Feeding Passage Research Articles

Does housing nulliparous dairy cows with multiparous animals prior to calving influence welfare- and production-related parameters after calving?

Abstract The aim of this experiment was to determine the effects of housing nulliparous cows with non-lactating multiparous cows during the pre-calving period, on welfare and production-related parameters during the post calving period. Twenty nulliparous Holstein Friesian dairy cattle were assigned to one of two treatments (‘Mixed and Unmixed’) pre-calving. The ‘Mixed’ treatment involved housing experimental animals with non-lactating multiparous cows for three weeks prior to their expected calving date. In the ‘Unmixed’ treatment, experimental animals were housed with other nulliparous animals during the 3-wk period prior to their expected calving date. During this pre-calving period animals in both treatments were housed in groups of 10 animals, with the ‘Mixed’ group comprising of seven multiparous non-lactating cows and three experimental primiparous cows. The experimental animals were added to a resident group that contained 15 animals (10 multiparous cows and 5 primiparous cows) within 24 h of calving. The behaviour of the experimental animals was assessed immediately after the mixing period and also after feeding during the first month after introduction to the resident group (days 2, 4, 10, and 1 day in wks 3 and 4). In addition, data loggers were attached to the animals for a 24 h period on five occasions during the first month after calving to assess lying behaviour. Lying location and synchronicity of lying with the rest of the group was assessed by direct observation on two consecutive days each wk during the 2-h period prior to evening milking. Milk production, serum cortisol levels and changes in body condition and live weight were assessed during the first month after calving. ‘Mixed’ animals received fewer butts ( P P P P P P P

Application of Numerical Simulation on Cast-Steel Axle’s V-Method Foundry

The V-method foundry is an advanced casting technology compared with traditional sand casting. The Pro/E software was used to generate three-dimensional model of cast parts. The solidification process of the automotive axle casting with V-method foundry was simulated by the numerical simulation software, ViewCast. The location and scale of the shrinkage defects caused by the original process were predicted. According to the simulation results, the position of the flange round cooled too fast, which blocked the feeding passage of the round near sprue. The reason was that solidifying sequence was unperfected. The casting process was optimized by means of adding runner and chill. Progressive solidification can be obtained and the shrinkage defects can be eliminated or transferred by the improved technology. The reasonable casting process was obtained and the process has been proofed by the productive practice.

Effects of habituation to the milking parlour on the milk production and reproductive performance of first calving Holstein-Friesian and Norwegian dairy herd replacements

AbstractTwenty-nine Holstein-Friesian and 20 Norwegian dairy herd replacements were used to investigate the effect of habituating heifers to the milking parlour environment prior to calving on subsequent lactational performance. The heifers commenced the study at 3 weeks prior to calving when they were allocated on the basis of breed, genetic merit and live weight to either a habituation or no habituation (control) treatment. Heifers were housed together in cubicle accommodation with grass silage offered ad libitum along with 1 kg of concentrates per head per day offered in the feeding passage (control treatment) or in the food managers in the milking parlour (habituation treatment). Animals in the habituation treatment were exposed to the full milking parlour routine once daily (afternoon milking) in a 20-point rotary herringbone parlour. Holstein-Friesian heifers averaged 2.6 kg/day more milk than the Norwegian replacements. Holstein-Friesian heifers also had higher fat and protein yields than Norwegian heifers, however they also lost more body condition during the first 3 months of lactation. Habituated heifers yielded on average 1.3 kg/day more milk (P < 0.001) than the control group of heifers over the first 100 days of lactation (26.7 v. 25.4 (s.e.d. 0.38) kg/day), with the difference being greatest in the first 2 to 3 weeks of lactation. In early lactation, animals on the habituation treatment lost more live weight (0.16 v. 0.02 (s.e.d. 0.061) kg/day) (P < 0.05) and body condition than those on the control treatment. Duration of milking was longer (P < 0.001) (378.4 v. 340.5 (s.e.d. 6.53) s) and milk flow rate slower (P < 0.001) (2.20 v. 2.46 (s.e.d. 0.041) kg/min) respectively for the habituation compared with control group. Somatic cell counts (SCC) were lower (P < 0.001) for habituation group (1.66 v. 1.79 (s.e.d. 0.037) log10SCC per ml), but there was no significant treatment effect on locomotion scores. Reproductive performance was lower for habituated heifers, with increased intervals to conception (P < 0.05) (102 v. 83 (s.e.d. 9.22) days). Habituating heifers to the milking parlour environment prior to calving increased milk production but appeared to have some detrimental effects on reproductive performance.

The Effects of Frequency of Feeding a Total Mixed Ration on the Production and Behavior of Dairy Cows

Two experiments were conducted to examine the response of Friesian dairy cows to different frequencies of feeding a total mixed ration. The first compared alternate day with daily feeding. Cows fed on alternate days spent longer feeding, had increased dry matter intakes, and produced more milk, but with reduced protein content, compared with cows fed daily. Those fed daily increased feeding greatly after the food was offered to them. Those fed on alternate days had a smaller increase in feeding when food was offered, and their feeding pattern was similar on feeding and nonfeeding days, suggesting that they could not anticipate the time that food would be offered. However, on days when no food was provided they were less aggressive than cows fed daily. Cows fed daily spent less time grooming themselves and more time standing, suggesting that the extra feeding caused disturbance. A second experiment compared frequent feeding (four times per day) with infrequent feeding (once daily), with the cows fed infrequently being either housed with or apart from the cows fed frequently, to determine whether the disturbance of feeding other cows would affect cows housed in the same building but not fed frequently. Both groups of frequently fed cows spent less time feeding in the morning and more in the evening and had less circadian variation in sleeping and lying ruminating, compared with both groups of cows fed infrequently. Cows fed infrequently and housed by themselves produced more milk but with reduced milk protein concentration, compared with the infrequently and frequently fed cows that were housed together. They also spent more time standing in the feeding passage, not ruminating, and more time grooming themselves, indicating less disturbance. Thus cows fed infrequently had reduced milk yield if they were housed with frequently fed cows, and it is concluded that in both experiments frequent feeding disturbed the cows and reduced milk production.

Differential response of dairy cows to supplementary light during increasing or decreasing daylength

AbstractTwo experiments were conducted to compare the response oflactating cows to supplementary light in their lying area during increasing and decreasing natural daylength. During decreasing daylength, supplementary light in the lying area increased the time cows spent lying down and considerably reduced calculated food intake, milk production, live weight and body condition, so that lights were installed in the feeding area for the last half of the experiment, which partially restored intake and live weight. Plasma cortisol concentrations and milk somatic cell counts were increased by supplementary light in decreasing daylength before, but not after, lights were installed in the feeding passage, suggesting that cows may have been stressed by the difficulties encountered during feeding in the dark. During increasing daylength supplementary light did not affect lying time, had less effect on food intake and no effect on milk production or live weight. There was a small reduction in plasma corticosteroid by the end of the experiment with supplementary light. It is concluded that providing supplementary light only in the lying area of dairy cows will have adverse effects on their production and welfare in decreasing, but not increasing daylength

AMMONIA VOLATILIZATION AND DUST CONCENTRATION AS AFFECTED BY VENTILATION SYSTEMS IN HOUSES FOR FATTENING PIGS

One way to improve air quality inside houses for fattening pigs is to locate the air inlet near the breathingzones of pigs and the stockman and the outlet near the main source of contaminants, i.e., slatted floor and slurry pit. Thismay increase the total emission of ammonia by speeding up the airflow above the emitting area. To investigate this, wecompared a ventilation system with the inlet in the feeding passage and the outlet just above the slatted floor (system F),with a system common in the Netherlands having a high, diffuse inlet and a high outlet (system C). The two ventilationsystems were installed in each of two rooms in an experimental house. A layer of oil was used on the slurry to reduce thevolatilization of ammonia from the pit. Ammonia concentrations, in the air inlet and outlet, in the slurry pit and at animallevel on the solid and slatted floors, and the ventilation rate were measured continuously. Dust concentrations weremeasured 1.5 m above the floor in the feeding passage. The urine wetted area of the solid floor was recorded. We foundthat system F caused a significant reduction in ammonia concentrations at animal level on the solid and slatted floor (P <0.05) and dust concentration in the feeding passage (P < 0.001) compared with system C. There was no effect onammonia emission or on the urine-wetted area of the solid floor due to the ventilation system. We conclude that air qualityin houses for fattening pigs can be improved by a low air inlet in the floor of the feeding passage and a low outlet justabove the slatted floor and slurry pit, instead of a high diffuse inlet and a high outlet. These locations do not affect thetotal emission of ammonia to the environment.

The effect of environment and stage of the oestrous cycle on the behaviour of dairy cows

Abstract In a series of four experiments, the changes over the perioestrous period in oestrus, and other behaviours in pasture, cubicle, and straw yard environments were examined. In Experiment 1, which was conducted in a cubicle environment, only standing-to-be-mounted behaviour was confined to the day of oestrus. Changes in time spent lying or standing in the cubicle or in the feeding passage were not significantly affected by oestrus, but standing in the cubicle passage was increased on the day of oestrus. In Experiment 2 there was no significant difference in the oestrous behaviour of cows at pasture day and night, or cows at pasture during the day and in a cubicle house at night. In both treatments lying time was reduced on the day of oestrus, but there was no compensatory increase on the day after oestrus. In Experiment 3 cows in a straw yard tended to show an increased incidence of most oestrus-related behaviours on the day of oestrus compared with cows in a cubicle house. Also in contrast to cows in the cubicle house, cows in the straw yard reduced lying time and increased standing time on the day of oestrus, and compensated for these changes by increasing lying time and reducing standing time on the day after oestrus. Feeding time was increased for these cows on the day before oestrus and reduced on the day of oestrus and the day after oestrus. In Experiment 4 the behaviour of paired cows that were either in oestrus or not in oestrus was observed in a small pen. Oestrous cows displayed standing-to-be-mounted behaviour with both oestrous and non-oestrous cows. Mounting activity by an oestrous cow on a non-oestrous cow was not successful. Over the series of experiments it was found that sniffing and licking the anogenital area and chin-resting activities were less predictive of oestrus than mounting, as they were sometimes performed in the non-oestrous state. Aggression tended to be confined to oestrous cows in the grazing or housed environment but in the confined pen was displayed by non-oestrous cows.

4825638 Method of and device for recovering heat energy of hot raw gas gererated a coal gasification arrangement of an electric energy generating plant

In an electric energy generating plant including a coal gasification arrangement and a combined gas turbine and steam combine, hot raw gas generated in the gasification arrangement is fed via a heat-exchanging and dust separating unit into a desulfurization unit from which cool purified gas is discharged. The heat exchanging unit includes a tubular pressure resistant housing serving as a feeding passage for the hot raw gas and enclosing a coaxial arrangement of a tubular pipe-wall housing of a waste-heat recovery boiler, and pipe spirals of a raw gas/purified gas heat exchanger. The waste-heat recovery boiler delivers superheated steam to the steam turbine and the raw gas/purified gas heat exchanger delivers heated purified gas to the gas turbine.

Level of airborne bovine epithelial antigen in Finnish cowsheds.

Samples of airborne particulate material were collected from 18 Finnish cowsheds both at stationary sites and in breathing zones. The concentrations of bovine epithelial antigen (BEA) in samples were analyzed by the immunochemical enzyme-linked immunosorbent assay (ELISA) inhibition test. For total dust and BEA measurements the range of results among cowsheds was wide. In the breathing zone the mean concentration of total dust was 2.4 +/- 1.5 mg/m3 and of BEA 460 +/- 300 ng/m3. The concentrations of total dust and BEA were significantly lower at stationary sites than in breathing zones. Correlation analyses of total dust and BEA concentrations revealed that only moderate correlations existed, and they were not statistically significant (P greater than 0.05). Correlations between BEA concentrations in feeding passage or manure passage and breathing zone were at most only moderate (rs 0.29, P = 0.12 and rs 0.42, P = 0.02, respectively). The correlation of BEA concentrations between the two stationary sites was relatively strong and significant (rs 0.71, P = 0.004), suggesting that the variation in BEA concentrations between cowsheds is real. The effects of brushing and number of animals on total dust and BEA concentrations were studied statistically in samples from the breathing zone. No high or significant correlations were observed.

Effect of three day-time stocking rates for dairy cows offered silage overnight

In a previous study (Phillips and Leaver, 1983) grass silage was offered indoors overnight to dairy cows which were set-stocked during the day. The intakes of herbage DM were high in spring and declined thereafter, with silage DM intakes showing the reverse trend. This suggested that a single daytime stocking rate could be practised throughout the grazing season if silage was available ad libitum as a buffer feed. In this experiment, three daytime stocking rates were compared.In a continuous design experiment lasting 24 weeks (17 April to 5 October 1983) 36 late winter calving Friesian dairy cows and heifers were housed and offered grass silage ad libitum overnight in a feeding passage. During the daytime the cows were set-stocked at 8, 10 or 12 cows/ha. Concentrates were fed at a level of 3 kg/day for weeks 1-16 and 22-24; 5 kg/day were fed for weeks 17-21.

Selection of piggery ventilation systems and penning layouts based on the cooling effects of air speed and temperature

Abstract A full scale experimental section of a pig finishing building was used to determine the distributions of cooling effect (air speed and air temperature combined) for a number of penning layouts and traditional straight-through ventilation systems. The suitability of the cooling component of the environment was assessed with reference to a mathematical model of the thermal balance and temperature requirements of the pig. Other important environmental factors considered included the degree of air mixing, retention of a stable airflow pattern, reduction of wind effects and provision of a warmer area for lying than for dunging. It is concluded that the most desirable conditions may be provided in a building with a central feeding passage and side dunging passages (without a partition wall between them) combined with a ventilation system in which air is projected horizontally in both directions from the ridge beneath a smooth ceiling at a speed of at least 4 m s −1 .