scholarly journals THE EFFECTS OF TOPDRESSING DAIRY PASTURES IN THE WAIKATO WITH SODIUM CHLORIDE

Author(s):  
M.B. O'Connor ◽  
B. Addison ◽  
A.D. Miller

Recent dairy farm survey data suggest the sodium (Na) concentration in pastuies could be too low to maintain stock health on a number of farms. Trials have been established on three major soil groups in the Waikato to study: (a) the rates of NaCl rauired to raise Na concentrations in pasture; (b) the time required to do this; (c) the duration of the response; and (d) the effect of KCi on Na uptake. Na uptake in pasture was rapid initially, reaching a peak some 6 weeks after application. Thereafter the Na concentration in pasture declined gradually but after 30 weeks was still some 2 to 3 times the initial Na concentration. Soil Na levels followed a similar trend. Conclusions to date suggest an annual topdressing of NaCl at 100 kg/ha wll provide an adequate Na concentration in the pasture for animal health and production on a range of Walkato soils. In practice salt can be applied alone or mixed with other fertilisers. Where potassium is already high some replacement of NaCl for KCI in the fertiliser mixture can be considered. Regular monitormg by pasture analysts is recommended. Although salt applications will increase the Na content in the pasture, animal responses to Na supplementation have yet to be conclusively demonstrated. Research is planned with dairy cows in the Waikato to investigate this important aspect. Keywords: Salt, sodium chloride, pasture sodium, ryegrass, white clover pastures, topdressing, dairy cows

PLoS ONE ◽  
2018 ◽  
Vol 13 (5) ◽  
pp. e0195286 ◽  
Author(s):  
Alejandra Gonzalez-Mejia ◽  
David Styles ◽  
Paul Wilson ◽  
James Gibbons
Keyword(s):  

Author(s):  
G.J.Rys I.M. Ritchie ◽  
R.G. Smith ◽  
N.A. Thomson ◽  
G. Crouchley ◽  
W. Stiefel

The performance of 'Grasslands Matua' prairie grass (Bromus catharticus) was compared with perennial ryegrasses under mowing or grazing in three trials conducted in the southern North Island. Production of Matua under mowing at Flock House and Waimate West was 13% and 19% greater than G.4708 and Nui ryegrass, respectively, with the extra production contributed in summer and winter. At Masterton no difference between Matua and Ariki ryegrass production occurred under grazing. A 31% increase in annual production was recorded for both Matua and G.4708 swards receiving N, compared with those sown with white clover, with the annual yield of G.4708 receiving N similar to Matua receiving no N. Less frequent defoliation increased production of Matua swards by 17% and the Matua component by 38%. Production of Nui in comparison with Matua swards was 14% lower under frequent and 9% lower under infrequent defoliation. Similar production was recorded from red clover under frequent, and infrequent defoliation for both Nui and Matua swards. A 48% lower yield of white clover occurred under infrequent defoliation of Matua swards. At Masterton a higher incidence of goitre in newborn lambs, accompanied by a 12% lower lamb liveweight at weaning, occurred on Matua- compared with Ariki-based swards. Aspects of seasonal production, fertility response, management, and animal health are discussed.


Author(s):  
K. Betteridge ◽  
D. Costall

In spite of ragwort flea beetle (RFB) being present on a Dannevirke dairy farm, pastures were sprayed each winter to reduce ragwort density and limit the risk of ragwort poisoning of stock. The trial on this farm from June 1999 - October 2001, aimed to determine whether herbicide (H) impacted on RFB and how H and RFB each impacted on ragwort growth and persistence. RFBfree areas were created by spraying with insecticide (I). Effects of ragwort on animal health are also reported. High ester 2,4-D (H) boom-sprayed once only, in June 1999, killed most ragwort plants and reduced RFB larvae densities to low levels before the plants died. Once new ragwort established in treatment H, the plants became infested with RFB larvae. RFB larvae were suppressed by I resulting in ragwort density declining more slowly than in treatments where RFB were not suppressed. Insecticide treatments were stopped after 15 months and, at 24 months, ragwort could not be found within the trial area. Ragwort control was attributed to the cessation of herbicide spraying allowing the RFB population to reach a sufficient density to kill both small and large ragwort plants. Sub-clinical ragwort poisoning was found in livers of culled cows that had grazed on ragwort-dense pastures. Keywords: animal health, biological control, Longitarsus jacobaeae, pyrrolizidine alkaloids, ragwort, ragwort flea beetle, Senecio jacobaea


2013 ◽  
Author(s):  
Leo L. Timms ◽  
Kristen Schulte
Keyword(s):  

1994 ◽  
Vol 77 (11) ◽  
pp. 3460-3472 ◽  
Author(s):  
H.M. Spicer ◽  
L.A. Goonewardene ◽  
A.O. McNeil ◽  
W.L. Slack

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Desiye Tesfaye Tegegne ◽  
Gezahegne Mamo ◽  
Hika Waktole ◽  
Yohannes Equar Messele

Abstract Purpose Staphylococcus aureus (S. aureus) is the most important pathogen involved in bovine mastitis in dairy production. S. aureus produces a spectrum of extracellular protein toxins and virulence factors which are thought to contribute to the pathogenicity of the organism. The aim of this work was to isolate and molecular characterize S. aureus associated with bovine subclinical mastitis in the central part of Ethiopia. Methods A total of 265 lactating dairy cows from various dairy farms in four different geographical locations were screened by the California mastitis test (CMT) for bovine subclinical mastitis. One hundred thirty CMT-positive milk samples were collected and transported to the laboratory. Different biochemical tests and polymerase chain reaction (PCR) were used for the identification of S. aureus isolates. Finally, PCR was performed for molecular detection of virulence genes. Results From a total of 265 lactating dairy cows screened, 49% (n = 130) were positive for bovine subclinical mastitis. One hundred thirty mastitic milk samples were subjected to bacterial culturing, and one hundred (76%) S. aureus isolates were identified based on phenotypic characters. Sixty-eight confirmed S. aureus isolates were obtained using PCR. The confirmed S. aureus isolates were tested for six virulence genes (tsst-1, hlb, eta, sea, clfA, and icaD) using PCR. Of the six virulence genes screened from all the isolates, only two (clfA and eta) were detected in the isolates. Out of 68 isolates, 25% and 22% were possessed the eta and clfA genes, respectively. Conclusion The presence of Staphylococcus aureus having virulence genes (eta and clfA) revealed that mastitis is a major concern nowadays affecting animal health, milk quality, and yield. Further genomic study of these isolates will provide broad new insights on virulence.


Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 41 ◽  
Author(s):  
André Brito ◽  
Yu Zang

Lignans are polyphenolic compounds with a wide spectrum of biological functions including antioxidant, anti-inflammatory, and anticarcinogenic activities, therefore, there is an increasing interest in promoting the inclusion of lignan-rich foods in humans’ diets. Flaxseed is the richest source of the lignan secoisolariciresinol diglucoside—a compound found in the outer fibrous-containing layers of flax. The rumen appears to be the major site for the conversion of secoisolariciresinol diglucoside to the enterolignans enterodiol and enterolactone, but only enterolactone has been detected in milk of dairy cows fed flaxseed products (whole seeds, hulls, meal). However, there is limited information regarding the ruminal microbiota species involved in the metabolism of secoisolariciresinol diglucoside. Likewise, little is known about how dietary manipulation such as varying the nonstructural carbohydrate profile of rations affects milk enterolactone in dairy cows. Our review covers the gastrointestinal tract metabolism of lignans in humans and animals and presents an in-depth assessment of research that have investigated the impacts of flaxseed products on milk enterolactone concentration and animal health. It also addresses the pharmacokinetics of enterolactone consumed through milk, which may have implications to ruminants and humans’ health.


2016 ◽  
Vol 37 (1) ◽  
pp. 155 ◽  
Author(s):  
Fransérgio Rocha de Souza ◽  
Carla Cristian Campos ◽  
Natascha Almeida Marques da Silva ◽  
Ricarda Maria dos Santos

This study aimed to evaluate the effects of rectal temperature (RT) on conception rate (CR), as well as the effects of seasonality (spring-summer vs. autumn-winter) and timing of artificial insemination (AI) (morning vs. afternoon) on RT and CR in crossbred dairy cows (Holstein x Gyr). The experiment was conducted on a dairy farm in Centralina, MG, where 1,219 conventional and fixed-time inseminations were analyzed. The RT was measured immediately before AI using a digital thermometer. Pregnancy diagnosis was performed using ultrasonography between 28 and 60 days after AI. T The effects of seasonality and timing of AI on RT were analyzed with a Mann-Whitney U test and the effects of RT (above or below the average), seasonality and timing of AI on CR were analyzed with a Chi-squared test, both using the SAS program. The RT average was 39.4°C. Cows with RT ? 39.4°C had lower CR than cows with RT < 39.4°C (25.78% vs. 32.54%; P = 0.0096). During spring-summer, cows had higher RT (39.44°C ± 0.025 vs. 39.27°C ± 0.022; P < 0.0001) and lower CR (25.49% vs. 31.75%; P = 0.0146) compared with autumn-winter. Cows inseminated in the morning had lower RT (38.96°C ± 0.022 vs. 39.60°C ± 0.018; P < 0.0001) and higher CR (32.86% vs. 26.06%; P = 0.0102) than cows inseminated in the afternoon. In conclusion, crossbred dairy cows with rectal temperature equal to or greater than 39.4°C had lower conception rate. Moreover, rectal temperature and conception rate were affected by seasonality and insemination time.


1999 ◽  
Vol 69 (3) ◽  
pp. 647-655 ◽  
Author(s):  
P. Chilibrostet ◽  
B. A. Williams ◽  
S. Tamminga ◽  
S. Calabro

AbstractThe effect of the duration of grazing (experiment 1) and starvation time and placement in the rumen of inert bulk material before grazing (experiment 2), on the rumen content ferment ability, was investigated by means of measuring cumulative gas production. In experiment 1, a comparison was made of four durations of grazing (1, 1·75, 2·50 and 3·25 h) after overnight starvation. Rumen samples taken from the cows after 1 h of grazing had higher values of total accumulated gas with less (P < 0·05) time required to reach the maximum fermentation rate than cows grazed for 3·25 h. Following grazing, a 7·75·h starvation period was imposed on the four treatments. The extent of fermentation was significantly lower (P < 0·01) after starvation than immediately after grazing (49·7 v. 60·8% of incubated dry matter (DM), respectively). Experiment 2 consisted of a factorial combination of two durations of starvation before grazing (16·5 (LS) and 2·5 (SS) h) with the presence or absence in the rumen of 12·5 kg of a synthetic indigestible material. Before grazing the total accumulated gas production was less (P < 0·05) for the LS than for the SS cows. After the grazing session, the total gas of rumen samples from the LS cows was significantly higher (P < 0·05) than for the SS cows.This was in agreement with the observed higher DM intake during grazing and DM rumen pools after grazing in LS cows. For both starvation periods, the presence of inert rumen bulk led to a higher total gas, a shorter half-time and less DM left unfermented. The measurement of fermentation kinetics by cumulative gas production was suitable to detect changes in rumen content fermentation patterns due to the clearance of material from the rumen (effect of starvation) or DM intake during the grazing sessions.


2016 ◽  
Vol 2 (2) ◽  
pp. 190-195 ◽  
Author(s):  
Mahmud Al Reyad ◽  
Md Abid Hasan Sarker ◽  
Md Elias Uddin ◽  
Raihan Habib ◽  
Md Harun Ur Rashid

The aim of this research was to observe the effect of heat stress on milk yield and milk compositions of Holstein Friesian crossbred (HF) dairy cows. To fulfill the objectives, a total of 9 Holstein Friesian crossbred cows were selected for this study. Green grasses (German, Para) were supplied adlibitum and concentrate feeds (mixture of wheat bran, rice polish, mustard oil cake, di-calcium phosphate and salt) were supplied at the rate of 2.0 kg/day/cow. Management practices for all the cows were similar following the BAU Dairy farm practices. Data were collected on milk yield (l/h/d), relative humidity (%) and barn temperature (0C). The obtained temperature humidity index (THI) of July, August, September and October were 84.95, 81.99, 81.40 and 79.57, respectively. The highest THI was found in July which indicated higher heat stress during this month. A significant difference (p<0.05) in milk yield of cows was found among different months of July to October. The highest milk yield (6.10±0.50 l/h/d) was found in October among observed months. The compositions of milk such as total solids (TS), solids-not-fat (SNF), fat, protein, lactose, and ash also differed significantly (p<0.01). The highest values (%) of TS, SNF, fat, protein, lactose and ash content of milk were found in October as 12.63, 8.80, 3.83, 3.69, 4.39 and 0.72, respectively and lowest values (%) were in July as 12.20, 8.50, 3.71, 3.50, 4.30 and 0.69, respectively due to the high THI value. From these results, it is concluded that heat stress has strong effect on milk yield and milk composition of HF cows in Bangladesh. Management strategies are needed to minimize heat stress and attain optimal dairy animal performance.Asian J. Med. Biol. Res. June 2016, 2(2): 190-195


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