scholarly journals Shortening or omitting the dry period in dairy cows : effects on milk yield, energy balance, metabolic status, and fertility

2016 ◽  
Author(s):  
Juncai Chen
2021 ◽  
Vol 53 (2) ◽  
Author(s):  
A. Boustan ◽  
V. Vahedi ◽  
M. Abdi Farab ◽  
H. Karami ◽  
R. Seyedsharifi ◽  
...  

2014 ◽  
Vol 97 (3) ◽  
pp. 1499-1512 ◽  
Author(s):  
A.T.M. van Knegsel ◽  
G.J. Remmelink ◽  
S. Jorjong ◽  
V. Fievez ◽  
B. Kemp

2006 ◽  
Vol 46 (7) ◽  
pp. 957 ◽  
Author(s):  
C. R. Stockdale

This review considers the research that has been conducted recently on reducing the length of the dry period of dairy cows, with particular emphasis on the effects of eliminating the dry period altogether. Milk yield in the subsequent lactation is reduced by up to 25%, but this loss is offset to some degree by the milk produced when cows would otherwise be dry. The lower subsequent milk yield in cows continuously milked is most likely to be a consequence of changes in the mammary gland during late gestation rather than insufficient feed or body condition to maintain milk synthesis. Shortening or eliminating the dry period may result in a lower incidence of metabolic problems post-partum, and a reduced negative energy balance in early lactation due to the maintenance of dietary intake while milk yields and body condition loss are reduced. The reductions in both body condition loss and negative energy balance may have a beneficial influence on reproductive performance. However, it is concluded that more research, particularly with cows that graze pasture during lactation, together with an economic appraisal, is needed before it could be recommended that Australian dairy farmers change their current dry period practices, particularly if continuous milking was to be considered.


2021 ◽  
Vol 36 ◽  
pp. 06033
Author(s):  
N.B. Nikulina ◽  
E.V. Baidak

A study was conducted on dairy cows aged 3-6 lactation, which were additionally fed with the Ketostop-El supplement at the rate of 300 g per head for 4 weeks after calving. The use of the feed supplement for 14 days led to a decrease in the number of monocytes, total protein, glucose, creatinine, total calcium and the activity of ALT and AST compared to their level before the use of Ketostop-El. Changes in the physical and chemical properties of urine and increase in the average daily milk yield were noted. The use of the supplement for 28 days contributed to a decrease in hematocrit, the sorption capacity of red blood cells, total protein, glucose, bilirubin, creatinine, total calcium, reserve alkalinity, ALT and AST activity and an increase in the number of basophils, eosinophils, and the concentration of inorganic phosphorus compared to the initial data. At the same time, a decrease in the level of protein and ketones in the urine was observed. An increase in the average daily milk yield and the mass fraction of fat in milk was also recorded. The feed supplement "Ketostop-El" has a positive effect on the body of dairy cows, as evidenced by the normalization of the clinical and metabolic status, as well as an increase in the dairy productivity of animals.


2021 ◽  
pp. 2392-2396
Author(s):  
Sumpun Thammacharoen ◽  
Sapon Semsirmboon ◽  
Somchai Chanpongsang ◽  
Narongsak Chaiyabutr ◽  
Pawares Panyasomboonying ◽  
...  

Background and Aim: Metabolism and environment are closely related. Under high ambient temperature (HTa), dairy cows may have different energy metabolism during summer and winter. The present study was carried out to investigate the effect of HTa on the milk yield and blood concentration of beta-hydroxybutyrate (BHBA) and glucose at the herd level. Materials and Methods: One large dairy farm in Thailand with more than 100 crossbred Holstein cows milked each month was selected. The first experiment was performed on non-lactating cows to determine the normal daily concentrations of blood BHBA and glucose. Under the HTa condition, there was no significant change in blood BHBA and glucose concentrations. The second experiment was performed using a prospective cohort clinical design to demonstrate the seasonal effect on milk yield and blood BHBA as an indication of energy metabolism at the herd level. Results: The temperature and humidity index for the winter (78.1±0.5) and summer (83.4±0.7) periods differ significantly. The average milk yield during the winter period was 17.8% higher than during the summer period. The reduction of body condition score (BCS) during early lactation was significant in the winter cows. Both higher milk yield and lower BCS in the winter cows suggested a state of negative energy balance. However, there was no difference in blood BHBA and glucose concentrations between winter and summer cows. The effect of HTa on insulin signaling appeared to be a counterbalancing factor for the ketogenic status. Based on the present results, it would be interesting to further investigate the incidence of subclinical and clinical ketosis in a dairy farm under tropical conditions. Conclusion: The present experiment revealed that HTa during summer decreased milk yield in dairy cows fed under tropical conditions. Higher milk yield in winter caused a greater reduction of BCS and suggested a greater negative energy balance. However, there was no seasonal effect on blood BHBA and glucose concentrations.


1999 ◽  
Vol 24 ◽  
pp. 99-112 ◽  
Author(s):  
R. Webb ◽  
P. C. Garnsworthy ◽  
J. G. Gong ◽  
R. S. Robinson ◽  
D. C. Wathes

AbstractAn effective method for enhancing milk production efficiency in dairy cows is to increase milk yield and significant progress has been achieved through intense selection, assisted by the application of new reproductive techniques. However this increased milk yield has been accompanied by a slow but steady decline in dairy cow fertility. The two main reasons for this reducing level of fertility appear to be selection for increased milk yield and large herd sizes, although the affect of the introduction of Holstein genes needs to be investigated. In addition, other negative consequences such as an increase in the incidence of metabolic diseases and lameness have been observed. This has given rise to public concern that the high-yielding dairy cow may be under a state of metabolic stress during peak lactation and therefore the welfare and performance of other body functions are compromised.The reason for this decline in fertility is not well understood, although a nutritional influence on the initiation of oestrous cycles, follicular growth, oocyte quality and early embryonic development has been implicated. In early lactation dietary intake is unable to meet the demands of milk production and most cows enter a period of negative energy balance. Negative energy balance has a broadly similar effect to undernutrition leading to a mobilization of body reserves. Furthermore diets high in rumen degradable protein lead to an excess of rumen ammonia, which before it is converted to urea by the liver and excreted in the urine, may cause an alteration in the reproductive tract environment reducing embryo survival. Such major changes in the metabolic and endocrine systems can therefore influence fertility at a number of key points.Possible reproductive sites where inadequate nutrition may have detrimental effects include: (i) the hypothalamic/pituitary gland where gonadotropin release may be impaired; (ii) a direct effect on the ovaries, where both follicular growth patterns and corpus luteum function may be directly influenced; (iii) the quality of the oocyte prior to ovulation may be reduced and coupled with an inadequate uterine environment will result in reduced embryo survival and (iv) there may be effects on subsequent embryo development. The initiation of normal oestrous cycles post partum is usually delayed in dairy cows with a higher genetic merit for milk production, confirming that intense selection towards high milk yield can compromise reproductive function. In addition, the effects of increased milk yield may include changes in circulating GH and insulin concentrations, which in turn alter both insulin-like growth factor (IGF) and IGF binding protein production. Nutrition has recently been shown to have a direct effect at the level of both the ovaries and the uterus to alter the expression of these growth factors.In conclusion, further knowledge is required to determine how the metabolic changes associated with high milk output reduce fertility. Identification and understanding of the mechanisms involved and the key sites of action responsible for compromised reproductive function, will enable the identification of possible indices for future multiple-trait selection programmes.


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