Urinary calcium excretion in non‐lactating dairy cows in relation to intake of fat‐coated rice bran

At calving, many older cows fail to compensate the sudden demand of calcium by an adequate activation of intestinal absorption. This results in a variable degree of hypocalcaemia. Reducing intestinal availability of calcium during the close‐up period can prevent milk fever. Fat‐coated rice bran (FCRB) was investigated for its potential to reduce Ca availability in pre‐calving cows. Fat‐coated rice bran was incubated in situ to estimate ruminal degradation of dry matter and phytic acid. Also, seven dry multiparous dairy cows were used for a feeding trial in three periods of approximately 1 week each: P1: adaptation; P2: feeding of 2 kg of FCRB and P3: withdrawal of FCRB. Feed intake was recorded and daily urine samples were analysed for pH, Ca and creatinine. The bypass fraction of phytic acid (passage rate: 5%/h) was 30%. Fat‐coated rice bran depressed dry matter intake in P2, resulting in a lower Ca intake. In P2 urine pH and calcium excretion were lower. Daily calcium excretion decreased after introduction of FCRB, peaked after withdrawal and dropped 2 days later. Changes in urinary Ca excretion by feeding FCRB indicate that FCRB affected Ca homeostasis in dry multiparous dairy cows.     

Effect of nutrient dilution on feed intake, eating time and performance of hens in early lay

1. An experiment with 480 ISA Brown layers was conducted to measure the effect of dietary energy (11.8, 11.2 and 10.6 MJ/kg) and non-starch polysaccharides (NSP) (128, 146 and 207 g/kg) concentration, soluble NSP content (64 and 85 g/kg), particle size distribution of the NSP fraction (fine and coarse) and feed form (mash and crumble) on feed intake, eating time and egg performance of laying hens in early lay (from 18 to 26 weeks of age). Twelve experimental diets were tested, each replicated 4 times. 2. Laying hens in early lay that were fed low- or high-NSP diets were able to compensate for 10% dietary dilution by 9.5 and 4.9% higher feed intakes, respectively. Feeding crumble or coarsely ground mash did not affect feed intake. 3. Eating time of the hens fed the undiluted diets increased over the experimental period from 16.4 to 24.6% of the observation period, but was not affected by sand or grit addition, particle size distribution or feed form. Feeding high-NSP diets increased eating time by 22%. 4. Egg performance and body weight gain of the hens that were fed low-NSP or high-NSP diets were similar or better compared to the undiluted diets, whereas coarse grinding of the diets showed 7 to 10% lower egg performance and weight gain. Egg performance and weight gain were not affected by feed form. 5. It is concluded that hens in early lay, fed energy-diluted diets, by adding sand or grit (low-NSP) or NSP-rich raw materials (high-NSP) to the control diet, were able to increase their feed intake, resulting in energy intake and egg performance comparable to the control group. Supplementing diets with insoluble NSP also decreased eating rate. Prolonged eating time using insoluble NSP could be useful in reducing feather pecking behaviour.     

Nutrition, key factor to reduce environmental load from pig production

In different parts of Europe animal production is highly concentrated. Pig production generally is the main animal production activity in these areas. Main concerns of these large numbers of pigs are the amount of surplus nutrients in excreta and gaseous losses to the environment. Main nutrients of concern are N, P, and heavy metals and main gaseous losses of concern are ammonia, odour, and methane. Although losses are inevitable to a certain extent, nutrition seems to be a key factor in reducing these losses. Main nutritional strategies to reduce N and P excretions from pigs are: phase feeding (N, P), supplementation of limiting amino acids to the diet (N), and addition of phytase to the diet (P). Nutritional strategies to reduce heavy metals excretions from pigs are: finding alternative, natural, growth promoters that could replace Cu and Zn in the diet; using feedstuffs for the diet that are less contaminated with Cd. Main strategies to reduce ammonia emissions are: 1) lowering crude protein intake in combination with addition of limiting amino acids; 2) Shifting nitrogen excretion from urine to faeces by including fermentable carbohydrates in the diet; 3) lowering pH of urine by adding acidifying salts to the diet; 4) lowering the pH of faeces by inclusion of fermentable carbohydrates in the diet. These strategies proved to be independent from each other and effects are additive. By combining these strategies a total reduction of ammonia emission in growing-finishing pigs of 70% could be reached. Strategies to reduce odour emission are: 1) reducing protein fermentation by balancing available protein and fermentable carbohydrates in the large intestine; 2) Minimizing breakdown of absorbed sulphur amino acids. More studies are needed in this area of research, but results until now are very promising. A clear relationship exists between fermentable carbohydrates in the diet and methane emissions. This disadvantage should be considered when tackling ammonia emission by this strategy. It is concluded that there is a large potential to reduce environmental load within pig dense areas by nutritional means.     

Effects of a lactoperoxidase system and lactoferrin,added to a milk replacer diet,on severity of diarrhoea,intestinal morphology and microbiology of digesta and faeces in young calves

The objective of the present study was to determine the effects of the combination of a lactoperoxidase system (LP‐s) and lactoferrin (LF) added to a milk replacer diet on severity of diarrhoea, the morphology of the small intestinal mucosa, and the microbiology of digesta and faeces in young calves, in comparison with a control diet. The experiment was conducted with 30 young calves, 15 per treatment, during the period of 7–21 days of age. During this period, calves are sensitive to gastrointestinal disturbances that can cause diarrhoea. The results showed a significantly (p < 0.05) reduced severity of diarrhoea in the LP‐s/LF group compared to the control group as assessed by faecal consistency scores. Numbers of CFU (colony forming units) of Escherichia coli in jejunal and colonic digesta and in faeces were lower in the LP‐s/LF group compared with the control group. The differences were significant in both colonic digesta (p < 0.1) and in faeces (p < 0.05). Examination of the small intestinal mucosa, using a dissecting microscope, indicated more finger shaped villi in the distal jejunum of LP‐s/LF‐treated calves compared with the control group (p < 0.05). Histometrical measurements showed that these villi were significantly (p < 0.05) longer.     

Practical use of a combination of a dopamine agonist and a synthetic prostaglandin analogue to terminate unwanted pregnancy in dogs

The combination of a dopamine agonist, caber-goline, and a synthetic analogue of prostaglandin F_2a, cloprostenol, was used to induce termination of pregnancy from day 25 after the estimated luteinising hormone surge (day 27 ± 4 after the first mating) in five mature beagle bitches. Caber-goline was administered orally at 5 μg/kg daily and cloprostenol was injected subcutaneously at 1 μg/kg every other day. Treatment efficacy, in terms of pregnancy termination, was 100 per cent. Termination always took place by resorption of the fetuses. No side effects were observed. A mean of three injections of cloprostenol and nine days of cabergoline treatment was necessary to eliminate all signs of gestation. Termination was in each case accompanied by a decline in plasma progesterone (to less than 1 ng/ml) within 72 hours of initiation of treatment. In a control group of five, untreated bitches, plasma progesterone remained elevated throughout a corre-     

A free-fall determination of the newtonian constant of gravity

Recent determinations of the Newtonian constant of gravity have produced values that differ by nearly 40 times their individual error estimates (more than 0.5%). In an attempt to help resolve this situation, an experiment that uses the gravity field of a one-half metric ton source mass to perturb the trajectory of a free-falling mass and laser interferometry to track the falling object was performed. This experiment does not suspend the test mass from a support system. It is therefore free of many systematic errors associated with supports. The measured value was G = (6.6873 +/- 0. 0094) x 10(-11) m3 kg-1 sec-2.     

Thermographic selection of effective catalysts from an encoded polymer-bound library

A general method is introduced for the rapid and simultaneous evaluation of each member of large encoded catalyst libraries for the ability to catalyze a reaction in solution. The procedure was used to select active catalysts from a library of potential polymer-bound multifunctional catalysts. From approximately 7000 beads screened (3150 distinct catalysts), 23 beads were selected for catalysis of an acylation reaction. Kinetic experiments indicate that the most strongly selected beads are also the most efficient catalysts.