Effect of exchanging Onobrychis viciifolia and Lotus corniculatus for Medicago sativa on ruminal fermentation and nitrogen turnover in dairy cows

Abstract

The objective of the study was to determine the effect of feeding sainfoin (SF; Onobrychis viciifolia) and birdsfoot trefoil (BT; Lotus corniculatus), 2 temperate climate forage legumes that contain condensed tannins (CT), on ruminal fermentation and N turnover in dairy cows. Six ruminally cannulated multiparous dairy cows (milk yield=40kg/d; 36 d in milk) were used in a replicated 3×3 Latin square design. All animals were fed basal diets containing 20% pelleted SF (223g of CT/kg of dry matter), BT (30.3g of CT/kg of dry matter), or alfalfa (AL) and concentrate to meet their predicted nutrient requirements. Each experimental period consisted of a 21-d adaptation period in a tiestall, followed by a 7-d collection period in metabolic crates, where feces and urine were collected quantitatively. During the 7-d period, milk yield was recorded daily and milk samples were taken at each milking. Blood, ruminal fluid, and papillae were sampled on d 2 and 5. The relative abundance of selected bacterial strains in ruminal fluid and the gene expression of transporter genes in the papillae were determined with quantitative PCR. Total volatile fatty acids and the abundance of the cellulolytic bacteria Prevotella spp. and Ruminococcus flavefaciens decreased with SF compared with AL. The relative gene expression of the monocarboxylate transporter 1 was increased with BT compared with AL and SF. Total yields of milk, milk fat, and milk protein were similar among treatments. The proportion of 18:3n-3 in milk fat was greater and those of 22:5n-3 and 22:6n-3 were lower with SF than with BT. The contents of urea N in blood (2.71, 3.45, and 3.90mmol/L for SF, AL, and BT, respectively), milk (79.8, 100.1, and 110.9mg/kg for SF, AL, and BT, respectively), and urine were lower with SF than with AL and BT, and a trend toward a lower ruminal ammonia content occurred with SF compared with BT. Intake and excretion of N with milk were similar among treatments, but urine N was lower with SF than with AL. The N excretion to N intake relation showed a shift in a part of urine N (17.5, 20.8, and 19.5% for SF, AL, and BT, respectively) to fecal N (45.2, 41.3, and 38.5% for SF, AL, and BT respectively) with SF compared with AL and BT. In conclusion, SF and BT differed in their effects on fermentation and milk fatty acid profile and SF also showed potential to decrease metabolic and environmental loads. The main reason for the different efficiency was likely a higher CT content of SF compared with BT.

Benefits of Condensed Tannins in Forage Legumes Fed to Ruminants: Importance of Structure, Concentration, and Diet Composition

“…Nutritional effects of CTs are currently understood in general terms, and information concerning the ways that CTs affect specific processes are only now being defined by determining the CT traits of forages used for in vivo and in vitro measurements and their effects on the microbiome (Grosse Brinkhaus et al, 2016. Binding to dietary proteins and reduction in rumen proteolysis, resulting in higher proportions of dietary protein passing to the small intestine, have been measured (Waghorn, 2008), but details and mechanisms are not understood.…”

“…Grosse Brinkhaus et al, 2016 Perly (ensiled with timothy grass) ND ND Lower growth rate of lambs than on red clover mixtures Copani et al, 2016 Perly (ensiled) ND ND Condensed tannins (CTs) had no effect on N retention compared with the +polyethylene glycol (PEG) control Theodoridou et al, 2012 Shoshone (grazed) ND ND Comparable weight gains by beef calves grazing sainfoin and alfalfa diets Maughan et al, 2014;Villalba et al, 2015 Renumex (grazed) ND ND Growth rate and slaughter data were the same for sainfoin-and alfalfa-fed lambs Karnezos et al, 1994 No details (fresh forage) ND ND CTs in sulla, but not in sainfoin, improved amino acid absorption compared with the +PEG control Bermingham et al, 2001 Zeus/Esparcette (ensiled) ND ND Dairy cows: higher milk yield compared with grass silage Huyen et al, 2016b UK accessions (Sombourne, Hampshire, Cotswold Common) 29:71-33:67…”

“…Cattle fed a grass-sainfoin (mixture of Zeus and Esparcette accessions) silage or sheep grazed on big trefoil ('Maku') partitioned energy towards protein synthesis, rather than lipid synthesis, compared with grass-corn (Zea mays L.) silage and white clover diets, respectively (Purchas and Keogh, 1984;Huyen et al, 2016a). Feeding dairy cows with sainfoin pellets lowered milk and blood urea concentrations compared with alfalfa and birdsfoot trefoil pellets (Girard et al, 2016b;Grosse Brinkhaus et al, 2016) because of the reduction in rumen proteolysis and ammonia absorption.…”

The Effect of Herbage Conservation Method on Protein Value and Nitrogen Utilization in Dairy Cows

“…Feed residues were recorded daily. Milk yield was recorded at each milking, and milk samples were taken from each cow and handled for later analysis of gross constituents, urea, and N concentrations as described by Grosse Brinkhaus et al [13]. Total feces were collected in a tub beneath the metabolic cage, and total urine was collected via urinals attached around the vulva via Velcro straps glued to the shaved skin.…”

“…At the same time points, blood was sampled from the jugular vein. Samples were prepared for later analysis of volatile fatty acids (VFA) and ammonia in ruminal fluid and urea in blood, as described by Grosse Brinkhaus et al [13].…”