The main objective of this study was to develop a dynamic energy balance model for dairy goats to describe and quantify energy partitioning between energy used for work (milk) and that lost to the environment. Increasing worldwide concerns regarding livestock contribution to global warming underscore the importance of improving energy efficiency utilization in dairy goats by reducing energy losses in feces, urine and methane (CH4). A dynamic model of CH4 emissions from experimental energy balance data in goats is proposed and parameterized (n = 48 individual animal observations). The model includes DM intake, NDF and lipid content of the diet as explanatory variables for CH4 emissions. An additional data set (n = 122 individual animals) from eight energy balance experiments was used to evaluate the model. The model adequately (root MS prediction error, RMSPE) represented energy in milk (E-milk; RMSPE = 5.6%), heat production (HP; RMSPE = 4.3%) and CH4 emissions (E-CH4; RMSPE = 11.9%). Residual analysis indicated that most of the prediction errors were due to unexplained variations with small mean and slope bias. Some mean bias was detected for HP (1.12%) and E-CH4 (1.27%) but was around zero for E-milk (0.14%). The slope bias was zero for HP (0.01%) and close to zero for E-milk (0.10%) and E-CH4 (0.22%). Random bias was >98% for E-CH4, HP and E-milk, indicating non-systematic errors and that mechanisms in the model are properly represented. As predicted energy increased, the model tended to underpredict E-CH4 and E-milk. The model is a first step toward a mechanistic description of nutrient use by goats and is useful as a research tool for investigating energy partitioning during lactation. The model described in this study could be used as a tool for making enteric CH4 emission inventories for goats.

On pig farms, a high proportion of the cost of production comes from feed costs. However, the use of alternative ingredients such as legume seeds may help to reduce this cost. In fact, legume seeds are an important source of essential amino acids (EAA) and can therefore be an alternative to oilseed meals. However, the accurate use of these legume seeds requires a precise knowledge of the standardized ileal digestibility (SID) of EAA, which may vary depending on its botanical variety. A meta-analysis was performed on a database compiling data from 41 studies published between 1981 and 2013 and 178 dietary treatments. Models of prediction of the SID of EAA as well as the dietary concentration of digestible standardized EAA (dEAA) were obtained, based on the chemical composition of ingredients reported in the publications. The effect of the type of legume seeds (faba bean, lupin, pea and soya bean), surgical procedures (T-cannula, re-entrant cannulas, post valve T-cannulas and ileo-rectal anastomosis), and BW of pigs (BW⩽25 kg BW>25 kg) were also tested in each model. Results showed that dietary CP and crude fibre (CF) were, respectively, the best predictors of each EAA SID for faba bean, lupin and pea (R2=0.42 to 0.89) and soya bean (R2=0.32 to 0.77). For the dEAA content, the best prediction models included dietary CP and ADF for faba bean, lupin and pea and soya bean, respectively, with R2 ranging from 0.66 to 0.98. Models developed in this study allow predicting the digestibility of EAA in these alternatives feedstuffs.

The application of ultrasonics to the evaluation of live cattle has been carried out in bull performance testing for several years. The machine used for this was the Scanogram. The fact that this machine is no longer being produced and the emergence of several new machines has prompted this trial to evaluate seven ultrasonic machines.

A total of 49 bulls, 27 Limousin x Friesian and 22 Charolais x Friesian, were evaluated and slaughtered in four batches of approximately equal size, over four weeks. Each batch was of one breed.

Age, live weight at evaluation and subjective assessments of fatness and conformation were recorded together with fat and muscle measurements by the Delphi (Delphi Instruments Ltd, New Zealand), Meritronics (Merit, Lowson and French, England), Scanogram (Ithaco Incorporated, USA), Vetscan (Company no longer in existence), Kaijo Denki (Medata Systems Ltd, England), Velocity of Sound (Prototype developed at IFR-Bristol, England) and Warren (Prototype developed by J Warren) ultrasonic machines.

In farmed salmonids the majority of consumed nitrogen is lost in metabolic waste products (mainly ammonia) and the faeces (Table 1). Any improvement in nitrogen retention, brought about by reductions in these components, would decrease environmental load. Inter-individual variation in retained nitrogen has been little investigated as a basis for selection of more efficient fish; this communication points to an experimental approach to measuring individual variation by concentrating on digestive efficiency and protein turnover as possible contributors to nitrogen retention. The utilization of dietary nitrogen was investigated in two species of farmed salmonid, the rainbow trout, Oncorhynchus mykiss and the Atlantic salmon, Salmo salar.

Grass silage provides an alternative feed for extensively kept sows, but previous experiments have indicated very variable intake and utilisation, dependant on silage quality. ‘Maxgrass’ silage additive (BP Nutrition) is a blend of compounds including ammonium hexamethanoate, ammonium hexapropanoate and octanoic acid. It is designed to modify fermentation, so that the resulting silage retains a higher proportion of water soluble carbohydrates. This should improve the nutritive value for pigs.

The experiment comprised two parts: an intake/growth study and a separate digestibility study. The same two experimental silages, either treated with Maxgrass or an untreated control, were offered to groups of pregnant sows in a randomised block experimental design in each experiment. Second cut, mainly perennial ryegrass herbage was cut by mower conditioner and direct ensiled. Alternate loads were left untreated or treated with Maxgrass at a mean rate of 6.04 litres/tonne.

Over recent years, the system of grazing management most commonly adopted by dairy producers has tended to oscillate between various forms of strip-grazing, on the one hand, and set-stocking, on the other. While arguments in favour of strip-grazing mainly revolve around the ease of grassland management, many of those for set-stocking are essentially behavioural -greater space for the cattle and, hence, less competition, aggression, and spoiling of localised areas of pasture. A current development in the southern hemisphere, ‘fast-rotation’ grazing, attempts to combine the merits of both systems. In this, the herd is given a fresh area each day, but a much larger one than in strip grazing, resulting in less close grazing and (given the same overall land allocation) a much quicker rotation over the total grassland.

This project, part of a larger one evaluating other aspects of the system, was designed to determine the effects a fast-rotation system, versus strip-grazing, on grazing, competition and aggression, and on the incidence and distribution of other basic activities.

Much of the early studies investigating the water consumption of pigs have measured water use rather than actual water intake. Water use includes an unknown component of waste from the drinking utensil used.

WATER USE = WATER INTAKE + WATER WASTAGE

One of the objectives of this study was to measure actual total water Intake of growing pigs and to calculate actual total water to feed ratio.

Recommendations of water feed ratio for liquid feed systems have been commonly made from experimentation with non wet fed pigs. The Code of Recommendations for the Welfare of Livestock : Pigs (1985) state that where water is not freely available, for example by means of bowls or drinkers, at least 2 litres of water should be added to each kg of meal. Water to feed ratios calculated in this way may be over estimated as they include an element of waste from drinking utensils which does not occur with wet fed pigs. Also recommendations of this nature make no allowance for the amount of water a pig may choose to consume with its feed. The second objective of this study was to investigate how much water pigs choose to drunk with their feed and how much is drink interprandially.

In animal housing ammonia is an aerial pollutant resulting from the microbial conversion of nitrogenous materials excreted in faeces and urine. Ammonia is an irritant to cells lining the respiratory tract and an increased incidence of pneumonia in pigs and humans and atrophic rhinitis in pigs have been correlated with elevated ammonia levels. In a survey of 12 farms and 49 pig buildings concentration of ammonia was identified specifically as a causative agent in the aetiology of atrophic rhinitis (Robertson, Wilson and Smith 1990). Furthermore, high levels of ammonia can delay the onset of puberty in gilts perhaps as a result of the masking of boar odour (Malayer, Brandt, Green, Kelly, Sutton and Diekman 1988).

Regulations have been introduced (Control of Substances Hazardous to Health (COSHH)) limiting the exposure of humans to atmospheric ammonia to a mean level of 25 ppm over an 8h work shift and 35 ppm for 10 minute exposure. As part of a study on the effectiveness of a feed additive formulated to control atmospheric ammonia, levels of ammonia in pig housing were monitored.

The production of colostrum by prolific ewes is of particular importance because of the increased demand of larger litters. Robinson (1985) has shown that there is a sharp increase in the ewe's net protein requirement for udder growth and colostrum production in the last 2 weeks pre-partum.

The trial was designed to investigate the effect of level of protein in the diet during the last weeks of pregnancy on the quantity and quality of colostrum produced by prolific ewes.

Forty-four Cambridge ewes aged 2 to 7 years and scanned as carrying two to four lambs were used. Ewes were housed and sheared approximately 2 months pre-partum and fed a complete diet at a restricted level and hay ad libitum until the commencement of the feeding trial at 2 weeks pre-partum. The ewes were then individually penned until 5 days post partum. During this period the ewes were fed ad libitum one of the two complete diets detailed in Table 1 together with hay ad libitum.

Milk output has been manipulated by dietary methods for many years, however the underlying mechanisms for changes in milk composition are as yet unclear. In an attempt to further understand these mechanisms we have compared the mammary uptake of metabolites on two isoenergetic diets with different protein levels expected to provide different amounts of amino acid to the mammary gland.

Early- to mid-lactation Friesian cows were used to examine the effect of increased dietary protein supply on the supply of metabolites to and uptake by the mammary gland in relation to milk protein synthesis. Two barley based concentrates were formulated to contain 20.8 (Cl) or 29.1 (C2) g N/kg DM, using fishmeal (Provimi 66, high UDP) as the supplementary protein and fed with grass silage (28.3 g N/kg DM) at a total dry matter intake of 17 kg/day. In Experiment 1 these diets were fed at 50:50 (concentrate:silage) to four lactating cows fitted with rumen and duodenal cannulae in a simple crossover design.

Premature loss of wool from fleece casting prior to shearing is a problem in some sheep genotypes, in particular in the North Country Cheviot. The reasons for this ocurrence are not fully understood, but it is believed that it is due to a complex of factors including heredity, nutritional and managerial (stress) practices, the wool growth cycle, and physiological parameters such as pregnancy. Prolonged stress is reported to be particularly important in the case of wool slip in ewes which are housed and shorn (Morgan et al, 1986).

The present study aimed to investigate the incidence of visible fleece casting in the North Country Cheviot (NCC), Scotch Halfbred (HB) (Border Leicester x NCC), and Border Leicester (BL), which has no history of premature wool loss. The study was implemented on 8 commercial farms in Scotland, and links between key productive parameters and wool loss were studied, and an attempt to identify fleece types most liable to cast was also made.

Aboud et al (1990) found that intake and selectivity of sorghum stover by Ethiopian sheep increased as the ad 1ibitum amounts offered (g/kg mass[M].day[d]) were increased from 25 to 50 and 75; the largest improvement in intake occurred with increasing the amount offered from 25 to 50 g/kg M.d. In the study by Aboud et al (1990), the stover offered was in chopped form. The present study investigated the effect of chopping per se, with stover offered at 25 or 50 g/kg M.d.

Following hand-harvesting of sorghum grain (non bird-resistant variety Dinkamash) in mid-November 1989, the stover (straw) was hand-cut from the field in mid-January 1990 and stored indoors until feeding in May. Forty eight Menz Highland rams of 17.2 kg initial M and ca.15 months of age were fed 113 g dry matter [DM]/ram.d of cottonseed cake and ad libitum sorghum stover over 56 d; salt licks were also provided.

Growing pigs spend considerable time orally manipulating their environment, which can include their pen-mates. In certain situations this leads to problems such as tail-biting. It is unclear if this active behaviour represents foraging or exploratory motivation, a problem exacerbated by the possibility that both share certain behavioural elements. The aim of this experiment was to distinguish appetitive foraging (extrinsic exploration) from intrinsic exploration by manipulating both feeding motivation and the content of the external environment. The objective was to discover which behavioural elements are common to either behavioural category. This would allow hypotheses to be proposed concerning the causation of oral-manipulation of the environment and inappropriate stimuli such as pen-mates, and furthermore to control for the effects of intrinsic exploration in continuing experiments concerning foraging behaviour.

Calf rearing systems vary greatly in the quantity of milk substitute fed and in the age of the calf at weaning (Webster, 1986). Husbandry conditions can affect disease incidence and welfare of young, bucket-fed calves and Andrews (1979) has suggested a relationship between age at weaning and disease incidence. This experiment was designed to investigate the effects of level of milk substitute powder fed and the age at weaning on the immune responses of bucket-reared calves compared with naturally suckled calves.

Two groups of 20 calves were kept at the Veterinary Field Station, University of Liverpool. All calves received pooled mixed-source colostrum at birth and were then randomly allocated to one of five treatment groups. After colostrum, bucket-reared calves were introduced to milk substitute (Volac Easi-Mix) which was reconstituted at 125g ADM per litre of water and fed twice daily. Calves were housed in individual pens arranged in four blocks with wood shavings as bedding. Suckled calves remained with their dams and were housed in the rear of the same building. These calves had access to a calf creep area. All calves were introduced to Keystart Quicklettes (BOCM Silcock) at 7 days of age and fed ad libitum. Small quantities of water and silage were also provided from 7 days of age. Table 1 lists the treatment groups, level of milk substitute received (g ADM/day), age of the calf at weaning and at inoculation with antigen (KLH), and also the age of the calf when the skin sensitivity response was measured.

Best Linear Unbiased Prediction (BLUP) is now the method of choice for the estimation of breeding values in dairy and beef populations. The advantages of this mixed model methodology over traditional methods are well documented and include the simultaneous estimation of fixed effects and prediction of random effects and the utilization of records from all relatives to predict an individuals breeding value. In addition, account is taken of genetic trend and of reduction in genetic variance due to selection. In Canada, BLUP is now used for breeding value estimation of pigs but the structure of the Canadian pig industry is one of many herds practising selection with the herds linked by a widespread use of artificial insemination. The advantages of BLUP have not been investigated for the situation of the UK pig industry where most selection is performed within closed nucleus herds.

The objectives of this study were to use computer simulation to determine rates of response, accuracy of prediction and accummulation of inbreeding for pigs in closed nucleus herds when selection decisions were based on estimated breeding values (EBVs) derived from BLUP compared to more traditional methods of phenotypic selection and index selection.

Oilseed rape meal is high in protein and available in the UK relatively cheaply. Toxic constituents limit its inclusion in feeds for pigs and poultry but this is not a problem with ruminant animals where microbial action in the rumen removes them. However, the bitter taste of rape meal has been thought to reduce its palatability for ruminant animals (Stedman and Hill, 1987) and it is recommended that its inclusion in compound feeds for cows should not exceed about 150kg/tonne; masking agents are incorporated to reduce this limitation.

The question to be addressed can be summarized as “can higher rates of inclusion of rape meal in dairy compound feeds be concealed by more mask?”. Twelve dry cows in late pregnancy were offered feeds with various levels of rape meal in combination with several levels of mask and rate of consumption was monitored.

Photostimulation is an effective means of manipulating reproductive activity in most British breeds of sheep. Short term light treatment can initiate oestrus cycles during June/July and thus provides the opportunity for autumn lambing (Williams, 1977). The most effective light treatments comprise a period of supplementary light followed by a period of long nights which requires controlled environmental housing. Recent investigations have demonstrated that melatonin treatment may replace the long night phase thus simplifying management (Williams, 1985). Attempts to dispense with the period of supplementary light by transferring Spring lambing Welsh Mountain ewes abruptly to long nights during early Spring were not as successful as the conventional type of light treatment (Williams, 1967). This investigation was undertaken to compare the response of adult Suffolk crossbred ewes given melatonin in the Spring with or without a priming period of supplementary light.

In countries with developed agricultural systems the proportion of dairy cattle inseminated artificially increased substantially following the Second World War, but a similar expansion in the use of artificial insemination (AI) has not been experienced for beef herds. The availability of deep frozen semen provided a further incentive to increase the percentage of dairy cattle artificially inseminated, for the more progressive herd owners soon realized that the technique offered the advantage of a long-term breeding programme with semen from progeny-tested sires available at a relatively modest cost. More recently, however, various developments in herd management have tended to militate against the use of AI in dairy herds, and during the past year there has been a substantial decrease in the total number of dairy cows inseminated which can only be partially explained by the smaller decrease in the size of the national herd. Amongst reasons advanced is the increase in average size of individual herds, resulting in more cows per man and therefore less time available for the observations of oestrus. Since accurate detection of the onset of oestrus is so important in obtaining high fertility following AI, some herd owners have returned to using natural mating. Evidence supporting this view can be derived from the fact that during 1973/74 there was an increase of over one thousand in the number of bull licences issued in England and Wales above the seventeen thousand issued in 1972/73. Of the 18.2 thousand bulls licensed, there were 3.2 thousand crossbred bulls, some obviously for use in dairy herds. The availability of synchronized and controlled ovulation would largely remove the difficulties which have been encountered, and would permit planned management techniques to be more widely applied within such herds.

For the past 20 years specialised sire and dam lines have generally exploited existing breed differences, and there has been little within-breed selection for litter size. However, some lines may now be approaching optimum fatness. At the same time, more accurate methods are evolving for estimating genetic merit for litter size. This study therefore re-examines the benefits of selection for litter size in specialised dam lines.

It is not clear when the optimum time of harvesting the winter barley as whole crop for silage should be in terms of feeding value for dairy cows and yield of the crop. Little information is available using whole crop barley as a buffer feed. The aim of these experiments was to evaluate the feeding value of whole crop barley (WCB) silage harvested at three stages of growth as a supplementary feed for grazing dairy cows during the late season.

Winter barley (var. Pipkin) was harvested at 4 stages of growth : T1:250, T2:350, T3:450 and T4:550 gDM/kg, at the following dates : 25/5, 19/6, 3/7 and 11/7/1991, respectively. The chopped material from T1-T4 was stored in minisilos and from T1-T3 in larger silos for animal studies.