Journal of the Department of Agriculture, Journal of the Department of Agriculture, Western Australia, Series 4 Western Australia, Series 4
Volume 2
Number 3 March, 1961 Article 19
1-1-1961
Time of lambing experiment : Merredin Research Station, 1959-60 Time of lambing experiment : Merredin Research Station, 1959-60 (Progress report)
(Progress report)
W L. McGarry I. K. Stott
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Recommended Citation Recommended Citation
McGarry, W L. and Stott, I. K. (1961) "Time of lambing experiment : Merredin Research Station, 1959-60 (Progress report)," Journal of the Department of Agriculture, Western Australia, Series 4: Vol. 2: No. 3, Article 19.
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TIME OF LAMBING
£ xperimen t
MERREDIN RESEARCH STATION, 1959-60
U' roareiS f\eportJ
by
W . L. McGARRY, Officer-in-Charge Sheep and W o o l Section
and
I. K. STOTT, B.Sc., (Agric.) Sheep and W o o l Adviser
F
OLLOWING upon the Time of Lambing Experiments at Esperance Plains Research Station (Journal of Agriculture, May, 1960) it was decided to carry out similar work with Merino sheep under the relatively harsher environment at Merredin Research Station.INTRODUCTION
It was considered that using Merinos for the experiment under this typical eastern wheatbelt environment would yield in- formation applicable to a wide area of the agricultural areas of W.A. If, under the short season at Merredin, spring born
lambs could reach satisfactory weaning weights, maintain these weights over the summer, with comparable wool cuts at their 2nd and 3rd shearing with autumn- born lambs, it could be assumed that the practice of late winter-spring lambing with Merinos was applicable in most parts of the agricultural areas.
Early results are particularly encourag- ing—especially in relation to the savings made in pre-natal supplementary feeding and the lower incidence of tender wool in the Spring lambing ewes.
EXPERIMENTAL PROCEDURE The experiment commenced in Novem- ber, 1959, when the main ewe flock was divided at random into two groups of 130 ewes.
Group 1 (Brown tags) was mated with 1 per cent, "teaser" rams on November 25th. After 14 days the "teasers" were removed and the fertile mating at 3 per
cent, commenced. The mating period was 8 weeks.
Pre-natal supplementary feeding com- menced on 21/3/60 and continued until lambing commenced on 8th May. The total grain fed to this date was 3,564 lb., or 27.4 lb. per ewe. This could be con- sidered the pre-natal ration. Owing to the inadequate pasture available during May and June, supplementary feeding was necessary and was continued for a further two months (until July 4th) during lamb- ing and lactation. Six thousand eight hundred and sixteen lb. of wheat or 52.4 lb./
ewe were fed during this period, making a total for grain fed per ewe of 79.8 lb.
Based at 13s. 5d. per bushel, the cost of supplementary feeding/ewe was 17s. lOd.
or 22s. 8d. per lamb marked (78 per cent, marking). This does not include cost of labour, feeding out, etc.
The lambs were weaned at 14 weeks from the date lambing commenced. They were weighed at weaning and subsequently on 14/12/60.
Ewes and lambs were shorn at the main shearing in October.
Group 2 (Yellow tags) was mated with 1 per cent, "teaser" rams on February 16th.
The "teasers" were removed after 14 days
279 Journal of Agriculture, Vol 2 No 3, 1961
and t h e fertile m a t i n g a t 3 p e r cent, com- menced. M a t i n g was a g a i n for 8 weeks.
These ewes were carried t h r o u g h without any s u p p l e m e n t a r y feeding.
The lambs were weaned a t 14 weeks from the d a t e lambing commenced on to a p a d - dock of mown a n d dropped p a s t u r e . They were weighed a t weaning a n d subsequently on 14/12/60.
Ewes a n d lambs were s h o r n a t t h e m a i n shearing.
Weaners, Groups 1 a n d 2. On 15/11/60, when Group 1 lambs were 22 weeks old a n d Group 2 lambs were 14 weeks old, t h e two groups were allowed to r u n together.
Supplementary feeding of t h e weaners commenced a t \ I b . / h e a d / d a y of w h e a t on 1/1/61 a n d was increased to i I b . / h e a d / d a y on 15/1/61.
RESULTS
Group 1 Group 2 Dec. Mated, i March Mated, Autumn born \ Spring born
Number of Ewes Mating Commenced Mating Period Lambing Commencing
Percentage of Lambs Dropped to Ewes Mated
Percentage of Lambs Marked to Ewes Mated
Weaning Weight (at 14 weeks from Date Lambing Commenced) ...
Weight at 14/12/60 Weight at 17/1/61 Ewe Deaths Shorn on
Average Greasy Wool Weight (Ewes)
Percentage of Tender Fleeces ....
Grain Fed (to Ewes) Cost at 13/5 bushel
}
lambs 130 11/12/59
8 weeks 8/5/60
86%
78%
49-3 lb.
15/8/60 77-14 lb.
75-0 lb.
10/10/60 4 11-2 lb.
23-6%
79-8:
17s. lOd.
Iambs 130 1/3/60 8 weeks
30/7/60 87%
80%
51-7 lb.
7/11/60 59-52 lb.
61-2 lb.
10/10/60 14 11-9 lb.
8-8%
Xil Nil
DISCUSSION
Contrary to o t h e r work, conception r a t e s and lamb m a r k i n g p e r c e n t a g e s were simi- lar in each group. I t was a n t i c i p a t e d t h a t t h e spring lambing group would have been superior, as M a r c h is regarded as a m o r e ideal m a t i n g t i m e . P e r h a p s n u t r i t i o n a l flushing at m a t i n g would h a v e given greater differences.
Weaning weights a t 14 weeks from t h e date lambing commenced were almost similar. T h e p e r f o r m a n c e of t h e weaners is being studied over t h e s u m m e r (body weight a n d d e a t h s ) a n d t h e 2 a n d 4 tooth shearing results a r e t o be considered. One criticism of spring (August) lambing h a s been t h e affect on t h e lambs, before a n d after weaning, of t h e season drying off
from September onwards—so far t h i s does not appear to have been a factor. (See respective weights 14/12/60 a n d 17/1/61.)
Perhaps t h e most significant difference so far between t h e groups h a s been in t h e cost of supplementary feeding—18s. 9^d.
per ewe for t h e a u t u m n lambing group a n d nil for t h e spring lambing group.
Another i m p o r t a n t difference was t h e f lb./head extra greasy wool cut by t h e non-fed ewes. The fed ewes were supple- mented for 3 m o n t h s a n d yet cut less wool.
The ration decided upon for t h e a u t u m n lambing group could have been too liberal, but the a m o u n t s fed p r e - n a t a l l y were those fed normally to a u t u m n l a m b i n g ewes on Merredin Research S t a t i o n a n d are typical or even low w h e n compared with those fed to m a n y a u t u m n l a m b i n g flocks in t h e agricultural a r e a s . Similarly with rations fed during lactation. P a s t u r e growth was late and slow in May a n d J u n e in this season, but t h e a m o u n t s fed p o s t - natally were similar to those given either a t the Merredin Research Station or on farmers' properties where lambing is timed to take place in a u t u m n . I n all, p r e - p o s t n a t a l supplementary feeding was n e c e s - sary for 3 months—this is n o t u n u s u a l in most flocks in t h e " a u t u m n d r o u g h t " t y p e environment in t h e agricultural areas.
CONCLUSIONS
The experiment so far h a s shown:—
(1) An a d v a n t a g e to t h e spring l a m b - ing group in t h e saving of t h e n o r m a l p r e - p o s t - l a m b i n g s u p p l e - m e n t .
(2) Less tender wool a n d a h i g h e r greasy wool weight in t h e wool of t h e spring lambing group.
(3) More ewe d e a t h s in t h e spring lambing group.
F u r t h e r investigations will be carried out on:—
(1) Greasy a n d clean wool weight differences.
(2) Incidence of t e n d e r wool.
(3) T h e differences in ewe d e a t h s . (It was considered t h a t a t least 11 of t h e 14 ewes dying in t h e spring lambing group died from e n t e r o toxaemia, despite n o r m a l inocula- tion. Extra inoculations will be given in future trials.)
280 Journal of Agriculture, Vol 2 No 3, 1961
