Drought feeding of sheep. 3. The relative importance of components of wool growth in explaining the wool growth differences between strains and diets

1973 ◽  
Vol 13 (60) ◽  
pp. 27
Author(s):  
DG Saville ◽  
AC Gleeson ◽  
WR McManus
Keyword(s):  
Fibre Diameter ◽  
Relative Importance ◽  
Protein Supplements ◽  
Wool Growth ◽  
Natural Pasture ◽  
Formaldehyde Treatment ◽  
Nutritional Environment ◽  
Growth Differences ◽  
Dietary Treatments ◽  
Maintenance Ration

This paper reports the changes in wool components with differences in wool growth resulting from differences in strain of sheep and diet, and the importance of these in relation to selecting a strain of Merino for the drier pastoral areas. Measurements of body weight, fold score, staple length, fibre diameter and follicle density were taken from Collinsville, Peppin and Bungaree ewes grazing natural pasture at Trangie and also when given a maintenance ration containing different grains, different protein supplements and formaldehyde treatment of these protein supplements. At pasture the Collinsville strain produced more wool with little increase in fibre diameter, when compared with the Peppins, and this resulted in the Collinsville strain being more profitable under pasture conditions than either the Peppins or Bungarees. When given a survival ration, similar changes in wool growth and the components occurred in each strain helping to maintain the profitable advantage of the Collinsvilles. The effect of the dietary treatments on wool growth occurred mainly through changes in fibre diameter and length. It is concluded that the choice of a particular strain of sheep for use in drier areas should not be influenced by the nutritional environment under which they are chosen.

The influence of type and timing of protein supplementation on wool growth and protein synthesis in the skin of young Merino sheep

1999 ◽  
Vol 50 (4) ◽  
pp. 497 ◽  
Author(s):  
D. G. Masters ◽  
G. Mata ◽  
S. M. Liu
Keyword(s):  
Protein Synthesis ◽  
Experimental Period ◽  
Protein Supplementation ◽  
The Other ◽  
Canola Meal ◽  
Protein Supplements ◽  
Wool Growth ◽  
Low Concentrations ◽  
High Concentrations ◽  
Dietary Treatments

There is limited evidence that the response in wool growth resulting from feeding protected protein supplements continues after the feeding has stopped. Feeding such proteins, alternated with traditional supplements, may increase wool growth as much as continuous feeding but at a lower cost. This experiment aimed to determine whether the response to protected protein continued after the sheep were switched to a cereal supplement. Over a 2-month experimental period, 56 weaners (5 months old, weighing 26 kg) were used in a 2 × 2 factorial experiment. Half were fed a diet containing 25% canola meal [partially protected protein with high concentrations of sulfur amino acids (SAA)] mixed with oaten hay, urea, and minerals. The other half were fed the same diet but with lupin seed (highly degradable protein with low concentrations of SAA) replacing the canola meal. Within each of the 2 dietary treatments and in each of 2 months, half of the weaners were fed the diet continuously, the other half were fed the diet for 2 weeks followed by 2 weeks of a barley, oats, hay, urea, and minerals diet. Another group of 8 weaners was fed the oats–barley diet continuously for 2 months. All sheep were fed to lose 35 g liveweight/day. Weaners fed canola meal grew 11% more wool during the experiment and had a higher rate of protein synthesis in the skin than weaners fed lupins. The response to canola meal of wool and skin was the same whether feeding was continuous or alternated with oats–barley, indicating that the benefits from feeding partially protected proteins continues after feeding has stopped.

Rape and sunflower seed meals as supplements for sheep fed on oat straw

1985 ◽  
Vol 36 (5) ◽  
pp. 717 ◽  
Author(s):  
JB Coombe
Keyword(s):  
Energy Content ◽  
Rapeseed Meal ◽  
Metabolizable Energy ◽  
Protein Supplements ◽  
Wool Growth ◽  
Production Experiment ◽  
Formaldehyde Treatment ◽  
Outflow Rate ◽  
Ruminal Degradation ◽  
Oat Straw

Rapeseed meal (RSM), sunflower meal (SFM) and formaldehyde-treated (F) forms of these were compared with urea- and formaldehyde-treated casein (FCAS) as N supplements for sheep fed pelleted diets containing c. 80% oat straw. Sufficient supplement was added to bring the N content of each diet to c. 1.7%, and starch was added to the urea and FCAS diets to make all supplements equal in metabolizable energy content. Based on an assumed fractional outflow rate from the rumen of 0.06 h-1, the ruminal degradability of dietary N varied from a mean of 0.42 for diets containing formaldehydetreated supplements to 0.74 for non-treated supplements. The diets were fed to Crossbred wethers weighing c. 40 kg in a production experiment lasting 12 weeks, and in a metabolism experiment. In the production experiment, penned sheep fed the urea diet ate 1300 g DM day-1, gained 30 g Day-1 and grew 4.5 g clean dry wool (CDW) day-1 . Each of the protein supplements increased DM intake (mean 1860g day-1 P < 0-0l), liveweight gain (mean 148 g day -I, P < 0-001) and wool growth (mean 10.5 g CDW day-1; P < 0.01). Intake and liveweight gain were higher, and wool growth rate lower, on the SFM than on the RSM diet, while formaldehyde treatment of both meals stimulated intake, gain and wool growth although these differences were not always significant. Efficiency of wool growth, expressed as g CDW per g N digested, was least for the urea and SFM diets (mean 0.30), higher for the FCAS, RSM and FSFM diets (mean 0.40) and highest for the FRSM diet (0.48, P < 0.05). Mean digestibilities of organic matter (OM) and cell wall constituents for all diets were 0.47 and 0.44 respectively, with few significant differences between diets. Apparent N digestibility varied from 0.41 to 0.61 for the FRSM and FCAS diets respectively, while estimated true N digestibility varied from 0.72 to 0.88 for the same two diets. Nitrogen balance for the protein-supplemented diets (mean 2.68 g day-1) was higher (P < 0.001) than for the urea diet (-3.77 g day-1). During 6 h post-feeding, the mean rumen pH (6.50) and volatile fatty acid levels (60.9 mM ) showed few differences between diets, whereas rumen ammonia concentrations were significantly reduced by formaldehyde treatment of the protein supplements. It was concluded that RSM and SFM were effective supplements for sheep offered straw, with little difference between them except for wool growth. Formaldehyde treatment to confer resistance to ruminal degradation reduced N digestibility, but increased the efficiency of utilization of digested N for wool growth.

The effects of short-term undernutrition and adrenocortical stimulation on wool growth

1972 ◽  
Vol 15 (1) ◽  
pp. 39-46 ◽  
Author(s):  
C. J. Thwaites
Keyword(s):  
Fibre Diameter ◽  
Wool Fibre ◽  
Minor Role ◽  
Short Term ◽  
Similar Treatment ◽  
Wool Growth ◽  
Prolonged Effect ◽  
Maintenance Ration ◽  
Maintenance Group

SUMMARYSeven daily doses of 60 or 120 mg cortisol administered to mature sheep given a maintenance ration depressed wool fibre diameter by approximately 10%. Similar treatment with 120 mg cortisol for 14 days produced a more severe and prolonged effect, though fibre diameter was unaffected by a series of seven injections of 40 IU ACTH given every second day.Fourteen days at 10% of maintenance and 14 days' cortisol treatment were applied to mature sheep fed either continually at 150% maintenance, or at 75% followed by 150% maintenance. Cortisol treatment was associated with a significant reduction in fibre diameter only in the animals fed at 150% maintenance. Restriction to 10% maintenance for 14 days had no such effect. Approximately 20% of fibres were shed following cortisol treatment in both nutritional groups, but a marked ‘break’ in the fleece occurred only in the 75% maintenance group.A low plane of nutrition is confirmed as a major factor predisposing to ‘tenderness’ and ‘break’, and short-term adrenocortical stimulation is shown to be sufficient to produce the reduction in fibre diameter and increased fibre shedding associated with these faults. However, semi-starvation (represented by restriction to 10% of maintenance) appears to have played a relatively minor role in their development.

Efficiency of conversion of food to wool in selected and unselected Merino types

1972 ◽  
Vol 23 (1) ◽  
pp. 117 ◽  
Author(s):  
DG Saville ◽  
GE Robards
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Surface Area ◽  
Fibre Diameter ◽  
Response To Selection ◽  
Gross Efficiency ◽  
Wool Growth ◽  
Selection For ◽  
Fleece Weight ◽  
Growth Differences

Comparisons were made between Collinsville, Bungaree, and Peppin Merino ewes in efficiency of conversion of food to wool. The effect of selection for some characters on efficiency of conversion within the Peppin Merino was also investigated. The Collinsville ewes grew 14% more wool and had an 8% lower food intake at maintenance than did the Peppins. Differences in wool growth between the Peppin and Collinsville types fed ad lib. were mainly due to efficiency and body weight differences. Efficiency, intake, and body weight each had a similar influence on wool growth differences between Peppins and Bungarees. Peppin ewes selected for wool production, either alone or together with crimp frequency, had a higher gross efficiency than unselected sheep fed below maintenance (13 and 8%) or ad lib. (14 and 13%). The efficiency difference between selected and unselected sheep increased, then decreased, with increasing intake. The decrease in efficiency differences at higher intakes did not appear to influence the ranking of selected or unselected sheep. The response to selection for clean fleece weight was shown to develop a plateau after about one generation of selection. Selection had resulted in the elimination of a relationship between efficiency and wool growth. The present results indicate that further progress in fleece weight is unlikely to be made either by selecting for fleece weight with some control on fibre diameter or by selecting for increased surface area.

A 'protein bank' of Lotus uliginosus cv. Maku as an alternative to conventional protein supplements for weaned lambs grazing on natural pastures during summer and autumn

2015 ◽  
Vol 55 (1) ◽  
pp. 27
Author(s):  
L. Piaggio ◽  
M. de J. Marichal ◽  
A. Pastorín
Keyword(s):  
Soybean Meal ◽  
Block Design ◽  
Average Daily Gain ◽  
Feeding Strategies ◽  
Homogeneous Groups ◽  
Protein Supplements ◽  
Natural Pasture ◽  
Performance Results ◽  
Protein Block ◽  
Lotus Uliginosus

The aim of this study was to evaluate the use of restricted grazing of an improved natural pasture as an alternative to conventional protein supplements for weaned lambs grazing natural pastures during summer–autumn. Two natural pastures that differed in dry matter allowances were used as basal diets. Sixty Corriedale lambs, 3 months old, were divided into 10 homogeneous groups. For each natural pasture, one group of lambs was randomly assigned to one of the following treatments (at 10 lambs/ha): continuous grazing (control); control + protein block (150 g/lamb. day); control + soybean meal (100 g/lamb. day); control + supplemental protein obtained from grazing for 3 h/day a natural pasture improved with Lotus uliginosus cv. Maku; or same as previous, except that grazing was allowed 1 in 3 days. Performance results (final bodyweight, average daily gain, and difference between initial and final body scores) were analysed as a completely randomised block design with subsampling. Lambs grazing 3 h/day or 1 in 3 days on improved pasture or supplemented with soybean meal showed better (P < 0.05) performance than non-supplemented lambs. Lambs consuming the protein block performed similarly (P > 0.05) to control lambs. The experiment demonstrated that feeding strategies using controlled grazing of natural pastures improved with lotus Maku or soybean meal supplementation are effective to achieve target growth rates of weaned lambs grazing natural pastures in summer–autumn.

The performance of pregnant and lactating Merino ewes and their lambs fed survival rations of wheat grain and sawdust

1978 ◽  
Vol 18 (90) ◽  
pp. 34 ◽  
Author(s):  
RA Hunter
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Survival Rate ◽  
Wheat Grain ◽  
Term Survival ◽  
Feeding Level ◽  
Wool Growth ◽  
Eucalyptus Maculata ◽  
Maintenance Ration

Merino ewes were mated at pasture and then fed in pens either a maintenance or an 80 per cent maintenance ration of wheat grain three times a week. Half the animals at each feeding level were offered Spotted Gum (Eucalyptus maculata) sawdust. Addition of sawdust to the ration did not affect liveweight change and the wool growth rate of ewes or the birth weight and growth rate of lambs. It did, however, affect the long-term survival rate of ewes. Of the ewes that died after three months of survival feeding, four were in groups fed wheat alone and one in a group fed sawdust with the wheat. The survival rate and growth rate of lambs in all treatments were poor.

scholarly journals Rumen degradation and fractional outflow rates of nitrogen supplements given to cattle eating sodium hydroxide-treated straw

1986 ◽  
Vol 55 (2) ◽  
pp. 387-398 ◽  
Author(s):  
K. Amaning-Kwarteng ◽  
R. C. Kellaway ◽  
Jane Leibholz ◽  
A. C. Kirby
Keyword(s):  
Sodium Hydroxide ◽  
Cotton Seed ◽  
Relative Importance ◽  
High Intake ◽  
Protein Supplements ◽  
Rumen Degradation ◽  
Cotton Seed Meal ◽  
Meat Meal ◽  
The Difference

1. Six rumen and abomasal cannulated heifers were used to study the effects of intake on the fractional outflow rates (FOR) of chromium-mordanted cotton-seed meal (Cr-CSM) and meat meal (Cr-MM), CrEDTA, ytterbium and lignin from the rumen. Values of FOR of Cr-CSM and Cr-MM were combined with values of nitrogen disappearance from the protein supplements, placed in porous synthetic (nylon) bags and incubated within the rumen (P), to calculate effective degradation (D)of CSM and MM when fed to heifers eating sodium hydroxide-treated straw. Also, N degradation in vivo (V) was measured as the difference between abomasal N flow and the sum of flows of microbial and endogenous N.2. FOR were positively related to intake and differences between supplements were significant (p<0.01). FOR pertaining to high and low intakes respectively were 0.073 and 0.052 for Cr-CSM, 0.082 and 0.071 for Cr-MM, 0.030 and 0.023 for lignin, 0.082 and 0.073 for CrEDTA and 0, 044 and 0.035 for Yb.3. A rise of 28.8 and 13.4% in FOR of Cr-CSM and Cr-MM respectively, associated with an increase in intake from maintenance to 1.5 times maintenance, resulted in 10.7 and 2.2% reductions inD, 24 h after feeding, for CSM and MM respectively.4. With the exception of CSM at the high intake, estimates ofVwere underestimated byDand were 8.6–25.0% greater than theDvalues when time of incubation (t)= ∞. The two techniques, however, ranked the degradation of the two supplements in the same order at both levels of intake.5. Underestimation ofVbyDmay be attributable to underestimation ofP, overestimation of FOR (both resulting in underestimation ofD) or overestimation ofVdue to biases associated with the estimation of this part of the comparison. The relative importance of these factors remains to be determined.

Wool growth regulation by local skin cooling

1967 ◽  
Vol 9 (3) ◽  
pp. 393-397 ◽  
Author(s):  
J. M. Doney ◽  
J. G. Griffiths
Keyword(s):  
Heat Transfer ◽  
Growth Rate ◽  
Blood Flow ◽  
Growth Regulation ◽  
Fibre Diameter ◽  
Systemic Response ◽  
Local Cooling ◽  
Local Skin ◽  
Wool Growth ◽  
Skin Cooling

Local cooling of the skin, produced by exposure to wind was shown to depress the rate of length growth of wool. The depression was associated with reductions in skin temperature and blood flow and with increases in heat transfer in the exposed regions. Fibre diameter did not appear to be affected and there were no indications of a systemic response of wool growth rate to exposure.

Liveweight and wool growth responses to a Mediterranean environment in three strains of Merino sheep

1998 ◽  
Vol 49 (8) ◽  
pp. 1187 ◽  
Author(s):  
N. R. Adams ◽  
J. R. Briegel
Keyword(s):  
Body Composition ◽  
Fibre Diameter ◽  
The Other ◽  
Wool Fibre ◽  
Growth Responses ◽  
Mediterranean Environment ◽  
Protein Loss ◽  
Broad Group ◽  
Wool Growth ◽  
Sources Of Variation

The present study examined changes in wool growth, liveweight, and body composition in groups of fine, medium, and broad wool Merino wethers grazed together at pasture in the highly seasonal Mediterranean environment, to determine the sources of variation in wool growth that may affect staple strength (SS). Seasonal changes in wool growth were measured using 6 dyebands placed at times of seasonal change in the nutrient supply from pasture, and liveweights were recorded fortnightly. Dilution of deuterated water was used to determine changes in body composition between the beginning of summer and the end of autumn. The sheep lost liveweight over this period, but loss of protein relative to fat over this period was unexpectedly high (7 : 1). The relative changes in liveweight, and loss of its components (fat and lean) during summer and autumn, were similar in all 3 groups, even though the Broad group was heavier than the other 2 genotypes at all times (P < 0·01). In contrast to the similar pattern of liveweight change, wool growth rates and changes in the fibre diameter were less variable throughout the year in the Broad group than the other 2 groups (P < 0·001). Stepwise regression indicated that the characteristics related to SS were standard deviation in fibre diameter (SDfd; P < 0·001), mean fibre diameter (P < 0·001), and variation in diameter within a 200-mm length of wool fibre (Sdfdwithin; P < 0·05). However, the relative importance of different factors for SS differed within each group. The most important factors were mean fibre diameter in the Fine group, the variation in fibre diameter along the staple (SDfdalong) in the Medium group, and the variation in diameter between fibres (SDfdbetween) in the Broad group. It is concluded that SS is a complex characteristic, depending on both the fibre diameter and several sources of variation in fibre diameter, all of which can differ among flocks. Protein loss made a disproportionate contribution to liveweight loss over summer and autumn, but the amino acids made available did not contribute substantially to wool growth or SS.

Sheep of divergent genetic merit for wool growth do not differ in digesta kinetics while on restricted intakes

2014 ◽  
Vol 54 (9) ◽  
pp. 1243 ◽  
Author(s):  
I. De Barbieri ◽  
R. S. Hegarty ◽  
V. H. Oddy ◽  
M. C. Barnett ◽  
L. Li ◽  
...  
Keyword(s):  
Compartmental Model ◽  
Genetic Selection ◽  
Amino Nitrogen ◽  
Feeding Level ◽  
Wool Growth ◽  
Selection For ◽  
Fleece Weight ◽  
Estimated Breeding Values ◽  
Growth Differences ◽  
Weight Groups

Sheep selected for high wool growth were previously shown to exhibit higher microbial protein outflow from the rumen and higher uptake of amino nitrogen in portal blood than those selected for low wool growth. This suggests that genetic selection for wool growth may induce changes in foregut physiology. This study was undertaken to determine whether differences in digesta kinetics, especially mean retention mime (MRT), are associated with differences in fleece production between sheep with low or high estimated breeding values (EBVs) for fleece weight. Twenty mature Merino wethers with uniform EBVs for liveweight were allocated to two groups of 10 animals on the basis of high or low EBVs for yearling fleece weight. Five sheep with low-EBVs and five sheep with high-EBVs for fleece weight groups were allocated in a crossover design to low and high feeding-level treatments, which comprised a blended hay diet fed at maintenance or 1.5 times maintenance. All sheep were given single doses of chromium-mordanted fibre and cobalt-EDTA as inert, non-digestible markers. Digesta kinetics was determined by analysis of the faecal marker excretion patterns using a compartmental model. Higher feed intakes from animals fed 1.5 times maintenance were associated with higher rates of wool growth and higher masses of indigestible fibre in the gut, but reduced MRT of digesta. Although sheep with higher EBVs for fleece weight had higher wool growth rates, there was no indication that these wool growth differences were associated with differences in digesta kinetics. The lack of interaction between feeding level and genotype suggests that MRT did not contribute to genotype differences in wool growth in sheep fed restricted intakes. The differences in wool growth among commercial Merino sheep with divergent fleece weight EBVs achieved by multi-trait selection are not attributable to differences in digesta kinetics, at least when feed is not available ad libitum.

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