Grazing management of native pastures in the New England region of New South Wales. I. Pasture and sheep production with special reference to systems of grazing and internal parasites

1959 ◽  
Vol 10 (4) ◽  
pp. 530 ◽  
Author(s):  
R Roe ◽  
WH Southcott ◽  
HN Turner
Keyword(s):  
New England ◽  
Fibre Diameter ◽  
Wool Fibre ◽  
Maximum Diameter ◽  
Late Winter ◽  
Parasitic Infestation ◽  
Wool Production ◽  
Skeletal Size ◽  
Significant Difference ◽  
Sheep Production

In a 4-year grazing experiment with Merino sheep, on a native pasture dominated by Bothriochloa ambigua S.T. Blake, three rates of stocking and continuous v. rotational grazing were compared. The effects of these treatments on the forage available and the botanical composition of the pasture and on sheep liveweights, size of sheep, wool production, wool fibre diameter, and parasitic infestation, both with and without drenching with phenothiazine, mere studied. The effects of seasonal conditions on the above and on the chemical composition of the pasture were also recorded. No consistently significant differences between grazing treatments in their effects on the pasture or on sheep liveweights or parasitic infestation were recorded, although during the final 3 years the total forage available was less under heavy stocking. Seasonal variations in total forage mere not marked, but, production of green forage increased greatly in the spring and declined to a very low level during winter. Similarly, sheep liveweights increased during spring and summer and declined in the winter. These liveweight changes were significantly correlated with the amount of green forage available. Wool fibre diameter showed similar seasonal fluctuations but the maximum diameter was attained earlier than maximum liveweight. Coincident with a spring rise in the amount of green forage there was also an increase in the percentages of crude protein and phosphorus in the green components of the pasture. Liveweight gains of the drenched sheep were significantly greater from the beginning of each experimental year in the late spring (November) to late winter (August) in all stocking treatments. In the spring, when the quality of the pasture improved and worm egg counts were low, drenching had no effect on liveweight gains in three out of four years. Drenching also significantly improved wool production and resulted in an increase in skeletal size of sheep in three out of four years. Drenching reduced egg counts of the parasites Oesophagostomum spp. and Haemonchus contortus (Rudolphi) Cobb but was less effective against Trichostrongylus-Ostertagia spp. For all grazing treatments there was no significant difference in the amount of wool produced per head, but over the 4-year period 56 per cent. more wool per acre was produced from the heavy than from the light rate of stocking.

Assessing Wiltshire Horn-Merino crosses. 1. Wool shedding, blowfly strike and wool production traits

1994 ◽  
Vol 34 (6) ◽  
pp. 717 ◽  
Author(s):  
KA Rathie ◽  
ML Tierney ◽  
JC Mulder
Keyword(s):  
Fibre Diameter ◽  
The Other ◽  
Wool Fibre ◽  
Production Traits ◽  
Wool Production ◽  
Phenotypic Correlations ◽  
Fleece Weight ◽  
Head Neck

Wiltshire Horn-Merino (WH-M) crosses of 1/2, 5/8 and 3/4 Merino content were compared over 10 years for wool shedding, blowfly strike frequency and wool production traits. Merinos and 1/2 Merino WH-M were compared over 4 years. For wool production traits, 1/2 and 5/8 Merino WH-M ewes were compared to Border Leicester-Merino (BL-M) ewes over 2 years. Shedding increased with age for all WH-M genotypes, with 3/4 Merinos showing less shedding than 1/2 Merinos at all ages. At 1 and 2 years of age, 5/8 Merinos were intermediate between the other 2 WH-M genotypes, but at later ages they were similar to 1/2 Merinos. All genotypes showed less shedding at the belly site than the head, neck and breech as lambs, but not at older ages. Phenotypic correlations between sites on the same sheep were high, averaging 0.85. Repeatability estimates for each site ranged from 0.26 to 0.45. Shedding increased most with age in the 1/2 Merinos, and least in the 3/4 Merinos. Little or no shoulder and back wool was shed by most sheep. All 1/2 and 5/8 Merinos and most 3/4 Merinos had bare legs and points. Blowfly strike incidence was far higher in Merinos than 1/2 Merinos, in all years. Among WH-M, blowfly strike incidence increased as Merino content increased, in all years. All WH-M were far inferior to both Merinos and BL-M in total greasy wool weight and all its components, and also in clean fleece weight, with their level of inferiority increasing as their Merino content declined. Wool fibre diameter for all WH-M was coarser than for Merinos, but was a little finer than for BL-M. Fibre diameter increased in the WH-M as their Merino content declined. All WH-M had lower wool yields than the Merinos or BL-M. In some years the 314 Merinos had lower wool yields than the 1/2 and 5/8 Merinos, which were similar in all years. Shedding caused numerous genotype x age interactions in wool weight and its components, as Merinos and BL-M did not shed, and with the WH-M shedding increased most with age in the 1/2 Merinos, and least in the 3/4 Merinos. Due to preferential shedding from the belly and other low-value areas, the WH-M inferiority in total wool weight was less severe for fleece weight. Winter shearing succeeded in harvesting some wool from WH-M that would be shed before a summer shearing, but not enough to alter rankings among genotypes. All WH-M genotypes have wool too coarse, and not enough of it, to compete as a wool sheep with the Merino at current wool prices under usual Australian pastoral conditions. In areas where mustering is difficult or blowfly strike unusually severe, WH-M genotypes may find a niche.

Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 2. Reproductive activity, liveweight and wool production of ewe lambs

1995 ◽  
Vol 35 (8) ◽  
pp. 1075 ◽  
Author(s):  
NM Fogarty ◽  
DG Hall ◽  
AR Gilmour
Keyword(s):  
Degrees Of Freedom ◽  
Fibre Diameter ◽  
High Standard ◽  
Reproductive Activity ◽  
Ovulation Rate ◽  
Late Winter ◽  
Production Traits ◽  
Wool Production ◽  
Ewe Lambs ◽  
The Difference

Liveweight, wool production, oestrous expression and ovulation rates of 260 Trangie Fertility Merino x Dorset (TD) and 278 Booroola Merino x Dorset (BD) ewes born in late winter-spring over 4 different years were analysed from post-weaning to first joining at about 19 months of age. The percentage of ewes expressing oestrus reached a peak of 68% in May-June, declined to 7% in September and rose to 93% in January prior to first joining. The proportion of ewes ovulating followed a similar pattern. The proportion of ewes expressing oestrus in March, May and June increased (P<0.001) substantially with increasing age and liveweight, which accounted to some extent for the large differences in oestrous activity between years. There was little difference between the strains in proportion of ewes expressing oestrus or ovulating throughout the year. TD ewes were heavier (P<0.001) than BD ewes, the difference increasing from 2 to 4 kg at 7 and 19 months. They also produced 0.3 kg more clean wool which had 1.2 pm higher fibre diameter (P<0.001). Ovulation rate, measured in each of 2 years at 2-monthly intervals, increased from 7 to 19 months of age. BD ewes had a higher ovulation rate than TD ewes on all occasions, and the difference averaged +0.4 ovulations. The mean ovulation rate in February (19 months) for ewes born over 3 years was 2.1 ova for BD and 1.4 ova for TD ewes (P<0.001). Based on subsequent ovulation rate and litter size records, 42% of the BD ewes were identified as carriers of the FecB gene. Ages at first oestrus and ovulation varied considerably between years (P<0.001). There was no difference between the strains in age at first oestrus, although BD ewes first ovulated at a younger age (P<0.05) than TD ewes. The stud of origin of the dam, dam age, dam parity and birth type were not significant for any reproduction trait. There was significant (P<0.001) variation in liveweight due to the origin of the dam. Half-sib estimates of heritability for ewe liveweight, ovulation rate at various seasons and wool production traits were generally high with relatively high standard errors as they were based on 23-40 degrees of freedom for sire.

Efficiency of conversion of food to wool. III. Wool production of ewes selected for high clean wool weight and of random control ewes on restricted and unrestricted food intakes in pens

1968 ◽  
Vol 19 (6) ◽  
pp. 1009 ◽  
Author(s):  
CHS Dolling ◽  
LR Piper
Keyword(s):  
Wool Fibre ◽  
Group Differences ◽  
Energetic Efficiency ◽  
Restricted Feeding ◽  
Significant Group ◽  
Wool Production ◽  
Phenotypic Correlations ◽  
Significant Difference ◽  
Ad Libitum ◽  
Ad Libitum Feeding

The clean wool production (W), gross energy intake (I), and body weight (B) of individually fed medium Peppin ewes representative of two groups, one (selected, S) genetically superior in W to the other (control, C), have been measured under restricted and ad libitum feeding of lucerne chaff in pens. Differences in favour of the S group were observed for W and W/I under both regimes, the respective relative values of S/C being under restricted feeding 110/100 and 112/100, and under ad libitum feeding 113/100 and 112/100. Of these between-group differences, only W/I on restricted feeding was significant (P < 0.05). Differences between groups for B and I were small and not significant. On restricted feeding the S/C values were 98/100 for both; on ad libitum feeding they were 99/100 for B and 101/100 for I. When the data from the two feeding regimes were combined, the between-group differences in both W and W/I were significant (P < 0.05), but no significant group x nutritional level interaction was observed in any character. The two levels of nutrition in the pens yielded wool production rates similar to those observed contemporaneously on natural pastures. There were large positive phenotypic correlations between net efficiency (W/I under restricted feeding) and gross efficiency (W/I under ad libitum feeding), and between net efficiency and W under both regimes. There were also positive phenotypic correlations between I and both W (moderate) and B (large) under ad libitum feeding. W/I accounted for 92% of the between-group (genetic) and 70% of the within-group (phenotypic) variation in W. There was no significant difference in plasma protein-bound iodine (PBI) between S and C ewes, while correlations between W and PBI were not significant within either group. The energetic efficiency of the wool production process is discussed; in this experiment no more than 1.5% of the energy consumed appeared as energy in the form of wool fibre.

The impact of rabbits on a grazing system in eastern New South Wales. 2. Sheep production

2002 ◽  
Vol 42 (7) ◽  
pp. 917 ◽  
Author(s):  
P. J. S. Fleming ◽  
J. D. Croft ◽  
H. I. Nicol
Keyword(s):  
Body Condition ◽  
Synergistic Effects ◽  
Fibre Diameter ◽  
The Body ◽  
Stocking Rate ◽  
Economic Implications ◽  
Wool Production ◽  
Sheep Production ◽  
Short Term Experiment ◽  
The Impact

Much research, time and money have been invested in the control of rabbits in Australia, yet the relationship between rabbit density and livestock production losses has not been quantified. We experimentally investigated the variations in sheep production parameters caused by 4 densities of rabbits, 0, 24, 48 and 72 rabbits/ha. Medium to strong wool merino wethers were run at a constant stocking rate in replicated plots with rabbits at 4� different densities. Sheep liveweight and body condition and wool production variables were measured over 3�years. Low to medium densities of rabbits were not found to reduce liveweights of wethers, whereas wethers run with the high density of rabbits were significantly lighter. The presence of rabbits reduced the body condition of sympatric sheep with the lowest body condition recorded at the high rabbit density. Mean greasy fleece weights, wool yields and clean-fleece weights were significantly different between densities of rabbits. Wethers run with the high rabbit density grew less wool than the wethers run with the other 3 densities of rabbits. The cumulative gross return per ha from wool production was highest for the medium rabbit density and lowest at high rabbit density. At the conclusion of this short-term experiment, the presence of some rabbits enhanced returns from wool production because of lower fibre diameter and comparable clean-fleece weights of fleeces grown at low and medium rabbit densities. These production characteristics might have been caused by synergistic effects on pasture growth or a sheep stocking rate that was too conservative for the prevailing seasonal conditions. At high rabbit density, competition for pasture between rabbits and sheep overrode possible synergistic and understocking effects. The economic implications of the presence of rabbits on merino sheep production are discussed.

Effects of defaunation of the rumen and supplementation with amino acids on the wool production of housed Saxon Merinos. 4. Cottonseed meal, analogues of methionine and avoparcin

1988 ◽  
Vol 28 (6) ◽  
pp. 707 ◽  
Author(s):  
DJ Cottle
Keyword(s):  
Amino Acids ◽  
Cottonseed Meal ◽  
Fibre Diameter ◽  
Cost Effective ◽  
Wool Fibre ◽  
Growth Responses ◽  
Wool Production ◽  
Wool Growth ◽  
Fleece Weight ◽  
Ciliate Protozoa

Ten groups, each of 6 superfine Merino wethers were individually penned indoors and hand-fed at maintenance level a ration of 70% oats and 30% chopped lucerne hay (w/w). The groups of sheep were fed 3 different supplementary pellets rotationally during three 9-week periods. Each group received 3 of the following 7 pellets: (1) control, (2) cottonseed meal (CSM), (3) CSM plus hydroxymethyl-methionine (MEP), (4) CSM plus methionine hydroxy analogue (MHA), (5) CSM plus avoparcin (AV), (6) CSM plus MEP plus AV, and (7) CSM plus MHA plus AV. The rations were offered 3 times a week. Half of the sheep had no rumen ciliate protozoa. Wool production was measured during the 7-month period. Defaunation resulted in a 6.9% increase in greasy fleece weight and a 7.7% increase in clean wool production. Average wool fibre diameter increased by 0.6 pm in defaunated sheep. The clean wool growth responses compared with sheep fed the control pellets were 4, 5, 12, 0, 3 and 9% respectively for sheep fed pellets 2-7. The most cost-effective supplement was the CSM plus MHA pellet, which increased clean wool production by 0.5 glday compared with sheep fed the CSM pellet but did not significantly affect wool quality. It was concluded that supplements containing MHA could be economically fed to housed superfine Merino wethers ('Sharlea'), but MHA appears to be relatively inefficient in supplying methionine to the intestines.

Nitrogen utilization and wool production by sheep

1961 ◽  
Vol 12 (2) ◽  
pp. 335 ◽  
Author(s):  
PJ Reis ◽  
PG Schinckel
Keyword(s):  
Fibre Diameter ◽  
Nitrogen Retention ◽  
Nitrogen Excretion ◽  
Wool Fibre ◽  
Gradual Change ◽  
Wool Production ◽  
Stable Level ◽  
Nitrogen Intake ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

The utilization of nitrogen was examined in sheep fed several diets; in some experiments the diet was supplemented with soluble casein given directly into the abomasum through a fistula. Casein supplements per abomasum were almost completely digested and absorbed. At the highest level of casein supplementation (55 g casein nitrogen per day) 95% of the casein was digested and absorbed. An increase in nitrogen intake resulted in an immediate increase in nitrogen balance, followed by a gradual return towards a stable level. There was also an immediate response of faecal and urinary nitrogen excretion to a change in nitrogen intake. Most of the adjustment in urinary nitrogen excretion occurred within 4 days, this period being followed by a gradual change towards a stable level of excretion during the next 6 weeks. Much higher levels of nitrogen retention were obtained from casein administered per abomasum than from similar levels of nitrogen given per os. Changes in wool production also occurred following changes in the nitrogen intake per 0s. The observed changes were variable, depending on the sheep and the feed change involved, and periods of up to 10 weeks were required before the rate of wool production became stable following a change in nutrition. Casein supplementation per abomasum resulted in a substantial increase in wool production and in a rapid increase in wool fibre diameter; most of the increase in fibre diameter occurred in the first week of supplementation. The efficiency of conversion of dietary nitrogen into wool nitrogen was much higher in experiments where a casein supplement was administered per abomasum than in experiments involving normal feeding; possible reasons for this difference are discussed.

Studies in the wool production of grazing sheep. 2. Variation in wool characteristics with season and stocking rate

1964 ◽  
Vol 4 (15) ◽  
pp. 404 ◽  
Author(s):  
WR McManus ◽  
GW Arnold ◽  
JR Paynter
Keyword(s):  
Fibre Diameter ◽  
Late Summer ◽  
Annual Growth ◽  
Late Winter ◽  
Stocking Rate ◽  
Wool Production ◽  
Grazing Sheep ◽  
Stocking Rates ◽  
Staple Length

A four-year study of the variation in wool characteristics of both periodic midside fleece samples and whole fleeces is reported. The wools are derived from an experiment (Arnold, McManus and Bush 1964) in which Merino wethers were continuously grazed on improved pastures at four widely different stocking rates. Despite very large differences in pasture availability and nutritional patterns between treatments the fleeces were essentially similar in staple length, fibre diameter, clean scoured yield, wax and suint content, in quality count and subjective characteristics of soundness, handle, colour, and character. The value of the fleeces was similar for all treatments. Staple length and fibre diameter were lowest in late summer and late winter, when feed quantity and quality, respectively, were also lowest. On all treatments over half the fleeces exhibited 'trade tenderness' attributable to undernutrition in summer. Winter shearing minimises the effects of undernutrition in winter on the soundness of the fleeces. The staple length on the tattoo midside was 21 per cent greater than annual growth on the alternate midside region. Possible reasons for this increase are discussed.

Effects of differential grazing of annual pastures in spring and age of sheep on pasture and sheep production

1997 ◽  
Vol 37 (7) ◽  
pp. 727 ◽  
Author(s):  
A. N. Thompson ◽  
M. W. Hyder ◽  
P. T. Doyle
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Fibre Diameter ◽  
Wool Growth ◽  
Period 2 ◽  
Significant Difference ◽  
Condition Score ◽  
Staple Strength ◽  
Sheep Production ◽  
Curvilinear Relationships

Summary. The effects of controlled grazing through spring on the production of young (age 1 year; liveweight 38.3 ± 0.09 kg; condition score 3.0 ± 0.03) and mature (age 3 years; liveweight 61.9 ± 0.36 kg; condition score 3.1 ± 0.04) Merino wethers was examined. The grazing treatments involved adjusting sheep numbers to maintain green feed on offer near target amounts of 800, 1200, 1600, 2000, 2400 and 2800 kg dry matter/ha. Liveweight and wool growth measurements were made on 8 sheep per plot, with additional animals added or removed as necessary to maintain pasture near the target feed on offer. Changes in wool-free liveweight were linear between days 0 and 42 (period 1), and days 42 and 111 (period 2) for both classes of sheep grazing low feed on offer treatments. Hoggets lost less liveweight than mature animals while grazing low feed on offer during period 1 and gained liveweight faster (P<0.05) than mature animals for any feed on offer during period 2. Curvilinear relationships existed between feed on offer and clean wool growth rate and fibre diameter, with feed on offer accounting for 65 and 81% of the variations in wool growth rate, and 65 and 73% of the variations in fibre diameter, for hogget and mature sheep respectively. There was no significant difference in wool growth rate between animal classes. Annual clean wool production, fibre diameter and staple length increased linearly (P<0.05) with increasing feed on offer. Staple strength was higher (P<0.05) in mature sheep compared with hoggets, but was greater than 30 N/ktex for both classes of sheep irrespective of feed on offer. These results indicate that intensive grazing in spring to predetermined feed on offer is a useful tactic for manipulation of wool growth and fibre diameter, but factors other than feed on offer also contribute to liveweight change and wool growth.

Selenium fertilizers for pastures grazed by sheep. 2. Wool and liveweight responses to selenium

1994 ◽  
Vol 45 (4) ◽  
pp. 877 ◽  
Author(s):  
BR Whelan ◽  
NJ Barrow ◽  
DW Peter
Keyword(s):  
New Zealand ◽  
Plasma Concentration ◽  
Western Australia ◽  
Whole Blood ◽  
Slow Release ◽  
Clinical Symptoms ◽  
Fibre Diameter ◽  
Selenium Deficiency ◽  
Wool Fibre ◽  
Wool Production

Two forms of selenium fertilizer, Na2 Se04 (quick release) and BaSe04 (slow release), prepared by Mintech of New Zealand, were applied in 1987 to pasture at Bakers Hill in Western Australia at 10 g Se ha-1. Merino wethers grazing the pasture over the following 3 years had significant increases in liveweight and wool production even though the control sheep showed no clinical symptoms of selenium deficiency. Sheep treated with selenium intra-ruminal pellets that also grazed the selenium-fertilized pasture showed no signs of toxicity and also had significant increases in liveweight and wool production. There was no significant increase in wool fibre diameter from the selenium treatments. Responses to blood selenium indicated that whole blood selenium should be maintained at a minimum value of 60 8g Se L-1 or a minimum plasma concentration of 40 8g Se L-1 to avoid subclinical selenium deficiency.

The response of broad- and fine-wool Merino wethers to differential grazing of annual pastures during spring

2002 ◽  
Vol 42 (2) ◽  
pp. 117 ◽  
Author(s):  
M. W. Hyder ◽  
A. N. Thompson ◽  
P. T. Doyle ◽  
K. Tanaka
Keyword(s):  
Average Rate ◽  
Fibre Diameter ◽  
Grazing Pressure ◽  
Wool Production ◽  
Wool Growth ◽  
Significant Difference ◽  
Grazing Period ◽  
One Year ◽  
Different Response ◽  
First 90 Days

Two experiments examined the effects of manipulating grazing pressure during spring on the liveweight and wool-growth response of fine- and broad-wool genotypes of Merino wethers grazing annual pastures. One-year-old broad- and fine-wool Merino wethers (Bungaree and Peppin; mean fibre diameter 25.4 v. 20.7 m and 22.1 v. 19.8 m before years 1 and 2, respectively) were grazed on annual pastures maintained near target amounts of green feed on offer (800, 1100, 1400, 2000 and 2800 kg green DM/ha), or set-stocked at the district average of 8 sheep/ha, during the spring of 1992 and 1993. Within the control-grazed treatments, there was no significant difference in the total amount of pasture produced during the experimental periods but more (P<0.05) pasture was produced under set-stocking (7900 v. 5400 kg DM/ha and 7700 v. 5600 kg DM/ha in years 1 and 2, respectively). Liveweight change was linear for most treatments over the first 90 days or so of the spring grazing period, and in both years the average rate of liveweight change was similar for both genotypes. Liveweight change increased (P<0.001) curvilinearly with increasing feed on offer, which explained more than 80% of the variance in liveweight change in both years. A significant (P<0.05) green feed on offer × year interaction indicated a different response to feed on offer between years, with liveweight maintenance occurring at about 500 and 1060 kg DM/ha in years 1 and 2, respectively. Within genotypes, there was no significant (P>0.05) difference in liveweight change during spring for sheep grazing treatments 2000 kg DM/ha or above. Sheep from the broad-wool genotype produced more (P<0.05) wool than those from the fine-wool genotype and, as expected, the wool was also significantly broader at all feed on offer levels. For both broad- and fine-wool sheep, feed on offer and liveweight change were closely correlated with wool growth rate and fibre diameter in both years. The asymptote of the relationships with feed on offer and the intercept of the relationships with liveweight change was greater (P<0.05) for broad- than fine-wool sheep. However, there was no significant difference between genotypes in either size and shape or slope of these relationships. In other words, the wool-growth and fibre-diameter response of broad-wool sheep to decreasing feed on offer in the spring was the same as that for fine-wool sheep. For both genotypes, annual clean-wool production (P<0.001) and mean fibre diameter (P<0.05) increased withincreasing feed on offer during spring. The total amount of wool grown per hectare during spring decreased linearly (P<0.001) with increasing feed on offer. Grazing to about 2500 kg DM/ha more-than trebled the total clean wool produced per hectare compared with set-stocking. Thus, irrespective of sheep genotype, managing feed on offer in spring is a useful tool for manipulating wool characteristics, and increasing pasture utilisation and total wool production per unit area.

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