scispace - formally typeset
Search or ask a question

Showing papers in "Livestock Production Science in 1991"


Journal ArticleDOI
TL;DR: Intake capacity might be considered as an additional trait in the selection goal to avoid an increase in negative energy balance during early lactation and to cover the additional requirements due to the increased production.

187 citations


Journal ArticleDOI
TL;DR: The purpose of this review was to determine with accuracy the effect of the lactation stage, length of under/over-feeding, age and production potential of the animals on the milk output and milk protein content response to variations in the energy supply.

176 citations


Journal ArticleDOI
TL;DR: It was concluded that in reasonably adapted genotypes, selection for growth in the Australian tropics would result in improved heat tolerance and reduced resistance to parasites.

153 citations


Journal ArticleDOI
TL;DR: The results show that predicted muscle weight loss during lactation increased with pregnancy feeding level whereas predicted fat weight loss was affected only by level of feed intake during lactations.

129 citations


Journal ArticleDOI
TL;DR: In this article, three main variation factors of the substitution rate between roughage and concentrates have been studied over a course of eight trials, over a period of one month, with three or four groups of Holstein-Friesian crossbred cows in midlactation.

101 citations


Journal ArticleDOI
TL;DR: There is increasing evidence that circulating IGF-1 may play an important role in metabolic adaptation during periods of nutritional limitation, and the cellular receptors for IGFs appear to be affected by nutritional changes, their endocrine regulation and biological role remain to be resolved.

85 citations


Journal ArticleDOI
TL;DR: In this paper, a bio-economic model of the dairy cow enterprise was used to evaluate biases in estimates of economic values of traits derived from systems with sub-optimal management decisions.

84 citations


Journal ArticleDOI
TL;DR: There is no evidence that the composition of beef carcasses at slaughter can be manipulated at an early stage of development by means of feeding techniques, thus suggesting that the feeding treatments during calfhood have no long-term effect on this parameter.

74 citations


Journal ArticleDOI
TL;DR: It is suggested that the loading density should be limited at about 232 kg/m2 (∼0.47 m2/pig) for animal welfare and meat quality reasons and that strong interactions between transport factors may veil main effects.

72 citations



Journal ArticleDOI
TL;DR: It is concluded that measuringFeed intake in addition to body weight could be important for reducing residual feed intake in growing heifers.

Journal ArticleDOI
TL;DR: In this paper, the effects of environmental temperatures of 12.0, 18.5, 25.0 and 31.5°C on performance, energy metabolism and body composition in pigs were evaluated.

Journal ArticleDOI
TL;DR: In this article, two experiments were conducted to identify which amino acids (AA) in a test protein, casein, were limiting for production in the lactating dairy cow, where casein was the sole source of protein.

Journal ArticleDOI
TL;DR: The trait residual feed consumption is defined as the regression residual from the optimum model of MECD on MBW 3/4, EMD c and BWG (including an intercept) within short time periods and within diet, and will be used for further study on the possibilities for selection.

Journal ArticleDOI
TL;DR: In this paper, genetic and environmental variances for fat yield were estimated for 26 large Holstein Friesian pedigree herds in the UK, using an Animal Model (AM), and three different transformations of the data to reduce the heterogeneity of variance were tried.

Journal ArticleDOI
TL;DR: Different approaches to modelling are considered, reviewing progress made to date, highlighting current inadequacies and discussing the future potential of these approaches, followed by empirical and mechanistic models of the response of the cow to dietary inputs.

Journal ArticleDOI
TL;DR: The results indicate that the within-litter birth weight distribution is neither an important determinant of the within -litter variation in birth weight, nor an importanteterminant ofThe preweaning death risk of liveborn piglets.

Journal ArticleDOI
TL;DR: With young cattle given high-grain diets processing will produce few if any benefits, but with mixed diets processing of grains except oats will considerably increase digestibility of starch and animal production.

Journal ArticleDOI
TL;DR: In this paper, the role of fat in adaptation to ruminating function and growth of male Holstein calves was studied, and a significant interaction of fat level and feeding system on average daily gain (ADG) was found.

Journal ArticleDOI
TL;DR: Investigation of genotype × environment interaction in farmed rainbow trout indicates sufficient additive genetic determination to enable selection with sufficient accuracy and genetic parameters derived from dam components indicate considerable influence of non-additive genetic and/or common environment effects.

Journal ArticleDOI
TL;DR: A stochastic dynamic programming model is designed on the personal computer to determine the economic optimal replacement policy in swine breeding herds, which maximizes the present value of expected annual net returns over a specified planning horizon, from sows present in the herd and subsequent replacement gilts.

Journal ArticleDOI
TL;DR: The three groups studied of FV, BS and BW cows exhibited significantly different values for bST, INS, IGF-I and milk yield during the first 8 weeks of lactation, but as lactation progressed, all of the investigated plasma parameters returned to values seen in pregnancy.

Journal ArticleDOI
TL;DR: In this article, the authors used conformation traits, stored in computer data banks, for genetic improvement of riding horses and found that the subjective scoring of the judging committee may be biased.


Journal ArticleDOI
TL;DR: It is indicated that selection on SPT of stallions before entering breeding service is an effective tool to breed for ability of performance in competition.

Journal ArticleDOI
TL;DR: Some algorithms intended to predict the evolution of the genetic variance and mean under the infinitesimal model are presented and discussed and the most critical point lies in the prediction of the effect of selection on drift.

Journal ArticleDOI
TL;DR: It is shown that the level of fat may affect ileal AA digestibilities, albeit to a small extent, in SMB and CM diets.

Journal ArticleDOI
TL;DR: This investigation demonstrates the applicability of regression equations to predict certain carcass merit traits in the meat rabbit industry.

Journal ArticleDOI
TL;DR: In this article, a selection experiment was carried out in Angus cattle to compare the effectiveness of selection on 13-month weight (with first mating at 14 months of age) or on 18-month (first mating as 2-year-olds) alongside a control Angus herd (AC0 line) and a yearling mated Hereford herd (HS1 line) was also established.

Journal ArticleDOI
TL;DR: Results of simulation showed that with model 1 sigmoid growth curves were simulated in agreement with literature data, and model 2 was able to regulate the rate of body mass retention and the use of nutrients for either synthesis or oxidation in response to a wide range of different feed intakes.