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Titre du document / Document title

Effects of feeding supplemental palmitic acid (C16:0) on performance and milk fatty acid profile of lactating dairy cows under summer heat

Auteur(s) / Author(s)

WARNTJES J. L. (1) ; ROBINSON P. H. (1) ; GALO E. (2) ; DEPETERS E. J. (1) ; HOWES D. (3) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) Department of Animal Science, University of California, Davis, CA 95616, ETATS-UNIS
(2) Dairy Consulting Services of California Inc, Madera, CA 93638, ETATS-UNIS
(3) Howes Management Services, Nampa, ID 83653, ETATS-UNIS

Résumé / Abstract

The objective was to determine performance and milk fatty acid changes of high producing dairy cows in early lactation, under summer heat, by adding a supplemental rumen inert fat in the form of a saturated free fatty acid (856g/kg C16:0/kg of total fatty acids) to the total mixed ration (TMR). Early lactation multiparous Holstein cows in two similar pens of 99 and 115 cows were used in a 2 × 2 Latin Square design experiment with 35 d periods during a period when daily high and low temperatures averaged 34.3 and 15.9 °C, the relative humidity averaged 51% and there were no rain events. The TMR was the same for both groups, consisting of approximately 435 g/kg forage and 565 g/kg concentrate, except that the vitamin/mineral premix had no added fat (control, C) or added fat (C16:0) at a level designed to deliver approximately 450g/cow/d of supplemental fat if cows consumed 26.5 kg/d of dry matter (DM). The two TMR averaged 905 g/kg organic matter (OM), 318 g/kg neutral detergent fiber (aNDF), and 186 g/kg crude protein (CP). The 'C' TMR had 58 g/kg total fatty acids with an estimated net energy for lactation (NE1) of 7.3 MJ/kg (DM), while the C16:0 TMR had 72 g/kg total fatty acids and 7.5 MJ/kg NE1 (DM). Whole tract digestibility of DM, OM, aNDF and CP tended (P<0.10) to increase, and that of fatty acids increased substantially (P<0.01), with C16:0 feeding, whereas, DM intake was not affected. Milk fat content decreased (P<0.01) with C 16:0 feeding (37.5 versus 36.0 g/kg), whereas, true protein content tended (P=0.09) to increase. There was a tendency (P=0.07) for increased milk yield (36.69 versus 38.04 kg/d), while milk protein yield increased (P=0.03) with C 16:0 supplementation (1.08 versus 1.13 kg/d). Milk fat yield was unaffected by treatment. Concentrations of short and medium chain milk fatty acids (C6:0-C15:0), decreased, or tended to decrease, with C16:0 addition (C13:0 and C15:0, P<0.10; all others, P≤0.05). The concentration of C16:0 increased (P<0.001) in milk triglycerides from cows fed C16:0 (27.10 versus 31.57 g/kg), the longer chain saturated fatty acids C17:0 and C18:0 decreased (P≤0.05) and other long chain unsaturated fatty acids were unaffected. Benefits of C16:0 feeding on cow productivity must be balanced against negative effects on the nutritive value of the milk (i.e., increased C16:0 in milk fatty acids) produced for human consumption. However, relatively low amounts of supplemental C16:0 (27.10 versus 31.57 g/kg in milk triglycerides for C and C16:0 supplemented cows, respectively) were actually secreted in milk, in spite of them being essentially fully digested in the digestive tract. Strategies to divide cows into production groups based on milk yield and/or milk fat proportions could further limit C16:0 secretion in milk. Supplemental dietary C16:0 may have positive effects on milk production that outweigh the negative health effects of the increased C16:0 content in the milk fat.

Revue / Journal Title

Animal feed science and technology    ISSN  0377-8401   CODEN AFSTDH 

Source / Source

2008, vol. 140, no3-4, pp. 241-257 [17 page(s) (article)] (1 p.1/4)

Langue / Language

Anglais

Editeur / Publisher

Elsevier, Amsterdam, PAYS-BAS  (1976) (Revue)

Mots-clés anglais / English Keywords

Farming animal

;

Lipids

;

Dairy product

;

Vertebrata

;

Mammalia

;

Ungulata

;

Artiodactyla

;

Saturated fatty acid

;

Stress

;

Milk production

;

Fat

;

Heat

;

Summer

;

Dairy cattle

;

Lactation

;

Fatty acids

;

Milk

;

Performance

;

Palmitic acid

;

Feeding

;

Mots-clés français / French Keywords

Animal élevage

;

Lipide

;

Produit laitier

;

Vertebrata

;

Mammalia

;

Ungulata

;

Artiodactyla

;

Acide gras saturé

;

Vache laitière

;

Stress

;

Production laitière

;

Matière grasse

;

Chaleur

;

Eté

;

Bovin laitier

;

Lactation

;

Acide gras

;

Lait

;

Performance

;

Acide palmitique

;

Alimentation

;

Mots-clés espagnols / Spanish Keywords

Animal cría

;

Lípido

;

Producto lácteo

;

Vertebrata

;

Mammalia

;

Ungulata

;

Artiodactyla

;

Acido graso saturado

;

Estrés

;

Producción lechera

;

Materia grasa

;

Calor

;

Verano

;

Ganado de leche

;

Lactación

;

Acido graso

;

Leche

;

Rendimiento

;

Palmítico ácido

;

Alimentación

;

Mots-clés d'auteur / Author Keywords

Fat

;

Milk production

;

Heat stress

;

Dairy cows

;

Localisation / Location

INIST-CNRS, Cote INIST : 17215, 35400017507774.0030

Nº notice refdoc (ud4) : 20106334



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