ALBERT

Description: Purpose Previously, the nutritional contribution, environmental and financial costs of dairy products have been examined independently. Our aim was to determine the nutritional adequacy, financial cost and environmental impact of UK diets according to dairy content. Methods In this cross-sectional study of adults (19–64 years) from the UK National Diet and Nutrition Survey years 1–4 (n = 1655), dietary intakes assessed from 4-day estimated food diaries were organized into quartiles (Q) total grams of dairy (milk, cheese, yogurt, dairy desserts) and analyzed using ANCOVA controlling for age, sex and energy intake with Bonferroni post hoc test for nutritional adequacy, Alternative Healthy Eating Index (AHEI-2010), environmental impact [greenhouse gas emissions (GHGE), eutrophication and acidification potentials], financial cost, markers of health and cardio-metabolic diseases. Results Nutritional adequacy, particularly for protein, calcium and iodine (+ 18 g, + 533 mg, + 95 g, respectively, all P 

Description: SummaryAn experiment was carried out on a site where the copper content of herbage was relatively low (4·7–6·2 mg/kg d.m.) to examine the value of copper contained in soluble glass rumen boluses as a means of providing supplementary copper to calves.Forty-five spring-born suckled calves (mean live weight 91 kg) were divided into three groups on the basis of body weight. Animals in group GB were given two boluses initially, those in group CI each received copper injections at approximately monthly intervals and those in group C remained as controls throughout. Group C calves became progressively hypocupraemic (minimum mean plasma copper 8·5 μmol/1) compared with those in groups GB and CI which showed an increase in plasma copper concentration. In addition measurements of plasma caeruloplasmin activity, blood haemoglobin concentration and erythrocyte superoxide dismutase activity all showed significant increases due to treatment. No response in live-weight gain was observed but overall live-weight gain was approximately 1·05 kg/day. Although the initial response in plasma copper was quicker with copper injections, measurements of erythrocyte superoxide dismutase activity and haemoglobin showed advantages of glass boluses not shared by copper injections. This possibly resulted from the slow release nature of copper in the glass. Under the conditions of the experiment where herbage molybdenum values were relatively low (1·2–1·9 mg/kg d.m.), copper contained in soluble glass boluses appeared to prevent hypocupraemia in calves as effectively as regular copper injections.

Description: SUMMARYBetween weeks 3 and 18 of lactation, 141 British Friesians all received concentrate (metabolizable energy (ME) 12·9 MJ/kg dry matter (DM), 202 g crude protein (CP)/kg DM) at 8·0 kg fresh weight/day. In addition, cows received ad libitum either grass silage (ME 11·7 MJ/kg toluene DM; 219 gCP/kg DM) or a mixture containing grass silage and 15, 25 or 40% (DM basis) of winter barley straw (cv. Igri) either untreated (UTS) or treated (TS) with 4% NaOH. Forage treatments were imposed at either week 3 or week 9 of lactation.The mean forage DM intake of cows receiving grass silage only was 8·60 kg/day. When 15, 25 and 40% UTS was introduced into the rations at week 3 or 9 of lactation, forage DM intakes were 884, 8·43, 7·62 and 8·63, 8·83, 819 kg/day, respectively; the corresponding values for TS were 8·88, 855, 8·99 and 8·97, 8·98, 9·35 kg7sol;day. The milk yield of cows receiving grass silage only was 22·1 kg/day. When 15, 25 and 40% UTS was introduced into the rations at week 3 or 9 of lactation, milk yields were 21·1 kg/3, 20·1 kg/1, 20·1 kg/5 and 20·1 kg/1, 21·4, 20·5 kg/day, respectively; the corresponding values for TS were 21·8, 22·1, 21·3 and 22·5, 21·4, 22·6 kg/day. When averaged across the three inclusion rates, TS significantly increased forage intake (P 〈 0·05) and milk yield (P 〈 0·01) compared with UTS. Intermediate values were recorded for the diet with grass silage alone. The inclusion of TS in the ration did not affect milk yield compared with grass silage alone. No major changes in milk composition were recorded by the inclusion of either TS or UTS. However, the yields of milk fat, protein and lactose for the TS treatments were higher than for UTS and were significant for protein (P 〈 0·01) and lactose (P 〈 0·001). Cows with UTS in their ration tended to have lower live weight gains than either the control group or treatments with TS.When compared with grass silage only, the inclusion of TS or UTS decreased digestibility coefficients and ME contents, determined in vivo using wether sheep fed at maintenance. However, the treatment of straw with NaOH (4%) increased its digestibility coefficients of dry matter from 0·-393 to 0·668, of organic matter from 0·445 to 0·686, of acid detergent fibre from 0·442 to 0·713, gross energy from 0·438 to 0·640 and ME content from 7·0 to 9·4 MJ/kg DM.

Description: SummaryA total of 225 herbage samples were taken from two areas with a history of bovine hypocupraemia and examined for their Cu, Mo, total S, Zn, Fe and Cd content.In general, the concentrations of Cu and Mo (mean values 10·4 and 1·6 mg/kgD.M. respectively) were normal, as were those of Zn, Fe and Cd (mean values 43, 255 and 0–59 mg/kg D.M. respectively). The total S concentrations (mean value 3·5 g/kg D.M.) were, however, higher than found by some other workers.The concentrations of available herbage Cu were calculated using the following relationship of Suttle & McLauchlan (1976):logTA Cu = –0·0019 Mo–0·0755 S–0·0131 Mo × S–1·153,where TA Cu is the true availability of Cu, and Mo and total sulphur (S) are dietary concentrations as mg/kg D.M. and g/kg D.M. respectively. Animal requirements for available Cu were derived from estimates of the factorial Cu requirements of various classes of livestock, and when these were compared with the calculated concentrations of available Cu in the herbage they provided a possible explanation for the widespread hypocupraemia experienced in these areas.

Description: SUMMARYSixty-four multiparous Friesian cows were given one of eight diets from weeks 4–20 of lactation at the former National Institute for Research in Dairying, Shinfield, Reading in 1983–84. The diets consisted of 13·5 kg/day of experimental concentrates plus hay at 4·5 kg/day (fixed) or ad libitum. Concentrates were high-starch (S) based on cereal grains and cassava, high-fibre (F) based on highquality by-products, and two intermediate types containing 2:1 (SF) and 1:2 (FS) starch:fibre, all with a crude protein concentration of c. 180 g/kg DM. The diets were designed to provide similar intakes of digestible energy and crude protein at fixed hay intakes.With ad libitum feeding, hay intake was lowest on S concentrates. With increasing fibre in the concentrates, the yields of milk, protein and lactose fell but fat concentration and yield were increased. These changes were linear and were unaffected by hay intake. Increasing hay intake to ad libitum had no effect on milk yield but increased the concentrations and yields of fat and protein. It also changed a net liveweight loss on fixed intakes to a gain on ad libitum intakes.Diet digestibility was measured using sheep at about maintenance and cows at production intakes. Digestibility was higher in the sheep, probably because of the difference in level of intake. In the cows, increasing fibre in the concentrates reduced the digestibility of dry matter, organic matter, energy and nitrogen but increased the digestibility of fibre fractions and ether extract. Level of hay intake had variable effects on mean digestibility and on the relationship with concentrate type.Increasing the fibre in the concentrates increased the molar proportions of acetate and n-butyrate in the rumen and reduced the proportions of propionate, n-valerate and n-caproate.It is concluded that, with mixed diets of hay and relatively high proportions of concentrates, changes in the starch:fibre ratio of the concentrates by substitution of high quality by-products for starchy ingredients can induce linear changes in the yields of milk and the principal solids constituents and in milk fat concentration. Since changes in yields of fat and protein went in opposite directions, the optimal concentrate composition depends on the milk composition required by the market. These conclusions may not apply if poorer quality by-products are used.

Description: SUMMARYThree in vitro methods, one enzymic and two microbial, were applied satisfactorily to the determination of the dry matter digestibility of forages, but failed when applied to a variety of concentrate feeds. The microbial methods had the advantage that the proportion of weight lost from forages during the in vitro process approximated closely with their determined in vivo digestibilities.The microbial method based on sheep faeces was as effective as that using rumen liquor in digesting ruminant feedstuff's in vitro. Since sheep faeces are readily obtained from intact animals, the faeces liquor method would seem to have a distinct advantage in use.

Description: SummaryIn an experiment, carried out over 3 years, two groups of dairy cows offered ad libitum access to grass silage received 8 kg/day concentrate differing only in phosphorus content (low P concentrate: 4·0–4·5 g/kg dry matter (D.M.); high P concentrate: 6·0–6·5 g/kg D.M.) during the winter feeding period of approximately 6 months. During the summer period all animals were grazed together on perennial ryegrass pastures. There were no consistent significant effects of P content on any of the variables measured. The mean calving indices were 371 (S.E. = 3·71, n = 122) and 379 (S.E. = 4·28, n = 95) days and overall conception rates were 0·70 and 0·68 for the low and high P treatments, respectively. Mean plasma P concentrations during the winter period were significantly reduced (P 〉 0·01 or greater) in years 2 and 3 of the study on the low P treatment. In 1 year milk yield was significantly higher (P 〉 0·01) on the low P treatment although the fat content was significantly reduced (P 〉 0·05) but these effects were not recorded in the other 2 years.

Description: SUMMARYA total of 187 animals (mainly Friesian dairy heifers) on nine farms in Wharfedale, Nidderdale, Calderdale and the Vale of York were weighed, condition scored and blood sampled on three occasions during the grazing season 1977. On each site, half of the animals each received two injections of a Cu preparation (200 mg Cu total), one in May and one in July. Herbage samples were taken in May, July and September.Despite the fact that many animals started the experiment with low blood total Cu concentrations, growth rates during the experimental period were all satisfactory (lowest mean value 0·70 kg/day) with a significant increase due to treatment being observed on only one site. The Cu treatment, however, had a significant effect on blood and plasma total Cu values with the treatment either increasing the level to normal in animals which had started with low values, or maintaining the value in animals starting with near normal concentrations. On certain sites, animals in the untreated group ended the experiment with very low blood and plasma total Cu values (0·02–0·03 mg/100 ml). To prevent the possibility of a Co deficiency on some sites interfering with the experiment, all animals received a Co bullet initially. Despite these, concentrations of vitamin B12 in serum samples taken during and at the end of the experiment were low by present interpretation. This suggests either that Co bullets were an ineffective treatment or that the present interpretation of serum vitamin B12 concentration in bovines is incorrect.The calculated concentrations of available Cu estimated from herbage analysis indicated that on most sites the value was below the optimum for the growing cattle under study. The results of the experiment suggest that even when blood Cu values and herbage available Cu values are low a growth response to Cu injections may not occur over the course of a grazing season.