bluuebunny/crossref_metadata_2025_split huggingface dataset:
The control of appetite in lactating cows
Authors: Monteiro L. S. 
Published: September 2010

SUMMARYA closed-loop system is proposed for the control of voluntary food intake in lactating cows, and an expression is deduced relating the response of food intake to changes in milk yield and body-weight gain.A closed-loop system necessarily involves a delay in the response to changes in production. The rate of increase of food intake is there- fore slower than the rate of increase in milk yield. The consequent deficit in energy during the rising part of the lactation curve is met by the mobilization of body reserves, which are partly accounted for by losses in body weight. During the declining part of the lactation the delay effect leads to an excess of energy intake and to the replacement of body reserves and, consequently, of body weight.The expression deduced from the model was fitted to four different types of lactation curve corresponding to long and short lactations of Friesians and Jerseys fed ad libitum on a complete diet. The expected food intake based on the control model was contrasted with a linear regression model. The former gave a better account of the variation in food intake in all four types of lactation.The total change in body weight during lactation was partitioned between changes in weight due to the mobilization and replacement of reserves and gain directly attributable to food intake. There was, in general, good agreement between the observed losses in weight occurring at the beginning of lactation and those predicted from the mobilization of reserves for milk production.The physiological implications of the model and the values estimated for the parameters are discussed.
Growth and herbage consumption of grazing Merino and Border Leicester lambs reared by their mothers or fostered by ewes of the other breed
Authors: Langlands J. P. 
Published: September 2010

SUMMARYEight Border Leicester castrated male lambs (wethers) were fostered on to 8 Merino ewes (MB) at birth, and 10 Merino wethers were fostered on to Border Leicester ewes (BM). Two additional groups of 10 wethers consisted of Border Leicester lambs (BB) and Merino lambs (MM) reared by their natural mothers. The lambs and ewes grazed together and growth rate, and milk and herbage consumption of the lambs were recorded.Live-weight gains to weaning at 74 days were 275, 245, 204 and 184 g/day for groups BB, MB, BM and MM respectively. Lambs reared by Border Leicester ewes received more milk and consumed less grass than lambs of similar genotype reared by Merinos, but BM lambs consumed less milk than BB lambs. Merino lambs also consumed less grass than Border Leicester lambs.It was concluded that Merinos grew more slowly than Border Leicester lambs primarily because of their lower voluntary food intake. The lower milk production of Merino ewes was considered to be of secondary significance since if herbage is available ad libitum, lambs with high voluntary intakes will compensate for the lack of milk by consuming more forage.
A note on seasonal fluctuations in milk production
Authors: Wood P. D. P 
Published: September 2010

SUMMARYRecords from 161 lactations completed in the year ended September 1969 were obtained from a herd of British Friesians kept indoors all the year round and fed grass silage with a concentrate supplement. Seasonal variation in milk production from the herd was compared with that from cattle traditionally managed.After allowing for variation due to parity, season of calving, and stage of lactation, there was a tendency for milk production to be stimulated during periods of feeding grass consumed in a rapidly growing state. Seasonal variation was considerably less evident in the indoor herd than in the traditionally managed samples.
The distribution of body fat in Scottish Blackface and Finnish Landrace lambs
Authors: McClelland T. H. , Russel A. J. F. 
Published: September 2010

SUMMARYSeven Scottish Blackface and seven Finnish Landrace wether lambs were slaughtered over the weight range 26 to 41 kg. Total chemical fat deposition in relation to fleece-free empty body weight was found to be similar for both breeds, pooled data giving the significant relationship y = 1·28+0·46x, where y was the percentage chemical fat in the fleece-free empty body and x the fleece-free empty body weight.Statistically significant differences in the rate of chemical fat deposition in different depots were found between breeds. The Scottish Blackface was found to deposit relatively more fat in muscular plus associated fatty tissue than the Finnish Landrace while the reverse situation occurred in respect of fat deposition in omental plus mesenteric fatty tissues and perirenal fatty tissues.No breed differences were found in the rate of deposition of subcutaneous fat or fat in bone or in the remainder (head, skin and viscera).
Influence of social conditions during rearing on the sexual behaviour of the domestic boar
Authors: Hemsworth P. H. , Beilharz R. G. , Galloway D. B. 
Published: September 2010

SUMMARYThree groups of six young male pigs (boars) were reared from 20 days to 7 mo of age under one of the following social conditions: a mixed sex group; an all-male group; or social restriction, without physical and visual contact with other pigs. The sexual behaviour of the boars was studied from 7 to 13 mo of age. The total number of copulations and the sum of all the courting behaviour activities were significantly greater (P<0·01) for the boars reared in the all-male and the mixed sex groups than for those reared in social restriction. Growth rate to 30 weeks of age, testicle size and semen quality were not affected by rearing treatment.
A note on the relationship between live-weight gain during calfhood and subsequent performance of intact male calves of the Israeli-Friesian breed
Authors: Folman Y. 
Published: September 2010

SUMMARYLive-weight gains were recorded for 459 intact male (bull) calves kept in 17 groups on three farms. The correlation coefficient between weight gained during the first 110 to 130 days of life and that gained during the subsequent period until slaughter was r = 0·53 (n = 459; P < 0·001). It is suggested that with bulls, nutritional and other factors which increase live-weight gain during the rearing period to about 4 mo of age may have a positive effect on subsequent performance to slaughter.
Performance of crossbred sheep from a synthetic Dam Line
Authors: Smith C. , King J. W. B. , Nicholson D. , Wolf B. T. , Bampton P. R. 
Published: September 2010

ABSTRACTThe performance of traditional Border Leicester × Blackface cross- breds (Greyfaces) was compared with Blackface crosses from a synthetic Dam Line developed from four breeds; Finnish Landrace (47%), East Friesian (24%), Border Leicester (17%) and Dorset Horn (12%). The Dam Line crosses were lighter (−10%), showed earlier sexual maturity, were more prolific (+12%) and weaned more lambs (+13%) than the traditional crosses but had similar litter weights and flock survival. The lambs from the Dam Line crosses grew more slowly (−5%) (comparing twins with twins and singles with singles) but their carcass composition and carcass grades were similar to those from the traditional crosses.An assessment of the relative biological efficiency for meat production of the two crossbred types indicated an advantage of about 10 to 12% in favour of the Dam Line crossbred type.
Lactation curves of Holstein-Friesian and Holstein-Friesian x Gir cows
Authors: Madalena F. E. , Martinez M. L. , Freitas A. F. 
Published: September 2010

ABSTRACTLinear y = a′ + b′x and gamma type y = ea−cx xb models for the lactation curve (y = daily production on day x of lactation) were adjusted to daily production records of 870 lactations. Within- lactations pooled R2 = 0·71 and R2 = 0·74 were respectively obtained for the linear and gamma type models, the latter being preferred for further analyses on account of its general validity under varied circumstances.The parameters a, b, c of individual gamma type lactation curves were analysed by least squares within a subset of 634 lactations from Holstein-Friesian (HPB), 1/2 HPB: 1/2 Gir (F1) and 3/4 HPB: 1/4 Gir (B1) cows. Crossbreds had both higher initial production and higher persistency of lactation than purebred cows. F1's had higher initial production than B1's, both groups having similar persistency of lactation. Cows calving during the rainy season had higher initial production than cows calving in the dry season, which, however, had more persistent lactations. Parity affected only the initial production a parameter, which was lower for first calvers, while the other parity classes had similar a values.
The effect of altering the hormone status of ewes on the outflow rate of protein supplements from the rumen and so on protein degradability
Authors: Ngongoni N. T. , Robinson J. J. , Kay R. N. B. , Stephenson R. G. A. , Atkinson T. , Grant I. , Henderson G. 
Published: September 2010

ABSTRACTFour experiments were carried out on individually penned Finn Dorset and Suffolk × Finn Dorset ewes receiving complete diets of milled hay and concentrates and rationed at various levels below voluntary intake. In the first experiment, 20 non-pregnant non-lactating ewes were each given daily 1·6 kg food and injected intramuscularly with either isotonic saline (control), progesterone plus oestrogen (20 mg + 80 ng per 24 h) to mimic hormone status in pregnancy, bromocriptine (1 mg per 12 h) to suppress plasma prolactin, or thyrotrophin releasing factor (TRF) to elevate plasma concentrations of prolactin and the iodothyronines. Fractional outflow rates of chromium-mordanted fish meal from the rumen were estimated from the rate of excretion of chromium in faeces and were proportionately 0·25 higher for ewes given TRF than for controls (P < 0·025). None of the other treatments had a significant effect on outflow rate.In experiment 2, fractional outflow rates from the rumen were determined during July (long daylength) and again during December (short daylength) in 12 ewes that had their seasonal pattern of plasma prolactin modified by removal of their anterior cervical sympathetic ganglia. Another 12 sham-operated ewes were used as controls. Neither the seasonal changes in prolactin nor their modification by cervical ganglionectomy significantly affected outflow rate.Twelve non-pregnant non-lactating ewes were used in the third experiment to test the effects of mid-winter shearing (mean ambient temperature −4°C) on fractional outflow rates from the rumen and on the plasma concentrations of prolactin, thyroxine (T4) and cortisol. Shearing caused a drop in plasma prolactin, gave proportional increases (P < 0·05) of 0·47 and 0·16 in T4 and cortisol respectively and gave a 0·12 increase (P < 0·01) in the outflow rate of chromium-mordanted fish meal from the rumen. The increases in T4, and outflow rate were sustained for at least 2 weeks.For experiment 4, 22 ewes each suckling two lambs were used in three trials to see if variation between ewes in milk production and in lamb growth rate was correlated with variation in outflow rate from the rumen. The only significant correlation (r = 0·68, P < 0·01) was between outflow rate and lamb growth rate for the eight ewes in trial 1. The results of all four experiments are discussed in relation to the mechanisms by which non-dietary factors, via their effect on the rate of outflow of digesta from the rumen, may alter the quantity of protein reaching the abomasum and the likely significance of this alteration on animal performance.
Reproduction in the gilt 7. Exposure of young gilts to the same mature boar and relocation: effects on the attainment of puberty
Authors: Eastham Philippa R. , Cole D. J. A. 
Published: September 2010

ABSTRACTTwenty-four Landrace × (Landrace × Large White) gilts were randomly allocated at a mean age of 70 days to each of two rearing treatments which were: (1) housing gilts with other gilts but in complete isolation from other pigs; or (2) housing gilts with fence-line contact with a mature boar. At 160 days of age all gilts were relocated, treatment 1 gilts being adjacent to a mature boar for the first time while treatment 2 gilts were adjacent to the same mature boar with which they had had contact during rearing. In addition, the gilts on each treatment were exposed to full contact with this boar for 30 min/day. There were no significant differences between the treatments in age (176 and 185 days) or weight at puberty (81·9 and 82·6 kg), in the interval from relocation and full boar contact to puberty (11 and 16 days) and in ovulation rate at the pubertal oestrus (11·6 and 11·5).In a second experiment, 72 gilts were reared with fence-line contact with a mature boar and at 160 days of age, half were relocated adjacent to a novel mature boar and the other half remained in the rearing house next to a novel boar with all gilts receiving full boar contact for 30 min/day. Significantly more relocated gilts reached puberty during the experimental period (25/32) than gilts which were only exposed to contact with a novel boar and not relocated (12/31) (P < 0·001) and those relocated gilts were significantly younger (187 v. 225 days; P < 0·001) and lighter (75·4 v. 93·9 kg; P < 0·001) at puberty and the induction interval was significantly shorter (20 v. 89 days; P < 0·001) compared with gilts on the second treatment.
Effects of a β-andrenergic agonist on growth performance, body composition and nutrient retention in finishing pigs fed normal or low amounts of protein
Authors: Bracher-Jakob A. , Blum J. W. 
Published: September 2010

ABSTRACTIn earlier studies with pigs the P-adrenergic agonist Ro 16·8714 ((3-AG) enhanced the efficiency of nitrogen (N) retention. Therefore effects of Ro 16·8714 were studied on growth rate, body composition, N, fat and energy retention in pigs fed isoenergetically, but given different amounts of protein (112 or 138 g/kg diet) without (groups LP and NP) or with 60 mg Ro 16·8714 per kg diet (groups LPP and NPP) from 60 to 100 kg live weight. Weight gain (898, 927, 855 and 810 g/day in NP, NPp, LP and LPp) decreased, whereas food: gain ratio (2·94, 2·82, 3·04 and 3·24 kg/kg in NP, NPP, LP and LPP) was increased by low protein intake (P < 0·05) and both weight gain and food conversion were modified by the interaction (P × P) of protein intake and Ro 16·8714 (P < 0·05). Killing-out proportion (820, 830, 830 and 830 g/kg in groups NP, NPp, LP and LPP) was modified by protein intake and Ro 16·8714 (P < 0·05). Carcass growth rate (760, 814, 748 and 723 g/day in NP, NPP, LP and LPP) was modified by protein intake and by P × p (P < 0·05), while non-carcass growth rate (90, 77, 76 and 56 g/day in NP, NPP, LP and LPP) was changed by protein intake and by Ro 16·8714 (P < 0·05). Compared with NP, weights of kidneys (−0·025 kg), small intestine (−0·26 kg) and large intestine (−0·17 kg) were decreased by low protein feeding, and weights of heart, spleen and stomach decreased in response to Ro 16·8714 (-002, -0·02 and -0·06 kg; P < 0·05) while both low protein intake and Ro 16·8714 reduced liver weight (−0·12 and −0·23 kg, respectively; P < 0·05) and blood volume obtained at slaughter (-0·12 and -0·23 kg; P < 0·05). Carcass N (1813, 1970, 1786 and 1825 g in NP NPp, LP and LPP) increased in response to Ro 16-8714, but was reduced by low protein intake (P < 0·05), while noncarcass N (330, 309, 312 and 285 g in NP, NPp, LP and LPP) was decreased by both low protein intake and Ro 16-8714 (P < 0·01). Carcass and non-carcass fat (22·1, 19·9, 23·4 and 23·0 kg, respectively 1·51, 1·41, 1·59 and 1·68 kg in NP, NPp, LP and LPP) increased with low protein feeding (P < 0·05), but were not significantly influenced by Ro 16·8714. The efficiency of N retention (295, 363, 321 and 327 g/kg N retained: N intake in NP, NPp, LP and LPP) was enhanced by Ro 16·8714 (P > 0·05) whereas the efficiency of energy retention was not influenced by Ro 16·8714 and protein intake. In conclusion, an adequate intake of protein is necessary for optimum expression of many, but not all, effects of the P-adrenergic agonist Ro 16·8714.
Absorption and metabolism of [U-14C] acetic acid in growing pigs
Authors: Latymer Eva A. , Keal H. D. , Low A. G. 
Published: September 2010

ABSTRACTBy tracing14C after an injection of [U-14C] sodium acetate into the caecum of pigs, it was found that proportionately 0·93 of the acetate injected was absorbed. About 0·25 of the administered acetate was recovered in the body 96 h later. It is assumed that the remainder was oxidized during this period and exhaled as carbon dioxide.The14C initially predominated in plasma lipids, but it progressively shifted over the 96 h to plasma proteins. In the lipid fraction of blood plasma there was a continuous shift of14C from triglycerides and free cholesterol to cholesterol esters over the 96-h period of measurement.In the body most of the14C was recovered in the fat, liver and intestinal wall. The highest concentration of14C was in the bile, especially in glycine-conjugated bile acids.It was shown that the absorbed acetate was a source of energy to the pigs and it was recycled and metabolized into more complex components in the body during 96 h.
An evaluation of two ultrasonic instruments for the prediction of carcass lean grade in growing pigs
Authors: Krieter J. , Kalm E. 
Published: September 2010

ABSTRACTUltrasonic 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.
Growth and furring of mink (Mustela vison) given diets containing the β-adrenergic agonist, cimaterol
Authors: Slayden O. , Oldfield J. E. , Stormshak F. 
Published: September 2010

ABSTRACTAn 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 note on the response of store lambs to iso-nitrogenous diets containing rapeseed meal or fish meal
Authors: Tan P. V. , Bryant M. J. 
Published: September 2010

ABSTRACTLive-weight gain responses were investigated using 36 individually penned lambs (mean live weight 35·2 kg) given three sodium hydroxide treated straw-based diets: low-protein, low-rapeseed meal (control) diet; high protein, high-rapeseed meal (HR) diet; or high-protein, fish meal (FM) diet. The diets were formulated to provide 3 or 9 g undegradable nitrogen per kg dry matter (DM) respectively for the diets without or with fish meal. Diets were offered once a day in a 50: 50 forage-to-concentrate ratio in amounts calculated to support maintenance plus 150 g gain and were adjusted weekly according to live weight. Live-weight gain, measured for 7 weeks, was improved by the FM diet only (P < 0·05).The three diets were given also to rumen-fistulated sheep. The FM diet maintained higher rumen ammonia concentrations during most of the day. The FM and HR diets reduced rumen solid particle outflow rate (P < 0·05) and increased the effective degradability of DM and acid-detergent fibre.