Effects of weaner nutrition on sire and flock rankings: a re-analysis of historical data

2009 ◽  
Vol 49 (12) ◽  
pp. 1100
Author(s):  
B. J. McGuirk
Keyword(s):  
Growth Response ◽  
Historical Data ◽  
Scale Type ◽  
Genetic Merit ◽  
Wool Production ◽  
Log Transformation ◽  
Wool Growth ◽  
Nutritional Effects ◽  
The 1950S ◽  
Fleece Weight

Early work in the 1950s on the wool growth response of sheep from diverse genotypes for wool production in response to varying planes of nutrition at pasture did not show the significant genotype × environment interactions exhibited in later pen studies with the same or very similar genotypes. However, this early study used a log-transformation on all traits to adjust nutritional effects for scale. Re-analysis of the original (i.e. untransformed) data shows that superior genetic merit for clean fleece weight, different sire progeny groups or selection flocks is more apparent when hogget ewes are fed a high plane of nutrition at pasture. However, only in the case of flocks was the interaction statistically significant, and this interaction was insignificant when data were either log-transformed, or when an appropriate test that accounts for scale-type effects was applied. When left untransformed, the data are, thus, in agreement with the subsequent pen studies that examined data on untransformed clean wool production.

Stimulation of wool growth by thyroxine implantation. I. Liveweight changes and wool growth of fine-wool Merino wethers

1964 ◽  
Vol 15 (4) ◽  
pp. 657 ◽  
Author(s):  
LJ Lambourne
Keyword(s):  
Dose Rate ◽  
Fibre Length ◽  
Dual Purpose ◽  
Wool Production ◽  
Wool Growth ◽  
Body Tissues ◽  
Four Seasons ◽  
Lower Body Weight ◽  
Native Pastures ◽  
Fleece Weight

Groups of 20 and 30 fine-wool Merino wethers were treated with L-thyroxine and their subsequent liveweight changes and wool production studied under a variety of grazing conditions for a year. Treatments comprised : (1) Single implantations of 60 mg in autumn, winter, spring, or summer. (2) Repeated implantations at all four seasons of 30, 60, or 90 mg. (3) Weekly subcutaneous injection of 7 mg in aqueous solution. These groups were grazed with untreated wethers on improved native pastures at one to two sheep per acre. (4) Repeated 60 mg implantations at four seasons in wethers grazed on native pasture providing a lower level of nutrition. (5) Repeated 60 mg implantations at four seasons in wethers grazed on sown pasture providing a higher level of nutrition. After every implantation there was a loss of 5–10 lb liveweight — more pronounced and more prolonged in the wethers given greater amounts of thyroxine, and more prolonged in those at lower levels of nutrition. Deaths occurred in several groups, increasing with dose rate or with poorer nutrition up to 30–50% of the group. Wool growth was not increased significantly by repeated 60 mg implants at the lowest level of nutrition, nor by the single 60 mg implant in late spring. Increases of 34% in annual fleece weight resulted from 60 mg implants in autumn and summer. Repeated implantation of 30, 60, and 90 mg in groups on a medium or high plane of nutrition increased annual fleece weight by 8, 14, and 19%, and 7 mg injected weekly by 11%. Increases in fleece weight were due partly to increased fibre length, and partly to an increase in grease and suint which reduced the clean scoured yield by 1–2%. It is concluded that line-wool Merinos, despite their lower body weight and greater specialization for wool production, react to thyroxine treatment in the same way as has been established for "dual-purpose" sheep. The safe maximum dose rate is critically dependent on the current level of nutrition, particularly for young sheep. Repeated implantations without adequate opportunity for recovery of catabolized body tissues may produce no increase in wool growth and may cause death.

The effects of pregnancy and lactation on wool production and liveweight in Polwarth ewes

1978 ◽  
Vol 18 (90) ◽  
pp. 58 ◽  
Author(s):  
RND Reid
Keyword(s):  
Growth Rate ◽  
Early Pregnancy ◽  
Wool Production ◽  
Wool Growth ◽  
Pregnancy And Lactation ◽  
Fleece Weight

Groups of Polwarth ewes which 1. were barren, 2, were pregnant but aborted with prostaglandins in early pregnancy, 3. lambed and reared a single lamb and 4. lambed but had their single lamb removed soon after birth, were used to estimate the effects of pregnancy and lactation on wool and Iiveweight. Pregnancy plus lactation reduced liveweight (17 per cent), wool growth rate (9 per cent) and clean fleece weight (11 per cent) ; pregnancy alone reduced liveweight (10 per cent), wool growth rate (7 per cent) and clean fleece weight (10 per cent) and its effects were greater than those of lactation in each of the characters studied.

Wool production and heterosis by the Merino, the Polwarth, and their reciprocal crosses

1993 ◽  
Vol 33 (4) ◽  
pp. 397 ◽  
Author(s):  
LG Butler ◽  
BJ Horton ◽  
PM Williams ◽  
RG Banks
Keyword(s):  
Maternal Effect ◽  
Reciprocal Cross ◽  
Fibre Diameter ◽  
Similar Amount ◽  
Or Efficiency ◽  
Weaning Weight ◽  
Wool Production ◽  
Wool Growth ◽  
Fleece Weight ◽  
Lower Production

Tasmanian Merinos and Polwarths were mated in each of 2 years to produce 2 drops of Merino, Polwarth, and F1 reciprocal cross progeny. Polwarths had weaning weights similar to Merinos but were 14% heavier as hoggets. Polwarths grew a similar amount of wool of 11% greater (P<0.001) fibre diameter; however, wool production was 9% less efficient based on metabolic weight. Polwarths displayed an advantage in resistance to footrot. There was a marked Polwarth maternal effect of about 16% on weaning weight but no elfect on hogget weight. The Polwarth maternal effect on fleece weight and efficiency was 9% (P<0.001). In a comparison with a single-born male, ewes weighed 5% less at weaning and 7% less at hogget shearing and produced about 6% less wool (P<0.001), although of comparable fibre diameter. Twins weighed 17% less at weaning, but only 3% less at hogget shearing (P<0.001). They grew about 5% less wool, which was of 2% greater fibre diameter (P<0.001) and 5% higher wool score, but efficiency was 2.5% lower. Production was generally lower (except for yield and wool score) in the 1988 drop than the 1987 drop by 3-10%. Differences in productivity between ram sources were of only slightly lesser magnitude than differences between breeds. The number of feet affected by footrot was reduced by 17% in the 1988 drop. Severe footrot affecting more than 1 foot reduced liveweight but did not significantly reduce fleece weight. There appeared to be some heterosis for weaning weight (10%) and hogget weight (6%), but little heterosis in wool growth (2-3%) or efficiency (-2%).

scholarly journals A Relationship Between Sulphur Content of Wool and Wool Production by Merino Sheep

1967 ◽  
Vol 20 (1) ◽  
pp. 153 ◽  
Author(s):  
PJ Reis ◽  
DA Tunks ◽  
OB Williams ◽  
AJ Williams
Keyword(s):  
Body Weight ◽  
Unit Area ◽  
Sulphur Content ◽  
Merino Sheep ◽  
Wool Production ◽  
Weight Index ◽  
Wool Growth ◽  
The Mean ◽  
Fleece Weight ◽  
The Relationship

The sulphur content of wool from 66 Peppin Merino wethers maintained together at pasture was measured in midside staples representing 49 weeks growth. The distribution of sulphur values was normal with a mean of 3�43 % and a range of 3�08-3�92 %. The sulphur content of the wool was inversely related to wool production among these sheep. There were no significant differences in the relationship when wool production was expressed as fleece weight index (F.W.I.), i.e. clean fleece weight/body weight (r = -0�48), as clean fleece weight (r = -0�42), or as wool growth per unit area of skin (r = - 0�37). The mean sulphur content of wool from sheep with the 10 highest values for F.W.I. was 3�27%, compared with a mean of 3 �55% sulphur for wool from sheep with the 10 lowest values for F.W.I.

scholarly journals Metabolism of Cystine by Merino Sheep Genetically Different in Wool Production III. the Incorporation of Radioactivity Into Wool Fibres During and After Intravenous Infusions of l-[35S]Cystine and its Relationship to Wool Growth and Efficiency of Conversi

1973 ◽  
Vol 26 (2) ◽  
pp. 465 ◽  
Author(s):  
AJ Williams
Keyword(s):  
Merino Sheep ◽  
Wool Production ◽  
Wool Growth ◽  
Intravenous Infusions ◽  
Fleece Weight ◽  
Dietary Treatments

Twelve mature ewes from a flock selected for high clean fleece weight (Fleece Plus) and twelve from a flock selected for low clean fleece weight (Fleece Minus) were randomly divided between two dietary treatments: 500 or 1100 g per day of chaffed lucerne hay.

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.

Effects of defaunation of the rumen and supplementation with amino acids on the wool production of housed Saxon Merinos. 3. Cottonseed meal and hydroxymethyl-methionine

1988 ◽  
Vol 28 (6) ◽  
pp. 699 ◽  
Author(s):  
DJ Cottle
Keyword(s):  
Amino Acids ◽  
Cottonseed Meal ◽  
Growth Response ◽  
Fibre Diameter ◽  
Diameter Ratio ◽  
Design Experiment ◽  
Growth Responses ◽  
Wool Production ◽  
Wool Growth ◽  
Ciliate Protozoa

In experiment 1 six groups, each of 10 superfine Merino wethers were individually penned indoors and hand-fed chopped lucerne hay with either control pellets, cottonseed meal pellets (CSM) or cottonseed meal plus hydroxymethyl-methionine pellets (CSMEP). Following their shearing, the 6 groups in experiment 2 were hand-fed 1 of 3 chopped lucerne hay:oat rations [75: 25,50: 50,25: 75% (w/w)]. Each sheep was also fed either control pellets (25 g/day) or CSMEP pellets (75 g/day) in a cross-over design experiment. In both experiments, the rations were fed at maintenance level and were offered 3 times a week. Half of the sheep had no rumen ciliate protozoa. In experiments 1 and 2, wool production was measured during a 4 and 6 month period respectively. In experiment 1, defaunation resulted in a 6% increase in clean wool production on the unsupplemented chopped lucerne hay ration. Inclusion of CSM and CSMEP pellets resulted in clean wool growth responses of 16% and 19% respectively. Unacceptable increases in fibre diameter were associated with the increased wool production. In experiment 2, the clean wool response to defaunation was highest (12%) on the 75% chopped lucerne hay ration, when the control pellet was fed. Inclusion of the CSMEP pellet resulted in clean wool growth responses of 0.73, 0.98 and 0.99 g/day in sheep fed on the 75,50 and 25% chopped lucerne hay rations respectively. The wool production responses due to the CSMEP pellet were associated with increases in fibre diameter (0.3 �m), length (4 mm/year) and length/diameter ratio (0.4 �m/day.�m) of the wool grown. It was concluded that CSMEP pellets are best fed with a mixed ration containing more grain than chopped lucerne hay. The wool growth response to feeding hydroxymethyl-methionine was considered uneconomic.

Early weaning of grazing sheep. 2. Performance of ewes

1976 ◽  
Vol 16 (79) ◽  
pp. 156 ◽  
Author(s):  
JL Corbett ◽  
EP Furnival
Keyword(s):  
Genotypic Differences ◽  
Early Weaning ◽  
Wool Production ◽  
Wool Growth ◽  
Grazing Sheep ◽  
Fleece Weight

Two similar groups of Corriedale ewes were formed from a flock of 231. These were grazed on separate phalaris (Phalaris tuberosa) pasture at 8.6 or 17.3 ewes ha-1, respectively high and low nutritional planes, from seven weeks before their first lambing in spring 1968 until after their second lambing. Within each group the 1968 lambs were weaned by removal to other pastures at six or 12 weeks of age, or were left unweaned for 21 or 29 weeks in the high and low planes respectively. Birth weights in 1968 did not differ between planes, and for all ewes an increase of 1 kg in lamb birthweight was associated with a reduction in clean wool production during the last seven weeks of pregnancy of 0.22 � 0.11 g d-1. Pregnancy appeared to reduce by about one half the expression of genotypic differences between sheep in wool producing ability, and reduced 12 months clean fleece weight by about 5 per cent. Low plane ewes produced significantly less milk containing less solids. Liveweight gains and rates of wool growth were reduced by lactation and increased after weaning, wool growth the more slowly. Both rates of recovery were less in the low plane where, unlike the high plane, lactation appeared to reduce expression of genotypic differences in wool production. Clean fleece weights were reduced by about 5 and 10 per cent by lactations of respectively six weeks and five months duration. At subsequent joining a smaller proportion of the low compared with high plane ewes was marked by the ram and of these a smaller proportion produced lambs. Within the low plane, the longer the preceding lactation the lower the liveweight at second joining and lambing, and the lower the mating and lambing percentages. The results indicated that when there was a shortage of feed at and after lambing the performance of ewes would be improved by weaning their lambs at about six weeks. Ewe liveweights were consistently greater after six week weaning than after later weaning, a result confirmed in other experiments on weaning within fixed total areas of pasture.

The effect of frequency and time of shearing on the reproduction and wool growth of Bungaree South Australian Merino ewes

1966 ◽  
Vol 6 (22) ◽  
pp. 305 ◽  
Author(s):  
BJ McGuirk ◽  
JR Paynter ◽  
RB Dun
Keyword(s):  
Agricultural Research ◽  
Dual Group ◽  
Research Station ◽  
Wool Production ◽  
The Third ◽  
Agricultural Research Station ◽  
Wool Growth ◽  
Dual Groups ◽  
Fleece Weight ◽  
Australian Merino

Two hundred and seventy-five Bungaree South Australian Merino ewes were divided into three groups after shearing in June 1963 at Trangie Agricultural Research Station. One group was shorn in December 1963 and 1964 (December group), another in June 1964 (June group), while the third group was shorn at all three of these times (Dual group). The ewes were joined with rams on February 25, 1964. Twenty-nine days later 88 per cent of the ewes shorn in December (December and Dual groups) had exhibited oestrus compared with 72 per cent in the unshorn (June) group (P<0.05). Shearing in December also increased the percentage of wet ewes. Pre-lambing shearing did not influence lamb losses. Shearing twice a year (Dual group) increased the wool production of dry ewes compared with shearing once in the same 12 month period. The increases in clean fleece weight when the additional shearing in the Dual group was in December and June were 15 and 10 per cent respectively. However, Dual shearing did not increase fleece weights over the December group when the ewes were pregnant at the time of the additional shearing in June. Dual shearing improved wool colour and reduced fleece rot, but the wool of the Dual group had fewer crimps per inch and poorer handle than the June shorn wool (P<0.05). Estimated wool returns favoured the groups shorn once per year (P<0.05).

The effect of previous and current nutrition on wool production in southern Victoria

1962 ◽  
Vol 2 (6) ◽  
pp. 160 ◽  
Author(s):  
MJ Sharkey ◽  
IF Davis ◽  
PA Kenney
Keyword(s):  
Fibre Diameter ◽  
Fibre Length ◽  
Initial Increase ◽  
Nutritional Treatment ◽  
Wool Production ◽  
Wool Growth ◽  
Short Period ◽  
The Mean ◽  
Fleece Weight ◽  
Autumn And Winter

The effect of different planes of nutrition on the wool production of Corriedale wethers at pasture was studied between August 1959 and December 1960. The plane of nutrition was controlled by rate of stocking. The effect of previous nutritional treatment on wool production was slight. It affected wool weight and fibre length for 160 one month and fibre diameter for two months. The differences in current nutritional treatment were accompanied by large differences in wool production except during the spring months. On the highest plane of nutrition the wool production showed little seasonal variation, apart from an initial increase in production during the autumn. On the medium and low planes of nutrition wool growth declined substantially in autumn and winter and increased again in spring. The mean fibre diameter of the wool that was clipped frequently was greater than that of fleece wool obtained from the opposite midside at shearing. Further, in the groups on medium and low planes of nutrition estimates of fleece weight based on the combined weight of periodical clippings were greater than actual fleece weights. It is concluded that, in the dry Victorian summer, wool production is influenced by the plane of nutrition in the previous spring for a short period only, and that in autumn and winter it is dependant almost entirely on the feed immediately available.

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