Symposium on Nutrition of Forages and Pastures: Collecting Forage Samples Representative of Ingested Material of Grazing Animals for Nutritional Studies

Cook, C. Wayne

doi:10.2527/jas1964.231265x

Cited by 67 publications

(37 citation statements)

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“…On days 20 and 27, forage samples (approximately 500 g) were collected simulating animal bite and using a hand plucking system (Cook, 1964;Muir, 2002). The samples collected were vacuum-packed, preserved at −20 °C, lyophilized (Martin Christ Alpha 1-4LD Plus), and ground using a 1 mm sieve Romer grinder.…”

Section: Methodsmentioning

confidence: 99%

Concentration of trans-vaccenic and rumenic acids in the milk from grazing cows supplemented with palm oil, rice bran or whole cottonseed

2014

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-The changes in the concentration of trans-vaccenic (C18:1 t-11 ) and rumenic (C18:2 c-9,t-11 ) acids in the milk from cows grazing on Pennisetum clandestinum, fed a supplement containing palm oil, rice bran or whole cottonseed were evaluated. Three supplements were assessed: one control supplement containing palm oil (C), with a low concentration of linoleic acid mainly from palm oil, and two supplements containing rice bran (RB) or whole cottonseed (CS) as the main source of linoleic acid. Six Holstein cows (4.2±1.7 years of age, 532.5±50.7 kg BW, 125±29 days in milk and a milk yield of 21.7±5.8 kg d −1 ; Mean±SD) were assigned to each treatment using a double 3 × 3 × 3 Latin Square Design. Compared with treatment C, the milk fat concentrations of trans-vaccenic acid (31.1 and 23.8 g kg −1 of fatty acids for RB and C, respectively), rumenic acid (14.1 and 11.3 g kg -1 of fatty acid for RB and C, respectively) and unsaturated fatty acids (348.7 and 325.4 g kg −1of fatty acid for RB and C, respectively) were higher for RB. Compared with C and CS treatments, the Δ 9 -desaturase index was higher for RB (0.37, 0.35 and 0.34 for RB, C and CS, respectively) and the thrombogenicity index was lower (3.09, 3.43 and 3.50 for RB, C and CS, respectively). The atherogenicity index was lower for RB treatment compared with C, but not compared with CS (1.85, 2.03, 1.97 for RB, C and CS, respectively). Supplementing rice bran to grazing dairy cows is a good alternative for producing a kind of milk beneficial to human health, due to its higher concentrations of trans-vaccenic and rumenic acids, unsaturated fatty acids and lower thrombogenicity and atherogenicity indexes.

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Section: Methodsmentioning

confidence: 99%

Concentration of trans-vaccenic and rumenic acids in the milk from grazing cows supplemented with palm oil, rice bran or whole cottonseed

2014

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“…The samples (400 g) were collected using the hand-plucking method (Cook, 1964) was analyzed according to Van Soest et al (1991); α-amilase (Sigma Aldrich, Saint Louis, Missouri, USA) but no sodium sulphite was added and results were corrected for residual ash content. Starch was analyzed using a POLAX-2L polarimeter (ATAGO Co., Ltd., Japan) according to "Gazzetta Ufficiale della Repubblica Italiana" (2000).…”

Section: Feed Sampling and Analysismentioning

confidence: 99%

Browsing ratio, species intake, and milk fatty acid composition of goats foraging on alpine open grassland and grazable forestland

Iussig

Renna

Gorlier

et al. 2015

Small Ruminant Research

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Aims of this study were to investigate diet selection of dairy goats foraging on two alpine vegetation types and to assess the related effects on milk fatty acid (FA) composition. Two enclosures laid out on an open grassland (OG) and a grazable forestland (GF) were exploited by 14 Camosciata goats. A commercial concentrate was supplemented during milking. Forty-five plots were randomly selected inside each enclosure and used to assess the species relative abundance (SRA) and phenological stage of plants, as well as goats' preferences (browsing ratio, BR) and intake (SI) for each species.Representative samples of the diet in each enclosure were built up considering the most ingested plant species and plant parts. Feed samples were analyzed for proximate, FA, and phenolic compositions.Milk samples were collected in each enclosure and analyzed for their FA profile. The enclosures showed a similar level of vegetation diversity. If compared to the GF enclosure, the OG one had higher proportion of Poaceae (81.2 vs 44.8% of SRA) and lower proportion of non-legume dicotyledons (14.6 vs 50.7% of SRA). The goats mostly selected eutrophic species in OG and forbs and woody species leaves in GF. The ingested vegetation was almost completely represented by grasses in OG (89.6% of SI), and by similar proportions of grasses and herbs and woody species in GF (54.9 and 45.1% of SI, respectively). The ingested forages from the OG and GF showed a comparable proximate composition; if compared to OG, the GF vegetation type was however richer in α-linolenic acid (ALA) and phenolic compounds (PC). Fatty acid analysis showed that GF milk had higher concentrations of ALA, total omega-3 FA, total trans-octadecadienoic acids, total conjugated linoleic acids, total trans-octadecenoic acids, and a reduced omega-6/omega-3 FA ratio than OG milk.Branched-chain FA were not significantly affected by treatment, suggesting that the activity of ruminal bacteria in the goats was not inhibited by the higher concentration of PC in GF plants. The main reason for the observed improvement of the FA profile in GF milk seems to be attributable to the FA profile rather than the concentration and composition of PC of the ingested plants. The abundance of herbs and woody species in the ingested vegetation was positively associated with the presence of nutritionally desirable FA in goat milk fat.

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“…To accomplish this pattern of consumption by the sheep was followed observing the heights and parts of the plant consumed, aiming to obtain a sample more closely to what the animal would spontaneously consume. To this end, the grass was grasped manually, in order to somewhat simulate the movement of the lips of lambs during grazing and then, a minimum of 200g of grass were cut with a jack knife in a height similar to naturally cut by a grazing lamb (adapted from Cook 1964). The total sample obtained was placed in a forced-air ventilation stove at 55 o C, for 96 hours.…”

Section: Methodsmentioning

confidence: 99%

Identification of lamb flocks susceptible and resistant against Brachiaria poisoning

et al. 2016

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This study was designed to assess the influence of genetic resistance against brachiaria poisoning in sheep. Two groups of sheep, one identified as susceptible (formed by two ewes and one ram) and the other as resistant against brachiaria poisoning (formed by three ewes and one ram) were selected. Sheep considered susceptible were those that presented clinical signs of brachiaria poisoning at any time of their life; resistant sheep were those that even raised on Brachiaria spp. pastures, did not developed any sign of the poisoning during their life. The offspring of the two flocks (15 lambs from the sensitive flock and 9 lambs from the resistant flock) were placed into brachiaria pasture (initially Brachiaria decumbens and B. brizantha,and only B. decumbens after weaning) and followed up during two years (2013)(2014). The determination of protodioscin levels in B. decumbens pasture was performed only in 2014 and revealed significant amounts of the toxic principle. Eleven lambs of the susceptible group were affected to some degree of brachiaria poisoning and six died; no lamb of the resistant group was affected. Clinical signs consisted of varying degrees of subcutaneous edema of the face and, erythema and loss of hair of the ears, crusts on the skin of ears, around the eyes and on planum nasale, scar deformation of the ears, and bilateral ocular discharge; affected lambs also sought for shadowy shelters and they were poor doers. Several sheep recovered from the condition and then relapsed. Necropsy findings in six lambs included pale mucous membranes, emaciation, dermatitis, scar deformation of the ears, large yellow livers with marked lobular pattern, and moderate infestation by Haemonchus contortus. Histologically the liver lesions were similar in all necropsied lambs but with varying degrees of severity; they were consistent with brachiaria poisoning and included architectural disruption of hepatocellular trabecula, clusters of foamy macrophages occasionally forming multinucleated giant cells, swollen and vacuolated hepatocytes, crystals or negative images of crystals in the biliary system, bilestasis, bile duct proliferation and lymphoplasmacytic infiltrate in portal triads. The skin lesions were those of photodermatitis and included epidermal necrosis, hyperkeratosis and dermal neutrophilic infiltrate. The results of this study allow to conclude that there is a genetic related resistance to brachiaria poisoning in sheep since the progeny of resistant sheep did not manifest the poisoning.

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Symposium on Nutrition of Forages and Pastures: Collecting Forage Samples Representative of Ingested Material of Grazing Animals for Nutritional Studies

Cited by 67 publications

References 0 publications

Concentration of trans-vaccenic and rumenic acids in the milk from grazing cows supplemented with palm oil, rice bran or whole cottonseed

Concentration of trans-vaccenic and rumenic acids in the milk from grazing cows supplemented with palm oil, rice bran or whole cottonseed

Browsing ratio, species intake, and milk fatty acid composition of goats foraging on alpine open grassland and grazable forestland

Identification of lamb flocks susceptible and resistant against Brachiaria poisoning

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