Influence of plane of nutrition and diet composition on rumen fermentation and energy utilization by dairy cows

1988 ◽  
Vol 110 (2) ◽  
pp. 261-270 ◽  
Author(s):  
J. D. Sutton ◽  
W. H. Broster ◽  
E. Schuller ◽  
D. J. Napper ◽  
Valerie J. Broster ◽  
...  
Keyword(s):  
Milk Production ◽  
Milk Fat ◽  
Energy Production ◽  
Diet Composition ◽  
Live Weight ◽  
Dietary Factors ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Early Lactation ◽  
Nutrition And Diet

SummaryMean digestible energy (DE) intakes of 147 cows of three parities receiving three levels of DE including one ad libitum (about 2·2, 2·6 and 3·3 multiples of maintenance (MM)) drawn from three mixed diets containing hay and 60, 75 or 90% compound were calculated.Rumen samples were taken from three-quarters of the cows at monthly intervals throughout the experiment. Molar proportions of volatile fatty acids (VFA) in the rumen were not affected by stage of lactation over the 36 weeks of the experiment. The proportion of acetic acid decreased and that of propionic acid increased with greater intakes and with higher proportions of compound in the diet. The proportion of n-butyric acid was little affected by level of intake but decreased with increasing proportions of compound. In young, non-lactating cattle given the same diets but at lower levels of intake, VFA proportions were unaffected by diet composition at intakes of about 0·7 MM but at intakes of about 1·3 MM the proportion of acetate decreased and that of propionate increased when the proportion of compound was increased from 75 to 90%.The efficiency of milk energy production in relation to DE or metabolizable energy (ME) above maintenance decreased with increasing level of intake but was little affected by the proportion of compound. Partition towards live weight increased with level of intake in early lactation but not in late lactation. It also increased with higher proportions of compound in mid and late lactation but not in early lactation.Estimates of the ME requirement for live-weight change (LWC) were in reasonable agreement with recently published standards in early lactation when live weight was decreasing, but later in lactation when live-weight gain was occurring, a much higher value was calculated which is difficult to reconcile with these standards.Rumen VFA proportions were related to dietary fibre concentration and level of intake additively. The relationship to VFA proportions was close for milk fat concentration, but less so for energy partition towards live weight and none was apparent for the efficiency of ME utilization for milk energy production. It is suggested that both the reduction in milk fat concentration and the increase in milk yield in response to reductions in the fibre content of diets may be independently related to the increase in the proportion of propionate in the rumen VFA.It is concluded that further progress in studies of the dietary factors affecting the efficiency of milk production will require measurements of nutrient uptake from the digestive tract and description of milk production and LWC in terms of their chemical composition rather than energy alone.

The influence of plane of nutrition and diet composition on the performance of dairy cows

1985 ◽  
Vol 104 (3) ◽  
pp. 535-557 ◽  
Author(s):  
W. H. Broster ◽  
J. D. Sutton ◽  
J. A. Bines ◽  
Valerie J. Broster ◽  
T. Smith ◽  
...  
Keyword(s):  
Milk Fat ◽  
Dry Matter ◽  
Diet Composition ◽  
Cumulative Effect ◽  
Live Weight ◽  
Early Lactation ◽  
Dry Matter Digestibility ◽  
Stage Of Lactation ◽  
Nutrition And Diet ◽  
Ad Libitum

SummarySeventy-six first-calf cows (heifers), 32 second·calf cows and 39 adult cows participated in a trial in which three diets composed of 60:40, 75:25, 90:10 proportions of compound to hay (hay dry-matter digestibility 0·6) were given for the first 36 weeks of lactation in amounts to provide daily an estimated 125, 156 MJ and ad libitum digestible energy (DE) for heifers, and 156, 187 MJ and ad libitum DE for the other parities. The ad libitum intakes were 150 and 200 MJ DE daily for heifers and for older cows respectively. Greater compound content of the diet and larger daily allowance of DE were associated with increased occurrence of mastitis and lameness but not digestive upsets. Dry·matter (D.M.) digestibility was increased with a greater proportion of compound in the diet but was not affected by the amount consumed or stage of lactation. Milk yield and live·weight change were increased linearly and additively by a greater intake of digestible dry matter and by a greater proportion of compound in the diet, throughout the lactation save for no effect of diet composition on live·weight change in early lactation. On equal feed intakes older cows gave more milk and lost more live weight than heifers in early lactation but not thereafter; responses to additional feed were equal for all parities studied. Milk fat concentration was reduced both by increased allowance and by the high compound diet. Milk solids·not·fat (SNF) concentration was not affected by the treatments. Yield of milk fat was not affected by amount eaten and was reduced by the 90:10 diet. Yields of SNF and milk energy were increased by amount eaten and by increased compound in the diet. Thirty-two primiparous cows continued on their experimental treatments without interruption to the end of the second lactation. In the second lactation the effects on yields of milk, milk energy, and SNF were magnified indicating a cumulative effect from lactation to lactation. Little cumulative effect was observed on either milk fat yield, or concentrations of fat and SNF in milk. More generous feeding was associated with reduced milk output/unit D.M. consumed in the first but not the second lactation. More generous feeding improved live·weight change less in the second than in the first lactation. No cumulative effects over two lactations were observed consequent upon variation in diet composition.

A comparison of starchy and fibrous concentrates for milk production, energy utilization and hay intake by Friesian cows

1987 ◽  
Vol 109 (2) ◽  
pp. 375-386 ◽  
Author(s):  
J. D. Sutton ◽  
J. A. Bines ◽  
S. V. Morant ◽  
D. J. Napper ◽  
D. J. Givens
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Energy Yield ◽  
Carbohydrate Source ◽  
Lactating Cows ◽  
Concentrate Inclusion ◽  
Friesian Cows

SummaryTwenty-four Friesian cows were allocated to one of four diets for weeks 3–14 of lactation following 2 weeks on a common diet. The diets (kg air-dry feed/day) were 7–2 kg hay and 10·8 kg either starchy or fibrous concentrates (60S and 60F) or 3·5 kg hay and 14·0 kg either starchy or fibrous concentrates (80S and 80F). Rumen samples were taken by stomach tube in weeks 10 and 12 of lactation and the digestibility of the diets was measured with four cows per treatment during weeks 13 and 14. The digestibility of the same feeds was also measured in sheep at maintenance.The principal carbohydrate constituents of the concentrates were barley, wheat and cassava in the starchy concentrates and citrus pulp, sugar-beet pulp and wheat feed in the fibrous concentrates. The concentrates were designed to have similar concentrations of metabolizable energy (ME) and the diets were planned to provide similar intakes of digestible energy and crude protein.Milk yield and composition were very similar for treatments 60S and 60F. With the higher proportion of starchy concentrates (80S), milk yield was about 20% greater than on 60S, fat concentration fell severely but protein and lactose concentrations were unaffected. With the higher proportion of fibrous concentrates (80F), milk yield and the protein and lactose concentration were similar to values on 60F but fat concentration was lower, though not nearly so low as on 80S. Milk energy yield was reduced by the higher proportion of concentrates but was unaffected by type of carbohydrates. Live-weight changes were small.In both the sheep, consuming at maintenance, and the lactating cows consuming at about 3 times maintenance, digestibility of dry matter, organic matter and energy was higher with the higher concentrate diets but was unaffected by type of concentrate. The digestibility of fibre was greater with the fibrous concentrates but the effect of level of concentrate inclusion was inconsistent. Digestibility coefficients were consistently lower for the lactating cows than for the sheep.The proportion of acetic acid in the rumen volatile fatty acids in the cows was higher and the proportion of propionic acid was lower with the fibrous concentrates. The differences were much greater with the higher proportion of concentrates.During weeks 15–22 of lactation the cows were reallocated to concentrate treatments and given hay ad libitum. Hay intake was about 1 kg/day higher with the fibrous concentrates but the difference was not significant. Hay intake fell by about 0·6 kg/kg concentrate intake for both concentrate types. No significant differences in milk yield or composition were established, probably because of incomplete adaptation even after 8 weeks.It is concluded that at concentrate intakes of about 10 kg/day, the source of carbohydrate in the concentrates has little effect on milk production when the concentrates are of similar ME concentration. However, at higher levels of concentrate inclusion, although the diets may have similar ME concentrations, important differences in the yields of fat, protein and lactose occur due to carbohydrate source and these can be related to differences in rumen fermentation.

The effect of genetic merit and concentrate proportion in the diet on nutrient utilization by lactating dairy cows

1999 ◽  
Vol 132 (4) ◽  
pp. 483-490 ◽  
Author(s):  
C. P. FERRIS ◽  
F. J. GORDON ◽  
D. C. PATTERSON ◽  
M. G. PORTER ◽  
T. YAN
Keyword(s):  
Dairy Cows ◽  
Energy Intake ◽  
Milk Production ◽  
Milk Fat ◽  
Nutrient Utilization ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Energy Output ◽  
Genetic Merit ◽  
Gross Energy

Sixty Holstein/Friesian dairy cows, 28 of high genetic merit and 32 of medium genetic merit, were used in a continuous design, 2 (cow genotypes)×4 (concentrate proportion in diet) factorial experiment. High and medium merit animals had Predicted Transmitting Abilities for milk fat plus protein yield, calculated using 1995 as the base year (PTA95 fat plus protein), of 43·3 kg and 1·0 kg respectively. Concentrate proportions in the diet were 0·37, 0·48, 0·59 and 0·70 of total dry matter (DM), with the remainder of the diet being grass silage. During this milk production trial, 24 of these animals, 12 from each genetic merit, representing three animals from each concentrate treatment, were subject to ration digestibility, and nitrogen and energy utilization studies. In addition, the efficiency of energy utilization during the milk production trial was calculated.There were no genotype×concentrate level interactions for any of the variables measured (P>0·05). Neither genetic merit nor concentrate proportion in the diet influenced the digestibility of either the DM or energy components of the ration (P>0·05). When expressed as a proportion of nitrogen intake, medium merit cows exhibited a higher urinary nitrogen output and a lower milk nitrogen output than the high merit cows. Methane energy output, when expressed as a proportion of gross energy intake, was higher for the medium than high merit cows (P<0·05), while urinary energy output tended to decrease with increasing proportion of concentrate in the diet (P<0·05). In the calorimetric studies, neither heat energy production, milk energy output and energy retained, when expressed as a proportion of metabolizable energy intake, nor the efficiency of lactation (kl), were affected by either cow genotype or concentrate proportion in the diet (P>0·05). However when kl was calculated using the production data from the milk production trial the high merit cows were found to have significantly higher kl values than the medium merit cows (0·64 v. 0·59, P<0·05) while k l tended to fall with increasing proportion of concentrate in the ration (P<0·05). However in view of the many assumptions which were used in these latter calculations, a cautious interpretation is required.

The effect of different levels of nutrition at two stages of the lactation on milk production and live-weight change in Friesian cows and heifers

1981 ◽  
Vol 96 (3) ◽  
pp. 677-690 ◽  
Author(s):  
M. J. Strickland ◽  
W. H. Broster
Keyword(s):  
Milk Production ◽  
Milk Fat ◽  
Live Weight ◽  
Residual Effects ◽  
Early Lactation ◽  
Or Groups ◽  
Regular Increase ◽  
Experimental Treatments ◽  
Two Stages ◽  
Friesian Cows

SUMMARYOver the 4 years 1965–8, a total of 105 mature Friesian cows and 84 Friesian heifers were fed various levels of nutrition at two stages of the lactation to study the effect on milk production. The experiments were carried out over a whole lactation at four Experimental Husbandry Farms, Boxworth, Bridget's, Great House and Trawsgoed. There were three treatment levels in early lactation (weeks 3–10) comprising 5·9, 7·8 or 9·8 kg D.M./day of concentrates for mature cows and 1·6 kg D.M./day less at each level for the heifers. In mid-lactation (weeks 12–18) the two lower levels of concentrates were fed arranged factorially with early-lactation levels. A basal forage ration usually of hay was fed to provide 85% of the basal maintenance requirements. During the remainder of the lactation all animals received the same level of nutrition. In addition to the pre-determined feed treatments, one further group of animals in each block was fed according to the milk production in the preceding week.Overall an increase in level of nutrition in early lactation produced a regular increase in milk production from successive increments with adult cows but only for the first increment with heifers. Raising feed level in mid-lactation increased milk production for all animals. There were considerable residual effects from early-lactation feeding but these were less with mid-lactation feeding. These same effects were also noted with yields of solids-not-fat and to a less extent in milk fat production.The experimental results indicated not only the mean effects of treatments but more important the interaction with individual animals. Study of the response of individual animals indicated that the effects of level of feeding varied in proportion to the potential of the cow. The presentation of mean results can therefore be misleading. The potential of a cow was indicated by milk production in the immediate post-calving period. This period could be used both in experimental designs for selecting animals in the allocation to experimental treatments and also in the practical context for rationing individuals or groups of cattle.The absolute plane of nutrition related to the potential of the animal was the most important factor in determining the efficiency of utilization of feed for milk production.

Experiments on the nutrition of the dairy heifer: VIII. Effect on milk production of level of feeding at two stages of the lactation

1969 ◽  
Vol 72 (2) ◽  
pp. 229-245 ◽  
Author(s):  
W. H. Broster ◽  
Valerie J. Broster ◽  
T. Smith
Keyword(s):  
Milk Production ◽  
Agricultural Research ◽  
Residual Effect ◽  
Live Weight ◽  
Fat Content ◽  
Metabolizable Energy ◽  
Early Lactation ◽  
Minor Variation ◽  
Body Reserves ◽  
Two Stages

SUMMARYEighty Friesian heifers were used to study the effect on milk production of two fixed levels of intake at two stages of the lactation. The rations were estimated to contain 7·9 and 6·2 kg starch equivalent per day, with adequate protein content. The heifers were allocated at random to these two levels of intake for weeks 1·9 of lactation and re-allocated at random to them for weeks 10–18 of lactation. Apart from minor variation the heifers were all fed alike for the remainder of the lactation.The higher level of feeding increased yields of milk and milk solids and solids-not-fat content in each period but had a smaller effect in mid- than in early lactation, a trend which was shown to continue further into later lactation. It also conserved body reserves.There was a residual effect in weeks 10–18 from the level of feeding in weeks 1–9 of lactation. This was directly additive to the effects of the current level of feeding. Those animals which had received the higher level of feeding in weeks 1–9 yielded more milk of higher solids-not-fat content than those which had had the lower level of feeding in weeks 1–9. The former group gained less live weight. The effect on milk production over the full lactation from additional feeding in early lactation was three times that observed in early lactation itself. Additional feeding in mid-lactation did not have a residual effect.The absolute output of milk per unit of food over the 18-week period was greatest for that group which had received the lower level of feeding throughout, followed by the group which received the higher level of feeding in weeks 1–9 only. This superiority was achieved at the expense of body reserves. There was a negative regression of live-weight change on milk production.Estimated intakes of metabolizable energy agreed closely with requirements for milk production as indicated by the Agricultural Research Council (1965).

Silages harvested at different stages of grass growthv.concentrate foods as energy and protein sources in milk production

1999 ◽  
Vol 69 (1) ◽  
pp. 251-263 ◽  
Author(s):  
M. Rinne ◽  
S. Jaakkola ◽  
K. Kaustell ◽  
T. Heikkilä ◽  
P. Huhtanen
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Milk Fat ◽  
Milk Protein ◽  
Rapeseed Meal ◽  
Protein Supplementation ◽  
Dietary Factors ◽  
Metabolizable Energy ◽  
Meadow Fescue ◽  
D Value

AbstractFour silages were prepared at 1-week intervals from a primary growth of timothy-meadow fescue sward. They were offered to 32 Finnish Ayrshire cows and supplemented with 7 or 10 kg of concentrate containing 0 or 1·15 kg rapeseed meal (RSM). The basal concentrate consisted of barley, oats and molassed sugar-beet pulp (2: 2: 1) and minerals. Diets were arranged 4 × 2 × 2 factorially in a cyclic change-over experiment with four periods of 21 days each.Silages contained 739, 730, 707 and 639 g digestible organic matter (D value) per kg dry matter (DM) for harvests I, II, III and IV, respectively. All dietary factors had marked effects on the performance of the cows but generally interactions between treatments could not be detected. A decrease of 10 g/kg in silage D value decreased energy-corrected milk (ECM) production of the cows by 0·50 kg/day and silage DM intake by 0·162 kg/day. An increment of 1 kg concentrate DM decreased silage DM intake by 0·61 kg and yielded 0·55 kg more ECM per day. Inclusion of RSM into the concentrate increased daily ECM production by 1·7 kg and silage DM intake by 0·60 kg/kg RSM when substituting the basal concentrate. Milk yield and yields of milk constituents decreased curvilinearly with delayed date of harvest the difference being greatest between the last two cuts and thus closely reflected the changes in silage D value. Milk protein concentration increased as apparent digestibility (P < 0.001) and concentrate level in the diet increased (P < 0.001). Milk fat concentration was not affected by the dietary treatments.Marginal ECM production responses to estimated metabolizable energy (ME) intake were higher when intake was manipulated with the date of silage harvest (0·138 kg ECM per MJ additional ME) compared with increased concentrate feeding (0·103); highest response was achieved by RSM feeding (0·244). Additional intake of calculated amino acids absorbed from the small intestine (AAT) manipulated by silage harvest time resulted in the highest marginal response (0·59 g milk protein per g additional AAT), while increased concentrate feeding and inclusion of RSM were equal (0·50 v. 0·49, respectively). Improving silage quality by earlier harvest resulted in higher milk yield, and in greater efficiency in the use of increments of estimated ME and AAT than was seen with increased concentrate feeding. Protein supplementation improved milk production irrespective of silage harvest date.

Increasing Energy Ration of Bali Cattle to Improve Digestible Nutrient, Milk Yield and Milk Quality

2017 ◽  
Vol 3 (1) ◽  
pp. 7
Author(s):  
Ni Nyoman Suryani ◽  
I Wayan Suarna ◽  
Ni Putu Sarini ◽  
I Gede Mahardika
Keyword(s):  
Energy Intake ◽  
Milk Production ◽  
Milk Yield ◽  
Milk Fat ◽  
Block Design ◽  
Parent Body ◽  
Milk Quality ◽  
Metabolizable Energy ◽  
Increase Energy Intake ◽  
Bali Cattle

To determine the effect of energy levels on digestible nutrient, milk production and milk quality of 7 months pregnant Bali cattle, was the purpose of this study. The study was conducted in Bali, Province of Indonesia on 12 pregnant breeding phase of pre-calving (2 months before the birth) with the parent body weight 329-340 kg/head. The treatment given is four types of Metabolizable Energy (ME) levels: 2000, 2100, 2200 and 2300/kg respectively as treatment A, B, C, and D. All ration contain 10% of crude protein. Variables measured: energy intake, digestible nutrient, milk yield, and milk quality. This research is a randomized block design. The results showed that increase energy ration until 2300 kcal ME/kg would significantly (P<0.05) increase energy intake and highest at cattle consumed ratio D is 22239.55 kcal/day. However, digestible nutrient was not affected. Milk production increased with increasing energy rations and highest (P<0.05) at cattle received treatment D is 2179.83 ml/day compared to treatment A 936.67 ml/day. Milk fat and milk lactose also highest (P<0.05) in treatment D are 8.56% and 4.76% respectively. Based on these results, it can be concluded that increase energy ration will increase energy intake, milk yield and milk fat and milk lactose of Bali cattle. 

The effects of plane of nutrition and diet type on metabolic hormone concentrations, growth and milk production in high genetic merit dairy herd replacements

2000 ◽  
Vol 70 (2) ◽  
pp. 349-362 ◽  
Author(s):  
A.F. Carson ◽  
A.R.G. Wylie ◽  
J.D.G. McEvoy ◽  
M. McCoy ◽  
L.E.R. Dawson
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Live Weight ◽  
Live Weight Gain ◽  
Genetic Merit ◽  
Grass Silage ◽  
Nutrition And Diet ◽  
Condition Score ◽  
Metabolic Hormone ◽  
Diet Type

AbstractSeventy high genetic merit Holstein heifers were used in two experiments to investigate (1) the effects of plane of nutrition and diet type during the pre-pubertal period and (2) the effects of plane of nutrition during the post-pubertal period on metabolic hormone concentrations, growth and milk production. In experiment 1, treatment 1 and 2 heifers were given food to achieve a live-weight gain of 0·70 and 0·95 kg/day from 3 to 10 months of age on a grass silage based diet, while treatment 3 heifers were given food to achieve 0·95 kg/day on a barley straw/concentrate diet. During the pre-pubertal period, heifers reared on treatment 1 had significantly higher growth hormone(GH) concentrations (ng/ml per 1 h) than heifers reared on treatment 2 (P < 0·01) and had significantly lower insulin concentrations than heifers reared on treatment 3 (P < 0·01). Heifers reared on treatment 1 had significantly lower insulin-like growth factor 1 (IGF-1) concentrations than those reared on treatment 3 (P < 0·01). At 10 months of age heifers reared on treatment 1 were of lower condition score (P < 0·01) than those on treatment 2 and had a smaller heart girth diameter (P < 0·01) than those on treatments 2 and 3. During the first lactation, milk yield and composition produced by the heifers was not significantly affected by treatment. In experiment 2, treatment A heifers were given, from 14 to 24 months of age, a low plane of nutrition to allow a live-weight gain of 0·65 kg/day on a grass silage and grass based diet during the winter and summer periods respectively. Treatment B heifers were kept on a high plane of nutrition to allow a live-weight gain of 0·90 kg/day on the same forage along with concentrate supplementation. During the rearing period, GH and IGF-1 concentrations were not significantly affected by treatment. Treatment A heifers weighed less before calving (P < 0·05), had a lower condition score (P < 0·01), and had a smaller heart girth diameter (P < 0·01) than those on treatment B. During the first 10 weeks of lactation, heifers on treatment A had a higher silage dry matter intake and lost less weight (P < 0·05) than those on treatment B, however, by 20 weeks of lactation these effects had disappeared. Milk yield and composition during the first lactation were not significantly affected by treatment. Overall, the findings of experiments 1 and 2 did not show any beneficial effects of higher weights at first calving in high genetic merit Holsteins and therefore indicate that accelerated growth in the pre- or post-pubertal period may not be required.

Effect of body condition at calving and level of feeding in early lactation on milk production of dairy cows

1982 ◽  
Vol 22 (115) ◽  
pp. 9 ◽  
Author(s):  
C Grainger ◽  
GD Wilhelms ◽  
AA McGowan
Keyword(s):  
Milk Production ◽  
Body Condition ◽  
Milk Fat ◽  
Body Condition Score ◽  
Early Lactation ◽  
Input Output ◽  
Fat Percentage ◽  
Feeding Management ◽  
Condition Score ◽  
Degree Of Confidence

Two experiments were carried out to measure effects of body condition at calving and different levels of feeding after calving on milk and subsequent reproduction.In experiment 1, which was conducted in two consecutive years, 162 cows (77 in year 1 and 85 in year 2) were group feed so as to reach a target body condition (condition scores ranging from 3-6) four weeks before calving. During the last four weeks before calving, all cows were managed so as to maintain their individual condition scores. At calving, cows in similar condition of similar breed and with similar previous milk production were allocated to high and low levels of feeding at pasture for the first five weeks of lactation. Mean pasture intakes were 13.0 and 7.0kg dry matter (DM)/cow.d in year 1 and 15.0 and 8.5 kg DM/cow.d in year 2In experiment 2, 40 cows were offered pasture and hay from 20 weeks before calving to achieve a body condition score of either 4 or 6 by two weeks before calving. During the first five weeks of lactation, cows were individually fed in stalls on freshly cut pasture at one of three levels of intake, 7 or 10 kg DM/cow.d or .In both experiments cows were grazed as one group from week 6 to 20 of lactation.Improved body condition at calving resulted in an extra 4.0, 11.0 and 7.4 kg milk fat per unit condition score over 20 weeks of lactation, for year 1 and 2 of experiment 1, and experiment 2, respectively. Cows in poorer condition partitioned a higher proportion of feed energy to liveweight at the expense of milk production than did the cows in better condition. However, increasing the plane of nutrition in early lactation resulted in higher levels of milk production and reduced the need for cows to mobilize bodyreserves. Improved body condition at calving had a positive effect on milk fat percentage, particularly in early lactation, but did not affect milk protein percentage. Input-output relations calculated from the experimental data showed that the benefit sf to improve body condition before calving was less than that of additional feeding after calvin changes in the condition of the cows were taken into consideration (25.8 vs 1 4.6 kg DM to yi kilogram of milkfat). Improvements in condition and feeding in early lactation reduced the anoestrus interval after calving by 5.7 d for each additional condition score at calving and 1. d for each additional kgDM/cow.d fed over weeks 1-5 of lactation. The input-output relations resented will enable farmers to assess the likely consequenes of changes in their feeding management in the crucial peripartum period with a greater degree of confidence than in the past.

scholarly journals Characteristics of the productive-economic indicators of cows of Yaroslavl breed of different genotypes

2020 ◽  
pp. 43-52
Author(s):  
N. Kosyachenko ◽  
Marina Abramova ◽  
M. Lapina
Keyword(s):  
Protein Content ◽  
Milk Production ◽  
Milk Yield ◽  
Milk Fat ◽  
Live Weight ◽  
Practical Significance ◽  
Holstein Breed ◽  
Blood Fraction ◽  
The Impact ◽  
The Relationship

Abstract. Aim. The study of the influence of crossbriding on the growth and development of heifers and subsequent productive and reproductive qualities of cows on the first lactation. Methods. Using statistical methods, correlation analysis and ANOVA for evaluated genetic indicators of economic-valuable traits of dairy cattle. In particular was studied live weight of heifers from birth to 18 months, first insemination age and first fecundation age, live weight at fecundation, frequency of insemination, first calving age, days open, live weight at first lactation, milk yield for 305 days (kg), fat (%, kg) and protein (%, kg) in milk. Results. Relationship between productive indicators and the genotype of the animal is established. When assessing the strength of the influence of the factor «blood on the Holstein breed» it was found that the greatest impact can be traced at the age of 6 and 18 months, and is respectively 12.7 % and 17.1 %.The reproductive qualities of the first-calf cows decreased with the increase percent of blood in the Holstein breed. Evaluation of the impact of crossbreeding on milk production at first lactation has revealed significant strong influence on milk yield for 305 days of first lactation, and related signs the amount of milk fat and protein. According to qualitative indicators, the low influence of the Holstein blood fraction was found, while to a greater extent on the fat content than on the protein content in milk. Evaluation of phenotypic and genotypic correlations of milk yield and quality components of milk revealed average negative phenotypic and low negative genotypic correlation in all groups. The exception was in heifers of Yaroslavl breed with percent of Holstein blood less than 50 %, in which the relationship of yield x protein was positive. The relationship between milk yield and fat and protein content in milk has the opposite moderate character and strength. Practical significance. Studies was established that breeding of animals of Holstein and Yaroslavl breeds in one herd allows to receive an optimum ratio of milk production with optimal percentage fat and protein. For this herd among animals of the improved genotypes of the Yaroslavl breed, the use of genotypes with a percent of blood in the Holstein breed from 75.1 % to 87.6 % is optimal, which should be taken into account when selecting bulls to the breeding program.

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