Forty pigs (half each of females and entire males) were used in an ad libitum feeding experiment from weaning to 33 kg live weight (LW). In period 1 to 16 kg LW, the pigs had either food L (134 g crude protein (CP) per kg) or food H (278 g CP per kg) alone. The aim was to delay the growth of pigs on L and create two groups of pigs with different body compositions. At 16 kg LW, eight pigs were killed and their empty bodies chemically analysed. The pigs given L had 1·06 (s.e. 0·08) kg more lipid and a lower protein: ash ratio in their empty body than pigs on H; growth rates, from 9 to 16 kg LW, were 386 (L) and 591 (H) (s.e.d. 17)g/day. Both aims were thus achieved.

In period 2 the pigs previously given L (no. = 16) or H (no. = 16) in period 1, were given L alone (no. = 4), H alone (no. = 4) or a choice between L and H (no. = 8) to 33 kg LW when the choice-fed pigs were killed and their empty bodies chemically analysed. The objective of the experiment was to test the idea that pigs previously given a food deficient in CP, when given a choice between foods, one of high and one of low, protein content will select a diet of a composition that allows them to correct the effects of the previous mis-feeding. The pigs given L alone in period 2 grew more slowly, and ate more per day, than those given H alone, with no effect of the food given in period 1. Of those given H alone in period 2, the pigs previously given L grew faster, and were more efficient, than those previously given H.

The protein contents (g CP per kg food) of the diets selected by the choice-fed pigs were significantly affected by both sex (228 for males v. 181 for females; s.e.d. 15) and the food given in period 1 (233 for L and 175 for H; s.e.d. 15) with no significant interaction between these factors. The pigs from L grew faster (1039 v. 780 (s.e.d. 70) g/day) had a higher daily food intake (1420 v. 1319 (s.e.d. 71) g/day) and were more efficient (0·736 v. 0·595 (s.e.d. 0·034) g gain per g food) than those from H. At 33 kg LW lipid weights were similar for the two period 1 treatments (L had 0·40 (s.e. 0·54) kg more lipid than H); females had 1·79 (s.e. 0·54) kg more lipid than males.

It is concluded that, where pigs are given a choice between foods of low and high protein contents, they will select a diet of a composition such that the effects of previous mis-feeding are corrected. Giving pigs a choice between an appropriate pair of foods allows them to select a diet of a composition suitable for their needs.

Eleven sun-cured hays with crude protein (CP) and neutral-detergent fibre (NDF) concentrations ranging from 57 to 207 and 428 to 744 g/kg dry matter (DM) respectively, were used to study the relationship between the DM and NDF degradation characteristics and the voluntary DM intake (VDMI) by sheep.

The VDMI was measured in the last 10 days of a 21-day period using 50 mature ewes in five groups of 10 ewes per group, with a mean live weight (LAY) of 55 kg and ranged from 41·2 to 69·8 g/day per kg LW075. Disappearanc e rates of DM and NDF were measured by incubating samples in nylon bags in the rumens of three hay-fed rumen-cannulated ewes for 3, 6, 9, 15, 24, 48 and 72 h and by fitting the exponential model Y = a + b (1 — e-ct) to the results. Potential degradabilities (defined as a + b) for DM and NDF ranged from 679 to 868 and from 445 to 808 g/kg respectively.

The VDMI was significantly correlated with the soluble fraction of DM (aDM; P < 0·05) and the rate of degradation of DM (cDM; P < 0·01) and NDF (cNDF; P < 0·01). The inclusion of aDM and cDM ni a multiple regression model resulted in the equation: VDMI = 21·3 + 0·0733 (s.e. 0·01577) aDM + 138 (s.e. 26·0) cDM (R2 = 0·897; residual s.d. = 2·79), with a significant increase of the variance explained by one single degradation characteristic (P < 0·05). The prediction was not improved by adding the constant cNDF to the equation (P > 0·05). These results indicate the possibility of predicting the VDMI of hays by sheep from the rumen soluble fraction (aDM) and the rate of degradation (cDM) of DM.

Thirty-seven Cambridge (C) and Suffolk (S) × C ewes and their lambs were housed and penned individually in family groups for 35 days post partum and then grazed on pasture until the lambs reached slaughter weight. Lambs were reared as twins (TR-TW). The lambs weaned at 35 days were artificially reared and formed the TR-AR group.

Dry matter intake of the complete diet and hay offered ad libitum during the housing period was unaffected by rearing type. TR-TR and TR-TW ewes produced more milk at 10 days than TW-TW ewes, 4·4 and 4·2 v. 3·6 (s.e.d. 0·257) kg/day. From 35 days onwards the decline in milk yield tended o t be greater in the TW-TW and TR-TW ewes which also gained more condition than TR-TR ewes, 0·33 and 0·37 v. 0·01 (s.e.d. 0·139) of a score.

TW-TW lambs grew faster than TR-TW and TR-TR lambs during the housed period, 336 v. 295 and 292 (s.e.d. 9·8) g/day but after 35 days TR-TW, TR-AR and TW-TW lambs had similar growth rates, 348, 350, and 348 (s.e.d. 14·2) g/day respectively whereas TR-TR lambs grew less quickly at 310 g/day. Forty-two male lambs were slaughtered. TR-AR lambs had a higher killing-out proportion and carcass fat content than naturally reared animals. In the latter group carcass fat content was negatively related to time reared as triplets and the kidney knob and channel fat weight was significantly lower in the TR-TR group. Crossbred lambs grew faster, had a higher killing-out proportion and greater weight of m. longissimus dorsi and m. psoas major in the half carcass.

It is concluded that weaning one lamb at 35 days provides a suitable alternative system for rearing triplets and that it is possible to produce good quality carcasses with some desirable reduction in fat content from lambs reared as triplets throughout their life.

A total of 805 Lacombe pigs of different genotype with respect to halothane sensitivity (halothane positive, nn = 205; heterozygote, Nn = 214; halothane negative, NN = 386) were slaughtered over a range in live weight (70 to 120 kg) to assess tissue growth patterns using the allometric equation (y = aXh). The nn genotype was older at slaughter than the NN genotype, but pigs from each genotype were killed over a similar weight range. The relative growth of the primal cuts was influenced by genotype, with nn pigs having a lower coefficient for the bottom shoulder (picnic) and a higher coefficient for the belly. The relative growth of bone was similar for genotypes (P > 0·05) but the relative growth of lean was lower and the relative growth of total fat and depot fat (subcutaneous and intermuscular) was higher for the nn genotype compared with the Nn and NN genotypes. On a within-tissue basis, the relative growth of the tissues in each primal was similar, except for the ham, where the relative growth of lean was higher for nn pigs compared with the two other genotypes. Small differences in tissue distribution were evident, but seldom exceeded 30 g/kg. Although nn pigs had a higher lean content and higher lean: bone ratio than Nn or NN pigs at similar live weights, their relative advantage in composition decreased with increasing live weight.

The variation of protein fractions in the milk of indigenous Greek goats fCapra prisca) during the milking period was studied. Total nitrogen (TN), non-casein or soluble nitrogen (SN), rennet whey nitrogen (WN), non-protein nitrogen (NPN) were determined and from these analyses crude protein (CP), true protein (TP), casein (Cas) rennet casein or coagulable protein (Coag P) were calculated. The NPN component is lost during the cheese process whereas Cas and Coag P are important constituents of the cheese itself. The ratios NPNICP, CaslTP and Coag PITP throughout milking, were for the groups A and B 0·0646 and 0·0648 (s.e.d. = 0·00025), 0·846 and 0·845 (s.e.d. = 0·0141) and 0·916 and 0·904 (s.e.d. = 0·0112), respectively, suggesting a high level of suitability for conversion of milk into cheese.

Continuously grazed rye grassl clover swards with surface heights of 8 to 10 cm at 5 weeks before a synchronized mating and 7·5 cm at mating were grazed by 151 Greyface ewes stocked at 12 per ha until mating. The effects of two stocking rates (eight and 16 ewes per ha) for 6 weeks over the mating and post-mating period were then studied on live weight, body condition and reproductive peformance. Sward height fell more rapidly post mating when stocked at 16 ewes per ha than at eight ewes per ha, but remained above 3·5 cm until 4 weeks after first mating under both rates. Ewes stocked at 16 per ha became significantly lighter and leaner than ewes stocked at eight per ha. There was no significant effect of post-mating stocking rate on reproductive performance in terms of conception rate and lambing rate to first mating or lambing rate to all matings. Reproductive performance of Greyface ewes is therefore unlikely to be adversely affected by post-mating stocking rate on swards of 7 to 8 cm which do not fall below 3·5 to 4·0 cm until 3 to 4 weeks after mating.

Over 4 years, a flock of mature North Country Cheviot ewes was grazed on different swards between weaning in August and mid October to achieve a range of condition scores at 5 weeks before mating (post-weaning period). During the subsequent 5 weeks before a synchronized mating (pre-mating period), all ewes were grazed on a perennial ryegrass/white clover sward, provided at high (H) or low (L) herbage masses (1600 to 2100 or 1200 to 1400 kg dry matter (DM) per ha, respectively). Ovulation rate was derived from the number of corpora lutea in 101 ewes slaughtered after first mating. Conception and lambing rates were derived from the number of lambs born to first mating of 406 ewes. In 2 out of the 4 years, 79 ewes were used to estimate herbage intake.

There was no effect of post-weaning management on reproductive performance. Herbage intake and reproductive performance were examined in relation to the body condition of the ewes at 5 weeks before mating. On an H herbage mass pre-mating, herbage intake in the period immediately prior to mating was greatest in ewes in low body condition and declined significantly with increasing condition. On an L herbage mass pre-mating, herbage intake did not vary significantly with condition. Ovulation rate was low in ewes in low body condition (scores =≤·25) at 5 weeks before mating, increased significantly with increasing condition up to scores 2·50/2·75 but did not change significantly above such intermediate scores. Conception and lambing rates increased significantly with increasing body condition up to scores 2·50/2·75 and then decreased significantly as condition increased above these levels. These effects of body condition were greater on an L herbage mass pre-mating than they were on an H herbage mass. Ewes in the intermediate body condition scores of 2·50 and 2·75 at 5 weeks before mating had a low sensitivity to contemporary nutrition pre-mating. Such condition levels are therefore considered to be above the range of condition in the North Country Cheviot breed within which reproductive response is affected by contemporary nutrition pre-mating.

The lower reproductive performance of ewes in high body condition (scores 3=3·00) at 5 weeks before mating was related to an increase in estimated ova and embryo loss and may be associated with a reduced herbage intake.

An experiment was conducted to study the effect of feeding level and semen collection frequency on semen quantity and quality of 62 Yorkshire boars at two artificial insemination centres during 10 successive periods of 2 weeks. The experiment had a 2 × 2 factorial design with two feeding levels (2·75 and 3·5 kg/day) and two semen collection frequencies (three and five times in 2 weeks).

In the first 2-week period boars on the high frequency semen collection scheme produced 94 × 109 sperm cells more than boars on the low scheme. In periods 2 to 10 the mean difference was only 18 × 109 sperm cells. Boars on the high feeding level produced 32 × 109 sperm cells more per 2-week period than the boars on the low feeding level (P < 0·05). Boars at the high collection frequency and the high feeding level tended to produce a higher number of sperm cells during periods 2 to 10 than the boars on the high semen collection frequency and the low feeding level (P > 0·05). No effects of food intake or semen collection frequency on semen quality were found.

Ultrasonic probe data were available on 199 crossbred pigs (98 females, 101 barrows). These animals were probed at approximately 30, 50, 70, 100 and 120 kg live weight with two probing instruments (Krautkramer USM2, Combison 310) at three sites along the back. The measurements were examined as predictors of the proportion of valuable cuts (part dissection) and estimated lean concentration (at 100 and 120 kg live weight).

The standard deviations for proportion of valuable cuts (after correcting for sex effects) were 24·8, 26·7, 23·4, 27·1 and 29·4 g/kg at 30, 50, 70, 100 and 120 kg. Residual s.d. for predicting proportion of valuable cuts from live weight and ultrasonic probes (Combison, quotient fat to muscle area) were 190, 20·9, 19·3, 213 and 19·6. For the USM2, the residual s.d.s were 19·2, 26·3, 19·9, 25·1 and 24·6. Thus the Combison probe provided a better prediction of proportion of valuable cuts. The standard deviations of estimated lean concentration as determined by a Fat-O-Meater reflectance probe were 28·9 and 39·3 at 100 and 120 kg live weight. The residual s.d.s from live weight and ultrasonic measurements were 15·4 and 19·2 for the Combison probe and 21·5 and 20·5 for the USM2 probe. If the estimated lean concentration is accepted as a selection objective the value of ultrasonic probes as criteria in selection indices will increase.

The effects of high-low (HL) and low-high (LH) patterns of nutrition during the 5 weeks prior to a synchronized mating were studied on the reproductive performance of 115 Welsh Mountain and 114 Brecknock Cheviot ewes in a range of body condition at the start of treatment. For 2 months prior to treatment imposition, ewes were grazed in a systematic way at different stocking rates on different sward heights to obtain a range of body condition scores. Target score groupings were 2·00 to 2·25, 2·50 to 2·75 and 3·00 to 3·25 and although scores of 1·50 to 3·25 were obtained, most lay in the 2·00 to 2·75 range. Two treatment groups, balanced for live weight and body condition score, received high and low levels of nutrition for 16 days from mid October, achieved, respectively, by a low stocking rate on a sward with a high surface height plus ad libitum concentrate and a high stocking rate on a sward with a low surface height plus 200 g hay per head per day. Treatments were then reversed for the 17 days prior to mating. Live-weight and body condition-score changes were recorded and reproductive performance at first mating was measured from counts of corpora lutea and viable embryos at slaughter either at return to service or at 4 weeks after first mating. There were no differences due to nutritional pattern in live weight or body condition score at mating. The LH treatment significantly increased the rates of ovulation, conception, multiple ova survival and potential lambing per ewe pregnant and per ewe mated in the Welsh Mountain breed but significantly increased only the rates of ovulation and potential lambing per ewe pregnant in the Brecknock Cheviot breed compared with the HL treatment. The relatively poorer response in the latter breed was partially due to a lower ovulation rate potential coupled with non-significantly lower rates of conception and survival of single-shed ova associated with the LH treatment. Much of this relatively poorer reproductive performance in the Brecknock Cheviot breed was in ewes with body condition scores 3= 2·75. Reproductive performance increased with increasing body condition at the start of treatment over the range of scores =≤ 2·25 to 2·50 in both breeds and, while continuing to improve in scores above 2·50 in the Welsh Mountain breed, in the Brecknock Cheviot breed it started to decline. Ewes with a body condition score of 2·50 in both breeds showed the greatest response in potential lambing rate to the LH treatment.

Thirty-nine Charolais × (Hereford × Friesian) autumn-born calves, whose dams had been given either 92 or 63 MJ metabolizable energy per day during winter and subsequently grazed at two sward heights, either 4-8 (short) or 7·6 (tall) cm from 6 May until weaning on 3 July in a factorially designed experiment, were used to examine the effect of pre-weaning performance on post-weaning growth rates. Following weaning the calves grazed as one group for a period of 76 days. There was no effect of winter treatment on postweaning performance. From weaning until 76 days later there was a significant (P < 0·01) effect of pre-weaning sward height on live-weight gain (0·94 and 0·69 kg/day for the calves from the short and tall swards respectively), so that the 41 kg liveweight difference at weaning was reduced to 22 kg (P > 0·05) with compensatory growth occurring independently of the height of the sward grazed.

An experiment was conducted to study the ability of the pig to recover from the effects of a period on a food deficient in crude protein (CP). Forty young pigs were given free and continuous access to foods with either 150 (L) or 252 (M) g CP per kg in period 1 of the experiment, from 6·3 kg to 13·4 and 12·3 kg live weight respectively. These live weights were expected to give equal lipid-free empty body weights. In period 2, four males and four females from each of the period 1 treatments were given access to either M or a food with 377 g CP per kg (H) to a live weight of 30 kg, when the 32 pigs were killed.

Pigs on L took 11 (s.e. 0·6) days longer to complete period 1, and had, at the end of this period, 0·20 (s.e. 0·03) kg less protein and 1·20 (s.e. 0·06) kg more lipid in their bodies than the M pigs, at a common ash weight. In period 2, pigs from L grew at a faster rate (750 v. 633 (s.e.d. 20) g/day), ate food at the same rate (1115 v. 1085 (s.e.d. 35) g/day) and converted food more efficiently (0·676 v. 0·585 (s.e.d. 0·016) g gain per g food) than those from M. At 30·3 kg live weight the pigs from L had corrected their protein deficit relative to ash and reduced their fatness, so that they had the same protein: ash ratio and only 0·47 (s.e. 0·12) kg more lipid in their bodies than those from M. This was the result of a higher rate of gain of protein and water, a lower rate of lipid gain and similar rate of ash gain by the pigs from L than those from M. In the first 7 days of period 2 the pigs from L gained weight at 1·4 times the rate of those from M. In the final 7 days there was no significant effect of period 1 treatment on growth rate. The pigs from L given food H in period 2 were more efficient than those given M in period 2 (food conversion efficiency (FCE) values of 0·884 and 0·791 respectively; s.e.d. 0·027), but this difference was reversed in the final 7 days (FCE values of 0·521 and 0·603 respectively). t I is concluded from these results that a period of eating a food of low protein content produces a reduced protein: ash and an increased lipid: ash ratio in the body and reduced growth rate and efficiency. When subsequently pigs are given a food of sufficiently high protein content, the protein: ash and lipid: ash ratios return to normal. The repletion of labile protein reserves, with their associated water, leads to a substantial increase in the rate of live-weight gain. The lower lipid content of the gain leads to a high efficiency. The duration of these effects depends on the protein content of the food given.

Fresh sperm motility declined from 79·2 (s.e. 0·9)% to 55·8 (s.e. 1·7)% while occurrence of normal acrosomes declined from 82·9 (s.e. 1·3)% to 71·3 (s.e. 1·2) % from the day of collection to 7 days after collection, and conception rate declined from 47·6% using 3-day-old semen to less than 30% from using 5· or 7-day-old semen. Neither the number of embryos nor embryo survival from pregnant sows were affected by the age of semen. Boar effects were evident but they did not interact with the effects of age of semen, indicating that semen quality after storage was proportional to initial semen quality.

Thirty-six 7-month-old gilts were used to study the effects of different levels of a-tocopherol (13, 48, 136 mg/kg food) and different source of fat (50 g/kg sunflower oil or animal fat) in gestation and lactation diets on α-tocopherol concentration in serum, colostrum and milk and on cell-mediated and humoral immune response of lactating sows.

Blood samples were taken from six sows per treatment after farrowing and at weaning (28 days of lactation) and were analysed for α-tocopherol concentration, total number of leucocytes and T- and B-lymphocyte counts. In blood lymphocyte stimulation with concanavaline, lysozyme activity and immunoglobulin concentration were also measured. In milk samples α-tocopherol and immunoglobulin concentration were determined at farrowing and at weaning. It was concluded that a high α-tocopherol level in the sow's diet including either sunflower oil or animal fat increased as expected the serum α-tocopherol concentration (P < 0·05) just after farrowing and at weaning. In colostrum the combination of high α-tocopherol with animal fat gave the highest (P < 0·05) α-tocopherol concentration. At weaning α-tocopherol in milk fat was highest in both fat groups with extra high α-tocopherol in the diet. The cell-mediated immunity of sows as tested were not systematically affected by α-tocopherol supplementation or fat addition to diet. However, the humoral immune system may be affected by the combinations of α-tocopherol and fat given.

An experiment was conducted to evaluate the effect of dietary cimaterol, a β-adrenergic agonist, on growth, carcass characteristics and pelt quality of kit mink. The 40 standard dark and 40 sapphire mink kits were assigned to a control or to one of three treatment groups (five males and five females of each colour phase per group). Treatment consisted of the inclusion of 0·5, 2 and 5 mg cimaterol per kg (dry) of a standard ranch mink diet (control). All animals were weighed at the initiation of the experiment (24 July) and at 28-day intervals until 16 October. At slaughter (12 December) body weights were recorded and pelts measured for length and evaluated for fur colour and quality by experienced fur graders. Samples of fur from similar sites on each animal were removed for measurement of guard hair and underfur diameter. Frozen carcasses were analysed for protein and fat content. Mink final weight decreased with increasing concentrations of dietary cimaterol (P < 0·05). Pelt length, which was found to be highly correlated with body size, was also reduced by cimaterol treatment. Feeding 2 and 5 mg cimaterol per kg diet to male kits, and 5 mg/kg to female kits caused a significant reduction in the proportion of carcass fat and increased the proportion of carcass protein (P < 0·05). Fur fibre diameter for both guard hair and underfur was not significantly affected by dietary cimaterol. There was also no significant effect of cimaterol treatment on fur quality. Cimaterol treatment did not result in diversion of nutrients from body proteins to the synthesis of fur and pelt proteins. Results of this research indicate that oral administration of cimaterol to mink will be of little practical value in fur production.

A long-term experiment was designed to study the effect of feeding different sources of crude fibre during pregnancy on the reproductive performance of sows. The four treatments imposed during pregnancy were: C, a control compound diet; CS, the same control diet with additional chopped straw (0·2 kg/day); CM, the same control diet in which 0·25 kg was replaced daily by 1·5 kg maize silage; and CFR, a compound diet with a higher crude fibre content. In total 567 sows were used. On the treatments C, CM, CS and CFR the number of sows was 147, 142, 147 and 133 respectively. The sows remained on the experiment for five successive parities on a treatment or until the moment of culling. Feeding levels were about 32 MJ digestible energy (DE) per day during the first months of pregnancy and about 40 MJ DE per day in the last month of pregnancy. During lactation the feeding level ranged between 75 and 90 MJ DE per day.

In sows giving birth to five litters, the effect of parity was calculated irrespective of the treatments. The optimum litter size was observed in the fourth litter and the percentage of successful services within 10 days post weaning stabilized after the third parity. The live weight of the sows increased gradually up to the fifth parity.

Compared with the sows on the control treatment the proportional changes in consumption of the sows on the other treatments were: 0·45 more crude fibre, up to 0·02 more digestible energy and up to 0·06 less digestible protein.

There were only slight differences in reproductive performance. The mean number of weaned piglets per sow per year were 19·7, 19·3, 20·1 and 20·2, respectively for the treatments C, CM, CS and CFR. Higher piglet birth weights were observed for sows on the CM treatment and a higher proportion of the culled sows had leg disorders. On the CS treatment a higher number of weaned piglets per litter was observed and this was due to the higher number of piglets born and lower piglet mortality during lactation. The sows on this treatment tended to have more difficulty in becoming pregnant after the third and fourth parities. The sows on the CFR treatment had the highest body weights and had a higher number of litters per year mainly due to lower numbers returning to service and less nonproductive days. The results from this experiment gave no clear evidence that either the inclusion of roughage or a higher crude fibre content in the diet improved reproductive performance.

A study was made of the wool production of 490 females and 137 males of a strain of French Angora rabbit. The female adults weighed 4107 g and produced 249 g of wool every 14 weeks. Production was low for the first harvest (35 g) which consisted mainly of short wool. It then increased rapidly (203 g for the third harvest). After the third harvest, three-quarters of long wool was also bristly. The length of bristles (102 mm) decreased by 4 mm, and that of downs (62 mm) increased by 3 mm when the harvest number went from two to four. The coefficient of correlation between wool production and live weight was lower than 0·30. Adult females born in autumn produced 16 g more than those born in summer. Wool production was at a maximum during autumn and winter harvests and at a minimum in summer.

Winter fleeces had longer bristles and down than summer ones. Males produced well wool than females. When a female dropped a litter, her wool production decreases by proportionately 0·1 to 0·2. Bristly fleeces were clearly different from woolly fleeces on account of higher weight, homogeneity and compression. Objective criteria to evaluate tautness will have to found.

An experiment was designed to test whether pigs can differentiate between two foods differing in their protein content. A control food (160 g protein per kg food) and six choice-feeding treatments, in which the diets differed only in their protein concentrations, were used in the experiment. Pigs were given the following choices of protein: 220 v. 180; 220 v. 140; 220 v. 100; 180 v. 140; 180 v. 100 and 140 v. 100 g protein per kg food. Group data were collected on 240 Landrace × Large White pigs during the growing phase (30 to 90 kg), all pigs used being of similar genetic background. A 2 × 7 factorial design was replicated twice, with 10 pigs per pen, and with barrows and gilts being penned separately. Food bins for the choice-feeding treatments were placed side-by-side and an 8-day training period, in which the pigs were allowed access to only one of the two foods on alternate days, was used at the beginning of the trial to allow them to learn the position, taste and physiological effect of each of the two foods. All pigs were weighed weekly, as was the amount of food consumed in each pen. The conclusion reached was that growing pigs were able to differentiate successfully between two foods on the basis of their protein content and to change the selected diet to match their changing requirement for dietary protein. As a result, there was a significant reduction in food intake (P < 0·001) and in the P2 backfat thickness (P < 0·01) and the food conversion ratio was significantly improved (P < 0·001) compared with the control treatment.