SUMMARYAssays using 15N2 and acetylene reduction showed that bacteria in the sheep rumen can fix atmospheric nitrogen. These bacteria are ingested when sheep are at pasture or provided with fresh, non-sterile, food. A permanent nitrogen-fixing microflora does not develop in the rumen. The addition of nitrogen-fixing bacteria to sheep rumina coupled with additional carbohydrate (10 yo molasses) in the feed increased the nitrogen-fixing capacity from 30 mg N to 800 mg N fixedlrumenlday.
This study analyzed individual water and feed consumption related to weight of weaned piglets and their link to diarrhea. Data were collected from 15 batches of 102 piglets each, using specific automata (connected feeders, connected drinkers, automatic weighing stations, RFID ear tags). Analyses were carried out every week on the 138 healthy animals compared by weight category. The average feed consumption had no significant difference between weight categories (light, medium, heavy pigs) whatever the week and was close to 4% of the live weight. For the average water consumption according to weight, it was close to 10%. There was no significant difference between weight groups, except at the end of the period, where the variability of one heavy pig was so high that its own water consumption caused significant difference when compared with the light group. But these overall stable averages do not highlight the high intra-individual variabilities, which was around 40% for both water and feed data at the beginning of trial. At the end, it was almost 16% for feed consumption and 25% for water. The comparison between healthy and diarrheic piglets showed no statistical difference for average water consumption on the day of the first clinical signs and even 1 and 2 days before. In contrast, the average feed consumption had a very significant difference (P ≤ 0.001) for days 5–7 after the weaning and a significant difference for day 8 (P ≤ 0.05). Differences were also significant for data 24 and 48 h before first clinical signs. This means either that diarrheic piglets decrease their feed consumption the first days after weaning or that it is because they eat less that they become diarrheic. So, the hypothesis was that feed consumption could be an interesting indicator to detect early sick animals. Nevertheless, despite this difference, machine learning methods failed in detecting individually diarrheic animals from water and feed consumption related to weight, because of considerable individual variability. To improve these results, one solution could be to collect other data from new sensors like automatic measurement of body temperature or location of piglets in the pen by image analysis.
The seasonal pattern of DM prodaction of Lolium perenne, Cynosurus cristatus. Anthoxanthum odoratum. Festuca ovina and Agrostis stolonifera. cnt to 3 cm at 6-week intervals was studied on five sites, ranging from 49 to 303 m above sea level, in north-west Lancashire. Total annual production declined from a mean of 704 g/m= on the lowest site, to 553 g/ni= on the highest, largely as a result of a severe depression in the spring peak of production, i.e. from 6 7 to 2-5 g/mp er day. Later in the year, the daily rate of DM production was similar on all sites. Species varied in their response to increased altitude; Lolium was worst affected by this and Festuca least. The significance of tbese results, and possible reasons for the decline in spring production are discussed. I>iTRODUCnONThe yields of a number of grass species and varieties under various cutting regimes in a range of environments have been tabulated by Hughes, Munro and Davies (12) and their predecessors at the Welsh Plant Breeding Station, and by Hughes and Nicholson (14) and Burnham, Court, Jones and Tinsley (6) in Scotland. Detailed descriptions of the weeic by week variation in DM production are available for a range of bred varieties at Hurley (4), while Alcock, Lovett and Machin (2) in Wales, and Hunter and Grant (17) in Scotland have studied the effect of altitude on this variation for three bred varieties. These varieties cover a relatively small proportion of the grassland of upland areas; there are very few observations available for the Pennines. The current experiment was therefore designed to investigate the seasonal patterns of production in grasses of widely-differing types, over a range of environments, in north-west Lancashire. MATERIALS AND METHODSFive Species were selected for this investigation: Lolium perenne S23, Cynosurus cristatus, Anthoxanthum odoratum, Festuca ovina, Agrostis stolonifera.These were selected to provide a range of types from a flexible, highly productive cultivar of ryegrass to the fescue, characteristic of many less productive upland pastures. Seed of all these grasses was obtained from commercial sources in the UK except for the Anthoxanthum seed which came from the Netherlands.Five sites were selected within the Forest of Bowland, an outlier from the Pennines, ranging in altitude from 49 to 303 m a.s.I. All sites had a south-westerly aspect, the lower two on enclosed pasture land, the remaining three on unenclosed common-grazing. Soil type, original pH and other details ofthe sites are given in Table I. During 1968, enclosures 24x14 m were fenced on each site, and the enclosed land ploughed to a depth of 15 cm. The loose surface mat was removed, the area rotavated and worked to a suitably fine seedbed. Lime was applied, if necessary, to raise the pH on each site to about 6-5 and 45 kg N, 20 kg P and 55 kg K applied per hectare as a basal dressing on all sites.Seeds were sown in plots 1-8 m square, at a rate of 55 kg/ha in blocks of 15 plots. Each block comprised three separate series of five plots, one per spe...
Herbage samples are often taken for analysis in advisory problems concerning suspected mineral deficiencies in livestock. The adequacy of single samples is here assessed on two dissimilar sites. For this purpose S23 ryegrass was cut at similar stages of growth throughout the growing season and analyses carried out to determine the variation in the levels of calcium, phosphorus, potassium, sodium, magnesium, copper, cobalt and manganese resulting from different cutting dates. In many cases significant differences occurred between the levels of a particular element at different times during the year. These differences were large enough in some cases to influence advice based on a single result if taken in isolation.
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