Effects of intraruminal infusions of propionate and butyrate with two different protein supplements on milk production and blood metabolites in dairy cows receiving grass silage-based diet
✍ Scribed by Huhtanen, Pekka J; Blauwiekel, Ruth; Saastamoinen, Ilkka
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 201 KB
- Volume
- 77
- Category
- Article
- ISSN
- 0022-5142
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✦ Synopsis
Four cows were used in a balanced 4 ] 4 Latin square with 2 week experimental periods to investigate the e †ects of intraruminal infusions of volatile fatty acids and protein source on milk production and blood metabolites. The four treatments in a 2 ] 2 factorial arrangement were isoenergetic intraruminal infusions of propionate (500 g day~1) or butyrate (417 g day~1) each given with isonitrogenous protein supplementation of Ðsh meal (FM) or barley protein (BP). The cows were fed restrictively with 9 kg dry matter day~1 of formic acid treated grass silage and 8 kg day~1 of concentrate. Propionate infusion increased milk yield (24É9 vs 23É4 kg day~1 ; P \ 0É05), milk protein yield (832 vs 778 g day~1 ; P \ 0É05) and milk lactose content (44É7 vs 43É5 g kg~1 ; P \ 0É05) and yield (1113 vs 1023 g day~1 ; P \ 0É01), whereas butyrate infusion was associated with a higher milk fat content (44É7 vs 39É4 g kg~1 ; P \ 0É01) and yield (1033 vs 974 g day~1 ; P \ 0É01). FM tended (P \ 0É10) to increase milk yield, but had no signiÐcant e †ects on milk composition or milk component yields compared with BP. Butyrate infusion increased blood ketones, plasma non-esteriÐed fatty acids and glycine relative to propionate infusion. The concentrations of ammonia N in rumen Ñuid and urea in plasma and milk were similar for both protein supplements. The proÐle of amino acids in plasma was similar for both protein supplements except for the higher concentrations of phenylalanine, proline and tyrosine with BP. The results show that protein utilisation can be improved by increasing the supply of propionate from rumen fermentation in cows given a grass silagebased diet.