Masters Degrees (Animal Sciences)

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Browsing Masters Degrees (Animal Sciences) by Author "Biggs, Simone"

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    The effect of fenugreek seed cotyledon extract on milk yield and composition in Holstein cows
    (Stellenbosch : Stellenbosch University, 2022-04) Biggs, Simone; Cruywagen, C. W.; Raffrenato, Emiliano; Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences.
    ENGLISH ABSTRACT: Trigonella foenum-graecum L. (Fenugreek) has traditionally been used for a wide range of medicinal properties of which its galactagogic, hypoglycaemic and hypocholesterolaemic properties have held particular promise. The effects of fenugreek, in the form of fenugreek cotyledon seed extract (FCE), on milk production and milk composition in lactating dairy cows were evaluated in two consecutive studies. The first study (Trial 1) was conducted under controlled conditions on a university experimental farm while the second study (Trial 2) was conducted on a commercial dairy farm. In Trial 1, thirty-nine lactating Holstein cows were allocated to three treatment groups (Control, Nutrifen® and NutrifenPlus®) in a randomized complete block design. The trial was conducted over a 9-week period. Cows received a standard TMR at approximately 50 kg/cow per day (25 kg DM) with lucerne hay and wheat straw as forage sources. Nutrifen® or NutrifenPlus® were formulated into a lactation cow concentrate to supplement 120 g/cow per day, delivered via the TMR. Wheaten bran was used in the control concentrate instead of the FCE products. No ionophores or antibiotics were included in the diets. In Trial 2, sixty Holstein cows were allocated to two treatment groups (Control and Nutrifen®) in a randomized complete block design. The trial was conducted over a 12-week period. Cows received a high-concentrate lactation TMR with maize silage as main forage source. Nutrifen® was included in the treatment concentrate to provide 120 g/cow per day. The Control concentrate contained monensin- Na to provide 500 mg/cow per day. In Trial 1, both the Nutrifen® and NutrifenPlus® groups manifested higher milk yields (P < 0.001) compared to the Control group. The milk response of the Nutrifen® group was 5 % higher than the Control treatment and that of the NutrifenPlus® group was 11.6 % higher over the entire experimental period. In Trial 2, the Nutrifen® group produced 9.4 % more milk than the Control group after only two weeks and the difference was sustained for the duration of the trial. Cows receiving FCE supplementation showed greater persistency overall. Milk fat and protein contents did not differ significantly among treatments in either trial. However, in Trial 1, the lactose content of cows receiving FCE supplementation was significantly higher (P = 0.013). Feed efficiency was improved by FCE supplementation in both trials. In Trial 1, milk was also evaluated by a sensory panel, who found no noticeable differences. In conclusion, it was found that fenugreek cotyledon extract supplementation has the potential to improve milk production and improve feed efficiency under controlled, as well as under commercial conditions. Furthermore, Nutrifen®, being a natural product, was used successfully instead of ionophores in the diets of dairy cows. As a second outcome of the first study (Trial 1), blood samples were collected on the final day of the trial from the coccygeal vein of eight top producing cows per treatment group. Blood was drawn at two time intervals, before feeding (0h) and six hours after feeding (6h). Using ELIZA kits, the plasma bovine growth hormone (bGH) concentration was determined. As the analysis kits could only accommodate a limited number of samples, the plasma of only six cows per treatment could be analysed. There were no significant differences in bGH concentration between treatments at either of the post-feeding times. Concentrations also varied greatly within treatment groups. The observed variation may be influenced by the rhythmic secretory pattern of GH. This could make it difficult to gain insightful understanding of changes in GH concentrations from single timepoint observations. From the current study it was not possible to link the observed effects on milk production and improved feed efficiency to changes in GH concentration. However, the documented and observed effects of fenugreek supplementation on milk production and efficiency bares close resemblance to that of rBST treatment and the homeorhetic nature of growth hormone (somatotropin) in dairy cattle.