Sire evaluations at different levels of milk production

1992 ◽  
Vol 1 (1) ◽  
pp. 9-14 ◽  
Author(s):  
A. Żarenecki ◽  
W. Strzałkowski
2021 ◽  
Vol 285 ◽  
pp. 04005
Author(s):  
Maria Grinchuk ◽  
Yulia Nesterova

The aim of work is to explore influence of first fruitful insemination, service period and dry period to dairy productivity of Simmental cows. The research is aimed at studying the milk production of Simmental cows with different levels of reproductive qualities. The result of the research, a relation was established between the age of the first fruitful insemination, the duration of the service period, the duration of the dry period and milk production performance. It has been established that the age of the first fruitful insemination at 18-24 months has the most beneficial effect on subsequent milk production. The service period of 90-120 days has a positive effect to an increase in milk yield per 305 days of lactation, the longer service period negatively affects to the mass fraction of fat. With an increase in the duration of the dry period, the mass fraction of fat increases, but milk yield decreases. The influence of reproductive qualities to the milk protein is negligible. It was revealed that the age of the first insemination at 18-24 months is the most profitable for production. According to the results of the research, it can be judged that reproductive qualities, in combination with other factors, affect the milk productivity of Simmental cows.


2015 ◽  
Vol 36 (5) ◽  
pp. 3329 ◽  
Author(s):  
Leison Rocha Bezerra ◽  
Ricardo Loiola Edvan ◽  
Ronaldo Lopes Oliveira ◽  
Aderbal Marcos de Azevedo Silva ◽  
Geraldo Fábio Viana Bayão ◽  
...  

<p>This paper aims to evaluate the influence of different levels of supplemental product-dehydrated cashew in the feed for crossbred Girolando cows on milk production and hemato-biochemical profile. The experiments were conducted using eight cows that were randomly distributed in a Latin square design (4×4), in which treatments consisted of four supplementation levels with product-dehydrated cashew (PDC) in animal diets, namely: 0% PDC (control diet), 1.0 kg of DCP, 1.5 kg of PDC and 2.0 kg of PDC in total dry matter . The milk and animals were weighed and the body condition of the animals were evaluated within seven days of milk collection during each experimental period. To determine the serum biochemistry and blood count of cows, three blood samples were taken in each period, at 7, 14 and 21 days before the daily supply of supplementation with samples collected from 5 ml of blood by puncturing the jugular vein. Supplementation with 2 kg of PDC reduced milk production and the levels of glucose and total plasma protein compared to the control group, due to the higher level of tannin in this group. Supplementation with PDC raised the total count of the erythrocytes, reduced the mean corpuscular volume (MCV) and non-changed number of leukocytes. Increased levels of phenolic compounds in the diet inhibited the absorption of dietary proteins, which decreased milk production.</p>


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