The number of breeding sheep in a flock and the number of generations under selection will directly affect the genetic improvement possible. Both in cattle (Donald and El Itriby, 1945, 1946) and in pigs (Donald and Auerbach, 1942) a small average herd size and short life were found to have set severe limits to the breeding policies possible. The present report discusses this problem in lowland registered sheep flocks.

The use of drinking water as a vehicle for the medication of early weaned pigs offers an advantage over infeed medication in that water intake postweaning is substantially higher than feed intake. A precondition for effective water medication is the accurate assessment of water intake. At present there is little published information on the water demand of early weaned piglets reared under contemporary conditions of housing and nutrition. The objective of this study was to establish whether the water intake of early weaned piglets could be predicted from easily measured variables such as feed intake and liveweight.

On hill farms where breeding cattle are kept there are advantages in retaining until the following spring at least a proportion of the surplus calves. The ability to winter them presents wider scope in choice of markets, while the sale of calves in spring, in addition to the dung produced, can provide a greater profit margin if wintering costs are minimised. Grass used efficiently in autumn offers an opportunity to reduce the requirement of the relatively expensive hay, silage, other crops and purchased feed. The value of extended grazing throughout autumn and winter months has been demonstrated by Smith (1953-4) for Blackface ewe hoggs, and for store stock and in-calf heifers by Hughes (1954) and Corbett (1954). In the case of calves, however, the period when late grass can be utilised depends on the continuance of moderate temperatures and availability of shelter from wind and rain, and therefore in most seasons will be relatively short. With these considerations in mind it was decided to compare the performance of two groups of weaned calves, one of which was housed and fed in courts immediately after weaning, while the other remained on grass for several weeks prior to court feeding.

The change in muscle-weight distribution from birth to maturity was examined in rams and ewes from strains of Australian Merino sheep which had been selected for high or low weaning weight, and from a randomly bred control flock. The proportional distribution of total muscle weight among nine anatomically standardized muscle groups was determined for 34 mature animals. The growth of each group was then assessed relative to the growth of the total musculature, using data from 106 immature animals. Maturity coefficients were calculated separately for pre- and post-weaning growth. Several muscle groups exhibited a diphasic growth pattern.

Selection for high and low weaning weight resulted in an increase and decrease respectively in total muscle weight in mature animals, but had no effect on mature muscle-weight distribution. There were no significant strain effects on maturing patterns of muscle groups, except during the pre-weaning growth of muscles around the spinal column and those connecting the thorax to the forelimb. When compared at the same stage of maturity there was little difference between the strains in muscle-weight distribution. However, at the same weight the larger mature-size strain had a more immature pattern of muscle-weight distribution.

The total muscle weight of mature rams was greater than that of mature ewes. Sex also had an effect on muscle-weight distribution at maturity for seven of the nine muscle groups. At maturity rams had a higher proportion of their muscle weight in those muscle groups associated with the neck and thorax, and a lower proportion in those associated with the limbs. Sex affected the pre-weaning maturing pattern of the muscles of the spinal column, and the post-weaning maturing pattern of all muscle groups, with the exception of those muscles associated with the distal hindlimb, the spinal column, and those attaching the thorax to the forelimb.

A technique for evaluating beef carcasses in terms of their retail value, has been applied to 132 half-carcasses from seven groups of cattle (Jersey, Hereford, Polled Hereford, Lincoln Red, Devon, South Devon and Charolais × Jersey) to test the general applicability of the method, in particular the regression equations for predicting retail value. Significant differences in retail value were found between the groups of animals, South Devon and Charolais × Jersey having a high retail value per kg side weight, and Jerseys a low one. There was a very high correlation between retail value per kg side weight and the proportion of muscle in the side. Relationships between retail value and proportion of fat in the side were also investigated. It is not possible to decide, from these data, whether the differences found in retail value are a true breed effect, or whether they are due solely to differences in composition.

Effect of breed, rapid inbreeding, crossbreeding and environmental factors on fleece weight and fleece shedding in sheep

G. Wiener, G. Lee and J. A. Woolliams

Animal Production 1994 59: 61-70.

The vertical axes on Figures 2a and 2b should be labelled Shedding score.

Foote, Tyler and Casida (1959) found that the birth weight of Holstein calves from the right horn was significantly heavier than that of calves from the left horn but found no significant effect of side on gestation length. In a further study Foote, Hauser and Casida (1960) found no effect of side of pregnancy on either birth weight or gestation length in an analysis of 128 gestations among Angus and Shorthorn cows. They did find, however, a significant interaction of breed and side of pregnancy on gestation length.

Feeding pregnant ewes on silage-based rations during housing is widely practised. However, silage making is a capital intensive procedure and the cost is likely to increase due to pollution legislation. Feeding ewes on a cereal-based ration may be a cost effective alternative. This is especially relevant due to the ban on straw burning and the possibility of CAP reform forcing cereal prices down. This experiment compares the effect of silage- and wheat-based rations during the winter housing period on ewe and lamb performance.

Approximately 260 mule (Bluefaced Leicester x Swaledale) ewes were selected from the breeding flock at the time of winter housing in January 1989, 1990 and 1991. They had previously been at grass and had run with Suffolk rams between mid-October and mid-December.

The use of Automatic Control of Natural Ventilation (ACNV) has been shown to give good temperature control in a range of circumstances [2, 3]. Information on the performance of the system in wide, solid floored, pig finishing houses under extreme climatic conditions is sparse. A study was made of a commercial pig finishing house during the hot summer of 1983. Information collected allows an assessment of the climatic conditions encountered in relation to long term meteorological records.

Ruminant production systems can have a negative effect on the environment within three main areas 1) loss of nutrients to aquatic environment, 2) loss of nutrient to the aerial environment and 3) contribution to the global increase in temperature (green house effect).

In Denmark area 1) is considered as a very serious problem in particular NO3-leaching from the agricultural land. Within area 2) the loss of NH3 from ruminant production is considered as a major problem. Concerning the green house effect (area 3)) the loss of N20, C02 and CH4 are considered as a problem in connection to ruminant production.

Architecture may seem an ambitious description to apply to the mass of observational data and conjecture which at present constitutes our knowledge of male sex behaviour, but it is well to keep in mind the existence of a complex integrated structure, genetic in origin but modified by environment, which determines the way an animal behaves in response to a given situation. The object of this paper is to suggest some of the ground plan of this structure. I have given a few references in the text, but wish to express my indebtedness in particular to the work of Beach (1948), Milovanov & Smirnov-Ugrumov (1940), and Gunn (1936), whose writings on the subject have been of such fundamental importance.

The present experiment was designed to investigate the influence of variations in energy intake during both pregnancy and lactation on changes in body weight, backfat and body composition of the sow after four parities and the extent to which these may have influenced overall sow productivity.

The experiment has been designed in a 2 x 2 factorial arrangement involving two levels of feeding during both pregnancy and lactation. The feeding levels in pregnancy were planned to produce net maternal body weight gains of 30kg (H) and 10kg (L). At each of these, two feeding regimes were applied during a 3 week lactation, one being at a conventional level (H) and the other 25% below this (L). The experiment thus involved four groups of animals given different levels of feeding during both pregnancy and lactation, designated: High-High (HH), High-Low (HL), Low-High (LH), Low-Low (LL). No creep feed was provided to the piglets during the suckling period. At the start of the experiment the gilts weighed 115kg live weight with a backfat thickness at the P2 position of 18mm. They remained on the same treatment throughout four parities and were slaughtered after weaning their fourth litters when the carcasses were retained for analysis. Data are presented from 66 sows; 17(HH), 17(HL), 16(LH), 16(LL).

Previous work has shown that treating moist grain with ‘Farmline’, a formalin acetic acid mixture, affords some protection of protein and perhaps starch from rumen degradation. A comparison with and without ‘Farmline’ treatment investigated the protection afforded to dried barley.

Before dealing with the marketing of livestock I will mention briefly the current arrangements for the disposal of our two main livestock products—milk and eggs. Milk is marketed through a Producers’ Marketing Board which operates on very much the same lines as the Milk Marketing Boards in Great Britain.

In the marketing of eggs we have a unique system for the control of egg quality. The eggs are collected in the normal way by packers, or collectors acting on their behalf, and are graded on a quality basis in the packer’s store. The producer is paid on the result of this grading, deductions being made for second quality eggs, cracked eggs, soiled eggs, etc. The grading and packing are supervised by officers of the Ministry of Agriculture who also carry out further checks on the standard of packing and quality of eggs being shipped to Great Britain. These further checks are carried out at the ports of shipment, random samples of eggs being subjected to further quality tests.

The farrowing crate is one of the most confining forms of animal accommodation found in intensive animal rearing systems and so is subject to criticism from welfare lobby groups. To determine how the welfare of the sow might be affected by the crate, we need to gain an understanding of pre-farrowing behaviour, and the factors that affect its expression. Free-ranging domestic sows will leave the herd on the day before farrowing and walk up to 6.5 km, build a nest and farrow in it (Jensen, 1986). Crated sows are known to become very restless in the day or so before farrowing, and as farrowing approaches they bite at the crate and paw and root at the floor and fittings (e.g. Jones, 1966). It is possible that this behaviour is an expression of the motivation to perform locomotion and nest-building as shown by sows in the wild. To investigate this, three experiments were designed to investigate pre-farrowing behaviour in domestic sows and the influence of straw (a nest-building substrate) on its expression.

In a consumer test involving 108 households, liver from pigs fed a sucrose solution in lairage overnight prior to slaughter was preferred on its appearance to that from pigs which had received water only during the resting period. Highly significant preferences were shown for fried and casseroled sugar-fed liver in relation to tenderness and juiciness but not flavour. When all eating characteristics were taken into consideration participants were equally divided in their preferences for ‘sugar-fed’ and normal liver.

During the year of my presidency of the Comparative Section of the Royal Society of Medicine, a continuous theme was selected for discussion, leading up, through the subjects which constituted the most rational means of appreciating its meaning and scope, to the culminating one, namely, that of Comparative Psychology and Animal Behaviour. Without such rational approach it would have been impossible, to my mind, for anyone not conversant with the immense and confusing literature that is now accumulating on the subject to grasp the transcending importance of animal behaviour study as a subject calling out for immediate exploitation, particularly by veterinary workers.

Studies with sheep suggest that accurate estimates of herbage intake can be obtained by using the herbage alkane tritriacontane (C33) and dosed dotriacontane (C32) as markers, since the faecal recoveries of both alkanes have been shown to be very similar. To validate the technique for herbage intake estimation in grazing cattle there is a need to compare in cattle, the faecal recoveries of both herbage and dosed n-alkanes. It has been observed in sheep that the faecal recoveries of n-alkanes increase as their chain lengths increase, suggesting that the recovery of hexatriacontane (C36), an alkane absent from herbage but available commercially at low cost, should be complete. C36 may therefore have potential as a dosed marker for estimation of faecal output. Thus it may .30 be possible to obtain estimates of both herbage intake and diet digestibility in the same individual grazing animal using n-alkanes as markers. The purpose of the experiment described here was to determine the faecal recoveries in cattle of odd-chain n-alkanes from fresh herbage and of C32 and C36 dosed n-alkanes.