In some areas it may also be necessary to supplement these piglets between pastures and when stubble is available. Overall, lambing on green fodder often allows ewes to graze at a higher stocking rate.
TIME OF LAMBING - EWE HEALTH
Research work by Edwards et al. 1985), showed that the prevalence of dermatophilosis in lambs steadily increased from a minimum in flocks lambing early (January to March) to a maximum in flocks lambing later in the season (July to December). In the absence of adequate vaccination coverage, this would suggest that the prevalence of enterotoxemia would be higher in late lambing flocks.
INCREASE PROFIT WITH LATE WINTER LAMBINGS
Lamb marking, mulching and weaning are easier to organize because there is a smaller range of lamb ages. It is also likely that over the summer there will be a smaller tail in the herd of weaned animals.
TIME OF LAMBING - BENEFITS AND COSTS OF CHANGING
The time of shearing is usually changed to autumn to fit in with the management of later lambing time. Changing the sheep program has a big effect on the cash flow and changes the time of the peak debt in the first 3 years.
HOW LATER LAMBING HELPS PASTURE MANAGEMENT
A pasture that is heavily grazed in the spring will use and need much less moisture than a lightly grazed pasture. Remember, the shorter the pastures in the spring, the more nutritious, palatable and weed-free they will be. By shearing and selling sheared sheep between October and March, the benefits of later lambing are even greater.
The minimum stocks will be at the break of the season, and the maximum numbers in spring or summer. Farmers will need to adapt their sheep and grazing management to make the most of later lambing. However, the farmers' experience has shown that it is very worthwhile for the entire farm management to switch to a later lambing.
GRASS CONTROL IN PASTURES USING HERBICIDES
If done correctly, grazing management should remove grass early in the season and no seed should be produced. Removal of grasses in the year before the crop should reduce the level that germinates in the year of crop establishment. The effect on legume seed set will depend on the choice of herbicide and the timing of application.
Extend periods of heavy grazing in the spring to extend the flowering time of the grass later in the season and avoid the more sensitive stages of legume growth (bloom). Areas in the northern wheat belt have less time between legume and grass blooms than areas in the south. The benefits of incorporating RLEM control into surgery are greater when pasture is tapped with glyphosate (legume more stressed after application) or when a.
WEANER MANAGEMENT WHEN LAMBING LATER
If hand feeding is expected, lead the lambs before weaning so they are used to the grain before feeding begins. If lambs are weaned early, it is ideal to leave the lambs in the paddock they are used to (ie remove only the ewes). In this way, the lambs do not have to deal with learning a new paddock, as well as drinking without milk.
If you use this technique, soak the lambs when they go into their first new pen - say 2 weeks later. Once the lambs are in the weaning pen, it is best to set them as long as the pasture is suitable. If these lambs do not gain weight over the summer, their survival rate and lifetime wool production will decrease.
SUMMER FODDER CROPS
To understand the place and economics of the forage crop, it must be considered in the context of the entire farm industry. In such cases the extra wool grown is increased because the extra live weight of the weaned calves on the forage crop is transferred to a marginally higher feed intake and therefore wool production, for a large part of the year. If a farm has an above-average stocking rate in the winter, keeping surplus sheep into the summer can increase the feed requirement, so that the pastures are grazed, leaving insufficient reserves for the rest of the sheep.
A high population level of weanlings on the crop enables a reduction of the population level on the rest of the farm. Let's compare this with the state of the fodder crop of 37 ha, which is part of the crop of 80 ha. It helps to understand the place of the forage plant in the previous system (15%).
FACTORS TO CONSIDER WHEN CHANGING TIMES OF LAMBING AND SHEARING
Management in July and August is a little easier than with a May litter and is similar to a June litter. The cover rate can be 3% higher than with a May laying for the same winter grazing pressure. July calving: as for June, but the degree of stocking can be 20% higher than with a May calving for the same winter grazing pressure.
Even then, the grazing pressure in May will still be lower than with an April or May calving. August lambing: stocking rate can be 50% higher than with a May lambing for the same winter grazing pressure. September, October, November clipping: any weakness will tend to occur in the middle of the staple.
OPTIONS FOR CHANGING TIME OF SHEARING WHEN LAMBING ON GREEN FEED
CHOOSING A TIME TO SHEAR
In a trial at Merredin Research Station, 24 per cent of autumn lambing/spring sheared ewes produced soft fleeces despite supplemental feeding. At a time of shearing experiment at Mount Barker Research Station, the spring-shorn wool, based on fiber length in the top, would have been worth about 14 percent less clean than the autumn-shorn wool, which at 1982 prices could be about 60¢/kg. In general, vegetable fault of any species of more than 6 percent increases the cost of processing Merino wool and therefore incurs a price penalty.
An average Western Australian fleece can command clean price penalties ranging from 2¢/kg for 2 to 3 per cent DM, to 20¢/kg for 6 to 7 per cent DM. In the shearing time experiment at Mount Barker, fall-shorn wool had an average full clip VM of 3 percent, while spring-shorn wool had an average VM of 1 percent. In 1977, the Newdegate Research Station clip averaged 5 percent V~/f in the wool and 14 percent in the piece line.
TIME OF SHEARING
This is the effect that hair removal has on the energy requirements of sheep. The timing of shearing is predicted to have little effect on the total annual grazing requirements of sheep. Grazing required (g DM/day) to maintain 42 kg dry ewes in June, July and August Shearing date Grazing requirement.
Note that changing clipping from October to June increased expected intake by 328g - a 67% increase. Due to the greater feed intake and normal heat production in pregnant and lactating ewes, shearing date did not have as great an effect on the predicted winter feed requirement of breeding ewes. For the July calving, changing clipping from October to June increased the expected intake by 203 g/hd/day - an increase of 18%.
TIME OF SHEARING AND WOOL QUALITY
The doubt of this early work was the reliability of the yield of the middle sample to predict the yield of the whole fleece when comparing different times of shearing. Also to be able to predict the outcome of shaving at times other than 'autumn' and 'spring'. Effects of shearing and lambing time on wool production, Yalanbee October sheared October sheared March sheared March sheared.
The effect of shearing on heat production and activity in sheep receiving dried grass or ground hay. Effects of shearing and herbage supplementation on intake, live growth and wool growth of Romney ewes hoggets in spring-summer. The effect of shearing frequency and time on reproduction and wool growth of Bungaree South Australian Merino ewes.
SHEARING LAMBS AT 15 MONTHS OF AGE
With prices moving upwards towards the end of the 1993/1994 season and continuing into the first 8 weeks of the 1994/1995 season, it was not surprising to see sharp increases in price differentials between fine and broad fleece. The net returns for the start of the 1994/1995 season of shearing lambs at two different time options are shown in Table 2. In the 1994/1995 season there is much to be gained from postponing shaving as long as is practical. the lambs that are shorn at 15 months of age have good strength wool.
Comparison of July with early November 1994/1995 net shearing benefits In July the number of lambs decreased at 3 and 12 months (option 1) with delayed shearing to 15 months (option 2). There are several reasons put forward by breeders for shearing lambs early, but most of the problems associated with delayed shearing can be corrected through careful management. This may include shearing lambs as weaned lambs in the fall so that the pile length is sufficient for the more expensive types of fleece wool.
LAMB SHEARING CF. HOGGET SHEARING
The HS group had a significantly higher mean live weight than the LS group on days 12 and 40, probably due to lamb wool sheared from the LS sheep. By day 214, there were no differences between groups, and by day 334, the mean live weight of the LS group was significantly greater than that of the HS group. Total greasy wool (lamb fleece + pig fleece) was similar for LS and HS groups (6.52 vs. 6.42 kg), but due to the higher yields of pig wool and lamb wool in the LS group, there is a significant difference in total clean wool, which was sheared by sheep in both treatments (3.52 kg for HS cf.
Pure wool production, yield, fiber diameter, plant matter, staple length, staple strength and wool value for LS group lamb shearing and hogget shearing for both groups are shown in Table 2. Ralph , Department of Agriculture, South Perth, Mr R Collins of the Wool Analysis Centre, Belmont and Mss. G. Grinham of the South East Wool Centre, Esperance, are well known for advice and technical assistance with wool.
SPLIT SHEARING
On the basis that competition might permit a slightly cheaper rate, the fall shearing cost was assumed to be 20¢/head less than the spring rate. The two influences are likely to be the cost of shearing and the differential wool price. Using the above standard herd assumptions, but using a fall shearing cost of $1.00/hd cheaper than in the spring, there is a shearing benefit of almost $4,000.
How large must this price difference be to favor a particular time of shaving. In fact, split shavers (and spring shavers) should both be thinking about changing to a full fall shave. If split shearing is to be discouraged, eg to make it easier to control lice, the argument should focus on the financial benefits of lice control rather than any other compelling factor.
TIME OF LAMBING/SHEARING - CASE STUDY
