The effect of bulky supplementary feeds on the intake of silage by dairy cows

Sabri, Mahmood Shaker (1987) The effect of bulky supplementary feeds on the intake of silage by dairy cows. MSc(R) thesis, University of Glasgow.

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Abstract

The literature is reviewed on silage production; voluntary intake of grass silage by ruminants; and on the growing and feeding of fodder beet. Three dairy cow feeding experiments were carried out: in Experiment 1 a study was made of the effects of feeding fodder beet with two levels of concentrate: Experiment 2 examined the feeding of high levels of fodder beet: and in Experiment 3 the effect of feeding fodder beet with two protein levels in the concentrate were examined. In a 12 week cyclic changeover design experiment with 12 British Friesian cows the effect of feeding fodder beet (Kyros) at three levels (0, 2 and 4 kg DM d-1) and two levels of concentrate (4 and 8 kg DM d-1) with ad libitum silage were examined. Silage dry matter intake was decreased when fodder beet was fed but total dry matter intake was increased. There were no significant effects on milk yield, milk composition, liveweight and liveweight change. There was a significant Increase in milk protein yield. There was no significant interaction between level of fodder beet feeding and level of concentrate. Experiment 2 examined the effects of feeding fodder beet (Kyros) at up to 6 kg DM d-1 on feed intake and cow performance. Feeding fodder beet increased total dry matter intake and decreased silage intake, improved milk fat yield, but there were no significant effects on milk yield or milk composition. There were no digestive disturbances recorded at any level of fodder beet feeding and there were no refusals of fodder beet. Experiment 3 was also a changeover design with three 3-week periods. The effects of feeding fodder beet (Trestel) with two levels of protein in the concentrate, low (129 g kg-1 DM) and high (229 g kg-1 DM) with ad libitum silage were examined. Silage dry matter intake decreased when fodder beet was fed with both the low and high protein content, but the total dry matter intake was increased. Feeding fodder beet with the high protein concentrate significantly increased milk yield, milk composition, milk yield constituents compared to the zero fodder beet/low protein treatment. There were no significant effects on liveweight or liveweight change. Experimental work was also carried out at the metabolism unit (Auchincruive) to evaluate the digestibility of fodder beet and the effect on rumen fermentation. Six Suffolk X Grey Face wether sheep (average liveweight 55 kg) were allocated to a cross over design to measure the digestibility of organic matter and gross energy of fodder beet in vivo. Fodder beet was fed at two levels with a complete standard diet. They were both supplemented with urea and minerals to meet requirements. Measurements of feed Intake and faecal output were taken over the last nine days of a 21 day period. The mean values obtained were: organic matter digestibility 0.962; gross energy digestibility 0.953; organic matter 924 g kg-1 DM, and ME 13.1 MJ kg-1 DM. The nylon bag technique described by Orskov and Mehrez (1977) was used to estimate the effect of feeding fodder beet on hay dry matter disappearance from nylon bags. Using 3 sheep fitted with permanent rumen canulae, the pH and VFA concentration in the rumen were measured when fodder beet (FB) was fed and compared with two control diets, barley/maize (BM) and sugar beet shreds (SBP). Hay was fed with all three diets in the ratio 50:50 on a DM basis. The rumen pH with feeding FB was 6.34 this value was intermediate between SBP 6.38 and BM 6.20. Hay dry matter disappearance from nylon bags feeding FB was Intermediate between SBP and BM. In a second experiment 3 wether sheep fitted with permanent rumen cannulae were used to calculate the organic matter disappearance of fodder beet. The sheep were fed standard diets (900 g DM hay + 200 g DM compound feed). The organic matter disappearance of fodder beet from nylon bags was very high compared with barley/maize, molassed sugar beet shreds and hay.

Item Type: Thesis (MSc(R))
Qualification Level: Masters
Additional Information: Adviser: D J Roberts
Keywords: Animal sciences
Date of Award: 1987
Depositing User: Enlighten Team
Unique ID: glathesis:1987-72284
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 24 May 2019 15:12
Last Modified: 24 May 2019 15:12
URI: http://theses.gla.ac.uk/id/eprint/72284

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