Abstract

The study "Effects of heat treatment on bypass of protein materials for dairy cows" was conducted at the Institute of Agricultural Science for Southern Vietnam, Nong lam University and Thanh Binh dairy farm, Cu chi district, HCMC from January 2008 to November 2009 for determination of appropriate temperature and time of heat treatment to increase rumen bypass protein for dairy cows and effect of protein materials on milk yield and quality. There were 3 experiments.

            In the first experiment, study on effect of appropriate temperature and time of heat treatment on protein materials such as soybeans, soybean meal, peanut cake, cottonseed cake and coconut cake. Temperature treatments were 110, 125, 140 và 155⁰C in 30, 60, 90 và 120 minutes. Moreover, soybeans were also extruded at 140⁰C and incubated in 5, 10, 15, 20, 30, 40, 50 and 60 minutes then cooling. Parameters were protein fractions and KOH soluble protein fraction. The best results were: Soybean meal at 125⁰C in 60 minutes and 140⁰C in 30 minutes; Coconut cake at 110⁰C in 60 minutes and 125⁰C in 30 minutes; Peanut cake at 110⁰C in 120 minutes, 125⁰C in 30 minutesand 140⁰C in 30 minutes; Cottonseed meal at 110⁰C in 60 minutes, 125⁰C in 30 minutes and 140⁰C in 30 minutes; Soybean at 125⁰C in 30 minutes, 125⁰C in 60 minutes and 140⁰C in 30 minutes; Extruded soybean incubated at 10, 20, 30 and 50 minutesand cooling.

            The second experiment, study on the digestibility of dry matter and crude protein of the treated materials in the first experiment by in sacco method by described procedure of Orskov (1985) with incubated time for 12 and 24h, 2 replicates for each samples and incubation time. The best results showed: Soybean meal at 125⁰C in 90 minutes, Peanut cake at 125⁰C in 60 minutes, Coconut cake at 110⁰C in 90 minutes, Cottonseed meal at 140⁰C in 30 minutes, Soybean at 125⁰C in 90 minutes, Extruded soybean incubated at 50 minutes and cooling.

            In the third experiment, study on effect of extruded soybean and treated soybean in diets on milk yield and quality of dairy cows. The experiment was conducted on 4 F2 HF dairy cows at calving 3^rd – 4^th, the 3^rd milking month with four diets containing soybean treated at 125⁰C in 90 minutes, soybean treated at 140⁰C in 30 minutes, extruded soybean incubated in 30 and 50 minutes. The 4 x 4 Latin square design was used for this experiment. The results showed that no significant difference was observed on milk yield and quality of dairy cows fed experimental diets.

Nguyen Van Phu, MSc.

Department of Animal Nutrition and Feedstuffs
Institute of Agricultural Science for Southern Vietnam
121 Nguyen Binh Khiem, District 1, Hochiminh city, Vietnam
Tel: + 84 8 39103962; Fax: + 84 38297650
Mobile: + 84 903649924

Email: phu.nv@iasvn.org or nguyenvanphu229@yahoo.com

Website: http://iasvn.org