In general cows have higher intakes and higher milk yields when outdoors grazing pasture compared to indoors consuming grass silage. However, this observation is not valid as a direct comparison of grass and silage due to the following reasons. Firstly, the cows consuming the silage and grass are usually at different stages of lactation and secondly the silage has not been produced from the herbage being grazed. There is little information available in the literature comparing the intakes of grass and silage harvested from the same sward at the same stage of maturity when fed to lactating dairy animals at similar stages of lactation. The present study was initiated as part of a series of studies at this Institute, to evaluate factors affecting silage intake. The main aims of this study were to determine the actual effect which ensiling “per se” had firstly on dry matter intake and secondly on animal performance by the lactating dairy cow.

There is little doubt that the lowest costs of beef or milk production are achieved when the animals are grazed on pastures from which they obtain most or all of their sustenance. On the other hand the most expensive phase of cattle production is the winter period when stock are usually housed and must be hand-fed. The results from numerous investigations firmly support these assertions. In the large mixed farming area of the North-East of Scotland virtually no grazing is normally available from the middle or end of October until the beginning of May when normal grass growth has resumed.

To study, after weaning at 6 weeks of age, the effect of age on energy utilization of growing calves and to estimate the requirements of metabolizable energy (ME) for calves weighing less than 100 kg, 243 energy balance trials were conducted using 68 Holstein-Friesian castrated male calves at 7, 9 and 13 weeks of age. Regression analyses of energy retention (ER, kj/kg M0·75) on intakes of ME (kJ/kg M0·75) gave the following equations at the respective age: ER = 0·479 (s.e. 0·070) ME — 197, for 7 weeks, ER = 0·521 (s.e. 0·052) ME - 216 for 9 weeks and ER = 0·523 (s.e. 0·043) ME - 236, for 13 weeks. Amounts of ME for maintenance (MEm) calculatedas ER = 0 were 413, 415 and 451 kJ/kg M0·75 for calves at 7, 9 and 13 weeks of age, respectively. The efficiency of utilization of ME for growth was not significantly different among the ages and was 0·500 (s.e. 0023). ME required for growth was estimated to be 510 kJ/kg M0·75 for each kg gain in weight, irrespective of age. The requirements of ME of calves weighing less than 100 kg were lower than those estimated by extrapolation of British and American standards.

The Milk Marketing Board beef shape (BS) score for a sire is derived from the beef conformation assessments made during the routine inspection of his first lactation daughters in the Dairy Progeny Testing Scheme. The trial compared the scores for seven Friesian/Holstein sires with the beef characteristics of their steer progeny. Two groups of cattle, 189 in total, all out of Friesian dams, were used in the trial. The dams were assessed for BS. The cattle were reared on a standard grass/cereal system designed to achieve an overall target live-weight gain of 0·85 kg/day and slaughtered at 530 kg live weight. An assessment of BS was made at seven points during the lifetime of each animal. Carcass classification and assessment together with dissection of the shin joint was undertaken by the Meat and Livestock Commission. In addition to this, 40 carcasses representing high and low BS scores were taken for full dissection of the left side.

The BS score of the dam had no significant effect on the score of the calf at any point during its life. The relationship between the sire BS score and the calf score did not become significant until the calf was 12 months old (P < 0·01) and was still significant immediately prior to the slaughter of the calf (P < 0·05). Carcass conformation scores showed highly significant progeny group differences (P < 0·001). The regression of the sire progeny group means, corrected for estimated proportion of subcutaneous fat, on the sire BS scores was significant (P < 0·001). The carcasses in the high BS score group had a significantly greater weight of lean than those in the low BS score group.

Differences in how individuals cope with stressful conditions (e.g. novel/unfamiliar environment, social isolation and increases in human contact) can explain the variability in data collection from nutrient digestibility trials. We used the collared peccary (Pecari tajacu), which is under process of domestication and shows high individual behavioral distinctiveness in reactions toward humans, to test the hypothesis that behavioral differences play a role in nutrient digestibility. We assessed the individual behavioral traits of 24 adult male collared peccaries using both the ‘behavioral coding’ and the ‘subjective ratings’ approaches. For the behavioral coding assessment, we recorded the hourly frequency of behaviors potentially indicative of stress during the 30-day habituation period to the experimental housing conditions. The subjective ratings were performed based on the individuals’ reactions to three short-term challenge tests (novel environment, novel object and threat from a capture net) over a period of 56 days. During the last 26 days, the collared peccaries were fed diets either high (n = 12) or low (n = 12) in dietary fiber levels, and we determined the total tract apparent digestibility of nutrients. The individual subjective ratings showed consistency in the correlated measures of ‘relaxedness’, ‘quietness’ and ‘satisfaction’ across the three challenge tests, which were combined to produce z score ratings of one derived variable (‘calmness’). Individual frequency of BPIS/h and calmness scores were negatively correlated and both predicted the total tract digestibility of acid detergent fiber (ADF), which ranged from 0.41 to 0.79. The greater the calmness z scores (i.e. calmer individuals), the greater the total tract digestibility of ADF. In contrast, the higher the frequency of BPIS/h, the lower the total tract digestibility of ADF. Therefore, our results provide evidence that by selecting calmer collared peccaries, there will be an increase in their capacity to digest dietary fiber.

When straw was included in a ration and given to calves from 14 up to 84 days of age, dry matter intake was increased by up to 30 per cent from 1.36 to 1.77 kg per day compared with calves given the diet without straw (Williams, unpublished data). The calves given straw apparently gained an extra 8 kg in weight by 84 days of age compared with calves given the diet without straw. In order to assess the effect of roughage inclusion on the live-weight gains of calves an estimate of the rumen volume of the calves was required. Further since the majority of measurements of the volume of the digestive tract of calves were made after slaughter no studies have described the relationship between diet and the development of rumen volume in individual calves. Differences in rumen volume may be responsible for the large coefficients of variation in intake reported in groups of calves.

Current strategies for sow feeding are based on maintenance of a constant body condition throughout the reproductive cycle by feeding at levels only slightly above maintenance in pregnancy and feeding generously for milk production in lactation. Recent evidence suggests that feeding at a low level during pregnancy, whilst meeting nutritional requirements, may be detrimental to sow welfare. The large intake capacity of the sow also offers opportunities for utilising cheaper, alternative feeds at this stage. If bulky feeds are available at low cost, it might be economically attractive to feed for fat deposition by the sow in pregnancy and utilise this during the subsequent lactation. This experiment was designed to investigate whether sows with increased body fat reserves at farrowing could be encouraged to utilise these efficiently during lactation by the provision of a high protein diet.

Grass silage constitutes a major proportion of the food offered to high producing dairy cows in the western regions of the European Union. In order to achieve optimal milk yield and quality from high genetic merit dairy cows, it is common practice to offer concentrates in addition to grass silage at feeding. The aim of the current study was to combine two existing empirical models in order to allow prediction of the response in milk production to offering varying ratios of grass silage and concentrates to high genetic merit dairy cows, allowing for the fact that grass silage quality can vary. Results have demonstrated that it is possible to predict, with reasonable precision, the milk production response to various combinations of grass silage and concentrates in the diet. This will facilitate investigation of production and economic responses of offering increased levels of concentrates in the diet on milk yield, milk quality and milk value.

European (no. = 36) and hybrid (¼ Mesopotamian, ¾ European; no. = 36) fallow deer (Dama dama) were evaluated for weight gain and energy intake from 10 to 21 months of age. Twelve each of bucks, does and castrated males (haviers) were tested for each genotype, in both concentrate-fed and pasture-based feeding systems. Based on weekly weighing hybrids (H) in each of the sex classes grew more rapidly (5 g/day across all groups) than the European (E) fallow deer (P < 0·05). Haviers given concentrates grew significantly faster than pasture-fed haviers (P < 0·01), whilst does grown on pasture grew significantly faster than those given concentrates (P < 0·01). There was no significant difference in pattern of growth between bucks on pasture and those given concentrates (P > 0·05). Does grew significantly less (P < 0·01) than bucks and haviers in spring, summer and winter but environmental differences between years could not be accounted for in the analysis.

Animals of all sexes and genotypes experienced rapid growth from 10 to 12 months of age (spring) and this was associated with energy intakes according to metabolic body weight (M0·75) these ranging between 0·8 and 1·1 MJ metabolizable energy (ME) per kg M0·75 per day. There were significantly (P < 0·01) higher levels of energy consumed by H does and haviers in the summer, compared with their E counterparts but this was not associated with greater growth rates. However, H does had significantly higher (P < 0·01) dressing proportions at slaughter than E does. The energy intake on a metabolic body weight basis for most groups declined to between 0·7 and 0·8 MJ ME per kg M0·75 per day from 12 to 21 months of age, except for the does, which declined even further to between 0·5 and 0·6 MJ ME per kg M0·75 per day from 17 months of age.

There were no significant differences between E and H deer for energy intakes per M0·75, and H deer were slightly more energy efficient than their E counterparts in terms of growth rate in relation to annual gross energy intake. The food intake : weight gain ratio increased considerably for both genotypes after 14 months of age, indicating the desirability for slaughtering as soon as animals reach the target live weight. It was concluded that the crossbreeding system described is production efficient and produced offspring that reached slaughter weight sooner than E fallow deer and thereby produced carcasses with a greater wholesale value than their E counterparts of the same age.

The dry sow is well suited to utilise high fibre diets and there are some suggestions that feeding such diets in pregnancy may enhance litter size and subsequent piglet performance. This experiment was designed to investigate the effects on performance of inclusion of a high level of fermentable fibre in the form of unmolassed sugar beet pulp (SBP) in the diet of dry sows.

24 gilts and 20 multiparous Landrace x Large White sows were allocated to one of two diets according to weaning or entry date, parity and liveweight. The diets comprised a barley/soya basal diet with either 450 g/kg wheat (diet W) or SBP substituting for this wheat to provide the same quantity of corrected digestible energy (diet B). The two diets were fed at differential levels, to supply the same daily total of corrected digestible energy, from weaning or gilt entry until farrowing. The allocated amount of diet was given in a single daily feeding period to animals confined in individual feeding stalls, and a period of one hour was allowed for the ration to be consumed. After farrowing all animals were fed twice daily on a standard diet, according to a scale related to litter size.

Climate change is producing an increase on extreme weather events around the world such as flooding, drought and extreme ambient temperatures impacting animal production and animal welfare. At present, there is a lack of studies addressing the effects of climatic conditions associated with energy intake in finishing cattle in South American feed yards. Therefore, two experiments were conducted to assess the effects of environmental variables and level of metabolizable energy intake above maintenance requirements (MEI) on performance and carcass quality of steers. In each experiment (winter and summer), steers were fed with 1.85 or 2.72 times of their requirements of metabolizable energy of maintenance. A total of 24 crossbred steers per experiment were used and located in four pens (26.25 m2/head) equipped with a Calan Broadbent Feeding System. Animals were fed with the same diet within each season, varying the amount offered to adjust the MEI treatments. Mud depth, mud scores, tympanic temperature (TT), environmental variables, average daily gain, respiration rates and carcass characteristics plus three thermal comfort indices were collected. Data analysis considered a factorial arrangement (Season and MEI). In addition, a repeated measures analysis was performed for TT and respiration rate. Mean values of ambient temperature, solar radiation and comfort thermal indices were greater in the summer experiment as expected (P<0.005). The mean values of TT were higher in steers fed with higher MEI and also in the summer season. The average daily gain was greater during summer v. winter (1.10±0.11 v. 0.36±0.06) kg/day, also when steers were fed 2.72 v. 1.85 MEI level (0.89±0.12 v. 0.57±0.10) kg/day. In summer, respiration rate increased in 41.2% in the afternoon. In winter, muddy conditions increased with time of feeding, whereas wind speed and rainfall had significant effects on TT and average daily gain. We conclude that MEI and environmental variables have direct effects on the physiology and performance of steers, including TT and average daily gain, particularly during the winter. In addition, carcass characteristics were affected by season but not by the level of MEI. Finally, due to the high variability of data as well as the small number of animals assessed in these experiments, more studies on carcass characteristics under similar conditions are required.

Previous studies conducted at Newcastle with a lactobacilli silage inoculant(Pioneer Brand 1177) had shown that when compared to an untreated control silage, the silage produced with the Inoculant had improved chemical composition. The benefits of applying the inoculant were further seen in improvements in nutritive value and voluntary food intake by sheep.

My work during the last few years has been to some extent concerned with attempts at the control of mastitis under ordinary farming conditions, and in speaking to you today I will confine my remarks to what I consider in that particular region of experience is relevant to your tasks and interests. I make no claim to have carried out any fundamental research on the micro-organisms associated with infections of the bovine udder. My aim has been rather to apply the results of primary scientific enquiries carried out at various research centres to practical problems in the field.

It will be appreciated that conditions existing on the average farm differ in many respects from those that pertain on the farms and premises of the field stations and research centres, where a more direct, complete, and constant control can be exercised by the research worker over animal management, milking practices and general hygiene, than is possible on farms scattered over a wide country area and where the investigator must of necessity work from a position somewhat remote. Much in the way of control has to be left in these circumstances to the farmer, his herdsman and the practising veterinary surgeon. The personal element therefore, will always weigh very heavily. The test of any scheme or programme designed to control mastitis is: Can it work under such conditions and produce the desired results ? I am convinced from my own experience that it can.

The choice-feeding method has been suggested as an effective way of estimating nutritional requirements and it may be helpful from a practical point of view for meeting the nutrient requirements of animals with great variability in nutrient intake and requirements, for example sows in lactation. Friend (1971) reported high variability in protein intake in lactating sows on choice feeding. Growing rats (Leshner et al.,1971) respond to temperature changes by modifying the proportion of protein selected in order to maintain their protein intake. The main objective of this experiment was to investigate the ability of sows offered diets of different nutrient content to select the combination that best fits their requirement, particularly in relation to problems of reduced food intake routinely encountered in high summer temperatures.

Approximately 480,000 maiden heifers surplus to herd replacements are slaughtered annually for beef in Ireland. They comprise approximately 150,000 Hereford and Angus x Friesians, 150,000 continental x Friesians, 100,000 Hereford and Angus crosses from the suckler herd and 80,000 continental crosses from the suckier herd. At times of calf scarcity and high prices some of these heifers could be bred to produce a calf before slaughter. Provided that calved heifers are slaughtered before 30 months of age, there is little difference in meat quality between such animals and maiden heifers slaughtered at 18 to 24 months of age (Joseph, 1975). The objective of the present experiment was to quantify the productivity of once calved heifers finished indoors or at pasture.

Preliminary studies at the Bernard Weitz Centre have shown that maize silage has the potential to increase forage intake and milk production. The trend towards earlier calving, encouraged by the Milk Marketing Board pricing policy, means that maize silage may not be available for early lactation; as most farmers rely on the current seasons crop, and few carry stocks over from the previous year. The objective of the current trial was to determine the eflect on forage intake and milk production of incorporating maize silage into grass silage based rations either from early or mid-lactation.

There is increasing interest in the addition of dry feed materials to grass at ensiling, primarily as a means of reducing effluent production, although other benefits claimed include improvements in silage fermentation and animal performance.

A large number of studies have demonstrated lower effluent outputs and improvements in silage fermentation due to the inclusion of materials such as cereals and sugar beet pulp, although experiments examining the effects on animal performance are limited.

Recently, Jones and Jones (1988) observed higher liveweight gains from beef steers fed silage produced by ensiling grass with molassed beet feed compared to animals fed the same quantity of beet feed mixed with silage produced from untreated grass at the point of feeding. The major objectives of the present study were to evaluate the possible use of sugar beet pulp as an absorbent material in silage making and to examine the effects of its inclusion with grass at ensiling on animal performance.

Artificial insemination of ewes has become commercially available in Britain on a small scale over the last few years. It allows the farmer to benefit from MLC recorded rams which have been selected for growth rate and more recently for carcass quality. However, proximity to an A.I. centre is an important consideration as A.I. of ewes requires the use of fresh semen. Frozen semen has not vet achieved the quality and reliability necessary on a commercial scale. Insemination is carried out at a fixed time after the removal of Intra-vaginal pessaries and an injection of Pregnant Mare Serum Gonadotrophin (PMSG). Synchronisation of oestrus using sponges and PMSG adds to the cost of using a commercial A.I. service. If A.I. is not used then one ram per ten ewes is necessary for a synchronised mating which either requires a ram sharing group or considerable financial investment if rams of equivalent quality to those used in A.I. centres are to be purchased.

There is little published data on the detailed performance of continental genotypes as suckler cows in a hill environment. The work presented investigates levels of blood metabolites and hormones in autumn calving heifers during the post-partum period. Reproductive performance of the herd is detailed in an accompanying paper (Keatinge et al 1994).