ALBERT

Description: SUMMARYThe effect of herbage allowance on the intake and performance of Scottish Half bred ewes with twin lambs was investigated over the first 16 weeks of lactation. Herbage allowances were defined as g herbage D.M./kg live weight (LW)/day, and were maintained by provision of fresh areas of ungrazed sward each day.Herbage allowances in the range 25–120 g D.M./kg LW/day were offered on an area of perennial ryegrass (Lolium perenne cv. S. 23). Parturition was synchronized and ewes and lambs were turned out to pasture 1 day after lambing.Measurements were made of the herbage intake, live-weight change and milk yield of ewes, of lamb growth rates and of the herbage intake of lambs from 10 weeks of age.Herbage allowance had a significant linear effect on intakes of grass by ewes and lambs. The highest intakes by the ewes were achieved during the second week, and were in the range 23–43 g OM/kg LW/day. Intakes declined, as lactation proceeded, to 19–29 g OM/kg LW/day at week 12. Intakes of lambs were similar in weeks 10 and 12 and were in the range 17–24 g OM/kg LW/day. Allowance had a significant effect on live-weight change of the ewes after the first month and upon final body condition.There was no effect of allowance on milk yield until week 6. Mean milk yields were 2·3 kg/day at day 14, 1·0–1·5 kg/day at day 42 and 0·7–1·1 kg/day at day 84. There was a positive effect of allowance on growth rates of the lambs after the first month. Mean overall growth rates to 84 days of age were 175–243 g/day.

Description: SummaryThe effect of daily herbage allowance on herbage intakes and growth rates lambs grazing perennial ryegrass and red clover was investigated in two experiments. Herbage allowances defined as g herbage D.M./kg live weight (LW)/day were controlled by varying the areas of plots grazed for 2 days by groups of six lambs.In the first experiment five herbage allowances in the range 20–120 g D.M./kg LW/day were offered on two areas of a perennial ryegrass (cv. S. 23) sward that received nitrogen fertilizer applications of 39 or 78 kg N/ha/28 days. In the second experiment five herbage allowances in the range 30–160 g D.M./kg LW/day were offered on perennial ryegrass (cv. S. 23) and red clover (cv. Hungaropoly) swards.Asymptotic curves were fitted to describe the relationship between herbage allowance and daily intake of herbage. In Expt 1 nitrogen fertilizer rates did not affect the yield of herbage or animal performance. In Expt 2 intakes were higher on the clover sward than on the ryegrass sward at the higher herbage allowances.The asymptotic curves to describe the relationship between herbage allowance and growth rate of lambs differed widely between periods. Growth rate of the lambs increased linearly with increase in digestible organic matter intake. Live-weight gain per unit of digestible organic matter intake was higher on the red clover than on the ryegrass.The conclusion is drawn that if the herbage present to ground level is not more than three times the daily intake of the animals, intake of herbage of the animals may bo restricted.

Description: SUMMARYThe effects of temperature and method of feeding on the intake characteristics and digestibilities of two milk substitutes were examined.Forty Finnish Landrace x Dorset Horn lambs (20 males and 20 females) were fed one of two milk substitutes from 3 to 25 days of age when they were slaughtered and chemical composition of the empty body was measured.The two milk substitutes contained 30% fat in the dry matter as butter fat (diet B), or tallow and coconut oil (diet TC).The diets were offered at either 34°C (W) or 5 °C (C) and three methods of feeding were used. The diets were given: ad libitumcold (AL1), four feeds to appetite per day either warm or cold (AL2W and AL2C) and four feeds restricted to an intake of 62 g D.M./kg live weight0·5 either warm or cold (RW or RC).Digestibilities of the milk substitutes were not affected by the temperature at which they were offered or the feeding regime used. Diet B had an apparent dry-matter digestibility of 97·6% and diet TC 92·5%. The fat digestibility of diet TC was 13·6 units lower than diet B and this affected the digestibility of all the other dietary components.Lambs tended to consume more of diet B and grow faster.Lambs on treatment AL1 consumed 21% more milk substitute than those on treatment AL2.The composition of the body-weight gain was found to alter with rate of gain.The temperature at which the milk substitutes were offered had only a minor effect on the performance of the lambs. The type of milk substitute and feeding regime used had a greater influence on both lamb intake and growth.

Description: SUMMARYThe effects of heat treatment, as measured by undenatured non-casein nitrogen (NCN gN/100 g total N), and of protein: energy ratio on the digestibility coefficients and utilization of milk substitutes by lambs were investigated.Twenty-four Finnish Landrace × Dorset Horn lambs (12 males and 12 females) were given milk substitute diets in which approximately 20 or 30% of the gross energy was supplied by protein (PE20 and PE30). NCN levels were approximately 7, 12, 18 and 5, 11, 16 for diets PE20 and PE30 respectively.All lambs were offered a daily allowance of milk substitutes containing 7·95 MJ of gross energy from 3 to 25 days of age, when they were slaughtered and the chemical composition of the empty body was measured. Gains in the chemical components were measured using the comparative slaughter technique.For each unit increase in NCN value there was an increase in the apparent digestibility coefficients of dry matter (D.M.), crude protein (CP) and ash of 0·13, 0·13 and 0·93 percentage units, respectively. The apparent digestibility coefficients of all the dietary components, except lactose increased by 0·24 (d.m.), 0·24 (CP), 0·63 (fat), 0·75 (ash) and 0·32 (energy) percentage units and the metabolizability by 0·24 units for each 1% increase in PE.Live-weight and empty body-weight gains increased with increasing PE and NCN. Lambs receiving diets PE20 had a daily live-weight gain 42 g less than those on diets PE30; increasing NCN from 5 to 18 gN/100 g total nitrogen, increased live-weight gain by 33 g/day.Increasing PE and NCN increased water gain and nitrogen retention; increasing PE also increased ash retention and decreased fat gain.Lambs on diets PE20 contained more fat and less protein, at the same empty body weight, than those receiving diets PE30.Efficiencies of conversion of dry matter and energy to live-weight gain, and energy and N utilization all increased with increasing NCN, but increasing PE did not affect energy utilization and decreased N utilization.Female lambs had lower growth rates than males (—14·5 g/day) and had a higher total fat gain (128 g).