Milk yield and mammary function in dairy cows milked four times daily

1990 ◽  
Vol 57 (3) ◽  
pp. 285-294 ◽  
Author(s):  
J. Eric Hillerton ◽  
Christopher H. Knight ◽  
Alan Turvey ◽  
Stephen D. Wheatley ◽  
Colin J. Wilde

SummaryGroups of lactating cows and heifers were milked four times daily in two diagonally opposed glands for 4 weeks, and the effects on milk yield studied relative to twice-daily milked glands as controls. Mammary enzyme activities, in vitro synthesis rates of milk constituents and histological scoring were determined in mammary biopsy samples obtained at the end of this period. These were used for assessment of mammary function. Frequent milking increased milk yield only in the treated glands, the contralateral control glands continuing to decline in yield at ~ 2%/week. There was no significant difference in response between cows and heifers; the mean increase in yield was 10·4%. The rate of decline in milk yield tended to decrease with frequent milking, to ~ 1%/week. Consequently the yield of the treated glands continued to be elevated above that of the controls for some time after reversion to overall twice daily milking. Milk protein content was increased slightly by frequent milking. Mammary enzyme activities were ~ 18% higher in the treated glands than in the controls. Synthesis rates of lactose, casein and total protein were unaffected by milking frequency, but were all lower in the gland selected for the second biopsy, reflecting the reduction in milk yield caused by the first biopsy. DNA synthesis was increased by milking frequency, as were the size and number of epithelial cells in histological sections.

2016 ◽  
Vol 64 (3) ◽  
pp. 301-312 ◽  
Author(s):  
Viktor Jurkovich ◽  
Barbara Bognár ◽  
Krisztián Balogh ◽  
Mária Kovács-Weber ◽  
Kinga Fornyos ◽  
...  

Milk yield, milk ingredients, health and other, production-related parameters of subclinically infected, Mycobacterium avium ssp. paratuberculosis (MAP-) shedding (positive faecal PCR, n = 20) and non-shedding (negative faecal PCR, n = 10) dairy cows were compared in the period from 10 days prepartum to 120 days postpartum. Body condition, rumen fill and faeces scores were lower in the MAP-shedding cows. There was no significant difference in plasma or urine metabolic parameters between the groups. Milk yield and lactose content tended to be lower (P = 0.074 and 0.077, respectively), somatic cell count tended to be higher (P = 0.097), while milk fat content was significantly higher (P = 0.006) in MAP-shedding cows than in the controls. Milk protein content did not differ between the groups. All other health and production parameters [number of reproductive tract treatments, number of udder treatments, number of artificial inseminations (AIs), calving interval, and service period] were significantly better in the control group. It is concluded that MAP infection, even in a subclinical form, has a significant impact on some production and health parameters of dairy cows.


Author(s):  
Gustav Chládek ◽  
Ladislav Máchal

Groups of 20 to 23 dairy Czech Pied cows were observed monthly for the period of 12 months (12 test days). The cows in experimental groups were in their early lactation. The mean number of lactation was 2,8, the cows were on average 54.8 days after calving and the mean glucose concentration in blood plasma was 3.93 mmol/l. During the first 100 days of lactation milk yield amounted to 2581 kg with 3.91% fat, 3.48% protein and 4.85% lactose.The coefficients of the correlation between blood plasma glucose and the observed milk production parameters calculated independently for each test day ranged as follows: -0.597 to 0.130 for number of lactation, -0.389 to 0.585 for days after calving, -0.462 to 0.361 for milk yield, -0.201 to 0.526 for milk fat content, -0.385 to 0.632 for milk protein content and -0.600 to 0.469 for milk lactose content. The calculated coefficients of the correlation between blood plasma glucose and milk production parameters did not reveal a clear tendency in the relationships. However, the graphic polynomial expression showed that glucose level had a positive relationship with days after calving and mainly positive relationship with milk protein content; glucose content had a negative relationship with milk yield and number of lactation and a mainly negative relationship with fat content and lactose content.


Author(s):  
Eisha Imran ◽  
Faisal Moeen ◽  
Beenish Abbas ◽  
Bakhtawar Yaqoob ◽  
Mehreen Wajahat ◽  
...  

Abstract Objectives The study aimed to evaluate and compare various commercially available local anesthetic solutions. Materials and Methods A total of 150 commercially available local anesthetic cartridges of similar composition (2% lidocaine with epinephrine 1:100,000) were randomly collected and divided into 3 groups. The designations of groups were selected from their product names such that each group consisted of 60 cartridges. Group S (Septodont, France) Group M (Medicaine, Korea) and Group H (HD-Caine, Pakistan). The samples were divided into five sub-groups, each consisting of 10 cartridges from each group to investigate each parameter. Results The acquired data was statistically analyzed and compared (using SPSS version 12). Compositional analysis revealed a non-significant (P>0.05) difference when the three Groups were compared with standard lidocaine and epinephrine solutions. The mean pH values of samples from group S, M and H respectively fell within the range of pH values of commercially available solutions. Non-significant difference in EPT values of Group S and H was found when efficacy was compared (p = 0.3), however a significant difference (p < 0.01) was observed in contrast to Group M. Anti-bacterial activity was observed in all the group and a non-significant difference in cell viability values of Group S and M was found (p = 0.6), while the difference was significant in comparison to Group H. Conclusion Within the limitations of these investigations, it appears that the properties of different manufacturers fall within the recommended ranges as mentioned in literature and do not appear to be statistically different in the variables we have tested.


2021 ◽  
Vol 95 ◽  
Author(s):  
C.I. Cortés-Martínez ◽  
A.I. Rodríguez-Hernández ◽  
M.R. López-Cuellar ◽  
N. Chavarría-Hernández

Abstract The use of native entomopathogenic nematodes as biocontrol agents is a strategy to decrease the environmental impact of insecticides and achieve sustainable agriculture crops. In this study, the effect of the surface culture of Steinernema sp. JAP1 over two solid media at 23–27°C on infective juvenile (IJ) production and pathogenicity against Galleria mellonella larvae were investigated. First, the bacterial lawn on the surface of the media with egg yolk (P2) or chicken liver (Cl) were incubated in darkness at 30°C for 48 and 72 h, and 100 surface-sterilized IJs were added. Four harvests were conducted within the next 35 days and the mean accumulated production was superior on Cl (210 × 103 IJs) than on P2 (135 × 103 IJs), but the productivity decreased up to 10% when the incubation time of the bacterial lawn was of 72 h. The mean pathogenicity of in vitro- and in vivo-produced IJs were of 47–64% and 31%, respectively. It is worth noting that none of the two solid media had a statistically significant difference in IJ pathogenicity. Considering that the maximum multiplication factor of IJs on solid media was 2108 and that the pathogenicity against G. mellonella was outstanding, Steinernema sp. has a good potential for in vitro mass production.


2008 ◽  
Vol 17 (4) ◽  
pp. 351 ◽  
Author(s):  
L. KRÍZOVÁ ◽  
J. TRINÁCTÝ ◽  
M. RICHTER

The aim of this study was to determine the influence of leucine supplement in the form of rumen-protected tablets on milk yield and composition and plasma amino acids in four high-yielding lactating Holstein cows. The experiment was carried out as a cross-over procedure and was divided into 4 periods of 14 d (10 d preliminary period and 4 d experimental period). Cows were fed ad libitum a diet based on maize silage, lucerne hay and a supplemental mixture. The diet, defficient in methionine, lysine, and leucine, was supplemented with methionine+lysine (Control) or methionine+lysine+leucine (Leu) in rumen protected form. The dry matter intake, milk yield and milk yield expressed in energy corrected milk did not differ significantly between the treatments. Milk protein content and yield did not show statistically significant variation. The contents and yield of casein, fat, lactose and urea were unaffected by the treatment. Blood metabolites did not vary between the treatments. The introduction of Leu resulted in higher plasma levels of proline (p


Author(s):  
Martin Skýpala ◽  
Gustav Chládek

Milk yield varies during lactation, following what is termed a lactation curve. ŽIŽLAVSKÝ and MIKŠÍK (1988) recorded changes in milk yield within a day, too. TEPLÝ et al. (1979) a KOUŘIMSKÁ et al. (2007) published variation within a day ± 1.10 kg in milk yield, ± 0.75 % in milk fat content and ± 0.20 % in milk protein content. Milk yield of cows can be expressed in many different ways, for instance, in kilograms per lactation or in kilograms per day. A practical parameter describing milk production is milk yield (kg) per milking.The object of experiment were 12 cows of Holstein cattle on the first lactation from the 100-day of lactation to 200-day of lactation. The samples of milk were collected from January to May 2007, once a month from the morning and evening milking (milking interval 12 h ± 15 min.). The following parameters were monitored: milk production – milk yield (kg), milk protein production (kg), milk fat production (kg); milk composition – milk protein content (%), milk fat content (%), lactose content (%), milk solids-not-fat content (%), milk total solids content (%); technological properties of milk – ti­tra­tab­le acidity (SH), active acidity (pH), rennet coagulation time (s), quality of curd (class) and somatic cell count as a parameter of udder health.Highly significant differences were found (P < 0.01) between morning milk yield (15.7 kg) and evening milk yield (13.8 kg), between morning milk protein production (0.51 kg) and evening milk protein production (0.45 kg) and between evening milk fat content (4.41 %) and morning milk fat content (3.95 %). A significant difference (P < 0.05) was found between morning milk total solids content (12.62 %) and evening milk total solids content (12.07 %). No significant differences were found between morning (M) and evening (E) values of the remaining parameters: milk fat production (M 0.62 kg; E 0.60 kg), milk protein content (M 3.24 %; E 3.27 %), milk lactose content (M 4.78 %; E 4.86 %), milk solids-not-fat content (M 7.69 %; E 7.71 %), somatic cell count (M 80 000/1 mL; E 101 000/1 mL), titratable aci­di­ty (M 7.75 SH; E 7.64 SH), active acidity (M pH 6.58; E pH 6.61), rennet coagulation time (M 189 s.; E 191 s.), quality of curd (M 1.60 class; E 1.57 class).


Animals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 57 ◽  
Author(s):  
Frank Dunshea ◽  
Kehinde Oluboyede ◽  
Kristy DiGiacomo ◽  
Brian Leury ◽  
Jeremy Cottrell

Betaine is an organic osmolyte sourced from sugar beet that accumulates in plant cells undergoing osmotic stress. Since the accumulation of betaine lowers the energy requirements of animals and, therefore, metabolic heat production, the aim of this experiment was to investigate if betaine supplementation improved milk yield in grazing dairy cows in summer. One hundred and eighteen Friesian × Holstein cows were paired on days in milk and, within each pair, randomly allocated to a containing treatment of either 0 or 2 g/kg natural betaine in their concentrate ration for approximately 3 weeks during February/March 2015 (summer in Australia). The mean maximum February temperature was 30 °C. Cows were allocated approximately 14 kg dry matter pasture and 7.5 kg of concentrate pellets (fed in the milking shed) per cow per day and were milked through an automatic milking system three times per day. Betaine supplementation increased average daily milk yield by over 6% (22.0 vs. 23.4 kg/day, p < 0.001) with the response increasing as the study progressed as indicated by the interaction (p < 0.001) between betaine and day. Milk fat % (p = 0.87), milk protein % (p = 0.90), and milk somatic cell count (p = 0.81) were unchanged by dietary betaine. However, betaine supplementation increased milk protein yield (677 vs. 719 g/day, p < 0.001) and fat yield (874 vs. 922 g/day, p < 0.001) with responses again being more pronounced as the study progressed. In conclusion, dietary betaine supplementation increased milk and component yield during summer in grazing dairy cows.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jolanta Opiela ◽  
Joanna Romanek ◽  
Daniel Lipiński ◽  
Zdzisław Smorąg

The objective of the present study was to evaluate the effect of hyaluronan (HA) during IVM on meiotic maturation, embryonic development, and the quality of oocytes, granulosa cells (GC), and obtained blastocysts. COCs were maturedin vitroin control medium and medium with additional 0.035% or 0.07% of exogenous HA. The meiotic maturity did not differ between the analysed groups. The best rate and the highest quality of obtained blastocysts were observed when 0.07% HA was used. A highly significant difference (P<0.001) was noted in the mean number of apoptotic nuclei per blastocyst and in the DCI between the 0.07% HA and the control blastocysts (P<0.01). Our results suggest that addition of 0.035% HA and 0.07% HA to oocyte maturation media does not affect oocyte nuclear maturation and DNA fragmentation. However, the addition of 0.07% HA during IVM decreases the level of blastocysts DNA fragmentation. Finally, our results suggest that it may be risky to increase the HA concentration during IVM above 0.07% as we found significantly higherBaxmRNA expression levels in GC cultured with 0.07% HA. The final concentration of HA being supplemented to oocyte maturation media is critical for the success of the IVP procedure.


2017 ◽  
Vol 40 (2) ◽  
pp. 82-87 ◽  
Author(s):  
Faika Y. Abdelmegid ◽  
Fouad S. Salama ◽  
Waleed M. Al-Mutairi ◽  
Saud K. Al-Mutairi ◽  
Sultan O. Baghazal

Introduction The aim of this in vitro study was to assess and compare the effect of different intermediary bases on microleakage between tooth and a nanocomposite interface in Class II box cavities in primary teeth. Methods Standard Class II box cavities were prepared in 52 primary molars and randomly divided into 9 groups according to the intermediary base used (Multicore Flow, Fuji II LC, SDR, Smart Dentin Replacement, and Biodentine). All specimens were subjected to thermocycling and prepared for microleakage testing and evaluation. Results There was significant difference in the mean ranks of microleakage between the 9 groups, which was observed in the gingival side (p<0.0001) and the occlusal side (p<0.0001). The mean ranks microleakage was significantly higher with experimental SDR, experimental Multicore Flow, and positive control materials when compared with the other 6 groups. The microleakage mean ranks were statistically significantly lower in experimental Fuji II LC, experimental Biodentine, and all negative control groups when compared with the other 3 groups. Conclusions Microleakage is affected by the application of intermediate material. Experimental Biodentine and Fuji II LC showed the lowest microleakage while experimental SDR and experimental Multicore Flow showed the highest microleakage.


1986 ◽  
Vol 37 (5) ◽  
pp. 549 ◽  
Author(s):  
RA Hunter ◽  
BD Siebert

The effects of genotype, age and liveweight, pregnancy and lactation on the voluntary feed intake by cattle of roughage diets of different qualities were studied in a number of experiments. The diets ranged from poor quality (low-nitrogen, high-fibre) spear grass (Heteropogon contortus) hay on which intakes were low ( 1 1 g DM/kg liveweight (LW)) to good quality lucerne (Medicago sativa) hay (26 g DM/kg LW). On the poorest-quality diet, differences in intake between Bos taurus and Bos indicus were not significant. However, on the higher quality diets Herefords (Bos taurus) ate significantly (P < 0.05) more than Brahmans (Bos indicus). In addition, as the quality of the diet improved from speargrass through to lucerne, the breed difference in favour of the Herefords became progressively greater and the variability between animals progressively smaller as a proportion of intake. Another study showed that with increasing age and liveweight of steers, intake per unit body weight declined, the rate of decline being significantly (P < 0.05) greater on good-quality lucerne compared to a poor-quality speargrass diet. There was no significant difference between Aberdeen Angus (Bos taurus) and Brahman steers in the rate of decline of intake of each diet with increasing age and liveweight of the steers. Another experiment which measured intake of pregnant and lactating heifers showed that the amount of feed eaten by pregnant heifers increased with increasing liveweight in late pregnancy, with intake per unit liveweight remaining constant. Lactating cows ate 35% more on a liveweight basis than their nonpregnant, non-lactating counterparts. These results are discussed in relation to mechanisms which control intake of roughage diets in ruminants, especially those associated with energy metabolism.


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