The experiment assessed the effects on performance from calving to the 20th week of lactation of milking cows three times daily (3 × ) compared to milking twice daily (2 × ). After 20 weeks all cows were milked 2 ×. Each treatment consisted of 18 cows and 11 heifers. The mid-calving date was 21 September 1979.Complete diets of the same composition were offered separately to each group in quantities equivalent to 1040 g/kg of their previous intake. The diet for the first 18 weeks of lactation was estimated to have an energy concentration within the range 11·0 to 11·3 MJ metabolizable energy per kg dry matter. After 18 weeks, the diet was reformulated to reduce the energy concentration to 10·3 MJ per kg dry matter. Total food intakes for the 20 weeks of treatment were 2352 kg dry matter (3 ×) and 2241 kg dry matter (2 ×). From 8 April 1980 the cows were turned out to grass to complete their lactations.During the 20 weeks the mean daily milk yields of heifers were 19·3kg (3×) and 171kg (2×) (P<005). Cow yields were 28·4 (3×) and 23·9 kg (2×) (P< 0·001) during the same period. After 3× daily milking ceased, there were some positive carry-over effects on milk yield and food intake.Lactation yields from heifers were 4881 (3 ×) and 4498 kg (2×), whilst for cows the equivalent yields were 6485 (3 ×) and 5694 kg (2 ×) (P<0·01). There were no significant differences in milk quality. At 20 weeks after calving the cows milked 3 × daily had gained less weight, but by 44 weeks from calving the weight gains were similar at 42 (3 ×) and 45 kg (2 ×).

A system of feeding concentrates at a flat rate was compared with a step system in which the rate was reduced every 6 weeks. Each system was evaluated at either medium or high level concentrates. There were two trials involving 40 British Friesian cows for weeks 3 to 20 of lactation. The flat rate treatments were 71 (medium) and 9·3 kg dry matter (DM) per day (high) and corresponding step allocations were 8·8, 7·1 and 5·4 kg DM per day or 11·7, 9·3 and 7·0 kg DM per day. Silage was given to appetite. In trial 1 this was lucerne silage of moderate quality (metabolizable energy (ME) = 8·9 MJ/kg DM) and in trial 2 high quality grass silage (ME = 11·1 MJ/kg DM) was used.In the comparison between systems of concentrate allocation, food intakes, milk production and live-weight change were similar in each trial. In the comparison between medium or high levels of concentrates, silage DM intakes were similar in trial 1 (7·1 v. 7·0 kg/day) but not in trial 2 (9·8 v. 8·7 kg·day, P < 0·05), and milk yields were lower in trial 1 (19·0 v. 21·4 kg/day, P < 0·001) but not in trial 2 (24·1 v. 25·2 kg/day). Milk composition was similar for medium and high concentrate intakes in both trials. Cows given the medium level of concentrates had higher live-weight losses than those given the high level in trial 1 (–58 v. –24 kg, P < 0·01) and trial 2 (–22 v. –kg). When concentrates were given at the medium level with moderate quality silage several cows had acetonaemia. Also, this feeding combination, especially when concentrates were given at a flat rate, reduced the proportion of cows which conceived within a limited breeding period.

ObjectiveAge is sometimes a barrier for acceptance of patients into a hospital‐based obesity service. Our aim was to explore the effect of age on the ability to lose weight through lifestyle interventions, implemented within a hospital‐based obesity service.DesignRetrospective study.PatientsWe included a cohort of randomly selected patients with morbid obesity (n = 242), who attended our hospital‐based obesity service during 2005‐2016 and received only lifestyle weight loss interventions.MeasurementsPrimary outcome measures were percentage weight loss (%WL) and percentage reduction in body mass index (%rBMI) following implemented lifestyle interventions. Data were stratified according to patient age at referral: group 1 (age < 60 years, n = 167) and group 2 (age ≥ 60 years, n = 75). Weight loss was compared between groups, and correlations with age at referral were explored.ResultsThe duration of hospital‐based weight loss interventions ranged between 1 and 143 months (mean: 38.9 months; SD: 32.3). Baseline BMI at referral differed significantly between groups 1 and 2 (49.7 kgm−2 [SD: 8.7] vs 46.9 kgm−2 [SD: 6.1], respectively; P < .05). Following implemented lifestyle interventions, between groups 1 and 2 there were no differences in %WL (6.9% [SD: 16.7] vs 7.3% [SD: 11.60], respectively; P = NS) or %rBMI (8.1% [SD: 14.9] vs 7.8% [SD: 11.7], respectively; p = NS). Overall, there was no significant correlation between patient age at referral and %WL (r = −.13, p = NS).ConclusionsOlder age does not influence the success of weight loss through the implementation of lifestyle modification within a hospital‐based obesity service. Therefore, age per se should not influence clinical decisions regarding acceptance of patients to hospital‐based obesity services.

I . An experiment is reported in which groups of six lambs were fed two basal diets supplemented at three levels with a mixture of sodium and calcium acetates.2. The basal diets were given in amounts that provided equal intakes of digestible organic matter and crude protein. One contained 85 % of concentrates (Hc), the other 40% of concentrates (Lc). Rumen contents from a sheep receiving diet Hc contained a lower molar proportion of acetate and higher proportions of propionate and butyrate than when diet Lc was given.3. The calculated metabolizable energy of the basal Hc diet was utilized more efficiently than that of the basal Lc diet, for promoting empty body-weight and carcass-weight gains.4. On both basal diets, lambs receiving the diets supplemented with acetate made greater live-weight, empty body-weight and carcass-weight gains than lambs given unsupplemented diets. The responses of weight gain to increasing levels of acetate were linear.5 . The responses to acetate were greater when it was given with the Hc diet than with the Lc diet. This effect was most marked for live-weight gain ( P < o.oor), intermediate for empty body-weight gain ( P < 0 . 0 5 )~ but not significant for carcass-weight gain. This order of effects was in part due to a greater weight of alimentary tract tissue, and its contents, in lambs fed the Hc diet supplemented with acetate. 6. It is concluded that under certain circumstances the energy of acetate may be utilized less efficiently than energy from propionate or butyrate.Conflicting results have been recorded from experiments in which the utilization of acetate for growth has been compared with that of propionate or butyrate. Armstrong & Blaxter (1957) and Armstrong, Blaxter, Graham & Wainman (1958) found that when acetic acid was infused into the rumen of sheep, its utilization for lipogenesis was less than that of propionic or butyric acid. Poor utilization was associated with a high heat increment, some of the reasons for which were indicated by McClymont (1952).In previous experiments of this series where salts of volatile fatty acids (VFA) were fed to growing lambs, 0rskov & Allen (1966a, b, c) and 0rskov, Hovel1 & Allen (1966) found no differences in the efficiency of utilization of energy from salts of different acids. In one experiment (0rskov & Allen, 1 9 6 6~) a high-roughage diet promoted lower weight gains than a high-concentrate diet; associated with this effect was a greater molar proportion of acetic acid in the rumen liquor of lambs fed the high-roughage diet. It was postulated that the poorer utilization of energy in this experiment might be associated with losses of energy in the formation of acetic acid rather than in its subsequent utilization.

In each of 2 years, 20 Friesian cows were given either a low-energy or a high-energy complete diet to appetite during weeks 3 to 20 of lactation. The diets for trial 1 contained concentrates, lucerne silage and chopped grass hay in the proportions 33:47:20 or 58:29:13. In trial 2, concentrates and lucerne silage were mixed in the proportions 38:62 or 75:25. These mixtures had energy concentrations of 10·2 or 11·2 and 10·3 or 11·9 MJ metabolizable energy per kg dry matter (DM) and crude protein concentrations of 144 or 160 and 140 or 157 g/kg DM in the low- and high-energy diets of trials 1 and 2 respectively.Cows offered the low-energy diet consumed less DM daily (14·5 v. 17·4 (P < 0·001) and 15·2 v. 18·2 (P < 0·001) kg DM per day in trials 1 and 2). Daily milk yields were lower with low-energy diets (19·2 v. 22·3 (P < 0·001) and 18·7 v. 24·2 (P < 0·001) kg/day in trials 1 and 2), and there were significant differences between treatments in milk composition and live-weight changes.The correlation between food intake and milk yield during weeks 3 to 20 was moderately strong (r2 = 0·58). Variation in food utilization efficiency between diets and parity groups was small in comparison to variation within parity groups.During weeks 21 to 44 of lactation the cows were at grass. In trial 2, but not in trial 1, cows previously given the low-energy diet gave less milk (1999 v. 2644 (P < 0·001) kg) but gained more live weight. There were also differences in the composition of milk produced in this period.