scholarly journals Effects of Somatotropin and Dietary Calcium Soaps of Fatty Acids in Early Lactation on Milk Production, Dry Matter Intake, and Energy Balance of High-yielding Dairy Cows

2000 ◽  
Vol 83 (9) ◽  
pp. 2085-2094 ◽  
Author(s):  
U. Moallem ◽  
Y. Folman ◽  
D. Sklan
2007 ◽  
Vol 87 (4) ◽  
pp. 591-600 ◽  
Author(s):  
H. V. Petit ◽  
C. Benchaar

A total of 153 lactating Holstein cows averaging 695 kg body weight (standard error = 11) were allotted 6 wk before the expected date of parturition to 51 groups of three cows blocked for similar calving dates to determine the effects of feeding different profiles of fatty acids from 6 wk before calving on feed intake, milk production and composition, conception rate, and embryo mortality in the subsequent lactation. Cows within each block were assigned to one of the three isoenergetic total mixed diets based on either whole flaxseed (FLA), Megalac® (MEG) or micronized soybeans (SOY). Diets were fed for ad libitum intake from 6 wk before calving to day 50 of pregnancy for pregnant cows, or 120 d postpartum for those not diagnosed pregnant after artificial insemination (AI). Diet had no effect on prepartum dry matter intake but postpartum intake was 9% higher for cows fed FLA than for those fed MEG or SOY. Milk production and fat concentration were similar among treatments. Conception rate at first AI was higher for cows fed FLA (54.3%) than for those fed SOY (26.9%). Conception rate at first AI was similar for cows fed FLA and MEG and it was similar for those fed MEG and SOY. Cows fed MEG tended to have higher embryo mortality than those fed FLA (41.7 vs. 10.5%, P = 0.06) and SOY (41.7 vs. 0%, P = 0.08) at first AI and there was no difference among treatments at second AI. Total embryo mortality was similar for cows fed FLA and SOY but cows fed MEG had higher total embryo mortality than those fed SOY (35.3 vs. 9.1%) and there was a trend (P = 0.07) when MEG was compared with FLA (35.3 vs. 9.5%). These data suggest that feeding flaxseed during the prepartum period has little effect on production in the subsequent lactation but could improve fertility of dairy cows. Key words: Dairy, flaxseed, milk production, reproduction, fatty acids


2010 ◽  
Vol 90 (2) ◽  
pp. 115-127 ◽  
Author(s):  
H V Petit

Flaxseed contains approximately 55% of total fatty acids of the oil as ?-linolenic acid and is rich in lignans, which are strong antioxidants. Diets rich in omega-3 fatty acids and antioxidants are known to have beneficial effects on human health such as a decrease in the incidence of cancer, cardiovascular diseases, hypertension, and arthritis. Flaxseed could then be an interesting natural feed to consider for changing milk composition. Cyanogenic glycosides (linustatin and neolinustatin) are present in flaxseed, but the concentration of hydrocyanic acid is very low in milk and ruminal fluid of cows fed flaxseed products. In general, feeding up to 15% of the total dry matter as whole flaxseed has a limited effect on dry matter intake. Heat treatments such as micronization and extrusion have no effect on dry matter intake and the effect of formaldehyde treatment on feed intake is unclear. The effects of flaxseed supplementation on milk production of dairy cows in the early stage of lactation have been neutral. Diet supplementation with whole flaxseed has had no effect on milk yield and composition of dairy cows in the mid or late stages of lactation. Physical processing of flaxseed increased milk production although heat treatment did not. Results on the effect of flaxseed processing on overall milk fat concentration have been controversial, but heat and formaldehyde treatments had no effect. Flaxseed supplementation had no effect on milk fat and protein concentrations, and processing of flaxseed had little effect. The extent of change in the concentration of fatty acids in milk is generally proportional to the level of inclusion of flaxseed in the diet. In conclusion, feeding flaxseed does not affect milk production or composition in the large majority of studies, but its long-term effects on health of cows and productivity still need to be determined.Key words: Review, flax, dairy


2015 ◽  
Vol 95 (3) ◽  
pp. 433-444 ◽  
Author(s):  
H. Khazanehei ◽  
S. Li ◽  
E. Khafipour ◽  
J. C. Plaizier

Khazanehei, H., Li, S., Khafipour, E. and Plaizier, J. C. 2015. Effects of dry period management on milk production, dry matter intake, and energy balance of dairy cows. Can. J. Anim. Sci. 95: 433–444. Effects of dry-period management on milk production, feed intake, and energy balance were determined in 11 second-parity (PAR 2) and 15 third or later parity (PAR 3+) cows. Cows were paired based on expected calving date, and randomly assigned to treatments including a conventional 60-d dry period with a 39-d far-off and a 21-d close-up diet (CONV), and a short 40-d dry period with only a close-up diet (SHORT). Treatment did not affect dry matter intake (DMI) and energy balance across the 6 wk before calving and the 4 wk after calving. Across the first 16 wk of lactation, cows on the short treatment had lower milk yield compared to cows on the CONU treatment that was mostly due to the lower production in PAR 3+ cows. Also, PAR 3+ cows on the SHORT treatment had lower milk protein yields and higher somatic cell counts than the other cows. In general, PAR 2 cows on the SHORT treatment had similar DMI, fat corrected milk yields, and protein and fat yields and percentages compared to cows in both parity groups on the CONV treatment. This suggests that the SHORT treatment may be suitable for PAR 2 cows, but not for older cows.


1990 ◽  
Vol 30 (4) ◽  
pp. 495 ◽  
Author(s):  
C Grainger

Three separate experiments were carried out to determine the effects of stage of lactation and feeding level on marginal production response by dairy cows to change in feeding level. In each experiment cows were individually offered cut pasture in stalls, ad libitum initially for 10 days, and for a further 28-day period when feeding treatments were imposed. In experiment 1, a total of 37 cows in early or late lactation were offered the same high quality pasture diet either ad libitum or at 0.60 x ad libitum intake. In experiments 2 and 3, 35 and 31 cows which were in early (experiment 2) or late lactation (experiment 3) were offered pasture at 1 of 3 feeding levels: ad libitum, 0.75 x ad libitum. 0.50 x ad libitum intake. In experiment 1 the marginal response was similar, 23.5 and 25.0 g milk fat/kg change in dry matter intake, for cows offered the same diet in early or late lactation. In experiment 2, cows in early lactation showed marginal responses which ranged from 0 to 80 g milk fat/kg dry matter intake and were greater at lower feeding levels and for cows with greater initial milk production. In experiment 3, the marginal response for cows in late lactation was similar to that in experiment 1 (24.4 g milk fat/kg change in DM intake) and was not significantly affected by the level of feeding or by the initial milk production of the cow. Reduced levels of feeding in late lactation appeared to accelerate the changes in milk composition which occur normally in late lactation: increases in the concentration of milk fat and protein; a decrease in lactose concentration. It is concluded that in early lactation, much of the published variation in marginal response can be explained by differences between experiments in levels of feeding studied and in the initial milk yield of the cows. In late lactation there was much less variation in the reported magnitude of the marginal response, and the variation which did exist can be explained by experimental error.


2007 ◽  
Vol 90 (4) ◽  
pp. 1729-1739 ◽  
Author(s):  
R.R. Rastani ◽  
N. Silva del Rio ◽  
T.F. Gressley ◽  
G.E. Dahl ◽  
R.R. Grummer

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