نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم دامی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج، ایران
2 گروه علوم دامی، دانشکده کشاورزی، دانشگاه ارومیه، ارومیه، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
In order to determine the effects of sodium acetate and conjugated linoleic acid (CLA) on dry matter consumed, feed digestibility, milk yield and milk fat profile, 33 Holstein cows several calving times during days 5-31 after calving in a completely randomized design with Three treatments and 11 replications were used. The experimental diets included 1- basic diet (control), 2- diet containing 300 gr of sodium acetate , 3- diet containing 100 gr of CLA. Daily dry matter intake and milk production, body weight and body condition score were measured at the beginning and end of the experiment. milk samples were taken at regular intervals to determine the amount of milk compounds. Also, on the last day, a sample was taken to determine the profile of fatty acids. Dry matter intake was not significant among dietary treatment (P>0.05). Milk production was increased by supplementing diets with sodium acetate (3.16 kg/d) and CLA (2.46 kg/d) compared to control treatment. CLA supplementing decreased milk fat content significantly and sodium acetate increased it. The yield and content of milk protein and lactose were not significantly different between the treatments. With the consumption of sodium acetate, the amount of milk fat and milk production increased, as probably the hypothesis that sodium acetate is lipogenic for adipose tissue was ignored and Acetate partition nutriunt toward milk fat production. CLA consumtion, negative energy balance did not change between as spared energy partition toward more milk yield. The use of CLA could be beneficial for the health of consumers by increasing the trans-10-cis-12 CLA isomer transfer to milk and reducing thrombogenic and atherogenic indicators.
کلیدواژهها [English]
Extended Abstract
Introduction
In most cases, high-yielding cows are not able to provide the requierd energy in the early lactation period, and as a result, they are in a negative energy balance, which may lead to metabolic abnormalities and reproductive disorders. Adding conjugated linoleic acid (CLA) to the diet can reduce milk fat production in early lactation, thus leading to improved energy balance. Considering that acetate is a precursor for mammary lipogenesis in ruminants, it is logical that acetate can affect milk fat performance in lactating cows. The purpose of this experiment was to investigate the effect of CLA and sodium acetate supplementation on dry matter consumption, digestibility, milk production and milk fat profile in fresh cows.
Materias and methods
This experiment was carried out in the educational-research station of the Department of Animal Science, Faculty of Agriculture, University of Tehran. 33 fresh Holstein cows were randomly assigned to 3 experimental treatments and 11 repetitions and were kept in individual stalls with free access to water during 5-31 days after parturition.
Results and discussion
Sodium acetate did not improve the negative energy balance, and an increase in atherogenic and thrombogenic indices was also observed. While, the supply of sodium acetate improved the synthesis of milk and milk fat in dairy cows. The use of CLA could be beneficial for the health of milk consumers by increasing the transfer of trans-10-cis-12 isomer of CLA to milk and reducing thrombogenic and atherogenic indices. It seems that in the early parturition period, when the cows are in a negative energy balance, the use of sodium acetate is risky and the consumption of CLA is more rational.
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