scholarly journals The voluntary intake of hay and silage by lactating cows in response to ruminal infusion of acetate or propionate, or both, with or without distension of the rumen by a balloon

1993 ◽  
Vol 69 (3) ◽  
pp. 713-720 ◽  
Author(s):  
J. N. Mbanya ◽  
M. H. Anil ◽  
J. M. Forbes

In order to test the hypothesis that negative leedback signals from abdominal receptors are integrated in an additive manner in the control of voluntary food intake, cows with rumen fistulas were given intraruminal infusions of sodium acetate or sodium propionate, cr both, with or without distension of the rumen by balloon. Intakes were monitored during the 3 h experimental period and for 2 h after and samples of rumen fluid were taken for estimation of short-chain fatty acid concentrations and osmolality. Six cows in mid-lactation were fed on hay and concentrates and given, into the rumen. 5.5 mol sodium acetate, 5.2 mol sodium propionate and 7.51 of distension. Compared with the control (water infusion), neither acetate, propionate nor distension significantly depressed hay intake when given separately. When given in combination, however, the following significantly depressed intake during the 3 h treatment period: propionate + distension, acetate + distension, acetate + propionate + distension. Seven cows in early lactation were fed on silage and concentrates and given, into the rumen, 9.0 mol sodium acetate, 4.0 mol sodium propionate and 10.0 litres of distension. Again, none of the three given alone depressed silage intake to a significant extent during the 3 h treatment period, whereas the following combinations had a significant effect: propionate + distension, acetate + distension, acetate + propionate + distension. Basal rumen osmolalities were similar for the two types of feed but infusion of the sodium salts caused a very much greater increase with silage than with hay. The results are discussed with regard to the implications for our understanding of the control of voluntary intake and the likely role of chemo-, osmo- and mechano-receptors.

1993 ◽  
Vol 69 (3) ◽  
pp. 699-712 ◽  
Author(s):  
M. H. Anil ◽  
J. N. Mbanya ◽  
H. W. Symonds ◽  
J. M. Forbes

Rumen-fistulated lactating cows were individually fed on hay or silage and intakes were monitored during 3 h treatment periods and for 2 h after. Each experiment used five, six or seven animals and the treatments were applied in a Latin Square design. Sodium acetate infusions of 1·8–11·0 mol in 4.5 litres water caused a dose-related depression in hay intake, the extent being 82 g dry matter (DM)/mol infused (P < 0·01). Sodium acetate infusions of 6·0–15·0 mol in 4·5 litres water caused a dose-related depression in silage intake of 118 g DM/mol infused. Rumen fluid pH for both diets was unaffected by treatment. Acetate and Na concentrations were increased and significantly negatively correlated with intake of both diets. Infusions of 2–8 mol sodium propionate caused a dose-related depression of hay intake which was significant when cow and day effects were accounted for. Sodium propionate infusions of 4–8 mol significantly depressed silage intake by 140 g DM/mol infused (P < 0·001). Rumen fluid pH was unaffected by treatment while propionate and Na concentrations were elevated and significantly negatively correlated with intake for both diets. Inflation of a rubber balloon in the rumen with 12.5–20 litres warm water resulted in a dose-dependent depression in hay intake of 66 g DM/1 distension (P < 0·05). There was significant overeating during the 2 h following the 20 litre treatment. With silage, 15–25 litres of balloon distension for 3 h resulted in a dose-dependent depression in intake of 28 g DM/l distension (P < 0·001). There was no significant overeating during the 2 h following distension. When given in physiological amounts, at the lower end of the range used in these experiments, acetate, propionate and distension of the rumen did not significantly affect hay intakes. However, in each case the linear relationship between intake depression and level of treatment suggested that these factors could contribute to the control of feed intake.


1994 ◽  
Vol 74 (3) ◽  
pp. 503-509 ◽  
Author(s):  
L. J. Fisher ◽  
N. Dinn ◽  
R. M. Tait ◽  
J. A. Shelford

This study was undertaken with the objective of providing more basic information on the absorption and excretion of calcium (Ca) and magnesium (Mg) by lactating cows when high levels of potassium (K) are fed. Employing potassium carbonate as the source of supplemental K, total mixed rations were formulated to contain 1.6 (low), 3.1 (medium) and 4.6% (high) K. The three rations were fed to 15 Holstein cows in mid-lactation in a 3 × 3 Latin square experiment replicated five times. The experimental periods were 21 d in length. Blood, rumen and milk samples were obtained during the 2nd and 3rd wk of each experimental period and two cows from each treatment group were subjected to total collection procedures for feces and urine during the last 4 d of each experimental period. Dry matter intake was 23.0, 23.8 and 22.3 kg d−1 for the cows fed the low, medium and high K diets, respectively. Milk yield was lower (P < 0.05) for cows fed the high compared to the low and medium K diets. Level of K in the diet did not influence the fat and protein content of the milk but Ca content was lower (P < 0.05) for cows fed the medium and high K diets compared with those fed the low K diet. Plasma K levels were 15.0, 15.7 and 16.2 mg dL−1 while plasma Mg levels were 2.35a, 2.25ab and 2.17b mg dL−1 for cows on the low, medium and high K diets, respectively. The acetate to propionate ratio in the rumen fluid was wider (P < 0.05) for the cows fed the medium and high K diets compared with those fed the low K diet. The apparent absorption of Mg but not Ca was reduced with increasing levels of K in the diet. Both water consumption and urine output were greater (P < 0.05) for the cows fed the medium and high K diet compared with those fed the low K diet. The concentration of Ca and Mg in the urine dropped markedly and total excretion of Ca and Mg was lower (P < 0.05) for cows fed the medium and high K diets compared with those fed the low K diet. It was concluded from the results of this study that high K levels in the diet interfere with absorption of Mg but not Ca. However, K did appear to interfere with the utilization of Ca as indicated by the lower amount of Ca in the milk and urine. Increasing K levels in the diet increased water consumption and urine output which has major implications for waste management. Key words: Lactating cows, excess potassium, calcium, magnesium


1979 ◽  
Vol 51 (1) ◽  
pp. 79-148
Author(s):  
Matti Näsi

The study investigated the utilisation of dried poultry manure as a protein source for lactating cows and its influence on the blood metabolic profile and rumen fermentation. Two consecutive feeding trials were carried out for the comparison of dried poultry manure (DPM) 20 %, soybean meal (SBM) 10 % and urea 1.5 % as protein supplement in a concentrate mixture. Eighteen cows were used in each of the two experiments. The experimental period was 13 weeks in Expt. 1 and 15 weeks in Expt. 2. The apparent DM digestibilities of the DPM, SBM and UREA rations were 69.9, 72.0 and 74.0 % (P < 0.05) and crude protein digestibilities were 72.0, 71.8 and 76.0 % (P < 0.01). The FU-value of the DPM ration was lower (P < 0.01) than the SBM and UREA rations. The palatability of the concentrate including DPM was depressed (P < 0.05). The differences in milk yield and milk constituents between groups were not statistically significant. Feed utilisation was equal in Expt. 1 0.37 FU/kg FCM but in Expt. 2 value of 0.39 for the DPM group was lower than 0.45 for the SBM or 0,43 for the UREA group (P < 0.05). The values obtained in hematological and blood chemical analyses were within normal ranges. The blood metabolic parameters indicate that DPM can be used as feed for dairy cows without any detrimental effect on health. The rumen fermentation was investigated with rumen fistulated cows in two experiments. With a constant feeding level and the DPM inclusion adjusted to 0, 10, 20 and 40 % of concentrate mixture, the rumen fluid ammonia-N increased with the increasing amount of DPM in the diet (P < 0.05). The NH3-N concentration was still lower (P < 0.05) in the isonitrogenous SBM diet. Furthermore, with increasing DPM inclusion the molar percentage of acetic acid of the total volatile fatty acids increased (P < 0.05), the percentages of propionic acid and butyric acid decreased. The total volume of microbial mass was 10—20 % higher with the SBM diet than the various DPM diets.


Author(s):  
Janet H. Woodward ◽  
D. E. Akin

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.


1971 ◽  
Vol 51 (3) ◽  
pp. 721-727 ◽  
Author(s):  
L. J. FISHER ◽  
J. D. ERFLE ◽  
F. D. SAUER

Glutamate, succinate, propylene glycol, or glycerol were added to a basic concentrate at 3.3% of air-dry feed. Each concentrate was fed both ad libitum and in restricted amounts to four cows in early lactation. Dietary intake, milk yield and composition, molar proportions of rumen volatile fatty acids and blood glucose, ketones and plasma free fatty acids were used as criteria of effect of these supplements. Propylene glycol in the diet resulted in a lower intake of concentrate compared with glycerol (11.44 versus 14.30 kg/day) and significantly decreased (P < 0.05) rumen butyrate and plasma beta-hydroxybutyrate. Glutamate supplementation prevented the fall in milk fat content which occurred when the other three supplemented concentrates were fed ad libitum, and this effect may have been related to the constancy in the ratio of acetate to propionate in the rumen fluid.


1979 ◽  
Vol 19 (98) ◽  
pp. 276 ◽  
Author(s):  
RG Holroyd ◽  
PK O'Rourke ◽  
PJ Allan

A study was made (1 970 to 1973) of the reproductive performance of Shorthorn and Brahman crossbred cows grazing pasture in the dry tropics of north Queensland. Breed had a variable effect on the conception rates of lactating cows, with Brahman crossbreds having significantly higher (P < 0.05) conception rates in the first year. The two breeds had similar conception rates in the following year. In the third year, overall conception rates of both breeds were reduced due to a prolonged dry season, with Shorthorn cows having significantly higher (P < 0.01) conception rates than Brahman cows. However, during this dry period, twice as many Shorthorn cows required survival feeding as did Brahman cows. Calving rates followed conception rates closely, prenatal loss in each breed being low. In all years, Shorthorns had significantly earlier (P < 0.05) calving dates than Brahmans. The interval from calving to first recorded ovarian activity was significantly longer (P < 0.05) in Brahman cross than in Shorthorn cows in only one of the three years. There was no significant difference between breeds for the interval from first recorded ovarian activity to conception, but this interval decreased with increasing age of the cow. Breed had a variable effect on gestation length. Brahman cows were generally heavier each year in April and in better condition throughout the experimental period than Shorthorn cows.


2010 ◽  
Vol 39 (10) ◽  
pp. 2262-2267 ◽  
Author(s):  
Raul Franzolin ◽  
Burk A. Dehority

In order to study the effect of pH on defaunation in the rumen, four rumen fistulated steers were fed a basal roughage diet for a 4-week adaptation period followed by 17 weeks of feeding with three diets and two feeding levels of high concentrate diet. Rumen outflow fluid rate was evaluated in both ration levels. Rumen protozoa population was monitored weekly and when animals became defaunated, protozoa were reinoculated with rumen contents from one of the faunated steers. At every two weeks, during all the experimental period, rumen pH was measured in all animals at 0, 4, 8 and 12 h after feeding. It was observed an individual animal influence on the establishment and maintenance of the rumen ciliate protozoa population. In all sampling times, mean rumen pH values were higher in faunated steers than in the defaunated ones. No differences were observed in rumen outflow fluid rates between the two ration levels. Extended periods of low rumen pH are probably more detrimental to the survival of ciliate protozoa in the rumen than other factors.


2020 ◽  
Vol 11 (4) ◽  
Author(s):  
João Marcos de Carvalho Vasconcelos ◽  
Sindynara Ferreira ◽  
Elisa De Souza Junqueira Rezende ◽  
José Luiz de Andrade Rezende Pereira

This study was conducted to investigate the thermoregulation of Holstein cattle in an adapted free-stall facility at IFSULDEMINAS, Campus Inconfidentes, by measuring thermal comfort indices. The experimental period was from the end of December 2012 to the start of January 2013, in a total of 16 days. 12 multiparous, lactating, black-and-white Holstein cows were used in a free-stall system. Rectal temperature, respiratory frequency, ambient temperature and relative humidity were recorded at 3:00 a.m., 7:00 a.m., 11:00 a.m., 3:00 p.m., 7:00 p.m. and 11:00 p.m. The results demonstrate that despite the temporal variations that occurred throughout the evaluation days, the confined animals maintained their body temperature in balance.


1979 ◽  
Vol 59 (4) ◽  
pp. 707-712 ◽  
Author(s):  
L. J. FISHER

Thirty-six lactating cows, after their first week on spring pasture, were subdivided into three groups of 12 cows each and assigned to one of three pelleted grain mixtures containing 0, 5 or 10% protected lipid. These grain mixtures were fed in the milking parlor at the rate of 1.0 kg/4.0 kg of milk yield for a period of 14 days and then the cows were switched to the next ration in the sequence. Milk yield and grain intake were recorded daily. Milk samples for fat, protein and lactose determinations were taken during the last week of the drylot feeding period, during the preliminary pasture period and on the last 2 days of each experimental period. The change in feeding system from drylot to pasture resulted in an average decrease of 0.65 and 0.10 percentage units in milk fat and lactose contents, respectively, and an increase of 0.27 of a percentage unit in protein content. Refusals of the grain mixture were greater (P < 0.05) but milk yields per kilogram of grain intake were higher (P < 0.05) for grain mixtures containing 10% protected lipid than for the control ration. Protected lipid was not effective in countering the milk fat depression caused by the onset of the spring grazing season. The feeding of protected lipid at the rate of 5 and 10% resulted in only a 10 and 27% recovery in total fat yield compared to cows fed the control ration.


Author(s):  
S. I. Nikolaev ◽  
D. A. Randelin ◽  
N. M. Kostomakhin ◽  
Yu. M. Batrakova ◽  
K. S. Arstanov ◽  
...  

The purpose of the research was to study the effectiveness of the use of rations for freshly calved cows during the increasing the milk yield period with the use of new mineral granulated complexes produced by Uralchem LLC. The results of research on the replacement of the mineral part of the vitamin and mineral premix in the rations of lactating cows with the mineral granular complex developed according to two recipes have been presented in the article. Research has shown that cows of the 1st and 2nd experimental groups during the experiment period gave more milk than their herdmates from the control group by 70,8 (P ≥ 0,95) and 106,2 kg (P ≥ 0,95). Due to the higher milk yield of animals that consumed the granulated complex, the yield of milk fat was greater than that of the control analogues by 3,21 (P ≥ 0,95) and 5,17 kg (P ≥ 0,95), protein by 2,70 and 4,30 kg (P ≥ 0,95). The milk yield of cows of the 1st and 2nd experimental groups for 305 days of lactation was higher than in the control group, respectively, by 205,3 (P ≥ 0,95) and 296,8 kg (P ≥ 0,95). In the milk of cows that consumed the granulated complex, there was a tendency for a higher content of dry matter (0,09 and 0,16 %), lactose (0,01 and 0,06 %), nonfat milk solids (0,09 and 0,07 %), ash (0,05 and 0,05 %) in comparison with analogues from the control group. A similar trend has been established between groups of cows in terms of milk density, acidity and rennet coagulability. The revenue from the sale of milk produced from cows of the 1st and 2nd experimental groups was more than in the control group for the experimental period (120 days) by 2074,6 and 3344,0 rubles and for the 305 days of lactation by 7055,4 and 9950,6 rubles.


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