Effects of body fatness at lambing and diet in lactation on body tissue loss, feed intake and milk yield of ewes in early lactation

1980 ◽  
Vol 95 (3) ◽  
pp. 497-514 ◽  
Author(s):  
R. T. Cowan ◽  
J. J. Robinson ◽  
I. McDonald ◽  
R. Smart

SUMMARYThirty-six mature Finnish Landrace × Dorset Horn ewes, each suckling two lambs, were used in a comparative slaughter experiment to measure changes in body tissues during early lactation. Two levels of body fatness at lambing were established by giving ewes a complete diet containing 10 MJ metabolizable energy (ME) and 139 g crude protein (CP)/kg d.m. either close to requirements or ad libitum during the second half of pregnancy. In lactation half the ewes in each group were given a complete diet containing either 90 (diet A) or 60 (diet B) % milled hay ad libitum. These diets contained 7·9 and 9·2 MJ ME and 121 and 132 g CP/kg d.m. respectively.Ewes fed at the two levels in pregnancy contained 8·4 and 19·6 kg chemically determined fat 5 days after lambing but had similar amounts of body protein, ash and water. Over 6 weeks of lactation ewes given diet A lost 60 and 69% of these weights of fat respectively, while ewes given diet B gained 5% and lost 30% respectively. Up to 26 g of body protein was lost daily from ewes given diet A but none from ewes on diet B. During early lactation the weight of the empty digestive tract increased while the weights of most other body components, particularly the carcass, decreased. The ratio of body energy change to live-weight change varied from 24 to 90 MJ/kg. Thus live-weight change did not accurately reflect relative or absolute changes in body energy.Voluntary food intake was greater for ewes given the high-energy diet (B) than for those given diet A and was depressed in the fatter ewes. Differences in intake could be explained by the effects of body fatness and diet on the weight of gut contents. Milk yield was not significantly affected by body fat reserves but was higher on diet B than A. Fat content of milk was higher and protein content lower for ewes with the higher fat reserves at lambing.As the contribution of fat loss to energy available for milk synthesis increased there appeared to be a reduction in the energetic efficiency of milk synthesis. A number of possible reasons for this are discussed.

1999 ◽  
Vol 68 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Y. Le Cozier ◽  
E. Ringmar-Cederberg ◽  
S. Johansen ◽  
J. Y. Dourmad ◽  
M. Neil ◽  
...  

AbstractFrom 74 to 180 days of age, a complete diet was offered either ad libitum (AL) or at proportionately 0·8 of the observed consumption (R) to two groups of purebred Yorkshire gilts, comprising 128 and 127 animals, respectively. Half of the animals in each group was served at the first detected oestrus, and the other half at the third detected oestrus, according to a plan defined at the start of the experiment. Animals which failed to show oestrus before 240 days of age were culled.At 100 kg live weight (LW), AL gilts were younger (-20 days) and had thicker backfat (+2.3 mm) than R gilts. At the first detected oestrus, AL females were also younger (198 v. 203 days), heavier (127 v. 117 kg LW) and fatter (17·8 v. 14·7 mm backfat thickness) than R gilts. No difference between feeding treatments during rearing was observed in the percentage of females detected on heat before day 240. Seventy-three animals were culled from the start of the experiment until service, half of them (54%) failing to show oestrus. At service, LW and backfat thickness in the four treatments ranged from 117 to 148 kg LW and 14·9 to 19·7 mm, respectively. The body fatness, estimated from the ratio of backfat to LW, was higher in AL than in R gilts (0·14 and 0·12 , respectively), whereas no difference was observed between E1 and E3 gilts (0·13 on average). After the first service 15% of the gilts came back into heat but the conception rate was not affected by feeding treatment during rearing.


1984 ◽  
Vol 103 (3) ◽  
pp. 629-637 ◽  
Author(s):  
C. L. Johnson

SummaryAn experiment has been made to study the effect of level of feeding in early lactation on the feed intake, yields of milk, fat and protein and on live-weight change over one lactation cycle. Adult British Friesian cows of high potential yield were randomly allocated to high (HP) or moderate (MP) levels of feeding for 20 weeks. They were then randomly allocated within treatments to controlled or ad libitum levels of feeding for the rest of the lactation.There were significant effects of feeding in the early part of lactation on the yields of milk, protein and lactose but not on milk fat or live-weight change. Cows on the MP treatment produced about 450 kg milk from body energy reserves but were unable to supplement fully the dietary energy deficiency. There was no significant response to feeding ad libitum in the second part of lactation and the differences in yields established in the first part were maintained in the second. There was no relationship between feed intake and milk yield for cows fed ad libitum nor did the level of feeding in early lactation influence the level of intake in the later part.There was little agreement between calculated energy balance and the live-weight changes but there was more between live-weight change and condition score.


1992 ◽  
Vol 55 (3) ◽  
pp. 331-337 ◽  
Author(s):  
R. W. Muinga ◽  
W. Thorpe ◽  
J. H. Topps

AbstractScarce and poor-quality food resources limit smallholder dairy production in the tropics. Food resources for zerograzing may be improved by intercropping Pennisetum purpureum (napier grass) with Leucaena leucocephala leguminous hedgerows. To evaluate dairy cow performance from this alley cropping system, 36 Ayrshire/Brown Swiss × Sahiwal cows in a 2×3 factorial design were individually fed from the 3rd week of lactation for 14 weeks on diets of napier fodder harvested at 1·0 m or 1·5 m and offered ad libitum, supplemented with 0, 4 or 8 kg fresh weight leucaena fodder. Average daily milk yield during the 2nd week of lactation was a covariate in the analyses of milk yield, and post-partum live weight a covariate in the analyses of dry matter (DM) intake and live-weight change.Napier harvesting height and leucaena level had independent effects on performance. Napier height (1·0 m or 1·5 m) significantly (P < 0·01) affected daily napier DM intake (9·3 and 6·8 kg), total daily DM intake (10·5 and 7·9 kg), daily live-weight losses (165 and 490 g) and daily milk yield (8·6 and 6·9 kg respectively). Leucaena supplementation (0, 4 or 8 kg) significantly (P<0·01) increased total daily DM intake (7·8, 9·3 and 10·4 kg), reduced daily live-weight loss (560,235 and 175 g), and increased daily milk yield (7·3, 7·7 and 8·3 kg respectively). The results show that reasonable dairy performance can be achieved in the tropics by supplementing a napier fodder basal diet with leucaena forage, and highlight the importance of the stage of harvesting of the napier fodder. The results are discussed in relation to the nutrient requirements for milk production given by the Agricultural Research Council (1980 and 1984).


1983 ◽  
Vol 37 (2) ◽  
pp. 183-188 ◽  
Author(s):  
Sandra A. Edwards ◽  
D. A. Poole

ABSTRACTTwo experiments examined the effects of including sodium bicarbonate in the diet of dairy cows in early lactation for two different feeding systems. In experiment 1, 28 Friesian cows were allocated to two groups according to parity, calving date and their milk yield in days 5 to 14. Cows were given either a standard home-mixed concentrate or a similar concentrate with sodium bicarbonate included at 25 kg/t. Concentrates were given to individual cows twice daily at a flat rate determined by their 5- to 14-day yield, and hay was group-fed to appetite. Milk yield in days 15 to 100 post-calving did not differ significantly between treatments, but cows given concentrate containing bicarbonate ate more hay and had a higher milk fat concentration (36·0 v. 32·5 g/kg, P < 0·01). In experiment 2, 80 cows were allocated to two treatments according to parity, calving date and previous lactation yield. There were two replicates of each treatment. All groups were given silage and concentrates as a complete diet for 8 weeks from calving, and 20 g sodium bicarbonate per kg total dry matter was included in the diet of half the animals. Cows given the diet containing bicarbonate had higher food intakes (14·9 v. 13·9 kg dry matter per head per day) and lower live-weight losses (13 v. 44 kg, P < 0·001). Milk yield and milk quality did not differ between treatments. Conception tended to be better in cows given the bicarbonate diet.


1992 ◽  
Vol 55 (1) ◽  
pp. 153-162 ◽  
Author(s):  
R. Parigi-Bini ◽  
G. Xiccato ◽  
M. Cinetto ◽  
A. Dalle Zotte

AbstractChanges in body composition during lactation in 40 primiparous rabbits were studied by comparative slaughter. The results were used to determine the utilization of digestible energy (DE) and digestible protein (DP) and their partitioning between maternal body, milk and foetal tissues.Twelve does were slaughtered immediately after their first parturition (first slaughter group) to estimate initial body composition. The 28 remaining does were remated 1 to 3 days after parturition and divided into two groups offered a pelleted diet at different levels: group L, fed ad libitum and group R, fed 0·75 of ad libitum. The 19 does that were pregnant (10 of L group, 9 of R group) were kept in individual metabolism cages until their second parturition. They were then slaughtered with their litters.Milk yield was higher (147·0 v. 117·2 g/day, P < 0·02) and live-weight loss was lower (–42 v. –294 g) in group L than in group R. The food intakes were 304·7 and 234·4 g/day, respectively. Body composition of the does changed substantially between the first and second parturition, with a considerable loss of fat and some loss of protein. A large decrease in empty body (digesta-free body) weight was observed in both groups. The loss of energy corresponded to proportionately 0·32 and 0·41 of the initial body energy, in L and R groups respectively.The DE requirement for maintenance was estimated to be 468 kj/day per kg M0·75 and the efficiencies of utilization of DE and body energy for milk production were 0·63 and 0·76, respectively. The efficiency of utilization of DE for foetal tissue synthesis was estimated to be 0·27 throughout pregnancy. The DP requirement for maintenance was 3·80 g/day per kg M0·75 and the efficiency of utilization of DP for milk protein production was 0·76 and of body protein 0·61. The efficiency of utilization of DP for foetal protein synthesis was 0·46.


1979 ◽  
Vol 92 (1) ◽  
pp. 133-138 ◽  
Author(s):  
J. N. Peart ◽  
J. M. Doney ◽  
W. F. Smith

SummaryMilk yield of 2-year-old Scottish Blackface and of East Friesland × Scottish Blackface ewes rearing single or twin lambs was estimated by the oxytocin method on 1 day each week up to the 14th week of lactation. Both groups of ewes had been reared from birth under good nutritional conditions. They were housed in individual pens from mid-pregnancy and offered a liberal ration of a pelleted concentrate food until parturition. Similar food was offered ad libitum during lactation.The cross-bred ewes rearing singles or twins produced significantly more milk in the first 12 weeks (181 and 258 kg respectively) than did pure Blackface ewes in the same period (144 and 208 kg respectively). The pattern of lactation differed between breeds. Cross-bred ewes attained higher maximum yields between the second and sixth weeks (2·37 and 3·32 kg/day, respectively, for single- and twin-suckled ewes) than did the Blackface ewes (1·97 and 2·88 kg/day). The yield from the cross-breds was sustained at a higher level throughout lactation. In the third 4-week period cross-bred ewes rearing single and twin lambs produced 116 and 92%, respectively, of their yield in the first 4 weeks whilst Blackface ewes produced 87 and 65%, respectively.In the sixth week of lactation the milk produced by the two breed groups was similar in quality (mean value of solids-not-fat 11·04% and fat 5·48%) but by the 11th week the fat percentage of milk produced by Blackface ewes had increased significantly to 7·34% whereas that of the cross-breds had remained almost unchanged.Single-suckled ewes gained weight throughout lactation but twin-suckled ewes remained relatively constant. Lambs reared as singles by cross-bred or Blackface ewes reached a mean live weight of 36·2 and 35·0 kg at 102 days of age, respectively, compared with 33·6 and 30·1 kg for twin lambs. Food intake of all ewes increased until the fifth or sixth week of lactation.


1981 ◽  
Vol 97 (1) ◽  
pp. 147-157 ◽  
Author(s):  
T. E. Trigg ◽  
J. H. Topps

SUMMARYMeasurements were made of changes in body water, estimated by the dilution of deuterium oxide, in six Hereford x British Friesian lactating cows in their second lactation and in four of the same animals in their third lactation. The animals were subjected to a prolonged period of underfeeding followed by a period of realimentation. Milk yields were measured twice daily whilst measurement of live weight and certain blood constituents were made at 7-day intervals during the experimental periods in both years. During underfeeding milk yield differed markedly among the cows and it appeared that the cows with a higher milk potential maintained a higher yield but in doing so they incurred a greater loss of body weight. On refeeding there was little or no response in milk yield. Weight losses during the second lactation consisted mainly of body fat (calculated by difference) but the four higher yielding cows lost appreciable amounts of body water and probably significant amounts of body protein. In the third lactation all four cows lost less body fat but more body water and probably body protein than they did in the second lactation. On refeeding all animals in both years except the two lowest yielders in the second lactation gained substantial amounts of body water and probably protein but relatively little or no body fat. Significant negative and positive correlations were obtained between plasma glucose and loss of body water and between plasma free fatty acids and loss of body fat respectively.


1975 ◽  
Vol 84 (1) ◽  
pp. 173-186 ◽  
Author(s):  
W. H. Broster ◽  
Valerie J. Broster ◽  
T. Smith ◽  
J. W. Siviter

SUMMARYFood utilization by lactating dairy cows was studied in a randomized experiment covering the first 24 weeks of lactation, with further observations on performance over the remainder of the lactation under farm conditions. Over a 3-year period 90 firstcalf cows each took part in the experiment for one lactation, making six groups of 14–16 animals.For the experimental period a fixed basal diet was given of hay, concentrates, and wet brewer's grains. One group received only the basal ration. Four groups received in addition a fixed concentrates supplement for 4, 8, 12, 16 weeks from calving onwards respectively. The sixth group also had supplementary concentrates for 16 weeks but for weeks 5–12 inclusive the amount was doubled so that this group's diet simulated broadly ad libitum feeding in early lactation.Milk yield was increased by extra concentrates. The greater part of the effect was apparent in the first 2 weeks of different levels of intake, with a further build-up over the next 6–8 weeks. The size of the response fell as time from calving to initiation of different intakes increased. Additional food increased and delayed peak yield level. Persistency of milk yield was not affected by fixed differences in intake. Rate of liveweight change was improved by extra concentrates, less so in the third compared with the first month on treatment.A higher level of feeding in early lactation led to a greater partition of nutrients in mid-lactation to milk at the expense of gains in body reserves. This advantage to milk production extended to the end of lactation. In it the greatest response per unit concentrates was obtained from supplementation in the first 4 weeks of lactation but the total effect was increased by giving a double allowance of concentrates, and by extending the period of extra feeding to 8 weeks after calving.Solids-not-fat content and yield, and fat yield but not fat content, showed a similar response pattern to milk yield.Animal-to-animal variation in output on constant diets was characterized by negative regressions of live-weight change on milk yield. The regression coefficients were greater in early than in mid-lactation but they were constant in size at any one time for the various groups. A change in ration induced a change in output of the individual in which that production pathway favoured naturally by the animal was the more affected.


Author(s):  
D.A.R. Davies ◽  
C.B. Gallo

In ewes rearing triplets high milk yields in early lactation are vitally important. The trial was conducted to investigate the influence of dietary protein intake on ewe milk yield and the performance of their triplet reared lambs.The trial involved 24 Cambridge (C) and 12 Suffolk x Cambridge (SxC) ewes rearing triplets. Ewes and their lambs were housed and penned in individual family groups until 35 days post partum. During the 7-35 day period ewes were fed ad libitum one of two coarsely milled complete diets differing in protein concentration (Table 1) together with a daily allocation of 510 g hay (oven dry).


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