Aus dem Institut für Nutztierwissenschaften der Humboldt-Universität zu Berlin

Dissertation

Pre-weaning growth performance of hair x mutton sheep crosses and post-weaning growth and physiological reaction in response to different feeding levels and high ambient temperature

zur Erlangung des akademischen Grades
doctor rerum agriculturarum (Dr. rer. agr.)

vorgelegt der
Landwirtschaftlich Gärtnerische Fakultät
der Humboldt-Universität zu Berlin

von
Herrn Willard Lumoma Bboonko Simukali

Dekan: Prof. Dr. Dr. h.c. E. Lindemann

Gutachter:
1. Prof. Dr. K. J. Peters
2. Prof. Dr. G. Seeland

eingereicht am:08.03.1999

Datum der Promotion:16. Juli 1999

Kurzfassung

Die Erhöhung der tierischen Leistung von Nutztieren in den Tropen kann am schnellsten durch Kreuzungszucht realisiert werden.

Ziel der vorliegenden Arbeit war es, die Leistung von Kamerun-Schafen (C) und Ihren Kreuzungen (Kamerun x Fleischschaf, F1) und (F2 aus Kamerun x Milchschaf) unter verschiedenen Fütterungs- und Haltungsbedingungen zu vergleichen.

Folgende Merkmale wurden analysiert:

• Wachstum vor dem Absetzen über 90 Tage; 127 Tiere; C, F1 und F2,
• Wachstum nach dem Absetzen unter verschiedenen Fütterungsbedingungen; Wechsel vom 1,5-fachen des Erhaltungsbedarfs zu ad libitum Fütterung und umgekehrt; 6 Wochen Dauer; 30 Tiere; C, F1 und F2,
• Haltung der Lämmer unter zeitlich begrenztem Temperaturstress (8 Stunden täglich bei 31°C und 50% rel. Luftfeuchte): Dauer 12 Wochen; 10 Tiere C und F,
• Analyse von Schlachtkörpern nach Versuchsende jeden Versuches; 40 Lämmer, C, F1 und F2.

Ergebnisse:

• Während der ersten Aufzugphase zeigten die Kreuzungstiere mit 213g/Tag (F1) und 236 g/Tag (F2) eine um 50 bzw. 65% erhöhte Lebendmassezunahme gegenüber den Kamerun-Lämmern (143g/Tag). Die Differenz zwischen F1 und F2 resultierte aus der unterschiedlichen Milchleistung der Muttertiere.

• Der zeitlich begrenzte Hitzestress führte zu keinen unterschiedlichen physiologischen Reaktionen zwischen den Rassen.
• Es gab keine signifikanten Unterschiede hinsichtlich der relativen Körperzusammensetzung zwischen den Rassen. Die Kreuzungstiere hatten eine signifikant erhöhte Masse des Verdauungstraktes.

Schlußfolgerungen:

Kreuzungszucht zwischen indigenen und exotischen Rassen ist in den Tropen eine geeignete Methode die Fleischerzeugung zu erhöhen, allerdings nur, wenn die Futterversorgung gesichert ist. Hitzestress über eine begrenzte Zeit am Tag ist für die getesteten Rassen ohne Leistungseinbußen verträglich.

Abstract

Crossbreeding between indigenous and exotic sheep breeds is the fastest method of increasing the performance of sheep in the tropics.

The aim of this work was to assess the performance of Cameroon sheep (C) and their crossbreds (Cameroon x Mutton, F1) and (F2 from Cameroon x Milk sheep) under different housing and feeding conditions.

The following traits were analysed:

• Pre-weaning performance during the first 90 days; 127 animals, C, F1 and F2.
• Post-weaning growth performance at different feeding levels; changing from 1.5 x maintenance to ad libitum feed intake and vice versa; duration 6 weeks; 30 animals; C, F1 and F2.
• Housing of lambs under temporal heat stress (8 hours daily at 31°C and 50% relative humidity); duration 12 weeks; 10 animals, C and F2
• Carcass traits; 40 lambs, C, F1 and F2.

Results:

• During the pre-weaning period the crossbred lambs showed a higher live weight gain than the Cameroon lambs, 213g/d (F1); 236g/d (F2) and 143g/d (C) respectively, that is an increase of 50% and 65% resp. The differences between the F1 and F2 resulted from the different milk yields of the ewes.
• The heat stress over 8 hours did not lead to different physiological reactions between the breeds.
• There were no significant differences in the relative carcass traits between the breeds. The GIT-weight was increased significantly in the crossbreds.

Conclusion:

Crossbreeding of indigenous and exotic sheep breeds is a suitable method for increasing meat production in the tropics if the feed supply is guaranteed. Heat stress over a limited time is not crucial for the performance of all breeds.

Eigene Schlagworte: Schafe, Kreuzung, Wachstumsleistung, Hitzestress, Fleischqualität

Keywords: sheep, crossbreeding, growth performance, heat stress, carcass traits

Dedication

Dedicated to the whole clan with its strong roots in Kalomo, Choma, Gwembe Valley and Namwala. Dedicated especially to the children.

Table of contents

• Zusammenfassung
• 1  Introduction
  • 1.1 Statement of the problem
• 2  Review of literature
  • 2.1 Production performance of sheep with relevance to the tropics
    • 2.1.1 Performance of mutton sheep breeds and their crosses under tropical conditions
      • 2.1.1.1 Growth performance
      • 2.1.1.2  Importance of vlies
      • 2.1.1.3 Milk yield performance
    • 2.1.2 Effect of restricted feeding and realimentation on growth
      • 2.1.2.1 Effect of restricted feeding
      • 2.1.2.2 Effect of realimentation on growth
    • 2.1.3 Physiological reaction to high ambient temperature
      • 2.1.3.1 Effect on body temperature
      • 2.1.3.2  Effect on breathing rate
      • 2.1.3.3 Effect on feed intake and digestibility
      • 2.1.3.4 Effect on production
• 3  Main findings from survey of literature and objective
• 4  Materials and Methods
  • 4.1 Comparative pre-weaning growth performance of lambs of different genotypes
    • 4.1.1 Animals used
    • 4.1.2 Feeding
    • 4.1.3 Housing of animals
    • 4.1.4 Management of experimental animals
  • 4.2 Milk yield performance of Cameroon and C1 ewes rearing lambs using the suckling method
    • 4.2.1 Animals used
    • 4.2.2 Feeding
    • 4.2.3 Housing of animals
    • 4.2.4 Management of experimental animals
  • 4.3 Comparative post-weaning growth performance of lambs of different genotypes
    • 4.3.1 Influence of different feeding levels
      • 4.3.1.1 Animals used
      • 4.3.1.2 Feeding
      • 4.3.1.3 Housing of animals
      • 4.3.1.4 Management of experimental animals
    • 4.3.2 Reaction to high ambient temperature during the day and of alternating feeding levels
      • 4.3.2.1 Animals used
      • 4.3.2.2 Feeding
      • 4.3.2.3 Housing of animals
      • 4.3.2.4 Management of experimental animals
  • 4.4 Carcass evaluation
  • 4.5 Analysis of data
  • 4.6 Basic models of the experiments
• 5  Results
  • 5.1 Pre-weaning growth performance of lambs
  • 5.2 Milk yield performance of Cameroon and C1 ewes using the suckling method
  • 5.3 Comparative post-weaning growth performance of lambs of different genotypes
    • 5.3.1 Influence of different feeding levels on performance
    • 5.3.2 Reaction to high ambient temperature during the day and of alternating feeding levels
      • 5.3.2.1 Post-weaning growth performance
      • 5.3.2.2 Physiological reaction to high ambient temperature
  • 5.4 Carcass evaluation
    • 5.4.1 Influence of different feeding levels on performance
    • 5.4.2 Reaction to high ambient temperature during the day and of alternating feeding levels
    • 5.4.3 Distribution of internal fat in response to different levels of feeding under stall temperature conditions (1995) and high ambient temperature during the day with alternating feeding levels (1996)
• 6  Discussion
  • 6.1 Comparative pre-weaning growth performance of lambs of different genotypes
  • 6.2 Milk yield performance of Cameroon and C1 ewes using the suckling method
  • 6.3 Comparative post-weaning growth performance of lambs of different genotypes
    • 6.3.1 Influence of different feeding levels on performance
    • 6.3.2  Reaction to high ambient temperature during the day and of alternating feeding levels
  • 6.4 Pattern of deposition of kidney and mesenteric fat of slaughtered lambs following exposure to different feeding levels under stall ambient temperature conditions (1995) and to high ambient temperature during the day with alternating feeding levels (1996)
  • 6.5 Limitations related to experimental conditions
• 7  Summary
  • 7.1 Comparative pre-weaning growth performance of lambs of different genotypes
  • 7.2 Milk yield performance of Cameroon and C1 ewes using the suckling method
  • 7.3  Comparative post-weaning growth performance of lambs of different genotypes
    • 7.3.1 Influence of different feeding levels on performance
    • 7.3.2 Reaction to high ambient temperature during the day and of alternating feeding levels
  • 7.4 Carcass evaluation
    • 7.4.1 Influence of different feeding levels on performance
    • 7.4.2  Reaction to high ambient temperature during the day and of alternating feeding levels
• List of Abbreviations
• Bibliography
• Acknowledgements
• Lebenslauf
• Eidestattliche Erklärung

Tables

• Table 1: Birth weight and Average Daily Gain performance of hair sheep and their crosses
• Table 2: Effects of increasing ambient temperature on the rectal and rumen temperature of wethers fed a low, average and high energy ration.
• Table 3: Effect of increasing ambient temperature on breathing rate of wethers fed a low, average and high energy ration
• Table 4: Effect of increasing ambient temperature (°C) on DM and raw fibre intake
• Table 5: Results of ANOVA for birth weight and pre-weaning growth of lambs
• Table 6: Effects of genotype and sex on birth weight and pre-weaning live weight of lambs, , LSQ-means ± se
• Table 7: Effects of genotype and sex on pre-weaning average daily gain of lambs, LSQ-means ± se
• Table 8: Results of ANOVA for milk yield performance of ewes
• Table 9: Influence of genotype on milk yield performance of ewes during 9 weeks of lactation, means ± se
• Table 10: Results of ANOVA for post-weaning growth, energy and feed intake of lambs
• Table 11: Effects of genotype and feeding level on post-weaning growth, energy and feed intake, means ± se
• Continuation: Table 11
• Table 12: Means and standard errors of live body weight, growth and feed intake of lambs of different genotypes in response to different feeding levels
• Table 13: Results of ANOVA of post-weaning live weight, ADG and energy and feed intake of lambs per week
• Table 14: Means and standard errors of post-weaning live weight, ADG and energy and feed intake of lambs per week by genotype and sex
• Continuation: Table 14
• Table 15: Results of ANOVA for rectal temperature and breathing rate per minute during the high, low and high feeding phases and over the whole experimental period
• Table 16: Rectal temperature and breathing rate per minute of lambs during the different feeding level phases at high and low ambient temperature, means ± se
• Table 17: Results of ANOVA of absolute and relative weights of important parts of the carcass of lambs and of measures of carcass quality, 1995
• Continuation: Table 17
• Table 18: Means and standard errors of absolute and relative weights of important parts of the carcass of lambs and of measures of carcass quality, 1995
• Continuation: Table 18
• Continuation: Table 18
• Table 19: Results of ANOVA of absolute and relative weights of important parts of the carcass of lambs and of measures of carcass quality, 1996
• Continuation: Table 19
• Continuation: Table 19
• Table 20: Means and standard errors of absolute and relative weights of important parts of the carcass of lambs and of measures of carcass quality, 1996
• Continuation: Table 20
• Continuation: Table 20
• Table 21: Results of ANOVA of relative deposition of total fat*, kidney and mesenteric fat of slaughtered lambs by treatment, genotype and sex in 1995 and 1996
• Table 22: Relative means and standard errors reflecting the pattern of deposition of total fat, kidney and mesenteric fat of slaughtered lambs by treatment, genotype and sex in 1995 and 1996.

Images

• Fig. 1: Milk performance of Cameroon and C1 ewes during 9 weeks of lactation
• Fig. 2: Post-weaning live body weight of lambs: Reaction to different feeding levels
• Fig. 3: Average Daily Gain in response to High-Low feeding
• Fig. 4: Average Daily Gain in response to Low-High feeding
• Fig. 5: Mean percentage wheat straw intake of lambs in the High-Low feeding treatment
• Fig. 6: Mean daily concentrated feed intake of lambs subjected to high ambient temperature and alternating feeding levels
• Fig. 7: Intake of energy above maintenance level by lambs subjected to high ambient temperature and alternating feeding levels
• Fig. 8: Mean daily wheat straw intake of lambs subjected to high ambient temperature and alternating feeding levels
• Fig. 9: Mean percentage wheat straw intake of lambs in response at high temperature and alternating feeding levels
• Fig. 10: Effect of fluctuating temperatures (high and low during the day and at night, respectively) on rectal temperature of Cameroon and Cameroon x Mutton lambs during the post-weaning growth phase
• Fig. 11: Effect of fluctuating temperatures (high and low during the day and at night, respectively) on breathing rate of Cameroon and Cameroon x Mutton lambs during the post-weaning growth phase