Showing papers in "Livestock Production Science in 1980"

TL;DR: A general genetic model for the study of maternal effects is developed and problems arising in the estimation of genetic variance and covariance using covariances between relatives are studied.

TL;DR: Ways and means of manipulating protein synthesis and the energy cost of growth by nutrition, anabolic agents and anti-microbial growth promoters are considered.

TL;DR: There is no contradiction between the slow progress of record times and low heritability values of timings, especially as selection is not made directly on timing measures, but on race performance criteria with which they are not necessarily strongly correlated.

TL;DR: Initial differences in liveweight between the two groups had disappeared by the middle of the second pregnancy, and there were no significant differences in the number of weight of pigs born or reared in any of the first five parities.

TL;DR: The difference between the groups was significant for daily gain, but there was no significant difference between maiden and calved heifers for killing-out percentage and the financial returns were low for the maiden as well as for the once-calved heIFers.

TL;DR: In this paper, the influence of various factors on feed conversion ratio (FCR) and growth performance of a fattening pig was discussed using results from growth and balance experiments, and interrelationships between the factors were described and integrated into a model which predicts FCR.

TL;DR: Varying cow replacement rate above involuntary removal rate by voluntary culling increased milk sold per cow in year 16 to a maximum of +5 to +10% after practicing a fixed strategy for 16 years.

TL;DR: Heat treatment, particularly of forages, and formaldehyde treatment of proteins, are methods which can be used to achieve high levels of duodenal NAN supply.

TL;DR: The mean gestation periods of mares belonging to different horse and pony breeds common in The Netherlands have been calculated using data from the birth registers of five stud-book societies, finding variations in the mean gestation period are greater in horses than in cows, sheep or pigs.

TL;DR: The results indicate that ‘fat corrected’ conformation is of value in commercial classification schemes particularly where breed cannot be identified, but it is less clear whether the relationships between conformation and composition are sufficiently precise to be of value within breed.

TL;DR: In this article, a group of eleven gilts was compared to a control group of littermates, analysed at the mating of the first group, and to a third group of non-pregnant (NP) sisters, slaughtered together with the pregnant (P) gilts near parturition (111 days of pregnancy).

TL;DR: Emphasis is placed on the interaction of P with other nutrients, particularly Ca, protein and energy, and it is stressed that phosphorus cannot be considered as an isolated nutrient and panacea for ill-thrift and infertility of rangeland cattle and sheep.

TL;DR: For all carcass and meat quality traits measured in the gilts, the heterozygote genotype (carrier) showed an intermediate position between the two homozygous genotypes, which suggests that carriers have a selection advantage over non-carriers.

TL;DR: In the second generation of a crossbreeding experiment with Holstein Friesian bulls and Dutch Friesians cows the difference in additive genetic merits between Holsteinfriesian and Dutch friesian bull genes was calculated and significant a effects were found.

TL;DR: In undernourished animals a sparing mechanism appears to be brought into action, and continues to operate during realimentation, and a production system in which feed supply fluctuates between undernutrition and realiments can therefore be as efficient as one in which the animals are constantly fed according to requirements.

TL;DR: Chemical analysis of different parts of the body revealed that reducing the daily energy intake caused an 8% lower protein deposition and a 28% lower fat deposition in the total body, however, there were differences between different anatomical parts ofThe body.

TL;DR: Copper is needed by pigs and rabbits to prevent microcytic hypochromic anaemia, dermatosis and bone marrow problems and to maintain the integrity of the cardiovascular system and some implications of Cu feeding on meat quality are discussed.

TL;DR: The results indicate the possibility of improving meat quality by selection in Switzerland and led to the following organisation of selection on meat quality and stress resistance in Switzerland.

TL;DR: The results indicate that the higher levels of calving difficulties and stillbirths encountered need not deter beef crossing, and beef crossing benefits the economics of the dairy herds, while the financial risk for the individual dairy farmer is relatively low.

TL;DR: It does not seem profitable to use blood and enzyme types or halothane test as a routine in selection against PSE under Danish conditions, but these tests are useful within herds with a high frequency of PSE.

TL;DR: Under standard conditions, susceptibility to MHS is a recessive trait governed by the Hal locus, and the data indicate a non-random combination of the genes corresponding to a linkage disequilibrium of D = −0.071.

TL;DR: Multiple regression analysis showed that the effect of protein on milk production was dependent on the energy intake and the mobilization of body reserves, and an additional 9–10 g crude protein per production feed unit was necessary to maximize the mobilize of the body reserves.

TL;DR: In dairy cows amino acids may be required for four processes: maintenance; as precursors for the synthesis of glucose (gluconeogenesis); for protein deposition in muscle or associated with foetal growth; and forThe synthesis of milk protein.

TL;DR: A total of 567 young pigs entering one of the national testing stations were tested for sensitivity to halothane between October 1976 and May 1978, with an indication that reactor pigs might have slightly reduced daily gains and lower backfat thickness.

TL;DR: Correlated responses in meat quality traits indicate a tendency towards a paler meat colour, but conflicting sire and dam trends are observed for pH 24 and water-holding capacity, which indicates a greater susceptibility to atrophic rhinitis as a consequence of the selection practised in this experiment.

TL;DR: The genetic effects on the length of post-insemination return cycles (RC) were studied by means of Israeli Friesians and Bavarian Fleckvieh and it was suggested that the effect of the mating sire was on the rate of fertilization, especially in inseminations at an early stage of the estrus.

TL;DR: In a comparison of Holstein Friesian from North America with Dutch Red and Whites (DRW) and Dutch Friesians (DF), the feed intake of 20 animals per breed was measured at different stages of lactation and at different ages.

TL;DR: A theoretical analysis is made of the optimal culling or selection policy among cows to maximize mean yield in herds which do not breed bulls, but use those nationally available by A.I.

TL;DR: The sexual season, i.e. the sexual cycle activity, of Finn × German Mutton Merino (Finn × GMM) ewes was found to extend from August to March, and in a group of purebred GermanMutton Merinos (GMM) eWes the sexual season extended from June to January.