Records of Nutritional Factors  in Fertility of Goats

The following paper is reprinted from the proceedings of the 2nd National Goat Breeders’ Conference, Perth, Australia, 1979.  It continues the history of the Narkoori herd and clover-related breeding difficulties.


by Mr C.L. Faudell,

Life Member of The Goat Breeders' Society of Australia

Federal President 1966-72.

The influence of nutrition on natural fertility is a highly complex subject beyond the scope of this paper.  Our object is to discuss how our herd records over a period of at least 12 years show a pattern relating diet to fertility and fecundity also how a radical change in pattern occurred when certain adjustments were made in that diet.

Prior to 1968 we had periods of unstable breeding results.

For example in the period 1964-68 we encountered the following serious problems which were not self-righting.

(a) Low fertility and delayed pregnancy.

(b) Low fecundity with single kids and twins of male sex.

(c) False pregnancies or cloudbursts.

(d) Lactation problems linked with the above.

The Toggenburgs were affected more than the Saanens.  Our records for the period 1953-67 show the Toggenburgs produced 39 males and inter-sexes to only 9 females; in several years no Doe kids were born.  Until 1967 our Saanen reproduction was not abnormal, however in circumstances to be discussed there was to be a dramatic change.

Prior to 1967 Toggenburgs and Saanens were run together, but individually bailed for their concentrate ration of lucerne chaff, oats and bran with a little linseed meal during lactation also a mineral supplement containing a generous limestone base.  Having found lucerne hay wasteful we settled on high clover content hay fed in open racks at the rate of' 3 lbs per head plus wastage.  Although we were aware that the Toggenburgs tended to monopolise the hay racks we did not appreciate how much this affected the Saanens' share.

In the autumn of 1967 the Saanens were housed and fed separ­ately and in due course their breeding behaviour followed the Toggenburg pattern.  After several returns to service 6 were eventually mated but only 4 kidded and produced male kids.  With such small numbers involved a coincidence was possible but the fact that the Saanens now had unimpeded access to clover hay proved to be a link.  We stopped feeding clover hay and subsequent remarkable improvements in breeding led us to suspect Bennett's clover disease.  This phase was detailed in the Australian Goat World, February, 1969.

Professional and academic advice was reserved, Bennett's disease was neither confirmed nor rejected.  The disease is usually associated with grazing green subterranean clover containing phyto-oestrogens which mimic the indigenous oestro­gens (female hormones) thereby upsetting the hormone balance.  It appears that in hay form the same clovers are considered safe.  However, CSIRO has reported some U.S. work showing that under certain conditions high levels of isoflavones (phyto-­oestrogens) can be retained in clover hay of particular varieties.

Unfortunately our clover hay was not identified but circum­stantial evidence suggests that it may have been Yarloop.  The clover content was about 90% suggesting it was grown for cutting; it was soft in texture and noticeably bleached, indicating slow drying in moist conditions; notably the seeds were brown.

Until recently Yarloop was the preferred species for damp conditions; it is a different sub-species from most other clovers whose seeds are blue-grey.  Yarloop is near the top of the list for phyto-oestrogen content - seven times the safe level for pasture!  It is also sensitive to clover scorch, a fungus disease said to considerably increase the level of a particular oestrogen (coumestrol) which causes temporary infertility in sheep.  The following extracts from our records strengthen our view implicating the clover hay.

False Pregnancies.  'Cloudbursts' may never be seen in small herds but occasionally occur in larger herds.  During the 3 years we fed rich clover hay more than a quarter of our goats had false pregnancies which ran a course of from 3 to 5 months.  During the 3 years following the elimination of clover hay we had no false pregnancies and the last 10 year average, with the herd size increasing to 50 adult females, was about two per year.

Fertility.  When a Doe fails to conceive after several normal services she may be classed as temporarily infertile because a proven buck can rarely be blamed. During the clover hay feeding period most of the Toggenburgs and later the Saanens returned to service several times before becoming apparently pregnant.  An inhibiting factor such as clover disease was present.

The action of phyto-oestrogens on the uterine cells produces a cystic glandular environment which is hostile to the develop­ing embryo and could cause early embryonic death.  In the acute stage the cervical mucous becomes so watery that the path of direction for the sperm is scattered and the prospects for the fertilisation are remote.  The acute condition usually shows externally an excessive wet discharge.  This was sometimes present but not very obvious with our goats so an acute condition was improbable.

As we saw the evidence at the time early embryonic death was more probable than fertilisation failure.  Assuming that fertilisation takes place and the embryo survives to about day 13 and then dies we would be unaware of this conception because the Doe will return to service at her normal time.

If however the embryo dies after day 13, the Doe will not return to service before day 33 or 34.  A significant number of our goats did in fact follow this latter pattern and so provided another basis for supposing early embryonic death in the hostile environment of clover disease.  We discarded the possibility of simple under-nutrition because this tends to depress growth of the embryo and foetus rather than cause its death.

Fecundity and Sex Ratios.  The reproduction rate during clover feeding was considered low - average 1.3 kids per birth.  Even more unusual was the preponderance of male kids.  In 1966-67 for example, 11 goats successfully mated produced 14 males, and only 2 females.  A preponderance of male kids has been charac­teristic of our Toggenburgs but occurred also with the Saanens when fed an abundance of clover hay.  Elimination of the clover in 1968 had a dramatic effect on fecundity and sex ratio.  Nine Toggenburgs produced 7 males and 8 females; 6 Saanens produced 7 males and 5 females, figures which strongly suggest that the previous low fecundity was due to the death of many females in embryo or foetus.

Now with little doubt about the fact of embryo or foetal death, the sex selective aspect was not explained within our limited knowledge, as a characteristic of' clover disease.  Some other aspect of clover could be involved, for example the well-­known presence of, goitrogens which depress the production of the hormone thyroxine.  A similar depression which is less well­-known is the blocking effect of a high calcium diet, particularly common lime derivatives, on the uptake of iodine by the thyroid gland.

The sex selection aspect suggests foetal rather than embryonic death so this would not occur before the 6th to 7th week of pregnancy.  In one instance of ‘false pregnancy’ we isolated from the cloudburst a foetus of about 7 weeks' development.  It has been shown by others that depressed thyroxine can arrest foetal development and it is known the female foetal development is much more dependent on thyroxine than the male.  This in itself may not explain female foetal deaths, especially in the absence of clinical goitre in the dams and surviving kids.  However, we may be justified in concluding that there was a combination of hostile uterine environment and thyroxine depression fatal to many female foetuses.

Subsequent History.  The elimination of clover hay and ground limestone from the diet resulted in a remarkable improvement in fertility and fecundity but up to 1974 sex ratios still favoured males 1.4 to 1.

We moved to a large property in 1970 and considerably in­creased the herd size.  A pellet ration containing twice the iodine normally included for sheep was introduced in 1973.  Salt licks also had elevated iodine levels but intake from this source was unreliable so from February to June some iodised salt was sprinkled on the pellets twice a week.  From September to January standard copper-cobalt licks were offered and an additional copper supplement during December fed as a salt to provide 10 mg of copper sulphate per day for 6 to 7 days.  We have never used copper injection on goats because the margin between sufficiency and excess is very narrow, as with sheep.  Pasture, pellets and grass hay is adequate for dry stock but to sustain lactation we fed 20 gms of di-calcium phosphate from June to February.

Fertility and fecundity during the period 1975-78 with the above diet bettered any previous period.  Approximately 80% of the goats were pregnant to the first service, births totalled 203 live kids - 104 males, 94 females plus 5 pseudo-female intersexes.  Assuming that an equivalent number of the destroyed males were pseudo-male intersexes, which are actually genetic females, the sex ratio is substantially genetic unity-

Conclusion.  Records show that a group of goats fed on rich clover hay had a very depressed fertility record.  A second group when also fed an abundance of clover hay declined in fertility also.  Removal of the clover from the diet dramatically improved fertility records.  Still further improvements in fecundity and sex ratio followed supplementary iodine and copper.  'The diet was reversed to gain more evidence because we overcame the fertility problems and rightly or wrongly came to the conclusion that aspects of the diet caused sub­clinical clover disease and an elevated demand for iodine etc.

No doubt a close examination of the subject is required for proper scientific conclusions; however, in Victoria other goat keepers have reported improved fertility following diet changes and mineral supplements.

Year    No. Goats      Fecundity_            Male*           Female   Intersex F.

1969 20     2.05 20 21 1

1970 19 1.53 18 11 1

1971 34 1.65 31 21 1

1972 40 1.70 42 26 3

1973 39 2.07 48 33 2

1974 49 1.47 38 34 2

1975 41 1.90 40 38 3

1976 29 2.00 29 29 2

1977 15 2.13 19 13 0

1978 15 2.00 16 14 0

301 1.85 301 244 15

*Including unrecognised intersex.

The table illustrates the 10-year pattern shows a mean fecundity factor of 1.85, however the average for the last 4 years is 2.03 with the male to female ratio close to unity when corrected for intersexes.  Males should only slightly exceed females but the appearance of genetic female intersexes produces an imbalance upon the presence of the polled factor in the herd.  Should males substantially exceed females over a period of several years the possibility of female foetal death exists especially if accompanied by a low fecundity factor.

Finally we recognise that genetic capability plays a very important part in fecundity.  Small herds with family histories of triplets and quads should have no problem in exceeding a factor of 2 kids per birth but the figure will decline with less selective larger herds; for example, a broad survey by Haugen (Norway) resulted in a factor of 1.54 in 1360 births.