摘要:

This paper reviews the effect of space allowance, feeding space and floor type in loose housing and the effect of tie stalls versus loose housing on voluntary feed intake, daily gain, feed conversion ratio, carcass and meat quality, and health. Possible physiological mechanisms involved in mediating housing-induced differences in performance are discussed. Furthermore, animal well-being, practical implications and need for future research are commented. From the review the following conclusions are made: (1) Reduced space allowance from 4.7 to 1.5 m2per animal changes feed intake, daily gain and feed conversion ratio to 92, 81 and 115%, respectively, for bulls and steers weighing 250–500 kg. (2) Only minor differences in performance are expected in animals kept on deep bedding and slatted floors when animals are compared at the same space allowance. (3) Reducing space at feed manger to less than one per animal in loose housing systems may reduce performance, but more data are needed to quantify the effects. (4) Compared to tethered animals, loose-housed animals (≥4.7 m2per animal) eat approximately 4% more and have an approximately 4% higher feed conversion ratio, probably due to increased exercise. (5) Loose-housed animals tend to have a higher conformation score and area of longissimus dorsi, less fat, darker meat and a tendency for tougher meat compared to tethered animals. (6) Loose-housed animals have a higher risk of inflamed legs and hoof problems compared to tethered animals. Loose-housed animals also have a higher risk of liver abscesses when they are fed high amounts of concentrates. A low space allowance on slatted floors increases the risk of tail tip lesions. Differences in performance due to space allowance are probably caused by stress. Stress results in changed levels of a multiplicity of hormones orchestrated by the neuropeptides corticotropin releasing factor (CRF), somatostatin (SS) and the catecholamines. A stress-induced reduction of feed intake may be mediated by increased levels of SS, CRF and possibly insulin, glucagon and gastrin. Evidence for the involvement of GH, ACTH, cortisol and testosterone, however, is weak. The mechanisms mediating stress-induced increase on feed conversion ratios are complex and not well understood in ruminants. However, stress may change the function of the gastrointestinal tract, nutrients absorbed, partitioning of nutrients and metabolism. A number of hormones are involved in these mechanisms, including somatotropic hormones. It is concluded that a low space allowance threatens the well-being of bulls and steers.

ISSN:0906-4702    

DOI:10.1080/09064709309410147

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Heritabilities, genetic and phenotypic correlations among yields of milk, fat and protein, fat percentages and protein percentages were estimated using a sire model and multivariate REML for 15357 first-lactation records of the Icelandic dairy cow. These heifers were daughters of 136 young and 55 proven Icelandic bulls. Proven sires were treated as fixed effects and did not contribute to the inter-sire variance. Heritabilities for milk, fat and protein yields and fat and protein percentages were 0.23, 0.17, 0.18, 0.18 and 0.37, respectively. Variance and covariance components were estimated for the same traits, using the first three lactations of 5705 daughters of 138 bulls. Heritabilities for milk yield in the first three lactations were 0.17, 0.12 and 0.10, for fat yield 0.17, 0.10 and 0.09 and for protein yield 0.14, 0.11 and 0.11. Genetic correlation was 0.76 between milk yield in first and second lactation and 0.66 between first and third lactation. Genetic correlations for fat and protein yields ranged from 0.51 to 0.99 and from 0.80 to 0.99 for the percentage traits. Phenotypic correlations between all traits were around 0.40. Repeatabilities were estimated as 0.40, 0.34, 0.40, 0.37 and 0.40 for milk, fat, protein, fat % and protein %, respectively.

ISSN:0906-4702    

DOI:10.1080/09064709309410148

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The relationships between 12 polymorphic systems and bull fertility were studied in the Swedish Red and White dairy cattle population. The material consisted of 1447 young bulls with non-return rates based on at least 500 inseminations each. A reduced animal model including a full additive relationship matrix was used. Multiple regressions were fitted for the estimation of the average gene substitution effects as well as the gene-frequency-independent effects of additive gene action and dominance. To evaluate the results a multivariate analysis of variance, classical segregation analyses and marker frequency studies were performed. Significant associations were found between theF, B, Tf, SandCsystems, and nonreturn rates, but the contribution of the markers to the total variation of non-return rates was small.

ISSN:0906-4702    

DOI:10.1080/09064709309410149

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Grazing Norwegian Red dairy cows were offered one of two roughage supplements ‘baled silage (S) or ryegrass (R)’ on anad libitumbasis for a limited period daily. A third group received concentrate (C). Milk and FCM yields were significantly (P<0.05) influenced by treatment (23.65 and 22.81, 23.20 and 22.05 and 22.58 and 22.73 kg d−1, for S, C and R, respectively). Milk composition was unaltered. The cattle offered ryegrass consumed significantly (P<0.05) more supplementary feed and less pasture, and spent less time grazing and more time ruminating than the other two groups. Cattle with high initial yields, despite higher intakes of both pasture and supplement, had reduced liveweight gains and a faster decline in milk production in comparison with low yielders.

ISSN:0906-4702    

DOI:10.1080/09064709309410150

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The amounts of endogenous fat and fatty acids in growing pigs were determined in digesta from the terminal ileum and in faeces. Graded levels of soybean oil were added to a diet poor in fat, and the endogenous fat secretion was estimated by the regression method. Both in ileal digesta and faecal material low concentrations of fatty acids were found in the extracted fat. The digestibility of fat as well as fatty acids increased when adding fat to the diets, indicating a strong influence of endogenous lipids. The amount of endogenous fat determined at ileum level or in faeces was calculated to be 4.7 and 4.4 g, respectively, per kg dietary DM intake. Although the values were low compared with other published data they correspond to about 10% of the fat intake from a standard Danish grower diet. The amount of endogenous saturated fatty acids in faeces was higher than that of unsaturated but lower than at the terminal ileum level, suggesting microbial hydrogenation of unsaturated fatty acids in the hindgut. The dominating fatty acids at terminal ileum contributed about 2% of dietary fatty acids when pigs were fed a standard Danish diet.

ISSN:0906-4702    

DOI:10.1080/09064709309410151

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A total of 165 group-fed bulls of the Swedish Red and White breed were used to investigate differences in weight gain, feed intake, feed conversion, carcass traits and health when housed either in an insulated building with slatted floors in the pens or in an uninsulated building with partly deep-littered pens. The total pen area was 1.5–2.3 m2/bull in the insulated building and 3.6–5.8 m2/bull in the uninsulated building. The animals were fed a restricted amount of concentrate which was calculated to cover 50% of the energy requirement and grass silagead libitum.They were slaughtered at about 470 kg live weight.

ISSN:0906-4702    

DOI:10.1080/09064709309410152

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Vitamin B12supplementation in the prevention of feed-induced iron deficiency anaemia was evaluated with six treatment groups of mink kits, comprising a control group and five groups fed an anaemiogenic diet either unsupplemented, supplemented with vitamin B12orally, or by intramuscular injection, with iron therapy by ferrous fumarate and cysteine, and iron therapy plus vitamin B12orally. Unsupplemented animals showed symptoms of anaemia including poor growth performance, achromotrichia and poor fur quality. Oral vitamin B12supplementation, but not injections, had some effect in preventing anaemia, indicating an influence on intestinal iron absorption. Iron therapy completely prevented the occurrence of anaemia, and simultaneous addition of vitamin B12had no further positive effect.

ISSN:0906-4702    

DOI:10.1080/09064709309410153

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

An effect of oral vitamin B12administration on growth performance and fur quality characteristics in mink kits fed an anaemiogenic diet has earlier been found. The present data confirmed that kits fed the unsupplemented anaemiogenic diet developed anaemia with low haemoglobin, haematocrit and erythrocyte counts, microcytosis, anisocytosis, and low iron and cobalt contents in the liver. Oral vitamin B12supplementation, but not injections, partly restored iron status, documented by haemoglobin and haematocrit values not being significantly different from the control group, and increased liver cobalt content. Iron therapy alone or combined with vitamin B12resulted in normal iron status. A mechanism for the effect of vitamin B12in preventing anaemia is suggested.

ISSN:0906-4702    

DOI:10.1080/09064709309410154

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue

ISSN:0906-4702    

DOI:10.1080/09064709309410146

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor