Effects of nitrogen fertilizer applied in autumn and winter on milk production from a tropical grass-legume grazed at four stocking rates

1976 ◽  
Vol 16 (83) ◽  
pp. 829 ◽  
Author(s):  
RT Cowan ◽  
TH Stobbs

The effect of applying 50 kg N ha-I in autumn and winter each year on milk yield of Friesian cows and dry matter yield and botanical composition of a green panic (Panicum maximum var, trichog1ume)- glycine (Glycine wightii cv. Tinaroo) pasture was measured over two years on the Atherton Tableland, north Queensland. Pastures were grazed at 1.3, 1.6, 1.9 and 2.5 cows ha-1. Milk yield and pasture yield were increased by nitrogen fertilization, particularly at the high stocking rates (P < 0.05). Increases in milk yield from mid-autumn to spring almost totally accounted for increases in annual milk production. Nitrogen fertilizer did not decrease the yield of legume, but legume content of the pasture was reduced in the second year (P < 0.01). Response by non-leguminous species to nitrogen increased (P < 0.05) with stocking rate, a change associated with decreasing legume contents of the pastures. Average fat corrected milk (FCM) yield per cow from mid-autumn to spring was restricted by less than 1600 kg pasture D.M. on offer cow-I or 2500 kg D.M. ha-1. When compared at the same dry matter yields, FCM yield was always higher from nitrogen fertilized pastures than from pastures not recieving fertilizer nitrogen.

1985 ◽  
Vol 25 (3) ◽  
pp. 515 ◽  
Author(s):  
TM Davison ◽  
RT Cowan ◽  
RK Shepherd

The effects of stocking rate and rate of nitrogen fertilizer application on milk yield from a Gatton panic (Panicum maximum cv. Gatton) pasture were studied over 3 years at Kairi Research Station on the Atherton Tablelands. Thirty-two Friesian cows were used in a 4x2 factorial experiment with treatments 2.0,2.5,3.0 and 3.5 cows/ha, each at 200 and 400 kg N/ha.year. Fat-corrected milk (FCM) yield per cow decreased (P<0.05) with increasing stocking rate according to the equation (� s.e.): Y=3476-276 ( � 111) X (P<0.05), where Y is FCM yield per cow (kg), and X is the stocking rate (cows/ha). FCM yield per hectare increased linearly (Pt0.01) with increasing stocking rate in each year and was represented by the following equations ( � s.e.) for nitrogen applications of 200 and 400 kg/ha.year, respectively: Y = 1584 + 1967 (� 289) X Y = 2366 + 1967 (�289) X (P<0.01), and where Y is FCM yield per hectare (kg) and X is the stocking rate (cows/ha). Milk yield per cow and per hectare were significantly increased by the higher rate of fertilizer application (P<0.01) in year 3, but not in years 1 and 2. Mean FCM yields per cow across years were 2574 and 2858 kg from 200 kg N and 400 kg N pastures respectively (P<0.05). The pasture parameters which were most closely correlated with milk yield were green dry matter (GDM) on offer or its components, namely green leaf and green stem. The relations between FCM yield per cow and green dry matter on offer per cow and per hectare were represented by the equations ( � s.e.): Y = 2211 +0.43 (� 0.12) X1 (P<0.01), And Y= 1656 + 0.35 (�0.08) X2 (P<0.01), where Y is FCM yield per cow (kg/lactation), X1 is GDM per cow (kg) and X2 is GDM per hectare (kg). For this environment, it is concluded that a stocking rate of 2.5 cows/ha with 400 kg N/ ha.year can be safely employed to maintain cows on a pure grass pasture from the opening rains in summer until the end of winter.


1985 ◽  
Vol 25 (3) ◽  
pp. 505 ◽  
Author(s):  
TM Davison ◽  
RT Cowan ◽  
RK Shepherd ◽  
P Martin

A 3-year experiment was conducted at Kairi Research Station on the Atherton Tablelands, Queensland, to determine the effects of stocking rate and applied nitrogen fertilizer on the pasture yield and composition, diet selection by cows, and soil fertility of Gatton panic (Panicum maximum cv. Gatton) pastures. Thirty-two Friesian cows were used in a 4x2 factorial design: four stocking rates (2.0, 2.5, 3.0 and 3.5 cows/ha), each at two rates of fertilizer application 200 and 400 kg N/ha.year. The higher rate of fertilization increased the pasture green dry matter on offer at all samplings (P < 0.01); the increase ranged from 1 106 kg/ha in summer to 548 kg/ha in spring. Green dry matter decreased ( P< 0.0 1) with increasing stocking rate, with mean yields of 3736 and 2384 kg/ha at 2.0 and 3.5 cows/ha, respectively. Weed yields increased over the 3 years at the higher stocking rates for pastures receiving 200 kg N/ha.year. The crude protein content of leaf and stem increased with increasing stocking rate and amount of applied nitrogen fertilizer. Values ranged from 12.1 to 26.5% of dry matter (DM) in leaf and from 3.7 to 13.8% DM in stem. In leaf, sodium concentration (range 0.05-0.20% DM) was increased, while phosphorus concentration (range 0.21-0.44% DM) was decreased by the higher rate of fertilizer application. Plant sodium and phosphorus levels were inadequate for high levels of milk production. Dietary leaf content and crude protein contents were consistently increased by both a reduced stocking rate, and the higher rate of fertilization. Cows were able to select for leaf and at the lowest stocking rate, leaf in the diet averaged 38%; while the leaf content of the pasture was 20%. Dietary leaf content ranged from 38 to 57% in summer and from 11 to 36% in winter. Dietary crude protein ranged from 13 to 15% in summer and from 7 to 11% in winter and was positively correlated with pasture crude protein content and dietary leaf percentage. Soil pH decreased (P<0.05) from an overall mean of 6.3 in 1976 to 6.1 at 200 N and 5.8 at 400 N in 1979. Soil phosphorus status remained stable, while calcium and magnesium levels were lower (P<0.01) after 3 years.


1978 ◽  
Vol 18 (90) ◽  
pp. 12 ◽  
Author(s):  
RT Cowan ◽  
TM Davison

Twenty-four Friesian cows grazing green panic (Panicum maximum var. trichoglume)-glycine (Glycine wightii cv. Tinaroo) pastures at 2 or 4 cows ha-1 were fed no supplement, 2.4 kg maize or 3.0 kg molasses cow-1 day-1. The experiment was a randomized block design and of six months duration. Milk yield and composition were similar for cows fed maize and molasses and these supplements increased average milk yield from 10.3 to 11.8 kg cow-1 day-1 (P < 0.05). Increased stocking rate reduced milk yield from 12.7 to 9.8 kg cow-1 (P < 0.01). Interactions of stocking rate with type of supplement were not significant (P > 0.05). The level of supplement intake and yield of pasture on offer accounted for 52 per cent of the variation in average milk yields (P < 0.01). Of the variation in milk yields between paddocks only 5 per cent was unaccounted for by this relationship.


1981 ◽  
Vol 21 (109) ◽  
pp. 196 ◽  
Author(s):  
TM Davison ◽  
RT Cowan ◽  
PK O'Rourke

Two experiments examined the effect different pasture management strategies had on individual cow milk yield during the summer wet season. In control treatments pasture was continuously grazed. In managed pastures the aim was to produce swards with a high leaf and low stem content. The grasses Panicum maximum cv. Gatton and Brachiaria decumbens were used in both experiments. Experiment one consisted of three pasture treatments; the stock were 1 8 Friesian cows. The control treatment was grazed continuously with no pasture management and was compared with two subjectively applied management treatments in which pasture was either slashed or stocked at variable rates in an attempt to increase pasture quality. The experiment lasted 17 weeks. Each time pastures were slashed or extra cows were added milk yield per cow fell. The lower each grass was slashed or the greater the number of cows added to a paddock the greater the fall in milk yield. Measurements of pasture yield, height and structural composition showed that slashing and variable stocking could increase the leaf percentage in the pasture, but not without seriously decreasing total leaf yield. In experiment two, 24 Friesian cows were used to compare the following treatments over a 10-week period (a) control-continuous grazing, (b) rotational grazing using a 2-week grazing, 2-week spelling regime and (c) rotational grazing with slashing after each grazing period. Milk yields averaged 10.6, 9.8 and 9.6 kg/cow day1, respectively (P> 0.05), and 10.1 and 9.9 kg/cow day-1 for B. decumbens and P. maximum pastures (P> 0.05). As in the first experiment, leaf percentage was increased by management treatments, but not without decreasing total pasture yield to the level where it limited milk production. Leaf yields could only be increased with an associated increase in total pasture yield. It was concluded that grazing management decisions should be based on total pasture on offer rather than any percentage component of total yield.


1985 ◽  
Vol 25 (2) ◽  
pp. 241 ◽  
Author(s):  
TM Davison ◽  
WD Jarrett ◽  
P Martin

Milk yields were compared over a 280-day lactation using four patterns of allocation of a fixed amount of grain. Four groups of four Friesian cows grazed a mixed tropical grass (Panicum maximum) and legume (Neonotonia wightii cv. Tinaroo) pasture at 1.1 cows/ha from January to December 1980. The lactation was split into four feeding periods: days 1 - 10,11- 100,10 1 - 190, 191-280. All cows were fed a total of 610 kg hammermilled maize, with 10 kg grain fed during the initial covariate period. The four feeding patterns were: (i) flat rate (FR), where cows received 2.22 kg grain/day; (ii) all early (AE), where cows received 600 kg grain between days 11 and 100; (iii) high early, low late (HELL), where cows were fed 3.5, 2.17 and 1.0 kg/day for periods 11-100,101-190and 191- 280 days of lactation; and (iv) low early, high late (LEHL), where cows were fed in the reverse pattern to HELL. Milk yields per cow over 280 days were 4145, 3942, 3794 and 3630 kg [l.s.d. (P=0.05)= 436 kg] for HELL, FR, LEHL and AE respectively. There was very poor utilization of grain by cows fed AE. The relation between milk yield and grain intake in days 1 1-100 of lactation was described by the equation: Y= 13.9+ 1.77X-0.18X2 (P<0.01, s.e.b1= 0.48, s.e.b2 = 0.06), where Y = milk yield (kg/cow.day) and X = grain intake (kg/cow.day). Apportioning more grain to late lactation, when pasture on offer was low, did not compensate for the loss of milk production in early lactation by cows fed LEHL. Cows fed LEHL lost more liveweight in early lactation than all other treatments, but regained this weight in late lactation. Cows in all treatments had similar liveweights (mean 518 kg) at 280 days. Milk butterfat and solids-not-fat yields over 280 days were not significantly different (P>0.05) for any of the four treatments.


1975 ◽  
Vol 15 (77) ◽  
pp. 740 ◽  
Author(s):  
RT Cowan ◽  
IJR Byford ◽  
TH Stobbs

Forty Friesian cows were grazed continuously on a green panic (Panicum maximum var. trichoglume)/glycine (Glycine wightii cv. Tinaroo) pasture at stocking rates of 1.3, 1.6, 1.9 and 2.5 cows ha-1 for two years on the Atherton Tableland, Queensland. A supplement of 3.6 kg crushed maize cow-1 day-1 was fed for 50 days post-partum to half the cows in each group in both years. Milk yield per cow was reduced from 3811 kg lactation-1 at 1.3 cows ha-l to 3289 kg lactation-1 at 2.5 cows ha-1. With increasing stocking rate milk yield per hectare increased linearly to 8309 kg ha-1 at 2.5 cows ha-1. At 1.9 and 2.5 cows ha-1 cows lost weight over the two years and in late lactation levels of milk solids were often low. Also at these stocking rates cows had to be supplemented for up to 60 days during the main dry season. Legume content of the pasture declined linearly (P < 0.05) with increasing stocking rates. Maize feeding in early lactation increased milk yield over the total lactation by approximately 12 per cent, the response being 2.3 kg milk per kg maize fed, Response was greater at lighter stocking rates as cows in the heavier stocking rate treatments dried off prematurely. It was concluded that per hectare milk production from tropical grass/legume pastures can approach that from temperate pastures and that energy supplementation early in lactation would substantially increase per cow production.


2018 ◽  
Vol 15 (4) ◽  
pp. e0608
Author(s):  
Ana I. Roca-Fernández ◽  
Antonio González-Rodríguez

The aim was to evaluate the prediction accuracy of pasture dry matter intake (PDMI) and milk yield (MY) predicted by the GrazeIn model using a database representing 124 PDMI measurements at paddock level and 2232 MY measurements at cow level. External validation of the model was conducted using data collected from a trial carried out with Holstein-Friesian cows (n=72) while grazed 28 paddocks and were managed in a 2×2 factorial design by considering two calving dates (CD), with different number of days in milk (DIM), early (E, 29 DIM) vs. middle (M, 167 DIM), and two stocking rates (SR), medium (M, 3.9 cows ha-1) vs. high (H, 4.8 cows ha-1), under a rotational grazing system. Cows were randomly assigned to four grazing scenarios (EM, EH, MM and MH). The mean observed PDMI of the total database was 14.2 kg DM cow-1 day-1 while GrazeIn predicted a mean PDMI for the database of 13.8 kg DM cow-1 day-1. The mean bias was −0.4 kg DM cow-1 day-1. GrazeIn predicted PDMI for the total database with a relative prediction error (RPE) of 10.0% at paddock level. The mean observed MY of the database was 23.2 kg cow-1 day-1 while GrazeIn predicted a MY for the database of 23.1 kg cow-1 day-1. The mean bias was –0.1 kg cow-1 day-1. GrazeIn predicted MY for the total database with a mean RPE of 17.3% at cow level. For the scenarios investigated, GrazeIn predicted PDMI and MY with a low level of error which made it a suitable tool for decision support systems.


1987 ◽  
Vol 109 (2) ◽  
pp. 375-386 ◽  
Author(s):  
J. D. Sutton ◽  
J. A. Bines ◽  
S. V. Morant ◽  
D. J. Napper ◽  
D. J. Givens

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.


2010 ◽  
Vol 39 (7) ◽  
pp. 1548-1557 ◽  
Author(s):  
Nelson Massaru Fukumoto ◽  
Julio Cesar Damasceno ◽  
Fermino Deresz ◽  
Carlos Eugênio Martins ◽  
Antônio Carlos Cóser ◽  
...  

The objective of this study was to evaluate milk yield and composition, dry matter intake, and stocking rate in pastures with tanzania grass (Panicum maximum cv. Tanzânia), star grass (Cynodon nlemfuensis cv. Estrela-Africana), and marandu grass (Brachiaria brizantha cv. Marandu). The grasses were managed in a rotational grazing system with Holstein x Zebu crossbreed cows, with a 30-day resting period and three days of paddock occupation. The pastures were fertilized with 1,000 kg/ha/year using the 20:05:20 (NPK) formula, split in three applications during the rainy season. It was used a complete random block experimental design with three factors being studied and two replications. In the experiment, four cows/paddock were used and, when it was necessary, regulator animals were added in order to obtain a supply of 7% body weight green forage dry matter. The animals were individually fed concentrate at 2 kg/day during the experimental period. Milk yield did not differ among the three grasses, with values of 9.1; 9.1; and 8.7 kg/cow/day for pastures with tanzania grass, star grass and marandu grass, respectively. Similarly, grass did not affect milk chemical composition. Stocking rate was similar among the three grasses, with values of 4.6; 4.5 and 5.0 UA/ha for tanzania grass, star grass and marandu grass, respectively. The highest dry matter intake was observed for tanzania grass with 2.6% of the body weight while stargrass (2.3%) and marandu grass (2.4%) did not differ among each other. The highest dry matter intake on tanzania grass pasture was not reflected on milk yield per animal. Milk yield and composition and stocking rate are similar among the evaluated grasses.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Magdalena Kolenda ◽  
Dariusz Piwczyński ◽  
Marcin Brzozowski ◽  
Beata Sitkowska ◽  
Piotr Wójcik

AbstractThe aim of the present study was to evaluate the changes in selected production and functional traits of Polish Holstein-Friesian cows after switching from a conventional (CMS) to an automatic milking system (AMS). The study consisted of 3398 Polish Holstein- Friesian dairy cows, from 16 herds in which CMS was changed to AMS. Cows were in their 1st (L1) or 2nd lactation (L2). The data consisted of milk yield [MY, kg], fat content [FC, %], protein content [PC, %], dry matter [DM, %], lactose content [LC, %], urea content [MU, mg/l], somatic cell count [SCC, thous./ml] and score [SCS, log]. The milking system had a significant impact on milk yield, fat, lactose, dry matter and urea contents. Regardless of lactation number, milk derived from CMS was characterised by higher values for FC, PC, DM SCC and SCS, while milk from AMS had higher MY, LC and MU. Multifactor analysis of variance also confirmed significant effect of herd, season, herd × milking system interaction on SCS in milk of cows in L1. In the studied herds change from CMS to AMS was evaluated separately for cows in L1 and L2. The transitioning from CMS to AMS resulted in the decrease of fat content in 6 L1 and 7 L2 herds, dry matter in 8 L1 and 5 L2 herds. SCS in milk also decreased in 4 L1 and 5 L2 herds. The change caused the increase of MY in 11 L1 and 9 L2 herds, lactose content in 6 L1 and 4 L2 herds and urea content in 9 L1 and 10 L2 herds. AMS may positively affect milk yield and health status, however, the change of milking system should be also accompanied by the change in herd management.


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