A DAIRY RECORDS STUDY OF THE EFFECTS OF FEEDING LEVELS ON MILK YIELD AND COMPOSITION

1976 ◽  
Vol 56 (3) ◽  
pp. 513-522
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Variance Components ◽  
Dairy Herd ◽  
Error Variance ◽  
Energy Concentration ◽  
Net Energy ◽  
Linear Effects ◽  
Net Energy Intake ◽  
Quadratic Effects

A total of 139,720 Holstein and 17,259 Ayrshire 305-day lactation records from the Dairy Herd Analysis Service were studied to estimate linear and quadratic effects of net energy intakes from silage, hay, pasture and meal and effects of silage:hay ratio, roughage:meal ratio and energy concentration on milk yield and composition. Effects of correcting for feeding levels on estimates of herd and cow variance components were studied also. Linear effects of increased net energy intakes from silage, hay, pasture and meal on milk, fat and protein yields were positive (P <.01) for both breeds. For Holsteins, all quadratic effects on milk yield were also positive (P <.01). Quadratic effects of each roughage source on fat and protein yield were negative, but meal had a positive quadratic effect (P <.01). Quadratic effects were inconsistent for the Ayrshires. Both linear and quadratic effects of feeding levels on fat and protein percent were inconsistent for the two breeds. For both breeds, greater silage:hay ratios and energy concentrations increased yields, and greater roughage:meal ratios decreased yields and fat percent (P <.01). Correcting records for net energy intake reduced estimates of herd, cow and error variance components. Repeatability estimates of yield traits were also reduced, but percentage trait repeatabilities were not altered.

EFFECTS OF CORRECTING FOR FEEDING LEVELS ON ESTIMATES OF GENETIC PARAMETERS OF MILK YIELD AND COMPOSITION

1976 ◽  
Vol 56 (3) ◽  
pp. 523-529 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY
Keyword(s):  
Energy Intake ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Relationships ◽  
Protein Yield ◽  
Net Energy ◽  
Yield Traits ◽  
Genetic And Phenotypic Correlations ◽  
Net Energy Intake ◽  
Quadratic Effects

A total of 13,561 Holstein 305-day lactation records were studied to examine the effects of correcting records for linear and quadratic effects of 305-day net energy intake from silage, hay, pasture and meal feeding on estimates of genetic parameters of milk, fat and protein yield and fat and protein percent. Correcting records for net energy intake reduced variances of yield traits, but had little effect on composition trait variances. When expressed as a percentage of the total variance, the relative importance of sire and sire–herd components were unchanged using corrected records, and heritabilities, except for that of protein yield, were unaltered. Cow components of yield traits were reduced relative to other components after records were corrected for feeding levels. Consequently, repeatabilities were reduced as well, suggesting that a large portion of the permanent environmental effects on yield traits may be of nutritional origin. Genetic and phenotypic correlations between yield traits were also reduced appreciably after records were corrected for feed intake. Genetic relationships between milk, fat and protein yield may not be as great as commonly believed.

REPRODUCTIVE EFFICIENCY OF ARTIFICIALLY BRED HOLSTEINS IN QUEBEC

1979 ◽  
Vol 59 (2) ◽  
pp. 419-425 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY ◽  
R. L. CHICOINE ◽  
G. L. ROY
Keyword(s):  
Milk Production ◽  
Variance Components ◽  
Error Variance ◽  
Herd Size ◽  
Maximum Likelihood Estimates ◽  
Reproductive Efficiency ◽  
Net Energy ◽  
Conception Rates ◽  
Net Energy Intake ◽  
Days Open

A total of 2216 lactations, initiated between July 1973 and June 1976, of 1382 Holstein cows in 36 herds from the Nicolet, Rock Forest and St-Hyacinthe regions of Quebec were studied. All cows were bred exclusively by AI. Mean services per conception, percent conception on first service, days from calving to first service and days open were 1.97 services, 47%, 88 days and 121 days, respectively. Based on maximum likelihood estimates of cow and error variance components, repeatabilities of services per conception, days from calving to first service and days open were 0.04, 0.09 and 0.07, respectively. Cows calving in spring had better reproductive performance than those calving during other times of the year. Reproductive efficiency was lower among both 2-yr-old and mature cows compared to intermediate aged cows. Lower reproductive efficiency was also associated with cows at high milk production levels. As herd size increased, conception rates declined. Herds feeding at high levels of net energy had higher conception rates than herds with low and medium net energy intake levels. Dairymen who managed their labor efficiently for milk production had herds with high reproductive efficiency.

Effects of feeding peas to high-producing dairy cows

1995 ◽  
Vol 75 (4) ◽  
pp. 625-629 ◽  
Author(s):  
R. R. Corbett ◽  
L. A. Goonewardene ◽  
E. K. Okine
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Milk Fat ◽  
Dairy Herd ◽  
Protein Source ◽  
Canola Meal ◽  
Stage Of Lactation ◽  
Nutrient Analyses ◽  
Protein Milk

The effect of substituting peas for soybean and canola meals as a protein source in a high-producing dairy herd was studied in 66 Holstein cows, divided into two groups based on stage of lactation, parity, level of milk production and days in milk. Two 18.5% crude protein grain concentrate diets were formulated based on the nutrient analyses of the forages available. The control grain mix contained standard protein sources, principally soybean and canola meal (SBM\CM) while the test grain mix was formulated to contain approximately 25% field peas as the major source of protein. Both grain rations were formulated to the same nutrient specifications and balanced for undegradable protein. The duration of the trial was 6 mo during which grain feeding levels were adjusted monthly based on milk yield. For cows in early lactation, 4% fat-corrected milk yield was higher (P < 0.05) for cows fed pea based concentrates (31.3 kg d−1) than for cows fed SBM\CM supplement (29.7 kg d−1). Fat-corrected milk yield was not affected by source of protein in mid- and late-lactation cows. Fat-corrected milk production was not different (P > 0.05) for cows fed SBM\CM compared with cows fed the pea supplement when cows across all stages of lactation were included in the analyses. Milk fat percent was significantly higher (P < 0.05) for early- and mid-lactation cows fed the pea supplement. The results suggest that peas can be substituted for SBM\CM as a protein source for high-producing dairy cows. Key words: Dairy cow, pea, soybean and canola meal supplement, undegradable protein, milk production

scholarly journals Structural and non-structural carbohydrates in concentrate supplements of silage-based dairy cow rations. 1. Feed intake and milk production.

1990 ◽  
Vol 38 (3B) ◽  
pp. 487-498
Author(s):  
H. de Visser ◽  
P.L. van der Togt ◽  
S. Tamminga
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Feed Intake ◽  
Milk Fat ◽  
Milk Protein ◽  
Basal Diet ◽  
Negative Energy ◽  
Net Energy ◽  
Rumen Degradation ◽  
Silage Maize

A feeding trial was carried out with 64 multiparous dairy cows, in which the effect of type of carbohydrate in concentrate mixtures (starch vs. cell wall constituents) and differences in rumen degradation (fast vs. slow) on feed intake and milk yield were studied. The experiment started immediately after parturition and lasted for 15 wk. The basal diet, which comprised 75% of the total DM intake, consisted of wilted grass silage, maize silage and concentrates. The remaining part of the diet consisted of barley (B), maize (M), pressed ensiled beet pulp (P) or moist ensiled maize bran (MB). All diets were given as totally mixed rations. Total intake of DM and net energy did not differ between diets, but differences were found in energy partition. There was a tendency for cows given diet B to show increased liveweight gain, while cows given P mobilized more body reserves compared with the other treatments. Milk yield did not differ between diets, but milk fat content was higher for diet P. Milk protein content was higher for diets B and M compared with P and MB. The lower protein content of the milk of treatment P can be explained by a longer period of negative energy balance, while the lower milk protein in cows given diet MB probably resulted from reduced microbial protein synthesis. (Abstract retrieved from CAB Abstracts by CABI’s permission)

SIRE BY HERD INTERACTIONS FOR MILK YIELD AND COMPOSITION TRAITS

1977 ◽  
Vol 57 (3) ◽  
pp. 383-388 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Dairy Herd ◽  
Protein Yield ◽  
Reduced Model ◽  
Parameter Estimates ◽  
Full Model ◽  
Reduced Models

A total of 13,561 Holstein 305-day lactation records from 779 Quebec and Maritime herds enrolled on the Dairy Herd Analysis Service were used to evaluate the importance of sire × herd interactions for milk yield and composition traits. Sire × herd interaction accounted for 4.1, 1.1, 0.3, 2.6 and 5.6% of the total variation of milk, fat and protein yield and fat and protein percent, respectively. Genetic parameter estimates obtained under two different models, a full model that accounted for sire × herd interaction and a reduced model that ignored it, were examined. Heritabilities of milk, fat and protein yield and fat and protein percent were, respectively: for the full model, 0.36, 0.47, 0.45, 0.59 and 0.31 and for the reduced model, 0.49, 0.50, 0.46, 0.66 and 0.46. Phenotypic correlations between the traits were not appreciably different when estimated under the full and reduced models. Genetic correlations between the yield traits were also similar when estimated under the full and reduced models, but genetic correlations between yield and percentage traits were more stongly positive, or less negative, when sire × herd interaction was accounted for. The genetic correlation between fat and protein percent was larger under the reduced model than under the full model.

Assessment of the Canadian model predicting daily milk yield and milk fat percentage using single-milking dairy herd improvement samples

2019 ◽  
Vol 99 (3) ◽  
pp. 521-531
Author(s):  
M. Duplessis ◽  
R. Lacroix ◽  
L. Fadul-Pacheco ◽  
D.M. Lefebvre ◽  
D. Pellerin
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Dairy Herd ◽  
Fat Percentage ◽  
Daily Milk Yield ◽  
Daily Milk

scholarly journals Complete rations containing coarsely chopped or ground hay for dairy cows in confinement vs. conventional grazing

1969 ◽  
Vol 75 (3) ◽  
pp. 241-251
Author(s):  
Paul F. Randel
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Net Energy ◽  
Fat Percentage ◽  
Period 2 ◽  
Randomized Design ◽  
Wheat Middlings ◽  
Completely Randomized Design ◽  
Daily Milk Yield ◽  
Daily Milk

Treatments A and B, based on complete rations, and a conventional control (C) were compared in a completely randomized design including 8 preliminary days and 3 successive 28-day comparison periods with 17 cows (13 Holstein and 4 Brown Swiss). Both complete rations incorporated 60% basal concentrates, principally ground maize, soybean meal, wheat middlings and cane molasses, and 40% grass hay, but differed in the coarsely chopped hay in A and ground hay (9.5 mm screen) ¡n B. Formulation specified 13% crude protein and 1.58 Mcal of net energy for lactation/kg of dry matter (DM). Each was fed to two groups of three cows, ad libitum in period 1 and restricted in periods 2 and 3 in late afternoon. During the hottest hours these animals rested under shade, which reduced thermal stress. Five control cows grazed rotationally at 2.5 animals/ha in gramineous swards of good quality, with individual supplementation of basal concentrates according to milk yield. Late in period 1, DM intake (DMI) of A and B reached maxima of 22 and 23 kg per per. Mean results for A, B and C, respectively, during 84 days were: daily DMI, 16.2, 16,4 and 6.0 kg (excluding pasture herbage), and as a percentage liveweight (LW), 2.96, 2.98 and 1.09; LW, 548, 552 and 550 kg; daily milk yield, 17.7, 16.5 and 16.0 kg; 4% fat corrected milk (FCM), 15.0, 13.7 and 14.0 kg; milk fat percentage, 3.00, 2.87 and 3.19; FCM/concentrates DMI ratio, 1.55, 1.39 and 2.34. One cow of B died of acute bloat in period 2, possibly because of insufficiency of effective fiber in the rumen. Complete ration A appears promising as a possible alternative for intensified dairying in Puerto Rico.

Survival feeding of pregnant and lactating ewes with combinations of wheat and lucerne hay

1979 ◽  
Vol 19 (99) ◽  
pp. 419
Author(s):  
BW Clements ◽  
AR Gleeson ◽  
PJ Nicholls
Keyword(s):  
Milk Yield ◽  
Energy Levels ◽  
Diet Analysis ◽  
Net Energy ◽  
Growth And Survival ◽  
Drought Conditions ◽  
The Mean ◽  
Net Energy Intake ◽  
Dietary Treatments ◽  
Lamb Growth

An experiment was performed to determine the proportion of roughage required by pregnant and lactating ewes fed wheat-based diets under drought conditions. Five dietary treatments ranging from wheat alone to lucerne hay alone were fed to pregnant and lactating Merino ewes, at levels estimated to give a similar net energy intake per ewe per day. The energy levels fed were altered during the experiment in an attempt to maintain ewe liveweight at a constant level. Wheat alone was unsuitable for lactating ewes, while a diet of 54% hay and 46% wheat (54:46) gave the best milk yields, lamb growth and lamb survival. The mean milk yields of the ewes ranged from 26.5 � (SD) 2.5 ml hour-1 for wheat alone to 38.1 � 2.2 ml hour-1 for the 54:46 diet. Lamb liveweight gains between birth and weaning (at seven weeks) were related to ewe milk yields, with lambs on the wheat alone diet gaining 3.17 kg and those on the 54:46 diet gaining 5.10 kg. Only half of the lambs born to ewes fed wheat alone survived to weaning, compared with 89% of lambs on the 54:46 diet. Analysis of the responses indicated that, for milk yield, the 54:46 diet was near optimum and that lamb growth and survival would be maximized at 60-67% hay.

scholarly journals Nutritional and net energy value of fermented olive wastes in rations of lactating ewes

2008 ◽  
Vol 52 (No. 12) ◽  
pp. 456-462 ◽  
Author(s):  
V. Christodoulou ◽  
V.A. Bampidis ◽  
P.H. Robinson ◽  
C.J. Israilides ◽  
A. Giouzelyiannis ◽  
...  
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Barley Grain ◽  
Net Energy ◽  
Equal Distribution ◽  
Low Protein ◽  
A Value ◽  
Beet Pulp ◽  
Concentrate Mixture ◽  
Net Energy Value

In an experiment with 18 lactating Chios ewes, the replacement of barley grain, wheat grain, sugar beet pulp and lucerne meal with fermented olive wastes (FOW), maize grain and soybean meal was used to formulate diets that allowed the net energy (NE) for lactation (NE<sub>l</sub>) density of FOW to be calculated. In the experiment, which lasted 8 weeks, ewes were allocated, after equal distribution for milk yield, body weight (BW) and lactation number, into three treatments of 6 ewes each in a Youden square experimental design with 4 consecutive periods of 14 days. Ewes in all groups were offered a concentrate mixture <i>ad libitum</i> (1.12 kg/ewe/day, dry matter (DM) basis) and lucerne hay (0.90 kg/ewe/day, DM basis). FOW were added to the concentrate mixture at inclusion levels (on an as-fed basis) of 0, 100 and 200 kg/t for treatments FOW0, FOW100 and FOW200, respectively. There were no differences among groups in milk protein (60.0 g/kg), lactose (53.0 g/kg) or ash (9.6 g/kg) contents, but milk fat content increased linearly (<i>P</i> < 0.01) with increasing dietary levels of FOW. Average milk yield (1 137 g/day) and yields of components tended (<i>P</i> < 0.10) to decrease with increased FOW feeding. The best estimate of the NEl density of FOW was 2.55 MJ/kg DM at 2.7×M NE intake, a value only slightly lower than that of 2.62 at 2.7×M based upon a Van Soest et al. (1984) discount from equations of Van Es (1978), who suggested 3.00 MJ/kg DM at 1.1×M of NE intake. FOW is a low protein, high fibre and low NEl feedstuff that will be of limited value in rations of high producing lactating ewes.

The utilization of wilted and unwilted silages by lactating cows and the influence of changes in the protein and energy concentration of the supplement offered

1986 ◽  
Vol 43 (3) ◽  
pp. 355-366 ◽  
Author(s):  
F. J. Gordon ◽  
A. C. Peoples
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Period Change ◽  
Metabolizable Energy ◽  
Energy Output ◽  
Energy Concentration ◽  
Food Utilization ◽  
Fresh Weight ◽  
Lactating Cows ◽  
Total Diet

ABSTRACTTwenty-four lactating British Friesian cows were used in a four-period partially balanced change-over design experiment to evaluate eight treatments consisting of two silage types (wilted and unwilted), each offered in addition to supplements containing both two crude protein (CP) levels (160 and 210 g/kg fresh weight) and two energy levels (10·8 and 12·9 MJ metabolizable energy (ME) per kg fresh weight) obtained by including 100 g spray-dried tallow per kg, in a 2 × 2 × 2 factorial arrangement. All supplements were offered at ttie same rate of 6·8 kg/day and total diet digestibility and food utilization studies were carried out on all animals at the end of the final period of the experiment. A separate two-period change-over design expeximent, using two lactating cows fitted with rumen cannulae, was undertaken to determine the influence of the two silages on volatile fatty acid (VFA) proportions in the rumen and to measure the rates of disappearance of dry matter (DM) and nitrogen in the silages and supplements from the rumen.There were no significant interactions between silage and supplement type in terms of animal performance. Animals offered unwilted silage consumed proportionately 003 less DM but produced 0·03 more milk than those offered wilted silage. Although total diet digestibility was not influenced by silage type because of the higher gross energy concentration of the unwilted silage the ME intake with this diet was higher than with the diet based on wilted silage and the ratios of milk energy output to ME available for production (0·54) were similar with both silages. Silage type had no effect on the rumen VFA proportions but influenced the jates of disappearance of DM and nitrogen from the rumen.Increasing the CP concentratioryof the supplement had no effect on the intake of silage DM but resulted in a significant incrase in milk yield (0·55 kg/day) but due to a reduction in milk fat concentration there was np etfect on yield of either fat-corrected milk or milk energy. The use of the higher energy supplement depressed the intake of silage DM by 0·46 kg/day but resulted in an increase in milk yield of 0·74 kg/day. Neither CP nor energy concentration of the supplement had any effect on DM or energy digestibility of the total diet but there were considerable differences between supplements in the patterns of nitrogen and DM disappearance from the rumen.

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