bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of sward height and concentrate supplementation on the performance of spring calving dairy cows grazing perennial ryegrass-white clover swards
Authors: Rook A. J. , Huckle C. A. , Wilkins R. J. 
Published: August 2016

AbstractForty-eight spring-calving, Holstein-Friesian cows were continuously stocked on perennial ryegrass-white clover swards maintained at compressed sward heights of 4, 6 or 8 cm and offered 0 (U) or 4 (S) kg concentrates. Milk yields and composition, live weights and intakes (estimated by the n-alkane technique) were recorded for periods 24 May to 27 June (P1) and 28 June to 8 August 1992 (P2) with 4 cm swards not used in P2. Milk and component yields were significantly lower at 4 cm than at 6 or 8 cm in P1 and significantly higher when supplements were offered in both periods with no significant interaction. Herbage intakes were reduced more by supplementation at lower sward heights. Live weight was significantly lower on the 4 cm sward. Fat concentrations were unaffected by height and supplementation in P1 but significantly increased by supplementation in P2. These results suggest that maintaining a sward height of 6 cm offers advantages in terms of individual animal output and output per ha compared with grazing at greater or lower sward heights.
Modelling foetal growth in pigs
Authors: van Oijen M. A. A. J. , Koops W. J. , Zandstra T. , Kemp B. 
Published: August 2016

AbstractA theoretical function is proposed which describes the individual weight-age relationship for foetuses in pigs. The function is based on total growth of the litter. A maximum uterus capacity, dependent on insemination weight of the sow, and a limitation of this capacity, dependent on litter size, is assumed. A modified Michaelis-Menten function is used as a basic growth function. The model was tested against experimental data and compared with four models from the literature. Goodness of fit, extrapolation outside the range of data, and biological interpretation of the parameters from the model were checked. A maximum uterus capacity of 20·3 kg for the average insemination weight of 119·0 kg was found. The inflexion point of the model was significantly (P&lt; 0·05) dependent on litter size.
Maintenance feeding of 100 kg pigs: effect on carcass lean and fat yield and on gastrointestinal organ size
Authors: Pekas J. C. 
Published: August 2016

AbstractThe study was conducted to test the hypotheses that sustained restriction of food to maintain constant body weight of market-ready pigs, hereafter terminal maintenance (TM), would (1) decrease the size of gastrointestinal and other visceral organs, (2) increase dressing proportion, and (3) increase lean and decrease fat content and improve the lean: fat ratio of carcass. Forty-eight crossbred castrated male pigs (initial body weight, 23·5 kg) were randomly assigned to eight treatment groups (six pigs per group; one pig per pen). Three comparison groups were included. Thead libitumcontrol group (AL) was slaughtered at the target weight, 105 kg. One group was continuously restricted (CR) to 0·8 of the intake by AL and slaughtered at the target weight. The terminally restricted (TR) group was given food ad libitum to 1·1 times the target weight; then food was restricted to effect weight loss to the target weight before slaughter. Five TM groups were given food ad libitum to the target weight; then TM was administered for various periods (7, 14, 21, 28 and 42 days) before slaughter. CR either had no effect or caused enlargement of visceral organs compared with AL. TR caused reduction of viscera, especially of abdominal-digestive organs. TM caused reduction of most viscera organs (0·001 &lt;P&lt; 0·05). Regression analyses indicated that most abdominal organs were reduced 50 to 70 g/kg per 10 days of terminal maintenance. TM and TR also increased carcass weight (P&lt; 0·05). Catabolism associated with reduction of viscera organs may provide nitrogenous substrates to support the continued lean accretion observed during terminal maintenance. The reduced viscera and increased carcass weight combined resulted in increased dressing proportion (P= 0·06). Regression analyses (weightv.TM-days) showed that lean mass increased (71 g/day;P&lt; 0·05) and fat mass decreased (−52 g/day;P&lt; 0·01). Weight of bone and belly did not change. Differential lean gain, lean gain minus fat gain, during TM occurred at a rate of about 120 g/day.
The continuum between preferences and aversions for flavoured foods in sheep conditioned by administration of casein doses
Authors: Arsenos G. , Kyriazakis I. 
Published: August 2016

AbstractThe main objective of the experiment was to investigate whether a continuum links the development of conditioned flavour preferences and conditioned flavour aversions (CFPs and CFAs) in sheep, towards food flavours associated with intraruminal administration of increasing doses of the same nutritive stimulus: casein. A secondary objective was to investigate the effects of dose of casein administration and the number of repeated exposures to casein on the rate of establishment, magnitude and degree of persistence of developed CFPs and CFAs.The experiment consisted of three conditioning periods (each lasted 8 days). A food with low crude protein (CP) (39.3 g/kg dry matter (DM)) and metabolizable energy (ME) (5.3 MJ/kg DM) contents was used in combination with one of two flavours, orange and aniseed, on a total of 48 Texel × Greyface male, 3-month-old sheep. The sheep were conditioned to associate one flavour added to the test food with a particular dose of casein (C) suspended in water (8.75, 17.5, 35 and 52.5 g per animal), or a different flavoured test food with an equal amount of water. Each dose was administered by gavage through a stomach tube twice daily to each animal. At the end of each conditioning period the preference for the two flavours was measured by a two choice preference test between the two flavoured test foods for 40 min. After the completion of the last conditioning period, three more preference tests (persistence tests), without any intervening exposure to the flavoured test food, were conducted at 7, 21 and 35 days. Preference for the flavoured test food paired with casein was affected by the interaction (P< 0·001) between the dose of casein and casein association respectively. Association with casein (DPR: intake of a flavoured test food paired with casein per g total intake of flavoured test foods during the preference test) led to CFPs (DPR > 0·70) at the two lowest and to CFAs (DPR < 0·30) at the two highest doses. CFPs and CFAs were established by the second conditioning and there was no difference in the rate of establishment between preferences and aversions. The persistence tests showed a strong and similar degree of persistence of both formed CFPs and CFAs, since these were not affected by time of persistence test or by any of the interactions with time. In view of these results a model is proposed which could account for the conditioned responses of sheep towards administration of increasing doses of the same nutrient. The existence of a continuum between CFPs and CFAs created by the same nutrient given at different doses, could be the basis of how ruminants select a diet which meets their nutrient requirements at a particular point in time and thereby avoid excess of nutrient intake.
Effects of nutrition pre-partum and post partum on subsequent productivity and health of N’Dama cows infected with Trypanosoma congolense
Authors: Bennison J. J. , Akinbamijo O. O. , Jaitner J. , Dempfle L. , Hendy C. R. C. , Leaver J. D. 
Published: August 2016

AbstractThis experiment studied the effects of body condition, long- and short-term levels of nutrition and trypanosomosis infection on the productivity of N’Dama cows using a 2 x 2 × 2 factorial cross-over design. Pre-partum, 23 cows received supplements for 6 months (H), the other group of 20 for 2 months (L). Both groups grazed native pastures. Two days post partum, half the cows from each group were placed on a basal (B) or supplemented (S) plane of nutrition. The diet of concentrate, groundnut hay and andropogon hay was the same, only the quantities differed. Four weeks post partum half the animals in each group were inoculated with T. congolense organisms (I), the others acted as controls (C). The trial continued for a further 6 weeks.Pre-partum nutrition (H, L had no effect on dry-matter intake (DMI) but pre-partum feeding (H) improved post-partum productivity, evident by higher dam live weights (P < 0·05), body condition (P < 0·001), calf birth weight (P < 0·05) and calf live-weight gain (P < 0·01). Post-partum nutrition had no effect on productivity. Trypanosomosis infection caused a reduction (P < 0·05) in total DMI. The decline in groundnut hay and concentrate intake was proportionally (P < 0·001) greater in the S-I group than in the B-I group. A low plane of nutrition pre-partum depressed milk yield but increased fat concentration (P < 0·05). Infection significantly reduced milk offtake (P < 0·05). The reduction in milk offtake (P < 0·01) and calf live weight (P < 0·05) were proportionally larger in the B-I than in the S-I group. Infection caused a decline in milk protein concentration (P < 0·05) and protein yield (P < 0·01) which was independent of dietary effects. Infection reduced (P < 0·01) the packed-cell volume but there were no interactions with diet. None of the cows was pregnant 150 days post partum but seven were cycling, 3(5) in the H-S-I group, 2(7) in the H-B-I group, 1(5) in the L-B-I group and 1(5) in the L-S-C group. These results suggest that S-I cows attempted to maintain milk yield at the expense of live weight whereas the B-I cows had insufficient live-weight reserves that could be mobilized. This suggests the nutritional balance and changes in weight at the time of infection might be more important than historical planes of nutrition.
Prediction of the metabolizable energy value of whole-crop wheat from laboratory-based measurements
Authors: Adesogan A.T. , Owen E. , Givens D.I. 
Published: August 2016

AbstractThe accuracy with which several laboratory-based measurements predict the metabolizable energy (ME) value of whole-crop wheat (WCW) was determined. Twenty-six WCW forages differing in variety (cv. Slepjner, Hussar and Cadenza), maturity at harvest (milk, cheese and dough stages) and treatment applied (urea-treated, untreated or acid-based additive treated) were harvested in 2 years and conserved anaerobically in 200·1 barrels. The forages were then scanned using near infrared reflectance spectroscopy (NIRS) and analysed for chemical composition,in vitrorumen fluid-pepsin digestibility,in vitroneutral detergent-cellulase plus gamannase digestibility,in vitrofermentation gas production and in situ rumen degradability. ME was calculated using measured energy losses in faeces and urine and predicted energy losses as methane. The relationships between ME and the laboratory-based measurements were determined by regression. Gross energy was consistently the best predictor of ME (R2= 0.53 and 0.86 in years 1 and 2 respectively). However the autocorrelation involved, militates against the prediction of ME from gross energy. None of the chemical constituents or biological techniques gave a good, robust prediction of ME. However, an NIRS calibration developed using the WCW samples was highly correlated (R2 = 0.68) with ME. This work therefore suggests that traditional laboratory-based, food evaluation techniques are unsuitable for predicting the ME content of WCW but that NIRS holds promise.
The influence of increased feeding on the susceptibility of sheep to infection with Haemonchus contortus
Authors: Wallace D.S. , Bairden K. , Duncan J.L. , Eckersall P.D. , Fishwick G. , Holmes P.H. , McKellar Q.A. , Mitchell S. , Murray M. , Parkins J.J. , Stear M.J. 
Published: August 2016

AbstractPrevious research has shown that supplementing the diet of growing lambs with urea enhances their ability to withstand gastrointestinal infection with the nematode Haemonchus contortus. This study compared lambs given two different amounts (χ 1 and χ 1·5) of the same urea-supplemented diet. One dietary allowance was sufficient to allow uninfected lambs to gain approximately 400 g/week without adverse clinical signs. In contrast half of the H. contortus infected lambs on this dietary allowance had to be humanely killed before the end of the experiment due to severe anaemia and anorexia. All infected lambs on this dietary allowance showed decreased mean red cell volumes and decreased plasma albumin concentrations indicating inadequate replacement of red blood cells and plasma proteins lost during the infection. The remaining lambs were offered proportionately 0·5 more of the same dietary allowance. Among lambs on this dietary allowance, there were very few differences between uninfected and infected sheep in clinical signs and growth rate. Therefore, dietary allowances that are adequate for uninfected lambs are not necessarily sufficient for infected lambs. As nearly all grazing lambs are infected with nematodes, dietary recommendations should take parasitic infection and its nutritional demands into account.
Studies on cannulation method and alternative indigestible markers and the effects of food enzyme supplementation in barley-based diets on ileal and overall apparent digestibility in growing pigs
Authors: Yin Y.-L. , McEvoy J. D. G. , Schulze H. , McCracken K. J. 
Published: August 2016

AbstractTwo different cannulation procedures (simple ileal ‘T’ cannula v. The post valve ‘T’ caecal cannula (PVTC)) and two indigestible markers (TiO2 v. Cr2O3) were studied with six male littermate pigs fitted with PVTC or simple ileal ‘T’ cannulae. Six diets were used, of which two were based on wheat and wheat bran and the other four were based on two barleys of different bushel weight without and with exogenous enzymes (ß-glucanase/xylanase). Proportional TiO2 and Cr2O3 recoveries in faeces were less than 1·00, the mean values for the six diets being 0·858 for TiO2 and 0·811 for Cr2O3. With both markers, recovery in faeces was lowest for the most digestible wheat-based diet (A). The ileal apparent digestibility (IAD) coefficients of dry matter (DM), crude protein (CP), energy and amino acids measured with Cr2O3 were significantly (P < 0·001) lower than those measured with TiO2. There was no difference in overall apparent digestibility of DM, CP and energy measured with simple ileal ‘T’ cannula and PVTC techniques. However, IAD of DM, energy and CP measured with the PVTC method were significantly higher than those measured with the simple ileal ‘T’ cannula method. The data also showed that the standard errors with the simple ileal ‘T’ cannula method were greater than when using the PVTC method. Diet significantly affected ileal and overall digestibility of nutrients (P < 0·001) with values being highest for diet A and least for the wheat bran-based diet (B). Overall digestibility (OD) of DM and energy were higher for the higher bushel weight barley-based diet (C) than for the normal bushel weight barley-based diet (E). Enzyme inclusion improved OD for both barley diets and ileal digestibility of energy (0·060) and CP (0·057) for the normal bushel weight barley.
Lamb production from diverse genotypes. 1. Lamb growth and survival and ewe performance
Authors: Fogarty N. M. , Hopkins D. L. , Ven R. van de 
Published: August 2016

AbstractGrowth and survival of 3673 female and cryptorchid lambs representing the range of types (second cross, first cross and Merino) produced in the Australian lamb industry are reported. The lambs were sired by a selection of Poll Dorset (D; no. = 7), Texel (T; no. = 10), Border Leicester (BL; no. = 12) and Merino (M; no. = 12) rams and born to Border Leicester × Merino (BLM) and Merino (M) dams, which resulted in six lamb genotypes (D×BLM, T×BLM, D×M, T×M, BL×M and M×M). The second cross lambs (D×BLM, T×BLM) were heavier at birth, weaning and post-weaning and had higher growth rates, than first cross lambs (D×M, T×M, BL×M), which were higher than M×M lambs (P< 0·01). For post-weaning weight (cryptorchids at 156 days) second cross lambs were 4·2 (s.e. 0·3) kg heavier than comparable sired first cross lambs, with the BL×M 2·6 (s.e. 0·5) kg lighter than other first cross types and the MxM a further 4·2 (s.e. 0·6) kg lighter. The average advantage of D over T crosses was 1·0 kg for post-weaning weight, with greater variation amongst individual sires.Lamb survival to weaning was 76% and it was affected by birth weight and birth type (P< 0·01). Sire breed had no significant effect on lamb survival, whereas lambs from BLM ewes had higher survival than those from M ewes (P< 0·01).Overall the proportion of ewes lambing was 84% with a mean litter size of 1·77. There was no difference infertility between AI (thawed frozen semen and laparoscopic insemination) and natural (single sire) mating, although the M were higher than the BLM ewes (P< 0·01). Gestation length was 2·3 days shorter (P< 0·01) for BLM than M ewes and there was no difference between D and T sire breeds. There was little effect of birth type on gestation length but it increased with birth weight within birth type categories. Between year repeatability of gestation length for ewes was 0·33 (s.e. 0·05).
Ileal apparent digestibility of amino acids in growing pigs given a cassava root meal diet with inclusion of cassava leaves, leucaena leaves and groundnut foliage
Authors: Phuc B.H.N. , Lindberg J. E. 
Published: August 2016

AbstractIleal apparent digestibility of amino acids (AA) in a cassava root meal and soya-bean meal diet without and with an inclusion (150 g/kg) of sun-dried cassava leaves, ensiled cassava leaves, leucaena leaves and groundnut foliage was studied in a change-over experiment (5 ✕ 5) with post-valve T-caecum cannulated growing pigs.The ileal apparent digestibility of dietary crude protein (CP) and AA were unaffected by the inclusion of groundnut foliage (P> 0·05). In contrast, when sun-dried and ensiled cassava leaves, and leucaena leaves were included in the diet the ileal apparent digestibility of dietary CP and AA were significantly reduced (P< 0·05).The estimated ileal apparent digestibilities of essential and non-essential AA in groundnut foliage were higher (P< 0·05) than those of the other leaf products and there were no differences among cassava leaves and leucaena leaves (P> 0·05). On average ileal apparent digestibility of essential AA was 0·71 in groundnut meal and 0·56 in cassava and leucaena leaves.It was concluded that, under tropical conditions, groundnut foliage has the potential to improve the dietary protein and AA supply and to replace partially soya-bean meal, in low fibre diets for growing pigs. Further, when conventional protein-rich foods are not available, cassava and leucaena leaves may also have the potential to improve the protein and AA supply for pigs.
The effects of selection for lean tissue content on maternal and neonatal lamb behaviours in Scottish Blackface sheep
Authors: Dwyer C. M. , Lawrence A. B. , Bishop S. C. 
Published: August 2016

AbstractBritish hill sheep are required to give birth to and rear their lambs under harsh extensive conditions. The aim of this study was to investigate whether genetic selection for increased (LEAN) or decreased (FAT) carcass lean content in the Scottish Blackface breed over 7 years had affected the ability of ewes to rear lambs by altering the expression of maternal and neonatal lamb behaviours. The behaviour of 61 ewes (32 LEAN and 29 FAT) and their 119 lambs were recorded at parturition and over the first 8 weeks of life. Overall there were very few effects of selection on the behaviour of the ewes. LEAN ewes were significantly faster than FAT ewes to start grooming their lambs after birth and FAT ewes tended to withdraw more frequently from their lambs than LEAN ewes. There was, however, a highly significant effect of selection line on lamb behaviour. LEAN lambs were significantly quicker than FAT lambs to perform all righting movements (median latency to stand (mins): LEAN = 11·7, FAT = 23·4,P< 0·01), were more likely both to suck (percentage that sucked: LEAN = 81·0%, FAT = 57·1%,P< 0·05), and to play within the first 2 h of birth. The higher rate of sucking in LEAN lambs persisted over the first 3 days after birth (percent observations where lambs were sucking: LEAN = 7·8 (s.e. 0·8), FAT = 5·1 (s.e. 0·6),P< 0·05), when LEAN lambs were also significantly closer to their mothers than FAT lambs. Thereafter, there were no significant effects of ewe or lamb line on behaviours recorded up to 8 weeks after birth. Overall lamb mortality to 8 weeks was 19·3% and was not significantly affected by lamb line. However, lambs that were slow to perform early behaviours had a reduced survival to 8 weeks of age. These data suggest that, although ewe maternal behaviour has not been significantly affected by selection for lean growth, the activity of the neonatal lamb has been affected. Lamb activity was related to lamb survival, even in our indoor lambing conditions. It is likely that the speed with which newborn lambs stand and suck will be even more important for survival under extensive conditions.
Efficiency of part lactation test day records for genetic evaluations using fixed and random regression models
Authors: Mrode R. A. , Swanson G. J. T. , Lindberg C. M. 
Published: August 2016

AbstractThe efficiency of part lactation test day (TD) records in first parity for the genetic evaluation of bulls and cows using a random regression model (RRM) and a fixed regression model (FRM) was studied, modelling the random and fixed lactation curves by Legendre polynomials. The data set consisted of 9 242 783 TD records for first lactation milk yield of 1 134 042 Holstein Friesian heifers. The efficiency of both models with part lactation TD records was examined by comparing predicted transmitting abilities (PTAs) for 305-day milk yield for 114 bulls and their 4697 daughters, from analyses where the maximum number of TD records of these daughters was restricted to the initial 2, 4 or 6 TDs with those estimated from 10 TDs. The correlations of PTAs estimated from 2, 4 or 6 TDs with those from 10 TDs computed for cows and bulls within each model were very similar. A rank correlation of 0·91 (0·92 FRM) was obtained for cows between PTAs based on 2 TDs and those from 10 TDs. The correlation increased to 0·96 with 4 TDs and 0·98 with 6 TDs. For bulls, correlations between PTAs estimated from 4 or 6 TDs with those estimated from 10 TDs were high at 0·98 and 0·99 respectively. With 2 TDs, the correlation was 0·95. The average under-prediction of PTAs with 2, 4 or 6 TDs relative to 10 TDs was generally higher and more variable with a FRM compared with a RRM for highly persistent cows and bulls. A similar trend was observed for mean over-prediction of PTAs, except for the initial predictions based on 2 TDs when the RRM gave a higher mean over-prediction for bulls and their daughters with low persistency but high initial TD records. The range of over and under-predictions were large (up to 200 kg milk) for some bulls when only 2 TDs were included in both models. A moderate correlation of 0·64 was obtained between persistency evaluations estimated from 10 TDs with those estimated from 2 TDs. The correlation increased to 0·71 with 4 TDs included and 0·85 with 6 TDs. The moderately high correlation between 6 TDs and 10 TDs of 0·85 was unexpected given the high correlation of 0·99 between PTAs for yield estimated from 6TDs with those estimated from 10 TDs.