Effects of Concentrate Source (Cottonseed vs. Barley) on Milk Performance and Fatty Acids Profile of Holstein-Friesian Dairy Cows
Milk performance (protein and fat content) and milk fatty acids (FA) profile of dairy cows under supplementation with two sources of concentrate, oilseeds (C, cottonseed) at two levels, low (5kg DM/cow/day) and high (7 kg DM/cow/day), and cereal grains (B, barley) at high rate (7 kg DM/cow/day), wer...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2011 |
| País: | España |
| Institución: | Universidad de Santiago de Compostela (USC) |
| Repositorio: | Minerva. Repositorio Institucional de la Universidad de Santiago de Compostela |
| Idioma: | inglés |
| OAI Identifier: | oai:minerva.usc.gal:10347/39236 |
| Acceso en línea: | https://hdl.handle.net/10347/39236 |
| Access Level: | acceso abierto |
| Palabra clave: | Cottonseed Linoleic acid Lipid feed supplements Milk fat content Total mixed ration 3104 Producción Animal 310308 Gestión de la producción vegetal |
| Sumario: | Milk performance (protein and fat content) and milk fatty acids (FA) profile of dairy cows under supplementation with two sources of concentrate, oilseeds (C, cottonseed) at two levels, low (5kg DM/cow/day) and high (7 kg DM/cow/day), and cereal grains (B, barley) at high rate (7 kg DM/cow/day), were studied in three herds (n=36) of spring calving Holstein-Friesian dairy cows (200 days in milk). Animals were randomly assigned to one of three indoors (n=12) silage feeding regimes (C5, C7 and B7), using a TMR (total mixed ration) basal diet, containing 70-80% silage (grass: maize, 36: 64) and 30-20% concentrate. Daily milk yield (MY) was higher (P<0.001) at high level of supplementation (B7, 18.1 and C7, 17.9 kg/cow/day, respectively) compared to low level (C5, 15.7 kg/cow/day), and dairy cows at the highest level of concentrate showed the highest (P<0.05) body weight (B7, 605 and C7, 598, respectively). Milk protein content was lower (P<0.05) in the high level of cottonseed (C7, 30.7 g/kg DM) than in the barley treatment (B7, 32.7 g/kg DM). There were no differences among treatments in milk fat and milk urea content. Weekly milk FA profile of cow milk was determined using gas chromatography-mass spectrometry, during seventy days in autumn, and no differences were found among treatments in short, medium and long chain FA. Despite this, higher (P<0.05) contents of polyunsaturated fatty acids (PUFA) and linoleic acid were found in the C7 treatment compared to the C5 treatment (2.48 and 2.22 vs. 2.16 and 1.92 g/100 g of FA methyl es ters, respectively). Including the high levels of cottonseed and barley as a concentrate source for feeding dairy cattle revealed similar MY and milk fat content. However, the high level of cottonseed in the diet of dairy cows showed decreased milk protein content and increased linoleic acid and PUFA levels. |
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