The prediction of voluntary intake of grazing dairy cows

1986 ◽  
Vol 107 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Lindsey Caird ◽  
W. Holmes
Keyword(s):  
Organic Matter ◽  
Measurement Techniques ◽  
Live Weight ◽  
Simple Equation ◽  
Factors Affecting ◽  
Farm Planning ◽  
Sward Height ◽  
The Mean ◽  
Major Factors ◽  
Grazing Dairy Cows

SUMMARYInformation on the total organic matter intake, concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY), herbage organic matter digestibility (HOMD), herbage mass, sward height (SHT) or herbage allowance (HAL) measured individually for 357 cows at one of three sites was assembled. Observed intake was compared with intakes predicted by existing intake equations and new prediction equations based on regression models or regression and least-squares constants were developed. Major factors affecting intake were MY, LW, WL, C and HAL or SHT. Although HOMD was correlated with intake, better predictions were obtained when HOMD was omitted. There were differences between sites possibly associated with differences in measurement techniques.The predictive value of some existing equations and new equations were tested against independent sets of data. A simple equation (A) based on MY and LW (Ministry of Agriculture, Fisheries and Food, 1975) gave satisfactory average predictions but the mean square prediction error (MSPE) was high. The equations of Vadiveloo & Holmes (1979) adjusted for bias gave a relatively low MSPE. The preferred new equations for grazing cattle included MY, LW, WL, C and HAL or SHT, and their MSPE were similar to or lower than for indoor equations.The discussion indicates that a simple equation (A) would give adequate predictions for farm planning. The more detailed equations illustrate the inter-relations of animal with sward conditions and concentrate allowances. Predicted intakes may deviate from actual intakes because of short-term changes in body reserves.

The herbage intake of cattle grazing lucerne and cocksfoot pastures

1963 ◽  
Vol 60 (3) ◽  
pp. 359-369 ◽  
Author(s):  
F. E. Alder ◽  
D. J. Minson
Keyword(s):  
Organic Matter ◽  
Sampling Methods ◽  
Live Weight ◽  
Ground Level ◽  
Cattle Grazing ◽  
Chromic Oxide ◽  
Grazing Experiment ◽  
Herbage Intake ◽  
The Mean

1. From 1955 to 1957 a cattle grazing experiment was carried out on lucerne and cocksfoot pastures. Hereford-cross steers were used. Results obtained on the assessment of herbage intake either by the use of chromic oxide and faecal index methods or by herbage sampling are presented here.2. Except in 1955, when techniques were being developed, the digestibility of the herbage on offer to the bullocks was estimated by cold storing herbage, cut with an Allen Autoscythe and later feeding it to sheep in indoor digestion trials. The in vitro digestibility of herbage samples cut in 1955 and 1956 was also determined.3. In 1956 the mean intake of organic matter (lb.) per 100 lb. live weight by faecal methods was 2·38, 2·07, 2·20 and 2·29 on pastures of lucerne, cocksfoot, lucerne/cocksfoot (broadcast) and lucerne/cocksfoot (alternate 1 ft. drills), respectively, and 1·99, 1·76, 2·02 and 1·97, respectively, in 1957.4. In 1956 the mean intake of organic matter (lb.) per 100 lb. live weight by herbage sampling methods was 2·14, 1·70, 2·11 and 1·99 on the same pastures of lucerne, cocksfoot, lucerne/cocksfoot (broadcast) and lucerne/cocksfoot (drills), respectively, and 2·49, 1·32, 2·35 and 2·03, respectively, in 1957. The modified Tarpen trimmer, cutting to within 1 in. of the ground was used for sampling in 1956 and the Allen Autoscythe cutting to within 2 or 3 in. of ground level in 1957.5. Detailed botanical separation of herbage samples showed that the bullocks were selecting the more digestible parts of the plants; the top 4 in. of lucerne and the ends of leaves and stems of cocksfoot. This and other factors which could affect the estimates of digestibility of herbage eaten by the cattle are discussed together with possible sources of error in the herbage sampling methods.

The effect of winter feeding level on subsequent grazing behaviour and herbage intake of Charolais heifers

1995 ◽  
Vol 61 (2) ◽  
pp. 211-217 ◽  
Author(s):  
R. Ferrer Cazcarra ◽  
M. Petit
Keyword(s):  
Organic Matter ◽  
Live Weight ◽  
Mean Difference ◽  
Feeding Level ◽  
Sward Height ◽  
Herbage Intake ◽  
Compensatory Gain ◽  
Winter Diets ◽  
Effect Of Feeding ◽  
Grazing Behaviour

AbstractTwo groups of eight Charolais heifers were used to examine the effect of feeding level during the post-weaning winter on the grazing behaviour and herbage intake over three periods during the first 2 months of grazing. The winter diets (L and H) were given to achieve a mean difference of 50 kg between groups at turn-out. The heifers were set-stocked together on a hill pasture where sward height was maintained at 12 cm.The winter live-weight gains were 0·31 and 0·70 (s.e. 0·032) kg/day for L and H heifers respectively, and spring gains 1·94 and 1·66 (s.e. 0·082) kg/day respectively. Intakes increased throughout the spring grazing for both groups. Absolute intakes were lower for L than for H heifers only during the first period (P < 0·05). Intake per kg live weight was higher in L than in H heifers (23·0 v. 21·1 (s.e. 0·54) g organic matter (OM) per kg live weight). Bite weights of H heifers were constant throughout (434, (s.e. 12·9) mg OM), while bite weights ofL heifers only reached those of H heifers in the last period. Bite weight was linearly related to live weight. Bite rates were not different between groups, but L heifers compensated for lower bite weight by grazing longer and they increased their grazing time after turn-out faster than H heifers. Grazing time was mainly responsible for higher relative intakes in L heifers, and thus, partly, for compensatory gain observed.

The prediction of the voluntary feed intake of dairy cows

1979 ◽  
Vol 93 (3) ◽  
pp. 553-562 ◽  
Author(s):  
J. Vadiveloo ◽  
W. Holmes
Keyword(s):  
Dry Matter ◽  
Live Weight ◽  
Dry Matter Intake ◽  
Predictive Values ◽  
Factors Affecting ◽  
Pooled Data ◽  
Voluntary Feed Intake ◽  
Major Factors ◽  
Different Sources

SUMMARYInformation on the total dry-matter intake (TDMI), concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY) and composition, quality of forage fed to, and parities of, 385 cows from five different sources were assembled to develop appetite prediction equations. The equations were based on multiple regression and least squares constants and were calculated using the data from each source and the data pooled from all sources. The major factors affecting total dry-matter intake (TDMI) were C, LW, WL and MY and for the pooled data these factors explained 73–76% (R2) of the total variation in TDMI. The predictive values of some of the equations were tested against independent sets of data and for groups of cows and individual cows, the equations predicted TDMI within ±1·1 and 1·6 kg, respectively. The application of the equations in the field is discussed and some suggestions made for increasing the R2 of future appetite equations.

Estimates of the energy required for maintenance by adult sheep 1. Housed sheep

1963 ◽  
Vol 5 (1) ◽  
pp. 1-9 ◽  
Author(s):  
J. P. Langlands ◽  
J. L. Corbett ◽  
I. McDonald ◽  
J. D. Pullar
Keyword(s):  
Organic Matter ◽  
Weight Gain ◽  
Functional Relationship ◽  
Live Weight ◽  
Heat Emission ◽  
Daily Weight Gain ◽  
Direct Calorimetry ◽  
Adult Sheep ◽  
Digestible Organic Matter ◽  
The Mean

SUMMARYEight adult ewes were fasted for 114 hr. During the last 48 hr. the heat emission of each sheep was measured by direct calorimetry and was found to be 35·2 kcal./kg.0·87/24 hr., that is, 973 kcal./24 hr. for a sheep of 45·4 kg. (100 lb.) live-weight. From this value it is estimated that the 100 lb. sheep would require daily 0·79 lb. digestible organic matter (DOM) from pasture herbage for maintenance.In a second experiment, 49 adult sheep were kept indoors and fed on fresh herbage for a period of 72 days. Measurements were made of the mean daily DOM intake (D), mean live-weight (W) and mean daily weight gain (G) of each sheep. The regression of D on Wk and G, and the underlying or functional relationship between D, Wk and G were both estimated for k = 0·73 and k = 1·0. From the underlying relationships, the preferred equations, the maintenance requirement of a 100 lb. sheep was estimated to be 0·82 lb. DOM daily. This value and those calculated for other live-weights are approximately two-thirds of the corresponding values given in ‘Rations for Livestock’ (Evans, 1960).

scholarly journals Studies of method of conserving grass herbage and frequency of feeding in cattle

1992 ◽  
Vol 67 (3) ◽  
pp. 319-336 ◽  
Author(s):  
L. R. L. Thiago ◽  
M. Gill ◽  
J. W. Sissons
Keyword(s):  
Organic Matter ◽  
Contractile Activity ◽  
Daily Intake ◽  
Eating Behaviour ◽  
Live Weight ◽  
Once Daily ◽  
Daily Feeding ◽  
The Mean ◽  
Spike Bursts ◽  
Daily Total

The influence of the method of conserving grass herbage and the frequency of feeding on eating behaviour, rumen motility and rumen fill was studied in growing steers. Silage and hay were offered to twelve rumen-cannulated Friesian steers (average initial live weight (LW) 128 kg) at a restricted level of intake (20 g dry matter (DM)/kg LW) either once or eight times daily. With once daily feeding, the daily intake of hay was consumed in a single large meal which lasted about 2 h, while silage was eaten in many small meals throughout the day. The proportion of the day spent ruminating was higher (0·39) for steers offered hay once daily than for those offered silage (0·28) or hay eight times per day (0·29). There was little effect of conservation method on frequency of rumen contraction, but contractile intensity (integration of frequency and amplitude) increased during the second half of the 24 h feeding cycle in steers offered hay either once daily or eight times daily, while the same effect was only observed when silage was offered once daily. Total daily contractile activity (the integration of the frequency and duration of myoelectric spike bursts) was significantly (P < 0·05) higher in steers offered hay, compared with silage, once daily. The mean weight of organic matter in the reticulo-rumen of steers offered hay was significantly higher than for silage both with once (1593 v. 1326 g organic matter (OM)/100 kg LW, P < 0·01) and eight (1367 v. 1160 g OM/100 kg LW, P < 0·05) times daily feeding. The proportion of the particulate pool which was present as small (< 1·2 mm) particles was always greater than 0·60.

The effect of sward height on beef cow performance and on the relationship between calf milk and herbage intakes

1987 ◽  
Vol 44 (3) ◽  
pp. 363-370 ◽  
Author(s):  
I. A. Wright ◽  
A. J. F. Russel
Keyword(s):  
Organic Matter ◽  
Live Weight ◽  
Milk Intake ◽  
Beef Cow ◽  
Sward Height ◽  
Herbage Intake ◽  
Continuous Grazing ◽  
Weight Gains ◽  
Calf Performance ◽  
Cow Performance

ABSTRACTGroups of 12 spring-calving cows and their calves were allocated to each of three continuous grazing treatments: cows and calves grazed a 4- to 5-cm sward (LI), cows grazed a 4- to 5-cm sward and their calves grazed an 8- to 10-cm sward (Lh) and cows and calves grazed an 8- to 10-cm sward (Hh). In each case cows and calves grazed separately. Sward height had a large effect on both cow and calf performance and intake. The short swards reduced cow herbage intake proportionately by 0·2 compared with that of the taller sward. Cow live-weight gains were −0·60, −0·59 and 0·42 (s.e.d. 0·103) kg/day on treatments LI, Lh and Hh respectively while calf live-weight gains were 0·80, 0·95 and 1·14 (s.e.d. 0·040) kg/day. Calf milk intakes were 7·05, 5·78 and 9·34 (s.e.d. 0·508) kg/day respectively while daily herbage intakes were 17·2, 22·0 and 19·8 (s.e.d. 1·35) g organic matter per kg live weight for treatments LI, Lh and Hh. There was a negative association between calf herbage and milk organic matter intakes in the treatments where the calves had access to a more generous sward height (treatments Lh and Hh), the regression coefficient being −0·89 (s.e. 0·381), indicating the calves' ability to increase herbage intake in response to a reduction in milk intake. On the LI treatment there was no significant relationship between milk and herbage intakes. The ability of grazing suckled calves to compensate for a reduction in milk intake is thus dependent on sward conditions, and may also depend on herbage digestibility. The increase in herbage intake cannot however compensate fully for a restriction in milk supply.

Effects of season of growth and digestibility of herbage on intake by grazing dairy cows

1963 ◽  
Vol 5 (2) ◽  
pp. 119-129 ◽  
Author(s):  
J. L. Corbett ◽  
J. P. Langlands ◽  
G. W. Reid
Keyword(s):  
Organic Matter ◽  
Dairy Cows ◽  
Live Weight ◽  
Late Summer ◽  
Practical Experience ◽  
Digestible Organic Matter ◽  
Feeding Value ◽  
Grazing Dairy Cows ◽  
Maintenance Requirements ◽  
Strip Grazing

SUMMARY1. The intakes of herbage organic matter (OM) and digestible organic matter (DOM) by twenty dairy cows were measured during two periods of strip grazing on one pasture, in spring and late summer of the same year.2. Results from the first 5-day measurement period in the spring suggested that intakes at this time were restricted primarily because the cows had difficulty in gathering the short herbage. Measurements on ten of the cows continued during a further 5 weeks while the digestibility of the OM of grazed herbage declined from about 80 to 68%. There was a fall of about 20% in DOM intake by the cows during this period; one-quarter of the fall could be ascribed to a reduction in OM intake and the remainder to the decline in digestibility as such.3. Intakes were measured during two weeks in late summer and were compared with those measured during two weeks in the spring when the digestibility of the grazed herbage was similar. Intakes of DOM expressed as lb./lb. live-weight0·73 were the lower by about 10% in the late summer, or by from 10 to 20% in terms of DOM available for production when allowance had been made for maintenance requirements. This finding is discussed in relation to practical experience of the feeding value of autumn grass.

Studies on some of the physical and biological factors affecting the abundance of the Aedes simpsoni (Diptera: Culicidae) complex-larvae and pupae in plant axils

1994 ◽  
Vol 84 (2) ◽  
pp. 255-263 ◽  
Author(s):  
J. J. Lutwama ◽  
L. G. Mukwaya
Keyword(s):  
Water Content ◽  
Habitat Segregation ◽  
Biological Factors ◽  
Factors Affecting ◽  
Developmental Rates ◽  
Dry Seasons ◽  
The Mean ◽  
Major Factors ◽  
Aedes Simpsoni ◽  
Indices Of Association

AbstractSome physical and biological factors affecting the abundance of larvae and pupae of the Aedes simpsoni (Theobald) complex, in leaf axils of different plants at several locations in Uganda, were investigated during the rainy and dry seasons. The mean number of axils per plant, axils containing larvae and pupae, and the mean number of larvae and pupae per ml of axil water all varied between seasons and locations. The percentage of axils containing larvae and pupae increased with volume of water in the axils of the different plants. The mean number of larvae and pupae per axil containing water also increased with water content of the axils. There was more water in the axils during the rainy than during the dry seasons. The mean temperature of water was lower in Xanthosorna sagittifoliurn (20.4°C) and Colocasia esculentum (22.1°–22.7°C) than in those of banana (25.0°–27.2°C) and this affected developmental rates of larvae and pupae. The indices of association between larvae and pupae of the A. simpsoni complex and Malaya taeniarostris (Theobald) did not indicate competition and there was some habitat segregation between them. The volume and temperature of water in the axils appeared to be the major factors affecting larval and pupal abundance of A. simpsoni in the axils.

An analysis of the influence of microclimate on partial discharge activity in emissions of electric machines in the conditions of industrial operation – own research

2013 ◽  
Vol 62 (4) ◽  
pp. 629-648
Author(s):  
Zbigniew Plutecki ◽  
Sławomir Szymaniec
Keyword(s):  
Partial Discharge ◽  
Measurement Techniques ◽  
Signal Propagation ◽  
Electrical Machines ◽  
Electrical Machinery ◽  
Factors Affecting ◽  
Discharge Activity ◽  
On Line ◽  
Major Factors ◽  
Winding Insulation

Abstract The article presents the results of diagnostic measurements of partial discharge signal propagation from the winding insulation in electrical machinery, which were performed using an on-line method. This paper describes the results of experiments and the acquired experience in the monitoring of winding insulation in high power and high voltage electrical machines which are important in industrial production processes. The authors show the measurement techniques employed in their research. Representative measurement results are presented along with their analysis. The authors use an SKF monitoring systems to measure: vibrations, temperature, and humidity, as major factors affecting partial discharge activity in the from winding insulation of electrical machines.

The energy requirements of sheep for maintenance and gain. I. Pen fed sheep

1962 ◽  
Vol 58 (2) ◽  
pp. 179-186 ◽  
Author(s):  
I. E. Coop
Keyword(s):  
Organic Matter ◽  
Weight Gain ◽  
Live Weight ◽  
Energy Requirements ◽  
Live Weight Gain ◽  
Rye Grass ◽  
Digestible Organic Matter ◽  
Final Estimate ◽  
The Mean

Four experiments have been conducted with sheep, housed and fed in pens, to determine the maintenance and live-weight gain requirements of sheep under such conditions.1. Fifteen Corriedale sheep of initial live weight 115 lb. were fed at maintenance for 13 weeks. Daily DOM (digestible organic matter) requirement for maintenance was 0·92 ± 0·07 lb.2. Twelve Romney ewes of mean live weight 106 lb. over the period were fed for 5 months, six on submaintenance and six on super-maintenance levels. Daily DOM requirement for maintenance was 0·99 ± 0·05 lb., and requirement for gain 2·29 ± 0·20 lb. DOM per lb. gain or loss.3. Thirteen Romney ewes of mean live weight 110 lb. over the period were fed at sub- and supermaintenance levels for 8 weeks yielding the result: daily DOM intake for maintenance 1·04 ± 0·13 lb. and for gain 2·25 ± 0·24 lb. DOM per lb. gain.4. Twenty-four Romney ewes of initial live weight 107 lb. were randomized into five groups and fed fresh grass, dried grass, sheep pellets, lucerne hay and rye-grass straw for 11 weeks at slightly below maintenance. There were no significant differences between groups and the mean estimate of maintenance was 1·00 ± 0·11 lb. DOM per day.Converting these estimates to those of a 100 lb. sheep using the ¾ power of live weight, and then taking the mean gives the final estimate for maintenance of a 100 lb. sheep 0·92 lb. DOM, 0·96 TDN or 0·89 lb. SE.

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