SHORT CONTRIBUTIONS

Feeding of feral goats before live export by ship

Sheep Industries Branch, SG GHERARDI Department of Agriculture, TJ JOHNSON Baron-Hay Court, South Perth, Western Australia 6151

There is a potential to export live goats for slaughter to both the Middle East and Asia. The development of these markets has been hampered by the inability of Australian exporters to provide a consistent supply of a quality product. Goats, primarily of feral origin, were not adequately prepared for live export and as a result mortalities during shipping were about 6% (RT Norris, personal communication).

The failure of goats to eat in feedlots is likely to be the main reason for their poor performance during shipping (Gherardi and Johnson 1994). They showed that a higher proportion of goats not eating at the end of lot-feeding either died, or were removed during simulated shipping because they had lost more than 20% of their initial body weight when compared with those eating. This result paralleled the findings of Norris et a1 (1989) who showed that sheep that ate pellets in feedlots are more likely to continue to eat and survive aboard ship than those that did not eat pellets.

Gherardi and Johnson (1994) also found that it was possible to reduce the proportion of goats not eating by increasing the period of lot-feeding from 7 to 14 days . Even then, the proportion of non-feeders was unacceptably high. It may also be possible to increase the proportion of feeders by altering the composition of the pellets and the method used to adapt goats to the pellets. Feeding feral goats pellets containing high levels of cereal grain could increase the risk of digestive disorders caused by the dominance behaviour of some goats (McGregor et a1 1994), and presumably could reduce the proportion of feeders, compared with feeding goats pellets low in cereal grains. Also, the commercial practice of feeding hay and pellets separately during adaptation may not be suitable because it has been found that,

with sheep, most eat the hay, and not the pellets (Kellaway 1988). Nevertheless, McGregor (1984) showed that a level of 13% hay was required for goats to maximise their intake of a barley-lupin whole grain diet. The experiment reported here examined the effect of 2 types of commercial pellets and 2 methods of introduction on feed intakes and body weight changes over a period of 19 days.

Between 7 and 9 March 1992, about 500 feral bucks were either trapped or mustered in the Murchison region (27" S and 116" W) of Western Australia. On 10 March, the goats were trucked 500 km to Bullsbrook (32" S and 116" W) where 240 goats of similar body weights were selected. The following day the goats were transported 100 km to the Department of Agriculture Research Station, Beverley (32" S and 117" W) where they were vaccinated against pulpy kidney, tetanus and caseous lymphadenitis*. The treatments (2 commercial pellets: pellet A - high cereal grain or pellet B- low cereal grain) by 2 methods of introduction (chaff in troughs or hay in racks ) were organised as a randornised block design with 3 replicates. The bucks were allocated to the treatments on a stratified body weight basis [mean (range) f SEM = 26.4 (17.5 to 35.5) f 0.32 kg]. The goats within each treatment were allocated at random to their respective replicates (20 goats per plot).

The experiment lasted 19 days from 12 March to 30 March during which the average minimum and maximum temperatures were 16 and 27°C. respectively, and rain fell on days 6 (12 mm), 7 (1 1 mrn), 8 (7 mm), 9 (4 mm) and 15 (1 mm).

The goats in each replicate group were located in separate outdoor plots (20 m 20 m). They were gradually introduced to the pellets over a period of 5 days after being put in the plots, by increasing the amount of pellets and decreasing the amount of hay or chaff fed in equal increments (0:100%, 25:75%, 5050%, 75:25% and 100:0% for days 1,2,3,4 and 5, respectively). The chaff and pellets were fed together in troughs, which provided 15 cdhead. On day 1 the goats were offered 650 glhead of hay or chaff. At the end of the introduc- tory period (day 5) the goats in each plot were offered pellets only, at 2.75% of mean body weight for each plot. This was increased to 3% of mean body weight on day 13 of lot-feeding. Feed residues from each plot were collected at 0900 h daily and the goats sub- sequently offered fresh feed. Fresh water was available at all times.

* Glanvac 3@, CSL Ltd, Parkville, Vic

TABLE 1 The intakes, changes in body weight, proportion of feeders, pH of rumen contents (feeders only) and number of deaths for goats fed

pellets with high (pellet A) or low (pellet B) cereal grain content after adaptation with chaff or hay

Measurement Period Pellet A Pellet B SED (days)

Chaff Hay Chaff Hay

Intake (g/goat.day) 5 -12 659 645 679 658 37.7 13 -19 765 776 753 749 38.3 5 -19 708 706 714 701 29.8

Body weight change (kg) 0 - 1 1 0.22 0.44 -0.04 0.71 0.32 - 0.33 11 - 19 -0.42 0.80 0.89 0.60 0.34 - 0.35 0 - 1 9 -0.12 1.6 1 .o 1.2 0.60 - 0.62

Feeders (%) 5 80 90 11 79 75 19 84 77

93 88 83 75 90 88 -

- -

pH rumen contents 6 6.83 6.89 6.96 6.80 0.074

Number of deaths 1-19 7 6 5 2 -

SED = standard error of difference between means

429 Australian Veterinary Journal Vol. 72, No. 11, November 1995

Where possible, dead goats were necropsied to determine the likely cause of death and whether or not the goats had been eating, by checking for solids in the rumen.

PelletAcontained(gkg): lupinseed(250), barley(l50),oats(l50), straw/oat hulls (410) and mineraldvitamins (40). It had a nitrogen (N) concentration of 19 f ig , an acid detergent fibre (ADF) concen- tration of 307 gkg , a dry matter digestibility (DMD) of 63.6% and an estimated metabolisable energy (ME) of 8.8 MJkg. The ME was calculated from the relationship: ME (MJkg) = 0.17 DMD -2.0 (Anon 1990).

Pellet B contained (gkg): lupins (250), oats (1 50), hayktraw (560) and mineraldvitamins (40). It had a N concentration of 19 gkg , an ADF concentration of 350 gkg, a DMD of 56.4% and an estimated ME of 7.6 MJlkg.

The chaff had a N concentration of 1.2 g k g and a DMD of 59.0% and the hay a N concentration of 0.75 glkg and a DMD of 56.0%.

The goats were weighed on day 0 , l l and 19 of the experiment just before feeding. Goats that ate pellets (feeders) on days 5, I1 and 19 were marked with Edicol blue dye (Gherardi and Johnson 1994). The pH of rumen contents, collected by stomach tube from 30 feeders per treatment group (10 per replicate), was measured before feeding on day 6, using a pH meter.

Samples of pellets A and B, chaff and hay were analysed for total N using a Kjeldahl procedure, for DMD by the pepsin cellulase method (McLeod and Minson 1978) and ADF by near infrared reflectance.

Intakes and changes in body weight for treatment groups were compared using analysis of variance. The effect of pellets, methods of introduction and their interaction on the proportions of feeders and deaths were tested using logit models (McCullagh and Nelder 1992). Goats that died were classified as non-feeders for analytical purposes.

The intakes, changes in body weight, proportion of feeders, pH of rumen contents and numbers of goats that died are shown in Table 1. Neither pellet composition nor method of introduction affected the intakes of pellets after the introductory period. There were also no differences in the intakes of pellets between treatments for either the period when the goats were fed at 2.75% (days 5 to 12) or 3% (days 13 to 19) of body weight. The changes in body weight were similar, with goats in 3 of the 4 treatments gaining weight. The percentage of goats recorded as feeding on days 5 and 19 of lot- feeding were similar for the pellets A and B. However, on day 11, the percentage of feeders was higher for pellet B (91 v 80%, P c 0.05). Neither the cornposition of the pellets nor the method of introduction affected the pH in the rumen of the goats after introduction to the pellets. The numbers of deaths were similar for the 4 treatment groups. It was not possible to necropsy all goats that died, but all of the 9 necropsied died with inanition.

The results showed that neither the composition of the pellets nor the method of introduction affected the intakes of pellets and changes in body weight of feral goats during lot-feeding. Three of the 4 treatment groups gained weight ( 1 .O to 1.6 kg) during lot-feeding, which contrasted with a previous study of Gherardi and Johnson (1994) in which feral goats lot-fed for 14 days lost weight (-1.4 to -2.9 kg). Gherardi and Johnson (1994) found that the longer the period of lot-feeding the more weight the goats lost (-2.2 v -0.08 kg for 14 and 7 days preparation), which contrasted with the findings of this study (Table I). The difference in the intake of pellets is the most likely explanation for the difference in body weight changes between the studies. The goats in the current study (mean body weight 26 kg) had higher intakes than both the LW1 (mean 20 kg) and LW2 (mean 40 kg) goats in the study of Gherardi and Johnson (1994) (707 v 379 v 576 g/goat.day).

The evidence from this study suggests that the failure of goats to eat was the major cause of death in the feedlot. Neither the composition of the pellets nor the method of introduction used in

this study affected the percentage of goats that died or were recorded as eating. The percentage of deaths recorded (8.8%) were unaccept- ably high, which suggests that there needs to be an early screening of non-feeders in the lot-feeding process. These goats would need to be separated from the main mob and fed a diet of hay and grain or sent for slaughter.

The results of this study show that neither the composition of pellets nor the method of introduction affected the performance of feral goats during lot-feeding. Further studies are needed to define the optimum management of feral goats during lot-feeding from both a welfare and commercial viewpoint.

We acknowledge the technical support provided by Mr G Morrell and the staff at Avondale Research Station. This study was partly supported by the Australian Meat and Livestock Corporation.

References Anon (1990) Feeding Standards for Australian LivestockRuminants, CSIRO

Gherardi SG and Johnson TJ (1994) Aust SOC Anim Prod 20.194 Kellaway RC (1988) In Standing Committee Agriculture Workshop on

Livestock Export, edited by Farquharson B, Lynch J and Kellaway R, Australian Government Publishing Service, Canberra, p 195

McCuIlagh P and Nelder JA (1 992) Generalised Linear Models, lpswich Book Company, Ipswich, UK

McGregor BA (1984) Aust J Exp Agric 24:77 McGregorBA,ButlerKLandHowseAM(1994)AusrSocAnimProd20:198 McLeod MN and Minson DJ (1978) Anim Food Sci Tech 3:277 Noms RT, Richards RB and Dunlop RH (1 989) Aust Vet J 66:97

Publications, East Melbourne

(Accepted for publication 5 April 1995)

The geographic distribution of hydatid infection in cattle in

Western Australia

Western Australian Department of Agriculture, Po Box 1231, Bunbury, Western Australia 6231

AJ LYMBERY

School of Veterinary Studies, RCA THOMPSON Murdoch University, CC CONSTANTINE Murdoch. Western Australia 6150

Australian Quarantine and Inspection Service, Department of Primary Industries and Energy, Po Box 1245, Canning Vale, Western Australia 6155

JG KRUGER

Hydatid disease in Australia is caused by the sheep strain of Echinococcus granulosus. There are thought to be 2 main cycles of transmission; one involving domestic herbivores as intermediate hosts and domestic dogs as definitive hosts, and the other involving macropod marsupials as intermediate hosts and feral dogs or dingoes as definitive hosts (Kumaratilake and Thompson 1982; Thompson 1992). There are no major genetic differences between the parasites in these cycles (Lymbery et a1 1990), and Constantine et a1 (1993) found ecological evidence that the 2 cycles overlap to a large extent.

The most commonly infected domestic intermediate hosts in Aus- tralia are sheep and cattle. In Western Australia, cattle are infected more often than sheep, although prevalence is low in both species. State-wide prevalences of hydatid disease in sheep and cattle were, respectively, 0.04% and 0.3% between 1965 and 1967 (Austen

430 Australian Veterinary Journal Vol. 72, No. 11, November 1995