Silage and milk production: a comparison between soya, groundnut and single‐cell protein as silage supplements

Abstract

Grass silage made in May from S24 perennial ryegrass was offered ad libitum to twelve Ayrshire cows in a 12-week feeding experiment. The silage had a DM concentration of 217 g kg ~', contained 147 g crude protein per kg DM and had a D-value of 64-6. In addition each cow consumed 1 kg hay per d plus concentrate supplements of dried sugar-beet pulp with (A) soya bean meal, (B) 'Pruteen', a single-cell protein (C) groundnut cake. The three concentrate supplements each contained 250 g crude protein per kg DM and were offered at the rate of 2-9 kg per 10 kg milk. The daily intakes of silage DM were 8-38, 7 94 and 7 49 kg on treatments A, B and C, respectively, with the extreme values being significantly different. The mean daily yields of milk on treatments A and B were both 16 2 kg per cow, and were significantly higher than the yield of 15 2 kg per cow on treatment C. The fat and lactose contents of the milk on the three treatments were not significantly different, but the CP content on treatment C was significantly lower than that on the other treatments. It is concluded that soya bean meal and 'Pruteen' were superior to groundnut cake as a protein supplement in a silage-based ration.

Silage and milk production: a comparison between long, chopped and ground hays as supplements to silage of high digestibility

“…However, when the cows were receiving the high rate of concentrate feeding the differences between the intakes of hay in the different forms were reduced, and the advantage in intake ofthe ground and cubed hay over the long hay was not significant. When silage chop-length is decreased silage intake generally increases (Castle et al, 1979), but this effect was not seen when comparing the long and chopped hays in the present experiment. The silage and the short hay were both chopped by the same forage harvester at the same chop-length setting and the median chop lengths were 12-4 and 12-1 mm respectively.…”

“…In a series of feeding experiments at this Institute with grass silages of high digestibility, a range of supplements including barley, dried grass and protein feeds have been investigated (Castle and Watson, 1975;1976;1979;Castle et al, 1977). The dried grass was of particular value in maintaining a high voluntary intake of silage, and this attribute of dried grass compared with barley was shown also by Tayler and Aston (1974) and Mcllmoyle et al (1975).…”

Evaluation of the nutritive value of single-cell protein (Pruteen) for lactating dairy cows

“…Furthermore, the mean milk yield with these N supplements was higher than that obtained with the urea-supplemented rations or with the control ration, although this effect was not significant statistically. Milk composition was not noticeably affected in the present experiments when Pruteen was substituted for soya-bean meal, a result also in accordance with those of Castle & Watson (1979). The percentage of milk nitrogen present in a non-protein form was not affected by the dietary nitrogen source, but was significantly correlated with the crude protein content of the dry matter ingested.…”

“…The incorporation of Pruteen into the rations did not adversely affect feed intake, nor did it significantly change metabolizable energy concentration in dry matter. Castle & Watson (1979) noted no difference in milk production of cows receiving about 25 % of total dietary nitrogen as Pruteen or soya-bean meal, but both N supplements were superior to groundnut cake. Our results for the yields of fat-corrected milk recorded with the first two supplements strengthen these observations.…”

“…It is nQt clear why the animals deposited such large amounts of protein under the latter conditions. Castle & Watson (1979) stated a more efficient utilization of metaboliz^ble energy for milk production with the Prut0en-supplemented rations than with those supplemented with soya-bean meal. No statistically significant difference was found in our trials, though the ratio FCM/metabolizable energy tended to be higher with the singlecell protein in Expt 1, but not in Expt 2.…”