Winter Feeding Period Research Articles

Changes in plasma and milk tocopherol levels in beef cattle turned out to pasture

SUMMARYChanges in tocopherol concentrations in the milk of Shorthorn cows, and blood of their calves associated with a change from a winter diet of hay to lush spring pasture were examined. During the winter feeding period the tocopherol levels in the colostrum (108 μg/100 ml) and milk (40 μg/100 ml) were low. A significant increase occurred in the milk tocopherol concentrations after the cows were turned out to spring pasture. Immediately before the animals were turned out to pasture the tocopherol levels were lower in calves with high serum levels of glutamic oxalacetic transaminase, indicative of muscular dystrophy. Plasma tocopherol levels in all calves increased throughout the grazing period, reaching a maximum average value of 919 μg tocopherol/100 ml after 63 days. Six Limousin × Shorthorn calves out of a total of 41 died with nutritional muscular dystrophy but no mortalities occurred among 26 purebred Shorthorn calves.

Beef production from grass and silage with autumn-born calves. 2. The effects on the performance of cattle fed on silage of barley supplementation and of previous grazing intensity

SUMMARY1. Two experiments are described in which the consequences of variation in grazing intensity were studied during the subsequent period of winter feeding from 12 months of age to slaughter at 18 months. The cattle were loose-housed and fed on silage ad libitum, together with allowances of rolled barley. Individual organic-matter intake was measured periodically, chromic oxide being used to estimate faecal output. The digestibility of the diet was estimated with stall-fed steers.2. Groups of 12 steers were grazed at different intensities over five-month periods, so that those grazed at the higher intensity were 38 and 16 kg lighter at the start of the 1966 and 1967 winter feeding periods respectively. They did not make significant compensatory growth over the subsequent winter feeding periods, although they had a significantly higher intake of feed organic matter per 100 kg live weight than the control steers.3. With supplements of 3·63 and 1·81 kg/head per day of barley, live-weight gains were 0·77 and 0·50 kg/head per dayin the first half of the winter, but in the second half, when barley allowances were raised to 4.54 and 2·72 kg/head per day, both groups gained weight at the same rate (0·94 kg/head per day).4. The higher level of barley feeding reduced silage intake by 0·4 kg OM/kg barley OM at all stages of the winter, and the additional 306 kg of barley was associated with the production of 21 kg more carcass weight at slaughter. This higher yield of carcass was reflected in a higher weight of fat in a three-rib sample joint.

The effect of energy, protein and vitamin supplementation on the performance and voluntary intake of barley straw by cattle

SUMMARY1. Daily allowances of 1·37 kg of concentrates, containing either 8·9 (treatment A), 13·6 (B), 19·1 (C) or 29·2% crude protein (D) were given to 40 individually-fed steers eating long barley straw to appetite over a 112-day winter feeding period. Voluntary straw intake on treatment B was 25% higher than that on treatment A. There were no signiicant differences in straw intake between treat-ments B, C, and D. Mean daily live-weight gains (kg) for the treatment groups were A, −0·22; B, 0·05; C, 0·04; D, 0·15. When the animals were turned out to pastore, group A showed very rapid compensatory growth, and it was concluded that this was mainly due to differences between the groups in their changes in alimentary tract contents. Vitamin A and D supplementation did not affect straw intake or performance.2. When the above supplements were given to steers in metabolism crates receiving barley straw in restricted or unrestricted quantities, it was found that an increase in the crude-protein content of the supplement significantly increased the digestibility of the organic matter, crude fibre and crude protein of the whole diet when straw intake was restricted, and significantly increased the digestibility of crude fibre and crude protein when straw was unrestricted.3. It was concluded that voluntary straw intake was limited, at the lowest level of supplementary protein, by a deficiency of absorbed protein. At the higher levels of supplementary protein, intake was probably limited by the capacity of the alimentary tract.

Variations in serum calcium, inorganic phosphorus and magnesium levels due to stage of lactation, season, and age in Ayrshire cows injected with vitamin D3 prior to calving

Blood mineral studies were carried out in the dairy herd of the Viik Experimental Farm, in which parturient paresis has been successfully prevented by intramuscular injections of vitamin D3 (2 X 5 million I.U.). The material consisted of 41 cows from which 207 blood samples had been taken in 1963 and 12 cows (6 controls, 6 vitamin D injected cows) from which 72 blood samples had been taken in 1969. All cows were either dry and pregnant or lactating and nonpregnant. Compared to values obtained during the dry period, the serum calcium level was only slightly lower shortly after calving. The calcium level increased in the vitamin D treated cows during the ascending phase of lactation, whereas both the calcium and inorganic phosphorus levels remained relatively low in the control cows, respectively. The highest mean magnesium levels occurred during the 2nd and 3rd weeks of lactation. The serum calcium level was higher during the grazing period than during the indoor feeding period. Inorganic phosphorus remained at a relatively high level in younger cows during the grazing period, whereas a significant decrease was noted in the phosphorus level of older cows, respectively. The lowest magnesium values were noted in May, i.e. already before the beginning of the pasture season, the concentration increasing towards the end of the grazing period especially in younger cows. As a whole, younger cows had slightly higher mean serum calcium and magnesium levels and significantly higher inorganic phosphorus levels compared to older cows. The effect of age on the inorg. phosphorus level appeared to be more marked in dry cows and during the grazing period than in lactating cows and during the winter feeding period. Special attention has been paid to the blood mineral values of four individual cows suffering from various illnesses during the study period.

The winter decline in the solids-not-fat content of herd bulk-milk supplies

Summary(1) A survey of the composition of the milk of individual cows in 4 commercial herds in the West Riding of Yorkshire was undertaken from October 1967 to May 1968.(2) In 3 of the 4 herds there was a decline in solids-not-fat (SNF) content throughout the winter feeding period. Milk protein content was at a minimum in January–February but in all 3 herds lactose content also declined and in 2 of the herds this was the major cause of the fall in SNF content.(3) The decline in lactose content was the result partly of the characteristic effect of an advance in lactation, partly of an increase in the incidence of mastitis throughout the winter period. In all herds there was a significant inverse relationship between lactose content and cell count in the bulked milk of individual cows.(4) In 3 of the herds autumn-calving (October–December) animals showed a pronounced fall in milk protein content in the early months of lactation which was not observed in summer-calving (July–September) animals. There was no response in SNF or protein content to supplementary concentrates offered towards the end of the winter-feeding period, whereas with the commencement of grazing in the spring there was an immediate increase in both protein and SNF contents.

The value of dehydrated alfalfa and delayed grain fed to young cows on winter bluestem

This test was to compared the following three winter treatments for young cows on bluestem pasture. Treatment 1 -- One pound of soybean oil meal and 2 pounds of ground sorghum grain per head daily during the entire winter feeding period. Treatment 2 -- One and a half pounds of soybean meal fed per heifer daily until 50 days before the feeding season ended, then ground sorghum grain was fed. The same total amount of sorghum grain as fed under treatment 1 throughout the winter was concentrated during the last 50 days with the soybean oil meal discontinued when grain feeding reached the quantity to supply the same amount of protein as those on treatment 1 received. Treatment 3-- Dehydrated alfalfa fed at 3.3 pounds and ground sorghum grain at 1 pound per heifer daily during the entire winter feeding period.

The value of dehydrated alfalfa and delayed grain feeding young cows on winter bluestem

Two primary objectives of this test were to: (1) compared dehydrated alfalfa with soybean oil meal as a winter supplemental feed on bluestem pasture for young cows to be bred shortly after the winter feeding period. (2) Determine any merit in feeding grain the last 50 days of the winter period compared with feeding the same total amount of grain throughout the winter when heifers are to be bred shortly after the winter feeding period.

Transfer Coefficients of Fallout Cesium-137 to Milk of Dairy Cattle Fed Pasture, Green-Cut Alfalfa, or Stored Feed1,2

The transfer coefficient (per cent intake per liter of milk) of fallout 137Cs was measured in the University herd under three feeding conditions. Groups of about ten Holstein cows were pastured for three summers and received supplemental alfalfa hay and grain. The entire University herd of about 100 cows of four breeds was studied during the winter feeding period, when they received alfalfa hay, corn silage, and a grain mix. Eight Holsteins were fed alfalfa cut daily, together with small amounts of hay and grain according to production. All 137Cs demonstrations were made by gamma-ray spectrometry.The transfer coefficient was found to average 0.35 under pasture feeding conditions during the summers of 1962, 1963, and 1964. A mean of 0.41 was found during the winter feeding period of 1963, and a value of 0.25 when green-cut alfalfa was fed in the summer of 1965. The range in values was lowest for the dry-lot trial in which no breed effect was evident. Within treatments the level of crude fiber intake was not related to transfer coefficient.

Nutritional Factors Affecting the Solids-Not-Fat Content of Milk

The nutri t ion of the cow has a marked effect on milk composition. Considerably more research has dealt with feeding factors affecting milk fat than solids-not-fat (SNF). However, several very good reviews have summarized known effects of diet on the SNF content of milk (7, 12, 20, 23, 42, 43, 55, 60). Dietary energy. As early as 1941, Ridett et al. (53) observed a decrease in milk SNF of cows fed about 50% of the recommended energy level. In 1944, Rowland (61) reported field observations that SNF decreased in the winter and increased when cows were put on spring grazing. In a subsequent study, Rowland (62) noted that a lower SNF (8.34 vs. 8.68%) resulted from feeding energy at 75% of Woodmau's standards, compared to 100%. It is now widely recognized that restriction of energy to less than the recommended standard causes a marked reduction in milk SNF (12, 20, 23, 54, 60). Smaller increases have resulted from raising the energy intake well above sta, dard (6, 8, 14, 15, 17-19, 31, 32, 34-36, 50. 57). For example, I-lolmes et al. (32) fed four leveis of concentrate (0, 0.9, 1.8, 2.7 kg/gal milk) and noted an increase in SNF frora 8.3% on the lowest level of feeding to 8.6% on the highest. When Huber and Boman (36) fed four levels of grain to cows on pasture (0, 0.14, 0.29, and 0.57 ke,'/kg milk), the SNF content for the respective levels averaged 8.51, 8.64, 8.86, and 9.08%. In many areas, it has been a general observation that cows placed on lush pasture in the spring undergo an increase in the SNF content of their milk (22, 31, 55, 61, 62, 66). Studies by Rook et al. (59) demonstrated that this was due to an increase in the plane of nutrition. They showed that cows which had received 75% of the Woodman Standard for energy during a winter-feeding period increased 0.33% in SNF when placed on lush pasture in the spring; whereas, a group receiving 130% of standard underwent a 0.12% decrease in SNF when they commenced to graze. Similar results we,'e observed by Castle and Watson (19) and Waite et al. (66). Increases noted in mill< SNF at hi~'h energy intakes have generally occurred in the protein

The lactation curve of the cow at the ascending phase

Since the year 1947 daily milk yields of Ayrshire cows at the ascending phase have been obtained at the University Farm Viik. In this paper only healthy cows are considered. Because the yearly milk production has considerably increased since 1947, the milk records have been divided into three sequences: the first consists of the control years 1946-47 – 1949-50, the second 1950-51 – 1956-57 and the third 1957-58 — 1960-61. In each sequence average lactation curves have been drawn separately for heifer-cows and older cows in both the winter and pasture feeding periods. The lactation curves have been designed in such a way that both productions and the durations of the ascending phase or fixed fractions of them (1/8, 1/4, 1/2, 3/4, 5/4) are averages (Figures 1—3). The designing of these curves has been more thoroughly described in an earlier paper (12, p. 162). In the present paper attention has been paid to some of the factors influencing the lactation curve at the ascending phase. The following points were noted. The average peak production of cows older than heifer-cows at winter feeding was 21.8 kg in the first sequence, 26.0 kg in the second sequence, and 26.6 kg in the third sequence. At pasture feeding the corresponding figures were 21.6 kg, 20.8 kg, and 24.2 kg. The duration of the ascending phase at winter feeding in cows older than heifer-cows in the first sequence was on an average 31 days, in the second sequence 32 days, and in the third sequence 36 days. At pasture feeding the corresponding figures were 25, 28, and 33 days. The average peak productions as well as the average of the times involved in reaching them were higher at winter than at pasture feeding. The feeding in both periods was intensive during the second and third sequences. At winter feeding the duration of the ascending phase was generally longer in heifer-cows than in older cows. The lactation tangent at the ascending phase, which is the ratio between the peak production and the duration of the ascending phase (kg/day), was on an average lower in heifer-cows both at winter (about 0.5) and at pasture feeding (about 0.6) than in older cows (both at winter and pasture feedings 0.8—0.9). No significant difference was found in the values of lactation tangent at winter and at pasture feedings. The influence of the condition of the cows on the peak production and the duration of the ascending phase of cows older than heifer-cows is slight, assuming that the cows at parturition are in normal or good conditions. Heifer-cows in normal condition, on the contrary, do not have an average peak production as high as cows in good condition. The duration of the ascending phase of the heifer-cows in normal condition is, however, about as long as that of cows in good condition. Only a few cows in a thin condition were included in this study. The length of the dry period has no great influence on the peak production if the dry period is at least one month in length. A too short dry period before the second lactation has a detrimental effect on lactation. It was found that at winter feeding the mean production of the three first days in per cent of the peak production was smaller in heifer-cows (about 50 %) than in older cows (about 60 %). According to this, lactation in heifer-cows begins both absolutely and relatively more slowely than in older cows. There is a rather close correlation between the mean production of the three first days and peak production. At winter feeding in cows older than heifer-cows, the peak production can be predicted on the basis of the mean production of the three first days by the aid of the regression equation. The accuracy, however, will be only 5 or 6 kg if a reliability of 95 per cent is desired. There is a very close correlation between the production of the tenth day (the mean of the 9th, 10th, and 11th day) and peak production. At winter feeding in cows older than heifer-cows, the peak production can be predicted on the basis of the production of the tenth day either by the aid of the regression equation or by adding to the production of the tenth day the difference between the peak production and the production of the tenth day. The accuracy will be 4 kg for areliability of 95 per cent. In the two latter sequences the most probable value for the peak production can be found by adding 4 kg to the production of the tenth day.

The effect of level of concentrate feeding before and after calving on the production of dairy cows

SummaryTwo levels of steaming-up and two levels of concentrate feeding after calving were compared in a feeding trial extending over a complete lactation using sixteen autumn-calving Ayrshire cows in each of 2 years. On the high and low levels of steaming-up 3·3 and 1·6 cwt of concentrates respectively were fed per cow in the 5 weeks before calving. On the high and low levels of concentrate feeding after calving the concentrates were fed at rates of 4·1 and 2·2 lb per 10 lb of milk respectively from the third day after calving until spring grazing began. The total weight of concentrates fed after calving was 25·8 cwt per cow on the high treatment and 12·1 cwt on the low treatment. All the cows grazed good pasture in the autumn and the following spring and had a ration of 9–11 lb of hay and 50–90 lb of grass silage per day during the winter feeding period. During this period the estimated mean intakes of starch equivalent on the high and low concentrate treatments were 17 and 13 lb/day, which were equivalent to 122 and 103% of Woodman's standards respectively.Milk yield, milk quality, length of lactation and live weight were not affected by the difference between the steaming-up treatments, and no interaction between steaming-up and post-calving treatments was found. Average milk yields in the first 70 and 140 days after calving and in the complete lactations were all higher on the high post-calving concentrate treatment than on the low treatment, and the response per 1 lb additional starch equivalent fed was 1·05 lb milk. The fat content of the milk was similar on all treatments whereas the S.N.F. content increased from 8·64% on the low treatment to 8·82% on the high treatment, giving a response of 0·045% S.N.F. per 1 lb of additional starch equivalent.Larger losses in live weight occurred on the low treatment in the first 10 weeks after calving than on the high treatment, but in both groups the weights were almost identical after 45 weeks.

The effect of the plane of energy nutrition of the cow during the late winter-feeding period on the changes in the solids-not-fat content of milk during the spring-grazing period

SummaryThree groups of eight Friesian cows, four of high and four of low milk yield, were given during the last month of the winter-feeding period rations that provided respectively low, normal and high planes of energy nutrition, at approximately 75,100 and 130% of the Woodman standards for starch equivalent (S.E.). They were then all changed to the grazing of good, spring pasture, without supplementary food. The changes with grazing in solids-not-fat (S.N.F.) content and yield of milk were markedly influenced by the previous level of winter feeding. After 15–18 days of grazing the mean changes in S.N.F. percentage were +0·33, +0·11 and –0·12 for the low, normal and high energy groups, and the corresponding changes in milk yield were +7·70, +2·13 and –0·68 lb per cow per day. The changes in S.N.F. reflected mainly changes in protein content, and to these casein, β-lacto-globulin and α-lactalbumin all contributed. Small, differential changes were found in the fat and lactose contents of the milk. The effects of the level of initial milk yield of the cow on the various responses to grazing are recorded.These observations support the view that when a rise in S.N.F. with spring grazing occurs it probably results from an improvement in the plane of energy nutrition. There appears to be no need to postulate a special effect of any specific herbage constituent.

Effect of Grass Silage on Milk Flavors and Blood and Milk Acetone Bodies1,2

Summary Acetone bodies were measured in the blood and milk of ten Holstein cows at intervals over a 5-mo. winter feeding period. Acetone body concentrations also were measured in the grass-legume silage which was fed as a part of the cows' ration. Milk produced by the cows was scored for type and intensity of flavor present. An interrelationship existed between the levels of acetone bodies in the silage, blood, and milk. Silage acetone bodies increased considerably in January and February, in relation to the other sampling periods, which extended from December to April. There was no apparent relationship between the levels of acetone bodies in the individual cows' milk and the flavors of the milk, as measured in this study. The most prominent off-flavors in the milk resulted from feeding the grass silage 2 hr. prior to milking.

Improvement of Native Range through New Grass Introduction

The stocking rates depicted by the graph represent a basis for conservative stocking rates over a period of years. In a year of high precipitation and consequently high forage yield, additional livestock numbers may be grazed during the summer and fall, or the grazing season may be extended to a greater length than usual. In event of drought, livestock numbers may be reduced by selling more th'an the usual number of livestock, culling more strictly, or shortening the grazing period and extending the winter feeding period. Until more is known about proper levels of utilization, the proposed graph may serve the purpose of adjusting stocking rates as deemed necessary. A regression equation Y = 27.17 + 78.48 X, where Y = estimated yield of forage in pounds per acre, and X inches of precipitation in May plus June, was developed. This equation may be used to estimate forage production as early as July 1 each year. Assuming that a mature beef cow (1,000 pounds) requires 660 pounds of forage (airdry basis) per month an estimate of carrying capacity is determined for the varying amounts of forage production estimated. The data presented may be of considerable value in forecasting r a n g e production and stocking rates within certain limits. In years of high precipitation, the forage production may be high and the carrying capacity may consequently be increased. In event of drought, livestock numbers may be decreased to cope with reduced production.

Additions of Hay to Corn Silage to Maximize Feed Intake and Milk Production

Summary Sixty cows were used in a series of feeding trials conducted at three North Carolina experimental farms over two winter-feeding periods to determine the optimum amount of hay to be used to supplement an ad libitum corn silage feeding regime for milk production. The four hay levels consumed were 0.83, 0.47, 0.24, and 0.00lb. per 100lb. of live weight. After a 28-day standardizing period, in which cows were offered silage ad libitum and 1lb. of hay per 100lb. of live weight, each cow was carried for a 56-day comparison period on one of the four experimental rations. Dry matter intake was highest in the group which consumed 0.83lb. of hay per 100lb. of live weight with the calculated maximum intake being at 0.79±0.37lb. of hay. Milk, fat, and FCM production was highest for the group consuming the 0.47lb. level of hay with the calculated maximum for FCM being at 0.52±0.22lb. of hay. Mean changes in live weight were essentially the same for the four treatment groups.

Compensatory Growth of Beef Cattle: The Effect of Hay Maturity

Native mountain meadow hay harvested at two stages of maturity was fed to 137 wintering weanling and yearling beef cattle from 1945–1953. Significantly greater gains were obtained by the cattle fed early-cut hay during the winter feeding period. The restricted animals gained significantly more during the following summer, and at the end of the first year, the cattle fed the better quality forage still weighed significantly more than the animals fed late-cut hay, but the difference was small. Animals kept during a second year completely compensated for the two winters of restricted growth and were as heavy the second fall as the animals fed early-cut hay. Animals restricted in growth were not permanently stunted and tended to compensate for this restricted period quite rapidly.

The Winter Feeding Period in the Southern Interior Plateau of British Columbia

(1954). The Winter Feeding Period in the Southern Interior Plateau of British Columbia. Annals of the Association of American Geographers: Vol. 44, No. 2, pp. 194-204.

The Winter Feeding Period in the Southern Interior Plateau of British Columbia

The Winter Feeding Period in the Southern Interior Plateau of British Columbia

Some Growth Relations in Range Cattle

Weight gains for five periods of growth and development were obtained on 88 grade and 67 purebred Herefords at the University of Nevada Experimental Range Station in northeastern Elko County. The 10 gross correlations between the five periods were calculated. None of the correlations involving weaning weight were significant. A positive correlation was observed between gains made during the two winter feeding periods. Correlations between succeeding periods were negative and significant. It is concluded that under the variable environmental conditions of this study there is an inverse relation between adaptability to winter feeding and summer grazing on the range. Genetic, environmental and phenotypic correlations were estimated from the purebred data for the four correlations found significant in the total data. A large, positive genetic correlation was found between gains made during the two winter feeding periods, indicating a common genetic influence on adaptability to winter feeding. In general, environmental correlations were larger than genetic correlations. It is concluded that environmental influences exert the greatest effect on the relation between gains at different periods, but that heredity is also effective.

Studies on Ketosis in Dairy Cattle. I. Effect of Stall and Pasture Feeding upon the Concentration of Blood and Urinary Acetone Bodies of Dairy Cattle

Summary A marked increase in the concentration of total blood and urinary acetone bodies and their component fractions of acetone and acetoacetic acid, and β-hydroxybutyric acid was observed during the late winter and early spring months with animals receiving molasses-treated grass silage. The lowest concentrations of these substances were observed in these animals when they were on early spring and summer pastures and were receiving grain, hay, and only a relatively small quantity of silage. It is believed that the relatively high values obtained for the group as a whole during the winter feeding period were due primarily to grass silage feeding. Although acetone and acetoacetic acid, and β-hydroxybutyric acid increased, the latter fraction was responsible for most of the rise. Since the feeding of fresh silage did not produce this effect, it appears that the increase in the acetone bodies on silage feeding was associated with the aging of the silage. In the light of the work of Bender et al . (2) and MacKay et al. (12) it is suggested that the increased production of the acetone bodies due to the feeding of aged molasses-treated grass silage is due primarily to the volatile acids in the silage. Frequent observations on the blood and urinary acetone bodies of six cows showed a sharp decline in these substances immediately after the animals were placed on spring pasture. The blood and urinary acetone bodies had decreased 52.8 per cent and 51.5 per cent respectively after 16 days of daily pasture feeding. The maximum decreases in acetone and actoacetic acid were observed following the first day of pasture feeding. Blood and urinary (β-hydroxybutyric acid, however, continued to decline throughout the 16-day period of observation. The sharp decline in acetone bodies after one day of pasture feeding was undoubtedly due primarily to the decreased silage feeding. The pasture grass feeding is believed to be partially responsible for the further continuous decline in the acetone bodies. The blood acetone body levels of four heifers which were pasture fed during the summer months and received only mixed grass hay of a fair quality during the winter months were much lower while on hay feeding than on pasture feeding. The blood acetone bodies increased following feeding, reaching a peak three hours after feeding, and then gradually decreased, returning to the pre-feeding level within nine hours. This effect was much more evident when aged grass silage was included in the ration.