Increase In Fleece Weight Research Articles

Factors affecting fleece traits of Angora goat in Argentina

Information collected over a fifteen-year period on an experimental flock were analyzed to evaluate the effect of year, age of dam, sex, and type of birth on the characteristics of the fleece at first shearing and the effects of year, age at shearing, and sex on the characteristics of the fleece at subsequent shearings. The variables analyzed were greasy fleece weight (GFW), average fiber diameter (AFD), percentage of medullated fibers (MF) and corrected greasy fleece weight (CGFW). At first shearing significant statistical differences were detected ( P<0.05) for year, dam's age, sex, and type of birth for GFW and CGFW. For AFD and MF, solely the shearing year was significant ( P<0.05). Data collected from the second and following shearings showed differences ( P<0.05) due to year of production, age at shearing time, and sex for the four variables analyzed. GFW increases to a maximum at 3–4 years of age, while CGFW is practically constant between 2 to 4 years of age, thus suggesting that the increase in fleece weight is due to an increase of AFD. On the other hand, MF shows a positive tendency related to age, for the analyzed interval of ages. In general, assuming comparisons are conducted within years of production, the results showed the importance of adjusting for age of dam, sex and type of birth for fleece weight, for traits collected at 12 months of age. For traits recorded at the second and later shearings adjustment for sex and age effects would be necessary for fleece weight, fiber diameter and log-transformed percent medullation. This result indicated, that to improve the estimation of breeding values in a selection scheme, it is necessary to use different models to adjust the data according to the yearly sequence of shearings.

Control of goitre in lambs by injection of ewes with iodized poppy seed oil

The value of a single injection of 1 ml of iodized poppy seed oil in ewes was examined to prevent goitre in their lambs in an iodine deficient area in northern Tasmania. Control of goitre was achieved for only two years as assessed by thyroidal radio-iodine uptake in the ewe and histological changes in the lamb's thyroid. On a group basis the slope of the radio-iodine uptake curve in ewes was found to give an accurate reflection of the animals' iodine status as shown by the lambs' thyroid histology. The treatment had no effect on liveweight gain or fleece growth in lambs, but in the year after the treatment the ewes had a 6% increase in fleece weight.

Effect of selenium on wool production body weight and mortality of young sheep in Western Australia.

SummaryThe effect of regular selenium supplementation on the body weight, wool production and mortality of young Merino sheep was investigated. Groups of Se‐treated and control sheep involving from 260–500 on each of 15 farms were observed from six weeks to 19 months of age. Ten mg Se as sodium hydrogen selenite was administered orally to the treated sheep at two‐monthly intervals. Treated and control sheep grazed together throughout the trial period.Statistically significant responses to selenium were recorded in body weight gains on four farms, in decreased mortality on five farms and as an increase in fleece weight on eight farms. The response in fleece weight varied from 2.9‐7.6% and could not be explained as a result of increased body weight.The increase in fleece weight was not due to an increase of grease in the wool but appeared to be due to an increase in fibre diameter and to a lesser extent an increase in staple length.A statistically significant decrease in the incidence of tender fleeces as a result of selenium supplementation was also recorded. All farms on which responses to selenium were obtained were in areas with average annual rainfall more than 20 inches.On two farms selenium caused statistically significant depressions in the parameters measured. Both farms were in areas with less than 20 inches average annual rainfall.

The influence of selection and plane of nutrition on the components of fleece weight in Merino sheep

The components of clean fleece weight were examined in five experimental flocks of medium-wool Peppin Merinos. Four single-character selection groups – clean fleece weight plus, clean fleece weight minus, crimps per inch plus, and crimps per inch minus – were examined by measuring fleece production in 18-month-old ewe progeny. Measurements were also made on progeny from the "nucleus" flock, which was selected for clean fleece weight with subsidiary selection for crimps per inch and against fold score. Data were collected in 1952 and 1954. The 1954 figures were obtained from a nutrition experiment in which sheep mere grown from weaning to 18 months on a high and on a low plane of nutrition. The mean measurements of the components of clean fleece weight (W) were compared between flocks using the "percentage deviation" technique. Four comparisons were made: (1) Nucleus/Fleece minus; (2) Fleece plus/Fleece minus; (3) Crimps minus/Crimps plus; (4) high nutritional plane/low nutritional plane. In comparisons (1) , (2), and (3), difference in weight of wool per unit area of skin (w) accounted for nearly all the difference in W. Body weight (S) made a small contribution while difference in fold score (R) was negligible. Fibre density (N) accounted for +86 per cent., and fibre cross-sectional area (A) for –28 per cent., of the difference in W in comparison (1). In comparison (2) the figures were N +47 per cent., A +21 per cent., while the figures for comparison (3) were N –26 per cent., A +121 per cent. The increase in fleece weight was invariably accompanied by a decrease in crimps per inch. In all three comparisons primary density (P) was the major cause of change in N. Fibre length (L) made a uniform contribution of approximately +15 per cent. in the three comparisons.The relative importance of the components of fleece weight was similar at both high and low levels of nutrition.The effect of a high level of nutrition was to produce large increases in A, L, and S. The increase in S was compensated by an equal decrease in P. The increase in fibre diameter was not associated with any change in crimps per inch.

The fleece growth of young Lincoln, Corriedale, Polwarth, and fine Merino maiden ewes under housed conditions and unrestricted and progressively restricted feeding on a standard diet.

Two experiments have been conducted with young Lincoln, Corriedale, Polwarth, and fine Merino maiden ewes to compare the growth of fleece by these breeds and to assess relations between the growth of fleece and some factors, nutritional and non-nutritional, likely to influence its growth. In both experiments four representatives of each breed were kept in a sheep house in single pens and fed a high quality diet of constant composition. The second experiment followed immediately on the first and the same sheep were used except for necessary replacements. In the first experiment, which lasted for about one year, the intake of the diet was continuously unrestricted; in the second the intake of the diet was progressively restricted by ordered steps and was finally maintained for 12 weeks at one-fifth of the unrestricted intake of the first 4 weeks of the experiment. With few exceptions, the absolute or relative values of the characters measured formed a smooth series from the fine Merino through the Polwarth and Corriedale to the Lincoln-either in ascending order (e.g. food and water intake; liveweight and chest dimensions; fibre thickness, length, and volume; clean wool, suint, and total skin products output; clean wool and suint output per unit food intake) or descending order (e.g. total and primary follicle density; ratio of secondaries to primaries; wax output and wax output per unit food intake) or showed little or no difference between the breeds (e.g. body length and height; food intake per unit net liveweight; total skin products per unit food intake). The relative positions of the breeds as shown in the first experiment mere generally maintained in the second as food intake was progressively reduced. The results of the two experiments were combined for the individuals and a series of partial regression analyses were undertaken to determine the regression of some variables of fleece production on the level of food intake, atmospheric temperature, fleece weight, and experimental time. Self-selected food intake decreased with increase in fleece weight and less obviously with increase in experimental time (or, possibly, with deposition of subcutaneous fat). Water intake increased with both increase in food intake and rise in atmospheric temperature. Wool weight produced, and fibre thickness, length, and volume growth, all increased with increase in food intake, and within the limits of observed food intake the relation between wool growth and food intake was adequately represented by linear regression. Increase in atmospheric temperature exerted no significant influence on wool growth, except by the Lincolns (through fibre thickness). A positive regression of wool growth rate on fleece weight, acting through fibre length growth, was found, but change in fibre thickness was not related to increase in fleece weight. Wax production was positively related to increase in food intake and negatively to rise in atmospheric temperature. Suint production was positively related to both food intake and fleece weight. Wool, wax and suint production per unit food intake decreased with increase in food intake. Wax per unit food intake decreased with rise in temperature and suint per unit food intake increased with increase in fleece weight.