Dried unmolassed sugar beet pulp contains complex polysaccharides which are highly fermentable in the growing pig and the neutral detergent fibre fraction is highly digestible. Fermentation in the hind gut of the pig is dependent on a supply of carbohydrate and nitrogen. The amounts of nitrogen available could limit microbial metabolism and hence sugar beet pulp digestibility at high levels of intake. The alms of the experiment were to examine:

1. 1. The effect of the level of protein on the digestibility of fibre from sugar beet pulp.

2. 2. The effect of the level of sugar beet pulp on nitrogen digestibility, nitrogen retention and nitrogen excretion.

Using primiparous autumn-lambing ewes, this study investigated nutritional effects on (i) pulsatile LH secretion, (ii) responsiveness of the pituitary-ovarian axis to exogenous GnRH, and (iii) oestrus and ovarian cyclicity during the early post-partum period. At lambing (25 October ± 0·3 days), 32 primiparous ewes rearing 2·1 ± 0·04 lambs were equally allocated to four dietary treatments in a 2 ✕ 2 factorial designed experiment. Diets comprised ad libitum hay and 1·5 kg per ewe per day of one of four concentrates (12·5 MJ metabolizable energy per kg dry matter) containing either fibrous (F) or starchy (S) ingredients with (P) or without (O) the inclusion of 120 g/kg fish meal. Throughout the study (lambing to 17 December) ewe body condition score was assessed and ewes and their lambs were weighed at weekly intervals. Blood samples were obtained from all ewes to measure circulating concentrations of progesterone and oestrous behaviour was monitored using vasectomized rams. On day 12 post partum, blood samples were obtained from all ewes at 2-h intervals (09:00 to 17:00 h) to measure concentrations of insulin and urea nitrogen, and at 15-min intervals (09:00 to 21:00 h) to measure pulsatile LH secretion. All ewes received 25 i. v. injections of GnRH (250 ng GnRH in 2 ml 0·9% saline) at 2-h intervals commencing 4 h before the end of the 15-min blood sampling period and their ovaries were examined via laparoscopy on day 17 post partum. There was no effect of dietary treatment on ewe live weight or body condition score throughout the study but inclusion of fish meal in the ewe diet increased lamb growth (FP/SP 255 (s.e. 8·9) v. FO/SO 234 (s.e. 8·2) g/day, P < 0·05). Circulating concentrations of insulin on day 12 post partum were lower in ewes given the fibrous compared with the starchy diets (P < 0·05) while dietary inclusion of fish meal increased (P < 0·001) urea nitrogen. Pulsatile LH secretion on day 12 post partum was not affected by dietary treatment. For ewes on diets F P, FO, SP and SO, the numbers that experienced an LH surge during the period of GnRH administration were 1, 2, 1 and 0, and that ovulated by day 17 post partum were 3, 5, 0 and 5 (FP/SP v. FO/SO, P < 0·05) respectively. Dietary treatment did not affect the intervals from parturition to the onset of ovarian cyclicity or oestrus (overall means were 23 (s.e.1·0) days and 38 (s.e.1·6) days respectively) but ewes on the fibrous compared with the starchy diet had a higher (P < 0·05) incidence of short (≤ 10 days) first ovarian cycles. Results of this study, which involved young growing animals, demonstrate that (i) inclusion of fish meal in the ewe diet influenced the sensitivity of the pituitary-ovarian axis to exogenous GnRH, and (ii) a fibrous compared with a starchy diet was associated with an increased incidence of premature luteal regression.

Thirty Hereford × Friesian steers initially weighing 320 kg were used in two experiments, to compare the effects of mechanical processing of barley straw and the amount of rolled barley offered on intake and live-weight gain. The straw was offered ad libitum either in the long form or shredded through a 40 mm screen and supplemented with 20, 35 and 50 g barley DM per kgW"75 per day (L, M and H respectively). A solution providing 12 g urea per kg straw dry matter (DM) was sprayed onto the straw and all the animals were offered daily 480 g of soya bean meal with minerals and vitamins. In the first experiment, which had a change-over design, the animals were weighed at the beginning and the end of each period. The daily consumption of shredded straw (kg DM) was L 3·38, M 3·29 and H 3·00 and of long straw L 3·94, M 4·02 and H 3·56 (s.e. of difference, 0·29). There were significant differences in straw intake between steers offered the long and the shredded straw (P < 0·001) but no differences in intake when different amounts of barley were offered within the same physical form of straw. The mean daily live-weight gains for treatments L, M and H respectively were 0·25, 0·66 and 0·80 kg for steers given shredded straw and 0·32, 0·62 and 0·87 kg (s.e. of difference, 0·1) for those offered long straw. At the end of the first experiment the same animals were kept for a further 10 weeks on the same straw treatment but only treatments L and H were continued, the steers from treatment M being distributed between L and H. The straw intakes and live-weight gains were in agreement with those observed in the first experiment

At least 25% of herbage grown in Britain contains Inadequate sodium (Na) for lactating cows (Baxter, 1968). The chances of defelcincy have been increased in recent years as more potassium (K) fertilizer has been applied which reduces herbage Na content. Voluntary DM intake of conserved feeds supplemented with Nacl is increased up to 5.5g Na/kgDM but thereafter declines (Shnelder et al., 1986). There is evidence that ruminants will select a high Na diet even when Na requirements are met (Michell and Moss, 1988). Milk yield responses to increased dietary sodium above ARC (1980) recommended allowances have been observed in some experiments (Mallonee, 1984; Schneider et al., 1988) but not in others (O'Connor et al, 1988). This experiment aimed to examine the effects of Nacl application to perennial ryegrass pasture on herbage and dairy cattle productivity, on the preference for Nacl fertilized pasture and to distinguish these effects from those of direct supplementation in concentrates.

There is a scarcity of information in the scientific literature on the effects of seasonal and nutritional factors on fibre production in the South American camelids. Without such information it is difficult to develop systems of management incorporating nutritional regimes and fibre harvesting strategies which will optimise the efficiency of fibre production. This paper presents preliminary results from an experiment designed to provide basic information on the effects of season and nutrition on fibre growth in llamas.

The experiment was conducted on 12 adult entire male llamas which were individually penned indoors under conditions of natural photoperiod and ambient temperature in north-east Scotland.

Two levels of nutrition were applied: the lower level (L) was calculated to supply approximately maintenance energy requirements (calculated as 0.44 MJ/kg0.75) and the higher level (H) to supply twice maintenance. The feeding comprised only hay for the L level and hay plus a proprietary cattle concentrate for the H level.

Grass forms a major component of the total ruminant feed in both Ireland and the UK. Much of the grassland consists of permanent swards of diverse botanical composition with many of the grass species present considered ‘secondary’ or ‘undesirable’ (Frame and Tiley, 1987). The objective of this study was to compare reseeded Lolium multiflorum and Lolium perenne swards with an old permanent grassland sward managed under intensive silage conservation systems, and to determine the annual production of grass silage and subsequent beef carcass output per hectare when the silages were offered to finishing cattle.

A Number of controlled environment studies (reviewed by Blaxter, 1962 and 1964) have emphasised the necessity of providing shelter for out-wintered ruminants. The nature of suitable shelter requires definition and this may be sought by observing the use animals make of different forms of shelter. Direct observation of livestock may, however, sometimes be an inappropriate investigational method. In the work reported here, shelter usage by cattle was assessed from the occurrence of defaecations in various regions of a pasture. Evidence of increased sheltering activity under weather conditions encouraging greater body heat loss would suggest that this method of recording behaviour may be recommended for application in relevant situations.

One of the advantages of keeping growing fattening pigs outside on pasture is that they are more healthy than those indoors (Fishwick, 1935), provided fresh ground, free from parasitic infections, is available. Reviewing American work, Morrison (1936) concluded that faster liveweight gains and improved efficiency of food utilisation are obtained from pigs full-fed on pasture compared with those full-fed in dry lot (also Fishwick, 1935; Smith et al., 1950). Pigs grazing outside in Great Britain usually receive enough sun on their skin to produce sufficient vitamin D to meet their requirements, except in adverse weather (Braude, 1954). Pigs at pasture have access to soil, which is a source of minerals (Davidson, 1930) and of vitamin B12 (Duckworth, 1955). Cunha et al. (1948) found that 5% of soil in a purified pig ration stimulated appetite and increased the haemoglobin value of the blood. Biggar (reported by Boden, 1952) obtained greater liveweight increases from pigs folded on pasture than from those folded on bare soil, showing that herbage is of value in addition to fresh air, sunlight and soil.

’Partial’ or ‘split’ weaning involves the earlier weaning of part of the litter before the normal weaning date. There have been isolated reports which claim that such a practice can reduce final weaning to service and conception interval and increase the size of the subsequent litter. However, these possible effects have not been quantified adequately and accordingly a study was carried out to further evaluate this practice.

The study was conducted on a 700 sow commercial unit in Aberdeen-shire with crossbred Large White (LW) x Landrace (LR) sows mated to LW, LR or LW x LR boars. Sows and litters were accomodated in conventional farrowing pens and weaning took place when litters averaged 17 days of age. Following weaning, sows were transferred to dry sow stalls adjacent to boar pens. Newly weaned pigs were transferred to flat-deck nursery accomodation.

1. The results of four experiments on the effects of oral and implanted hydroxyzine on lambs are reported.

2. The effect of hydroxyzine on daily rate of live-weight gain ranged from +7·8% to −6·2% improvement with a mean value of +2·3%.

3. Lambs receiving hydroxyzine in the creep feed manifested significantly higher killing-out percentages and lower thyroid weights than the controls. Pituitary weights were not affected by hydroxyzine.

4. In an experiment on individually-penned, weaned wethers, given a high energy diet, hydroxyzine by either route did not affect live-weight gain but significantly increased killing-out percentage, rate of gain of carcass weight and fat deposition in certain tissues. Hydroxyzine did not affect the fresh weights of the pituitary, thyroid and adrenal glands or the weights of the teats.

Information relating to the carcass composition of grass-fattened beef cattle in the UK is not only limited in extent, but is also frequently uni-dimensional, in that the quantitative changes in carcass composition with time cannot be readily assessed. Furthermore, the methods used in selecting animals for slaughter (the visual appraisal of condition) introduces a source of non-random variation that cannot be removed with statistical confidence.

The primary objective of the analysis reported here, therefore, was to evaluate the effects of time on carcass composition and thereby provide information upon which objective production strategies could be based.

48 fattening steers and heifers (16-19 months old and 355 kg liveweight) of two contrasting breed types (Charolais x Hereford x Friesian and Hereford x Friesian) were summer grazed at a stocking rate of 5 animals per hectare. The animals were randomly allocated (at the start of the grazing season) to three slaughter points covering a 12 week period from early July to early October. The commercial saleable meat yield of the left side of each animal was measured together with compositional data from rib sample joints.

The antibiotic Actaplanin is a complex of glycopeptide compounds produced by Actinoplanes missourrensis. When included in feed as a performance enhancer it has been shown to increase milk production of dairy cows (McGuffey et al. 1983). Actaplanin is associated with reduced proportions of acetate and increased proportions of propionate in rumen fluid and a depression in milk fat proportion may result (Clapperton et al. 1987). The aim of the trial reported here was to monitor the effects of feeding 960 mg Actaplanin/head/d to dairy cows throughout two successive lactations.

One problem encountered in the widespread application of sheep artificial insemination (AI) is the rapid decline in fertility of fresh or liquid chilled ram semen. An effective deep-freezing procedure would enable semen to be collected and stored from selected rams throughout the year for subsequent use in controlled breeding programmes, as well as facilitating the import and export of semen.

Following some encouraging results from the use of pooled semen frozen by an Australian pellet method (Maxwell et al 1980), further field trials were conducted to investigate fertility of semen frozen from individual rams as well as pooled semen. The effects of season of freezing and number of inseminations on fertility were also investigated.

The performance of 273 Hereford calves from lines previously selected for lean growth rate (LGR) or lean food conversion efficiency (LFCR), on a concentrate diet, was evaluated on a grassland diet over a period of 3 years. Both bull and heifer calves were tested, and each year the performance test ran from the 1st week of May (average age of 233 days) until the 1st week of October. Carcass lean content was predicted from body weight and ultrasonic backfat depth, and lean gain was calculated from the product of live-weight gain and predicted carcass lean content. The LGR line was superior to the control (C) line for live-weight gain on test, lean gain on test and lean gain from birth until the end of test. The LFCR line performed similarly to the C line for live-weight gain on test and lean gain on test, but was inferior for total lean gain. For lean gain on test, the proportional differences between the lines were similar to those predicted from parental breeding values for LGR, but they were smaller for total lean gain. The lines did not differ significantly for either fat depth or predicted carcass lean content.

Heritabilities were high for all growth traits, e.g. 0·52 (s.e. 0·17), 0·54 (s.e. 0·17) and 0·59 (s.e. 0·17) for live-weight gain on test, lean gain on test and total lean gain, but lower for fat depth and carcass lean content, 0·25 (s.e. 0·17) and 0·14 (s.e. 0·16), respectively. Genetic correlations with LGR, measured on a concentrate diet, were 0·57 for lean gain on test and 0·56 for total lean gain. If only males were considered, these correlations rose to 0·80 and 0·70, respectively. Coheritabilities between the two environments for lean growth were close to 0·3. It is concluded that although there is some evidence for genotype × environment and genotype × sex interactions, selection for lean growth on a concentrate regimen will still be effective in improving grassland performance.

The cultivation and uses of trees is important and varied in many areas of the world. The benefits include soil improvement and stabilisation, shade for other plants, provision of wood and fodder for ruminant animals.

Tree leaves are important sources of micro- and macro-nutrients for ruminants in many parts of the world including Nepal and Portugal especially when other plant fodders are scarce (Topps, 1992). Thus improvements in livestock production may benefit from an increased and/or selective use of tree fodders. The proximate composition and tannin (flavanol) content of plants including tree leaves, considerably influences the nutritive value (Goodchild & McMeniman, 1991; Kumar & Vaithiyanathan, 1990; Longstaff, et al.,1991; Makkar et al 1991).

The effects of three diets on the performance and carcass quality of lambs of the Makui and Moghani breeds of sheep were studied. Thirty-two Makui and 33 Moghani lambs, 6 to 7 mo of age, were kept on feedlots and given three diets for 77 days. The diets each contained a barley, alfalfa meal and corn silage base plus different levels of urea, molasses and dried beet pulp.

The average daily live-weight gains (ADG) of lambs fed on diets I (no urea), II (0·8% urea) and III (1·4% urea) were 218, 208 and 204 g respectively, while feed conversion ratios (FCR) were 6·3, 6·6 and 6·8 respectively. The overall ADG for Makui and Moghani lambs were 213·6 and 206·6 g respectively and the FCR were 6·4 and 6·9 respectively. None of these differences was statistically significant. The mean dressing percentages of lambs fed on diets I, II and III were 52·5, 52·7 and 53·9 respectively, and those of Makui (53·1) and Moghani lambs (53·3) were similar. There were only minor differences between the carcass characteristics of the two breeds and these were not influenced by the different diets.

Two experiments were carried out in the springs of 1986 and 1987 to investigate the effect of energy concentration in complete diets on the performance of heifers and mature cows. In 1986, all animals were on trial for an 8-week indoor period. In 1987, 14 heifers were on trial for 8 weeks, four heifers were on trial for 7 weeks and six heifers were on trial for 4 weeks. Carry-over effects were compared while animals were on pasture. Two diets offered ad libitum were compared. Diet H contained 0·7 concentrates and 0·3 grass silage. Diet L contained 0·5 concentrates and 0·5 grass silage. In 1986, the concentrate portion of diet H had a higher metabolizable energy (ME) content than diet L whereas in 1987 the same concentrate mixture was used in both diets.

Increasing the energy concentration of the diet from 10·66 MJ ME per kg dry matter (DM) to 11·21 MJ ME per kg DM resulted in a significant proportional increase of 0·36 in DM intake for heifers and mature cows in 1986. The proportional increase in DM intake in 1987 for heifers was 0·17. DM intake (kg DM per day) for heifers and mature cows in 1986 and for heifers in 1987 for diets H and L was 11·8, 8·7, 15·0, 11·0, 14·9, 12·7 respectively. The energy concentration of the complete diet did have a significant effect on average milk yield during the treatment period in the 1986 trial for mature cows but not for heifers in either year. Milk yields were 19·1, 17·5, 26·3, 240, 19·8, 18·9 kg/day respectively for heifers and mature cows in 1986 and for heifers only in 1987. In vivo digestibility coefficients in 1986 for energy, DM, organic matter, modified acid-detergent fibre and protein for diet H (0·708, 0·702, 0·724, 0·678, 0·671) were significantly higher than those for diet L (0·677, 0·666, 0·694, 0·653, 0·625).

The total lactation yield for the heifers and mature cows was not significantly influenced by the energy concentration of the diet given in early lactation.

Braude (1965) has recently reviewed the literature on the subject of supplementation of rations for growing pigs with copper, and concluded that as much as 0·1% copper sulphate could be added to the feed without toxic effects, and that this increased growth rate by about 8·1% and improved efficiency of feed conversion by about 5·4%. Both these values are average responses from a very large number of experiments. Similar results have been reported from the Soviet Union by Volkopjalov, Lebedjeva, Spiridonova and Matuskova (1962).

In the decade up to the outbreak of World War II. in 1939, the counties of Devon and Cornwall accounted for nearly 10% of the pig population of England and Wales. It is an exporting area for all classes of livestock, but the preponderance of exports over home consumption is indicated in pigs more than any other class of livestock as the figures in Table I., based on information obtained in a survey into the movements and slaughtering of livestock in 1930, show.*