blades had the highest and the stems the lowest values. The degradabilities of DM in the components and in the whole straw were determined by measuring DM loss from samples incubated in nylon bags for various periods in the rumen of sheep. Responses were measured using the mathematical model p = a+b (1–e−ct) where p is DM loss, (a+b) potential degradability, c the rate constant of DM loss and t is the time of incubation. DM losses decreased in the order leaf blades > leaf sheath > whole plant > chaff > stems. Leaf blades also had the highest potential degradability and rate of degradation.In another trial, five sheep were offered unchopped barley straw ad libitum. There were five treatment periods in which sheep were allowed to leave uneaten proportionately 0·2, 0·3, 0·4, 0·5 and 0·7 of the straw on offer for assessing the animal's selection of the morphological components of that straw. The amount of leaf blade in the material consumed increased in largely a linear (P < 0·01) fashion with the amount of excess allowance. The proportion of stem eaten varied conversely. The selection of leaf sheath was less apparent. Little stem was consumed until the proportion of leaf blade in the food available decreased below proportionately 0·4. The practical significance of the study is discussed.


1978 ◽  
Vol 91 (2) ◽  
pp. 483-486 ◽  
Author(s):  
E. R. Ørskov ◽  
D. A. Grubb

SUMMARYMilled barley straw, either untreated or treated with 70 g of NaOH/kg straw was supplemented with four levels of urea, namely 0, 6, 12 or 18 g/kg and fed ad libitum to young sheep. For the untreated straw, dry-matter intakes were (g/day) 423, 451, 441 and 463, while the digestibility of organic matter was 458, 467, 490 and 483 g/kg, respectively. For the treated straw, the intakes of dry matter were 355, 402, 531 and 567 g/day and the digestibility of organic matter was 423, 480, 589 and 628 g/kg respectively.The different responses to urea supplementation of treated and untreated straw are discussed in relation to a new system of estimating protein requirements for ruminants put forward by the Agricultural Research Council.


1999 ◽  
Vol 68 (1) ◽  
pp. 211-215 ◽  
Author(s):  
J. E. Velasquez ◽  
E. Owen ◽  
F. L. Mould

AbstractA 28-day experiment with 12 9-month-old cattle (275 kg initial weight, M1), used a 2 × 2 arrangement of treatments to compare the effect of doubling the ad-libitum quantity of long barley straw offered daily (25 or 50 g dry matter (DM) per kg M1) and sex/genotype (Limousin × Friesian steers or Friesian heifers) on intake and selection. All animals received a protein concentrate at 20 g DM per kg M10·75 per day. Prior to the experiment the cattle had grazed for 6 months and were given no pre-experimental change-over period. On day 1 animals were weighed (M1), allocated to treatment and penned individually. Animals were weighed on day 28 (M2). Doubling the amount offered did not affect straw intake (g DM per kg M3 per day; M3 = mean of M1 and M2) during days 22 to 28 (steers: 17·9, 17·2; heifers 14·3, 13·3; s.e. 0·50) but increased the proportion (g DM per kg DM offered) refused (steers: 258, 635; heifers: 412, 721; s.e. 22). During days 22 to 28, at each level of offer (25, 50), refused straw contained (g DM per kg DM) less leaf-plus-sheath than offered straw (25 g steers: 251, 430, s.e. 16·7; 50 g steers: 393, 450, s.e. 19·7; 25 g heifers: 304, 420, s.e. 7·2; 50 g heifers: 405, 446, s.e. 9·6). The sex/genotype effect on intake was attributed to differences in growth potential. Straw intakes increased significantly over the first 14 days, but there were no differences between days 15 to 21 and days 22 to 28. It is concluded that an excess-feeding strategy, involving a doubling of the ad libitum amount of barley straw offered did not result in growing cattle consuming more straw, in contrast to published results with sheep and goats. However, the cattle did show a limited ability to selectively consume leaf-plus-sheath in preference to stem but the improvement in diet digestible organic content (estimated in vitro) was presumably insufficient to stimulate intake.


Author(s):  
Md. Shahiduzzaman ◽  
E. Owen

Calcium hydroxide (Ca(OH)2) is widely available in Third World countries because of extensive limestone deposits. Previous studies (reviewed by Owen et al 1984) have shown Ca(OH)2-treated straw to be prone to mouldiness and low intakes. Urea was added to Ca(OH)2 in the present study to inhibit mould and supply nitrogen. Two experiments are reported which investigated the amounts of Ca(OH)2 and urea required for improving intake and digestibility of barley straw in sheep.Forty Suffolk x Mule store lambs (20 castrates, 20 ewe lambs) aged 8 months were used to measure intake and digestibility of 5 straws (Table 1) in a randomized block experiment, with blocking according to weight and sex. Animals were fed restricted concentrates (Table 1) and ad libitum straw (allowing refusals of 25% of intake) over a period of 35 days, with collection of faeces over the last 8 days. For treatment, straw was chopped, mixed with chemical solutions (Table 1) in a concrete mixer, and “ensiled” for 60 days (September & October) at 500 g dry matter (DM) per kg, in plastic bags contained in 45-gallon oil drums. Straw was aerated for 3 days before feeding. Untreated straw was simply chopped before feeding.


1995 ◽  
Vol 46 (8) ◽  
pp. 1579 ◽  
Author(s):  
JF Perez ◽  
J Gasa ◽  
C Castrillo ◽  
JA Guada

Rates of passage of liquid and particulate markers (Co-EDTA, Cr mordanted fibres and Yb) were measured in ewes at late pregnancy, lactation and non-breeding status. Animals were given ammonia treated barley straw ad libitum supplemented daily with 250 and 550 (pregnancy), 550 and 850 (lactation) and 250, 550 and 850 (non-breeding) g of concentrate. The effect of the reproductive state was analysed only on ewes fed on 550 g of concentrate. Lactating ewes showed a higher voluntary straw intake (970 g/day) than pregnant or non-breeding ewes (720 and 790 g/day respectively), but there were not significant differences in the OM digestibility (OMD) among reproductive states. Increasing concentrate supplementation promoted significant decreases in the voluntary intake of straw, associated with an enhanced OMD ( P < 0.05). Fractional outflow rates (FOR/h) were higher in pregnant and non-breeding than in lactating ewes, although differences were only significant ( P < 0.01) for Chromium derived values. Ewes given 250 g of concentrate showed lower ( P < 0.05) FOR than those given 550 and 850 g/day. Results support the idea that in ruminants fed on low quality roughages, voluntary dry matter intake is mainly restricted by rumen capacity, although the energy status of the animals might influence the extent of this restriction.


2006 ◽  
Vol 46 (7) ◽  
pp. 783 ◽  
Author(s):  
B. S. Davidson ◽  
S. J. Chaplin ◽  
C. Laird

Sheep on spring pastures may scour excessively due to the low levels of neutral detergent fibre. Scouring leads to dag formation, which predisposes sheep to flystrike, particularly in the breech area, posing a considerable challenge to sheep producers. This trial was undertaken to test whether supplementing sheep on spring pasture with fibre would reduce diarrhoea and thereby reduce dag formation and flystrike. Four hundred first-lambing Merino ewes were randomly allocated to control (no fibre supplementation) and fibre treatment (ad libitum cereal hay or wheat straw supplementation) groups in a 2-paddock crossover trial, which was conducted from August through the spring flush to crutching in October. The bulk fecal egg counts of each group were no different at the start of the trial but the fibre group had a higher (P<0.05) fecal egg count than the control at crutching. Fecal egg count was not correlated with dag score. Fecal dry matter percentage was higher (P<0.05) in the fibre group but there was no difference in dag wet weight or dry matter percentage between the treatment groups. Dag scores of a sample of 100 sheep from each group were significantly (P<0.01) lower at crutching. There was no difference between the groups in the incidence of flystrike, however, there were significantly (P<0.001) more sheep with high dag scores (>3) in the control group than the fibre treatment group. These results indicate that the supplementation of spring pasture with low quality hay or straw can reduce dag formation by improving the consistency of feces and, thereby, reduce the number of sheep with dag scores greater than 3.


1976 ◽  
Vol 16 (82) ◽  
pp. 656 ◽  
Author(s):  
H Jeffery

Three experiments were conducted in which the amount of feed offered to caged sheep was varied. Fresh kikuyu grass (Pennisetum clandestinum) was fed in one experiment and hays in the other two. Within each experiment a significant correlation between dry matter digestibility and liveweight occurred; no differences were detected between the slopes found with the various diets (slope = 0.34 per cent increase in digestibility per kg liveweight). Up to 60 per cent more kikuyu grass was offered to sheep than they could consume. Over this range a significant positive correlation was found between the ratio of the unconsumed to consumed feed and digestibility. This result indicates that great care should be exercised if the results of sheep digestibility experiments are used to interpret field data.


1974 ◽  
Vol 19 (1) ◽  
pp. 77-86 ◽  
Author(s):  
J. F. D. Greenhalgh ◽  
G. W. Reid

SUMMARY1. Four groups of eight castrated male lambs, weighing initially about 37 kg, were fed ad libitum for 18 weeks on: C, chopped dried grass throughout; P, pelleted grass throughout; C/P (or P/C), the two forms alternated every 3 weeks; or C + P, both forms on offer.2. Daily dry-matter intake (g/kg W0·75) was 58·2 for treatment C and 814 for treatment P; thus the long-term difference in intake was 40%. However, in the alternated sheep, dry-matter intake was 53·6 g/kg W0·75 for chopped grass and 86·5 g for pelleted; this short-term difference (61%) was significantly greater than the long-term difference. Dry-matter intake for treatment C+P was 84·9 g/kg W0·75; after the first week, chopped grass comprised only 10% of this. Dry-matter digestibility coefficients (%) were: C, 740; P, 61·4 and C+P, 62·0.3. The sheep were killed in week 19 and the dimensions of digestive organs and their contents were adjusted to an animal of 50 kg empty body weight. The weight of the reticulo-rumen was greater for C (1·30 kg) than for P (0·94) or C+ P (1·05), C/P and P/C being inter-mediate (1·15). The water-filled volume of the rumen was proportional to weight, except that C/P (alternated sheep finishing on pelleted grass) had low volumes. Reticulo-rumen fill was greater for C (7·28 kg) than for P (3·97) or C+ P (4·53), P/C (5·90) and C/P (4·34) being intermediate. There were no other significant differences in organs or contents.4. Gains in empty-body weight (g/day) were: C, 112; P, 181; C/P and P/C, 126; C + P, 195.


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