Abstract:
FURTHER EXPERIENCE WITH EARLY WEANING OF PIGS IN AUSTRALIA J. M. HOLDER* and R. H. KERRIGAN* I. INTRODUCTION The technique of weaning piglets at an age earlier than the usual 56 days has been examined in many countries (e.g. Grummer 1954; Smith and Lucas 1956; Smith 1960). The only published report of the results of early weaning in Australia appears to be that of Osbaldiston (1959) who weaned piglets at 28 days old but did not compare the results of early weaning with normal weaning in terms of overall pig production. Both early weaning (at 14 or 21 days) and normal weaning (at 56 days) of pigs are practised at Wollongbar Agricultural Research Station. The opportunity has been taken to report further experience with the technique under Australian conditions. II. MATERIALS AND METHODS Sixty-one litters were farrowed over a two year period; 44 were Tamworth x Large White, the remainder being 7 pure bred Tamworth and 10 Large White. Sixteen litters were weaned at 14 days, 12 at 21 days and 33 at 56 days. As early weaning was used to ensure a close concentration of farrowing dates in the Wollongbar herd, the litters of sows farrowing toward the end of a farrowing 'season' were usually those weaned early. The diets used are recorded in Table 1. During Diets used for sows and piglets TABLE 1 *N.S.W. Department of Agriculture, Wollongbar Agricultural Research Station. j-Present address: Wm. Cooper & Nephews, P.O. Box 12, Concord, N.S.W. 135 gestation sows received 3 to 5 lb (1 36 to 2 -7 kg) meal daily according to their body condition and had free access to grass. Each day after farrowing, sows whose litters were to be weaned at 56 days received meal in quantities increasing gradually, during the 21 days after farrowing, to a maximum of 2 lb (O-91 kg) plus 1 lb (0.45 kg) for each piglet suckled. This schedule was maintained to weaning. Sows whose piglets were to be weaned at 14 days and 2 1 days received a daily ration of meal to a maximum of 8 lb (3 -64 kg) before weaning, the amount fed depending on litter size. Sows rearing eight piglets or more received the maximum ration. The maximum daily level was reached by gradual increase over the first week after farrowing. Early weaned litters received diet No. 1 to 28 days of age, a mixture of the No. 1 and No. 2 diets (50:50) to 35 days then No. 2 diet to 56 days. At 14 days a supplementary diet was introduced to piglets to be weaned at 56 days. These diets were available ad libitum and the quantity of meal consumed by litters was measured daily. Water was freely available. Sows and their litters were weighed individually at farrowing and at weaning and the early weaned litters were weighed again at 56 days. At weaning the sow was removed from the litter and placed with a boar for mating at the next oestrus. l III. RESULTS AND DISCUSSION Results are presented in Tables 2 and 3. TABLE 2 TABLE 3 There was no indication that the number of pigs alive at 56 days was influenced by weaning treatment. The small differences were attributable to mortality in the first few days following farrowing. Litter performance was similar on all three treatments although there was a non-significant trend toward higher average weights at 56 days in pigs weaned at that age. It was noticeable that average litter weights improved as experience was gained in using the early weaning technique. Further, it is known that piglets 136 weaned at 56 days at this Station receive a temporary set back to growth for about 10 days. Over this period early weaned pigs generally eliminate any previous difference in weight compared with those weaned at 56 days. An independence test of the farrowing interval data between weaning treatments could have arisen by chance chi-square value with two degrees of freedom was 3 -7 1 14, 2 1 and 56 day weaning treatments 2.74, 0.19 and 0 indicated that differences (O.l<P<O.2). The total with the contribution of -78 respectively. Smith and Lucas (1956) demonstrated that with litters weaned at 10 days, sows were effectively mated within three weeks of farrowing. They state that the time saving should be enough to ensure at least one extra litter per sow over a two year period, compared with four produced when litters are weaned at 56 days. In our study (Table 3) the extra litter in a two year period would have been possible most consistently where litters were weaned at 21 days. There was considerable variation in ability of sows to farrow again in the shortest time theoretically possible where litters were weaned at 14 days. However, most confidence could be placed in sows being effectively mated at the first oestrus following weaning at 56 days. The small differences (Table 3) in quantities of meal consumed by sows on different weaning treatments at the same stage of lactation are a direct reflection of the differences in litter size. It is unlikely that the irregularity in breeding performance of sows weaned early could be due to the variations in meal intake. No data appear to be available in the literature of the effect on lifetime breeding performance of sows whose litters were consistently weaned early. We have information of only one sow whose first five litters were early weaned. Her performance in no way suffered by comparison with another three sows with three of the first five litters weaned early nor with Large White sows whose litters were weaned at 56 days after each farrowing. Our results, therefore, agree with other workers in suggesting that earl y weaning at 21 days could have advantages over 56 day weaning by producing one extra litter over a two year period. IV. ACKNOWLEDGMENTS The authors thank Messrs. B. L. Dircks, D. R. Burry and G. H. Kennedy for the care of the pigs used in this study. V. REFERENCES G O S R. H. ( 1954). Baby pig nutrition. Proceedings of 1954 Cornell Nutrition Conference for Feed Manufacturers. Cornell University, Ithaca, New York. SBALDISTON , G. W. (1959). The nutrition of young pigs including studies in early weaning. RUMMER , Australian Veterinary Journal 35: 217. MITH , D. M. ( 1960). The effect of early weaning upon the energetic efficiency of the reproductive cycle of sows and upon management and marketing methods. New Zealand Journal of Agricultural Research 3: 896. S MITH , H., and L UCAS , I. .A. M. (1956). The early weaning of pigs. I. The effect upon growth of variations in the protein, fat, sucrose, antibiotic, vitamin and mineral contents of diets for pigs of 8-25 lb liveweight and a comparison of wet and dry feeding. Journal of Agricultural Science 48: 220. 137