Trichostrongylosis and wool growth. 3. The wool growth response of resistant grazing sheep to larval challenge

1975 ◽  
Vol 15 (73) ◽  
pp. 167 ◽  
Author(s):  
IA Barger ◽  
WH Southcott
Keyword(s):  
Growth Rates ◽  
Growth Response ◽  
Moderate Level ◽  
Sheep Grazing ◽  
Trichostrongylus Colubriformis ◽  
Growth Depression ◽  
Intestinal Nematode ◽  
Wool Growth ◽  
Grazing Sheep ◽  
Presence And Absence

Wool growth rates of grazing sheep that were resistant to infection with the intestinal nematode Trichostrongylus colubriformis were measured in the presence and absence of a larval challenge. In one experiment, resistant sheep exposed to a moderate level of larval challenge grew 11 per cent less wool than unchallenged resistant sheep grazing the same paddock. A second experiment confirmed the previous results but showed that the magnitude of this wool growth depression did not depend on the severity of the challenge

Trichostrongylosis and wool growth. 2. The wool growth response of infected sheep to parenteral and duodenal cystine and cysteine supplementation

1973 ◽  
Vol 13 (63) ◽  
pp. 351 ◽  
Author(s):  
IA Barger ◽  
WH Southcott ◽  
VJ Williams
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growth Response ◽  
Infected Sheep ◽  
Trichostrongylus Colubriformis ◽  
Intestinal Nematode ◽  
Wool Growth ◽  
Cysteine Hydrochloride ◽  
Significant Difference ◽  
Maintenance Ration

Two experiments are reported. In experiment 1, light infections with the intestinal nematode Trichostrongylus colubriformis reduced wool growth of sheep by 42 per cent compared with pair-fed controls. There was no significant difference in wool growth between those sheep given a cystine supplement as an intraperitoneal pellet and those given a daily intra-duodenal injection of cystine, although cystine was poorly absorbed from the peritoneal cavity. In experiment 2, fifteen sheep were fed a maintenance ration and their wool growth rates defined. When six of the sheep were given a daily intra-duodenal drip containing 2 g cysteine hydrochloride, and six sheep were given the same drip intravenously, their wool growth rate increased by a mean of 33 per cent compared with the wool growth of the three untreated sheep, irrespective of the route of administration of the cysteine. Three sheep in each group of six were then lightly infected with Trichostrongylus colubriformis and the wool production of all sheep was measured in the presence and absence of the daily cysteine supplement via the two routes. The infection depressed wool growth, but did not influence the wool growth response to either route of cysteine supplementation. It was concluded that the reduced wool growth induced by trichostrongylosis could not be attributed to malabsorption of cysteine. Evidence was obtained that sheep resistant to Trichostrongylus colubriformis produced less wool when subjected to a larval challenge.

The use of urea-molasses supplements for sheep grazing semi-arid tropical pastures

1974 ◽  
Vol 14 (66) ◽  
pp. 17 ◽  
Author(s):  
KW Entwistle ◽  
G Knights
Keyword(s):  
Growth Rates ◽  
Reproductive Factors ◽  
Experimental Period ◽  
Dry Season ◽  
Sheep Grazing ◽  
Tropical Pastures ◽  
Nitrogen Levels ◽  
Wool Growth ◽  
Urea Group ◽  
Semi Arid

The performance of unsupplemented Merino ewes grazing dry season semi-arid tropical pastures was compared with that of other sheep supplemented with either urea-molasses or molasses. Over the experimental period from September 1970 until late January 1971 mean daily intakes per head of urea and molasses respectively were: low urea group, 11.7 g and 35.1 g; high urea group, 15.2 g and 45.6 g; molasses, 38.9 g. Monthly estimates of the proportions of animals consuming the supplement over the period September to January varied from: urea-molasses-71 per cent to 97 per cent; molasses-75 per cent to 96 per cent. Unsupplemented sheep lost significantly more liveweight than did supplemented groups in the period September to February. However, during the period of greatest nutritional stress from December to February, sheep recewing molasses lost significantly more weight than did those supplemented with urea-molasses, and liveweight loss was greater in the low urea group than in the high urea group. Wool growth rates were significantly higher in groups receiving urea-molasses, with highest wool growth rates in animals on the high level of urea. Total fleece weights were unaffected by treatment as were the reproductive factors examined. Faecal nitrogen levels declined until the onset of pasture regrowth in February and were associated with low digestibility of the available forage. Compensatory liveweight gains following pasture regrowth outweighed any advantage of the dry season supplementation. It was concluded that urea-molasses supplements were of little direct benefit to sheep grazing these pastures.

Some effects of three glucocorticoid analogues on wool growth and their efficacy as defleecing agents in sheep

1975 ◽  
Vol 15 (73) ◽  
pp. 193 ◽  
Author(s):  
BA Panaretto ◽  
RE Chapman ◽  
AM Downes ◽  
PJ Reis ◽  
ALC Wallace
Keyword(s):  
Growth Response ◽  
Experimental Period ◽  
Parenteral Administration ◽  
Growth Depression ◽  
Obvious Effect ◽  
Body Regions ◽  
Wool Growth ◽  
Pre Treatment ◽  
Second Category ◽  
Head Neck

Some effects of the parenteral administration of three glucocorticoid analogues, namely Opticortenol (dexamethasone-21 -trimethylacetate), Decadron phosphate (dexamethasone-21 -phosphate) and the heterocyclic corticosteroid, Cortivazol, were observed on wool growth in sheep. None of the glucocorticoids was satisfactory for defleecing sheep, principally because of variation between sheep and between body regions in the wool growth response. Four main types of response to dosing with glucocorticoids were observed : Firstly, with some animals there was no obvious effect on wool growth. In a second category there was a well-defined 'break' in some wool fibres but the fleece as a whole was retained by other unbroken fibres. Thirdly, complete or partial shedding of the fleece was seen, unshed portions usually being present on the head, neck and shoulder regions and consisting mainly of broken wool fibres but also a proportion of whole fibres. Finally, prolonged wool growth depression without shedding of the fleece during the experimental period was also seen. Results indicated that to obtain shedding of the fleece in 15-20 days after dosage, wool growth needs to be reduced below 20 per cent of its pre-treatment values and regrowth must be rapid.

Effect of high intakes of sodium chloride on the utilization of a protein concentrate by sheep. I. Wool growth

1975 ◽  
Vol 26 (4) ◽  
pp. 709 ◽  
Author(s):  
JA Hemsley
Keyword(s):  
Drinking Water ◽  
Sodium Chloride ◽  
Growth Rates ◽  
Crude Protein ◽  
Growth Response ◽  
High Protein Diet ◽  
Protein Concentrate ◽  
Linseed Meal ◽  
Wool Growth ◽  
Ruminal Degradation

Both the water intakes and wool growth rates of sheep fed on a high protein diet (37% crude protein), consisting mainly of linseed meal, were significantly increased when salt (c. 130 g sodium chloride per day) was given in both the food and drinking water. Offering the food once a day resulted in a higher wool growth response to salt (22%) as compared with offering the food at 3-hr intervals (14%). It is suggested that the effects of salt were due to reduced ruminal degradation of protein, which remained in the rumen for a shorter time than usual when salt was given.

Effect of condensed tannins upon body growth, wool growth and rumen metabolism in sheep grazing sulla (Hedysarum coronarium) and perennial pasture

1992 ◽  
Vol 119 (2) ◽  
pp. 265-273 ◽  
Author(s):  
T. H. Terrill ◽  
G. B. Douglas ◽  
A. G. Foote ◽  
R. W. Purchas ◽  
G. F. Wilson ◽  
...  
Keyword(s):  
Growth Rates ◽  
Condensed Tannins ◽  
Rumen Fluid ◽  
High Ratio ◽  
Early Summer ◽  
Body Growth ◽  
Sheep Grazing ◽  
Rumen Metabolism ◽  
Wool Growth ◽  
Hedysarum Coronarium

SUMMARYAreas of sulla (Hedysarum coronarium) and pasture (Lolium perenne/Trifolium repens/Holcus lanatus) were grazed by young sheep (29·5–34·8 kg initial liveweight) in four experiments, and effects upon body growth, wool growth and rumen metabolism were measured.Sulla contained 40–50 g condensed tannins (CT)/kg DM, whilst the pasture contained small amounts of CT (2–6 g/kg DM). After chewing during eating, a lower proportion of total CT was readily extractable and greater proportions were protein-bound and fibre-bound. Nutritional effects attributable to CT were assessed by oral administration of polyethylene glycol (PEG), which binds and inactivates CT, to half the animals grazing each forage. Rates of body growth were consistently higher for lambs grazing sulla than those grazing pasture, with the CT concentration in sulla being neither stimulatory or inhibitory to body growth or voluntary feed intake (VFI). The action of CT reduced carcass fatness in sheep fed both diets, in the one experiment where this was measured. CT present in both sulla and pasture decreased rumen ammonia concentration and decreased molar proportions of iso-butyrate and iso and n-valerate. During spring and early summer, when wool growth rates were highest, CT present in both pasture and sulla increased wool growth rate; when wool growth rates were low during winter, CT had no effect upon the wool growth of sheep grazing either forage. Numbers of protozoa and molar proportions of n-butyrate in rumen fluid were increased by CT in sheep grazing sulla but not pasture.It was concluded that the higher rates of body growth and VFI in lambs grazing sulla was most likely to be due to its very high ratio of readily fermentable: structural carbohydrate.

Efficiency of wool production of grazing sheep. 3. The use of sulphur-containing amino acids to stimulate wool growth

1970 ◽  
Vol 10 (47) ◽  
pp. 665 ◽  
Author(s):  
JP Langlands
Keyword(s):  
Amino Acids ◽  
Peritoneal Cavity ◽  
Sheep Grazing ◽  
Merino Sheep ◽  
Wool Production ◽  
Wool Growth ◽  
Grazing Sheep ◽  
Native Pastures

Merino sheep grazing native and improved pastures were given up to 2.2 g DL-methionine each day through an abomasal cannula. Wool growth of sheep grazing improved and native pastures was increased significantly by up to 30 and 41 per cent respectively. Nine sheep with abomasal camulae were maintained in pens, and were infused into the abomasum with 7 g DL-methionine per week given on either one, two, or seven days each week. Wool growth was significantly increased by daily infusions of DL-methionine but the response was less when the methionine was given on only one or two days each week. Dorset Horn wethers were given single injections of up to 50 g DL-methionine or L-cystine subcutaneously or into the peritoneal cavity. The rate of excretion of urinary sulphur was recorded following the injection. DL-methionine was rapidly excreted but L-cystine was excreted more slowly. In a series of trials quantities of DL-methionine, methionine hydroxy analogue (MHA) or L-cystine were injected subcutaneously or intra-peritoneally into grazing Merino sheep. DL-methionine did not increase wool growth and MHA was toxic. Twenty-eight g L-cystine given as two compressed pellets each month into the peritoneal cavity increased wool growth by approximately 22 per cent over the 8-week experim6ntal period.

Selection of sheep for response to Trichostrongylus colubriformis larvae: genetic parameters

2001 ◽  
Vol 73 (1) ◽  
pp. 41-48 ◽  
Author(s):  
R. R. Woolastont ◽  
R. G. Windon
Keyword(s):  
Genetic Correlation ◽  
Secondary Infection ◽  
Selection Criterion ◽  
Breeding Programme ◽  
Secondary Field ◽  
Trichostrongylus Colubriformis ◽  
Phenotypic Correlations ◽  
Intestinal Nematode ◽  
The Mean

AbstractData were analysed from a long-term selection experiment with Merino sheep, based on immunological responsiveness to the intestinal nematode Trichostrongylus colubriformis. For the first 14 years of selection, the criterion was the mean of five fortnightly faecal worm-egg counts (FECs) of pen-housed lambs that were vaccinated with irradiated larvae then challenged with normal T. colubriformis larvae. For most of the lambs born in the subsequent 6 years, the selection criterion was the mean of three weekly FECs of grazing lambs following a secondary challenge with T. colubriformis larvae. Data from 2233 lambs were included in the analyses.At the end of the experiment, the lines selected for high and low response to challenge differed by 2·3 to 2·9 phenotypic standard deviations. The heritability of average pen-tested FEC was 0·38 (s.e. 0·04), similar to that for average FEC after secondary field challenge (0·37, s.e. 007). Average FECs from the primary field challenge were less heritable (0·21, s.e. 006). Counts recorded on pen-tested animals at 3, 5, 7, 9 and 11 weeks after infection were all highly correlated genetically (estimates 0·93 to 0·99) and of similar heritability (0·33 to 0·39) with a non-significant tendency for later FECs to be more heritable. Phenotypic correlations were lower, ranging from 0·60 for counts 8 weeks apart, to 0·78 to 0·81 for adjacent samples 2 weeks apart. Single-record heritability estimates at 3, 4 and 5 weeks after secondary infection in grazing lambs did not differ statistically from each other but were highest at the 5th week after infection at 0·33 (s.e. 007).FECs determined in pens were imperfectly correlated with FECs determined at pasture (genetic correlation 0·72, s.e. 013). Phenotypic correlations of single-record FECs across primary and secondary field challenges were low (around 0·2), although the genetic correlation between mean primary FEC and mean secondary FEC was not significantly different from unity. Testing under standardized conditions in pens did not result in consistently higher heritabilities than testing immunologically primed lambs at pasture. Repeated measurement in a breeding programme offers little additional benefit, except when lambs have had ample prior experience of parasite infection, with the two measures separated by an anthelmintic treatment. If an objective of a Merino breeding programme is to reduce FEC under field conditions, then using one measure in the field, approximately 3 to 5 weeks after a secondary artificial infection, is likely to lead to long-term progress.

Concentrations of glucose, albumin, inorganic phosphate and sodium in the blood of beef calves at 2 ½ months of age and their relationships with subsequent weight gain

1980 ◽  
Vol 94 (1) ◽  
pp. 95-104 ◽  
Author(s):  
G. J. Rowlands
Keyword(s):  
Growth Rate ◽  
Blood Glucose ◽  
Growth Rates ◽  
Inorganic Phosphate ◽  
The Body ◽  
The Other ◽  
Growth Depression ◽  
Blood Samples ◽  
Beef Calves ◽  
Body Weights

SummaryBlood samples were taken at 9, 10 and 11 weeks of age from 230 male Hereford × Friesian calves, the progeny of 12 Hereford bulls. Concentrations of blood glucose, serum albumin, inorganic phosphate and sodium were measured and correlated with body weights and growth rates until slaughter at 19½ months of age.Correlations between growth rates and glucose concentrations (0·44) and between growth rates and albumin concentrations (0·38) were observed until 4 months of age. Similar correlations between body weights and blood glucose or albumin concentrations persisted until 6 months of age. By 10 months, however, the correlations had begun to decline, and by slaughter they had become insignificant.Correlations between growth rates and inorganic phosphate or sodium concentrations were smaller, and also decreased with age.The effect of hypoglycaemia on growth rate was compared with the effect of enzootic pneumonia. Although the 10% of calves with the lowest glucose concentrations were growing 24% more slowly than the other calves at the time of sampling, this growth depression was not related to pneumonia, and they subsequently made up for most of the early loss of growth.Three blood samples were also taken from 22 Hereford bulls. No significant correlations were observed between the blood composition of the bulls and the body weights or weight gains of their progeny.

scholarly journals The Growth and Composition of Wool III. Variations in the Sulphur Content of Wool

1965 ◽  
Vol 18 (3) ◽  
pp. 671 ◽  
Author(s):  
PJ Reis
Keyword(s):  
Growth Rates ◽  
Dry Weight ◽  
Sulphur Content ◽  
Wool Growth ◽  
Different Levels

The sulphur content of wool was measured during experiments in which the nutritive status of sheep was altered by changes in the amount or composition of the diet. Three experiments were carried out, involving 13 sheep and five diets given at different levels of feeding. Wool grown on delineated areas was collected and its clean dry weight and sulphur content were determined. Wool growth rates varied between 0�3 and 1� 8 mg clean dry wool/cm2/day.

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