LIVE BODY MEASUREMENTS FROM FIRST-CROSS AND BACKCROSS FEMALES

1990 ◽  
Vol 70 (2) ◽  
pp. 389-400
Author(s):  
R. M. McKAY ◽  
G. W. RAHNEFELD ◽  
G. M. WEISS ◽  
H. T. FREDEEN ◽  
J. A. NEWMAN ◽  
...  

Live body measurements were evaluated in F1 and backcross females ranging in age from 1 to 5 yr, inclusive, maintained at Manyberries, Alberta (extensive range management) and Brandon, Manitoba (semi-intensive management). The objectives of this study were to examine measures of size, weight, and subcutaneous fat cover to determine: (1) their relationship with age of cow; (2) the impact of varying proportions of Simmental and Charolais breeding; (3) the similarity between generalized and specific contrasts involving 1/4 and 3/4 European continental and British breeding; and (4) differences between four consecutive lactations and three out of four possible lactations. Body length, height at the hips and withers, and cow weight at weaning reached or approached their mature levels by 5 yr of age and subcutaneous fat cover was more dependent upon environmental factors than age. Incremental increases in Simmental and Charolais breeding in the cow crosses resulted in corresponding increases in body size and weight. The generalized comparisons between 1/4 and 3/4 Simmental, Charolais, Angus, Hereford, and Shorthorn breeding provided useful information regarding generic comparisons but there was a need for evaluating specific backcross comparisons. Cows experiencing four consecutive lactations, compared to those that had three lactations out of a possible four, had decreased physical dimensions in addition to weight and subcutaneous fat cover. Key words: Beef cattle, body measurements, backcrosses, heifers, cows

1990 ◽  
Vol 70 (1) ◽  
pp. 45-54
Author(s):  
R. M. McKAY ◽  
G. W. RAHNEFELD ◽  
G. M. WEISS ◽  
H. T. FREDEEN ◽  
J. A. NEWMAN ◽  
...  

Calving ease and calf mortality were evaluated for calves out of first-cross and backcross cows maintained under two contrasting environments. All calves were sired by Limousin bulls. The dam crosses at Brandon were HA, SN, CN, ACA, CCA, ASA, SSA, HCH, CCH, HSH, SSH, NCN, CCN, SSN, and NSN with H = Hereford, A = Angus, N = Shorthorn, C = Charolais, S = Simmental and a SSA cross was 3/4 Simmental-1/4 Angus. At Manyberries the dam crosses were HA, SN, ASA, SSA, HSH, SSH, NSN, and SSN. The calves were born between 1982 and 1986, inclusive, at Brandon, Manitoba (semi-intensive management) and Manyberries, Alberta (extensive range management). At Brandon, when calf birth weight was not a covariate, the significant dam cross contrasts for calving ease included less difficulty for SN cows than either the SSN or NSN cows, and for 3/4 A-1/4 European continental (E) cows than 1/4A–3/4E cows. When adjusted to a common calf birth weight the significant contrasts were HA cows had more difficulty than SN cows and the combination of SN and CN cows, SN cows had less difficulty than NSN cows, and 3/4A–1/4E cows had less difficulty than 1/4A–3/4E cows. At Manyberries, regardless of whether calf birth weight was excluded or included as a covariate, the SN cows had less difficulty than the SSN and the SSN cows had less difficulty than NSN cows. No significant dam cross comparisons were observed for calf mortality scores. Adjusting the calving ease scores to a constant calf birth weight did not significantly alter the magnitude of the contrasts but it did shift their probability levels. Location and sex of calf effects were not significant except for calving ease at Brandon where more difficulty was associated with male calves than female calves. Key words: Beef cattle, crossbreeding, backcrosses, calving, mortality


1990 ◽  
Vol 70 (1) ◽  
pp. 35-44 ◽  
Author(s):  
R. M. McKAY ◽  
G. W. RAHNEFELD ◽  
G. M. WEISS ◽  
H. T. FREDEEN ◽  
J. A. NEWMAN ◽  
...  

Preweaning performance was evaluated for calves out of first-cross and reciprocal back-cross cows maintained under two contrasting environments. All cows were bred to Limousin bulls and the calves were born between 1982 and 1986, inclusive, at Brandon, Manitoba (semi-intensive management) and Manyberries, Alberta (extensive range management). Dam cross comparisons revealed that calves out of Hereford × Angus dams were inferior to calves out of European continental × British dams for all preweaning traits at both locations. Comparisons between calves out of F1 dams and calves out of backcross (1/4 or 3/4 European continental) dams generally favored the calves out of F1 females. Specific and nonspecific comparisons between the reciprocal backcrosses demonstrated that calves out of dams with 3/4 European continental breeding were heavier and grew faster than calves out of dams with 1/4 European continental breeding. Male calves exceeded female calves for all preweaning traits and calves born at Manyberries were heavier and grew faster than calves born at Brandon. Key words: Beef cattle, preweaning growth, crossbreeding, backcrosses


1993 ◽  
Vol 73 (4) ◽  
pp. 805-821
Author(s):  
D. R. C. Bailey ◽  
T. Entz ◽  
G. W. Rahnefeld ◽  
R. M. McKay ◽  
H. T. Fredeen ◽  
...  

Growth patterns of first-cross (F1) and reciprocal backcross cows, 3–5 yr old, were evaluated under two contrasting environments: extensive range conditions at Manyberries, Alberta, and semi-intensive management at Brandon, Manitoba. Cows resulting from crossing Hereford (H) × Angus (A), Simmental (S) × Shorthorn (N), Charolais (C) × Shorthorn and reciprocal backcrosses from Charolais × Hereford (CH), Charolais × Angus (CA), Charolais × Shorthorn (CN), Simmental × Hereford (SH), Simmental × Angus (SA), and Simmental × Shorthorn (SN) were evaluated at Brandon. At Manyberries, HA, SN and reciprocal backcrosses of SH, SA and SN were evaluated. All cows were bred to Limousin (L) bulls. Cow weights and backfat estimates were recorded at breeding, calving and weaning. The HA cows were the lightest group for all weigh periods at both locations. At all weigh periods, the SSN (3/4 S 1/4 N) dam crosses at Manyberries and the CCN (3/4 C 1/4 N) and CCH (3/4 C 1/4 H) at Brandon were the heaviest. At Brandon, females gained weight during gestation and usually lost weight during summer nursing. Cows at Manyberries usually gained weight during nursing, with significant gestation weight loss. Nursing status of the cow had a significant effect on weight change, with barren status providing an opportunity for large compensatory gains. The CN dams were significantly heavier at all weigh periods than their 1/4 C back-crosses. At Brandon, the SN dam cross weights exceeded those of their reciprocal backcrosses at breeding, calving and weaning and at calving for the 1/4 S dams. At Manyberries, SN weights exceeded those of the 3/4 S crosses at weaning. Over the duration of study, average backfat estimates for cows at Brandon exceeded those at Manyberries (10.8 and 8.6 mm, respectively). Specific dam crosses performed differently at the two locations, and commercial cattlemen need to closely evaluate the F1 and backcross comparisons to determine the optimal level of performance under their particular management and environmental conditions. Key words: Beef cattle, growth, nursing status, crossbreeding, environment


2021 ◽  
Author(s):  
Joel L Pick ◽  
Hannah Lemon ◽  
Caroline Elizabeth Thomson ◽  
Jarrod Hadfield

The major frameworks for predicting evolutionary change assume that a phenotype's underlying genetic and environmental components are normally distributed. However, the predictions of these frameworks may no longer hold if distributions are skewed. Despite this, phenotypic skew has never been decomposed, meaning the fundamental assumptions of quantitative genetics remain untested. Here, we demonstrate that the substantial phenotypic skew in the body size of juvenile blue tits (Cyanistes caeruleus) is driven by environmental factors. Although skew had little impact on our predictions of selection response in this case, our results highlight the impact of skew on the estimation of inheritance and selection. Specifically, the non-linear parent-offspring regressions induced by skew, alongside selective disappearance, can strongly bias estimates of heritability. The ubiquity of skew and strong directional selection on juvenile body size implies that heritability is commonly overestimated, which may in part explain the discrepancy between predicted and observed trait evolution.


2020 ◽  
Vol 58 (9) ◽  
pp. 48-51
Author(s):  
Firangiz Agadadash Jabrailova ◽  

The article considers the medical environmental assessment of the effects of abiotic factors on human health, as well as analyzes the impact of extreme environmental factors on the prevalence of disease. It is explained that rhythmic changes in the natural environment cause the spread of different diseases among people. Key words: abiotic, photosynthesis, radiation, electromagnetic, meteorological, meteoneurosis, aerophobia


1994 ◽  
Vol 74 (4) ◽  
pp. 613-619 ◽  
Author(s):  
J. A. Newman ◽  
A. K.W. Tong ◽  
G. W. Rahnefeld ◽  
J. E. Lawson ◽  
H. T. Fredeen ◽  
...  

Data on post-weaning gains and final test weights are reported for 2010 Limousin-sired steer and heifer calves from cows of 15 different F1 cross and back-cross breed types incorporating Charolais, Simmental, Hereford, Angus and Shorthorn breeding. Calves representing all 15 dam breed types were born and weaned under semi-intensive management at Brandon, Manitoba, then finished there on a self-fed all-concentrate diet. A subset representing eight dam breed crosses was born and weaned under extensive range management at Manyberries, Alberta, then fed at Lacombe, Alberta, on a lower energy diet of silage and concentrate mixed and fed to appetite in bunks. A comparison of common breed types revealed that the Brandon calves were lighter at weaning but gained more rapidly in the post-weaning test than the Manyberries/Lacombe calves. Under the Lacombe feeding regime, there were no significant differences in rate of gain on the feedlot test, but progeny of breed types containing some Simmental breeding generally reached a higher final weight than progeny of Hereford × Angus cows because of differences in weight at the beginning of the test. Under the higher energy feeding regime at Brandon, progeny of breed types containing Charolais or Simmental generally gained faster and attained higher final weights than progeny of Hereford × Angus cows. Progeny of Charolais × British and Simmental × British F1 cross cows generally performed as well as, or better than, the progeny of either backcross. Key words: Beef cattle, post-weaning gain, crossbred dam, back-cross dam, European cross


1999 ◽  
Vol 1 (1) ◽  
pp. 1-25 ◽  
Author(s):  
A. H. Johns

Job (Ayyūb) is a byword for patience in the Islamic tradition, notwithstanding only six Qur'anic verses are devoted to him, four in Ṣād (vv.41-4), and two in al-Anbiyā' (vv.83-4), and he is mentioned on only two other occasions, in al-Ancām (v.84) and al-Nisā' (v.163). In relation to the space devoted to him, he could be accounted a ‘lesser’ prophet, nevertheless his significance in the Qur'an is unambiguous. The impact he makes is achieved in a number of ways. One is through the elaborate intertext transmitted from the Companions and Followers, and recorded in the exegetic tradition. Another is the way in which his role and charisma are highlighted by the prophets in whose company he is presented, and the shifting emphases of each of the sūras in which he appears. Yet another is the wider context created by these sūras in which key words and phrases actualize a complex network of echoes and resonances that elicit internal and transsūra associations focusing attention on him from various perspectives. The effectiveness of this presentation of him derives from the linguistic genius of the Qur'an which by this means triggers a vivid encounter with aspects of the rhythm of divine revelation no less direct than that of visual iconography in the Western Tradition.


2020 ◽  
Vol 18 (5) ◽  
pp. 891-908
Author(s):  
T.A. Smirnova

Subject. This article deals with the issues of functioning of the region as a system. Objectives. The article aims to identify the problems of the region's functioning as a system, develop methodological tools to monitor the sustainable development of the Siberian Federal District territories, and determine the the impact of socio-economic and environmental factors on the sustainable development of the region as a whole. Methods. For the study, I used the methods of theoretical, statistical, and empirical analyses taking into account an integrated approach. Results. The article reveals the impact of some individual components of regional development on the sustainability of the territorial system as a whole. Relevance. The results of the study can be used to analyze the sustainability of regions' development.


Author(s):  
L.Z. Khalishkhova ◽  
◽  
A. Kh. Temrokova ◽  
I.R. Guchapsheva ◽  
K.A. Bogаtyreva ◽  
...  

Ensuring the sustainable development of agroecosystems requires research into the justification of the impact of environmental factors on the formation of territorial agroecosystems and identifies ways to take them into account in order to justify management decisions and ensure environmental safety. The main goal of the research within the article is to identify the most significant environmental factors in predicting the formation of agroecosystems. Provisions are devoted to the study of the laws governing the functioning of agroecosystems in order to increase their stability. The methods of comparative analysis, generalization, abstraction, logical analysis are applied. A number of provisions are formulated regarding ways to account for the influence of factors on the formation of key elements of agroecosystems.


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