Comparison of body weight gain performance and carcass characteristics of the two Ethiopian cattle breeds under natural pasture grazing management

The study was conducted to see the effect of breed and age on the body weight gain and carcass traits of Borana and Kereyu breed kept under natural pasture grazing management at Adami Tulu Agricultural research center. A total of 32 Borana and 32 Kereyu breed bulls of four age categories from each breed were used for the experiment. The parameters showed an increasing trend across age groups for Borana breed. The highest average daily weight gain were registered at the older age (4, 6, 8 years) respectively and the lowest at younger age (2 years). Fat thickness and dressing percentage of Borana breed was high, however statistically it is not significant (p>0.05). Borana breed managed under similar condition deposited significantly higher (p<0.05) internal fat. Similarly hot carcass and rib eye area were also recorded significantly higher (p<0.05) in Borana breed. There was no significant difference (p>0.05) observed between the two breeds among different age groups of bulls with regard to average total body weight gain (ATG) and average daily body weight gain (ADG). Leg total and accumulation of muscle on it was significantly higher (p<0.05) in Borana than Kereyu breed, but leg bone and fat did not significantly (p>0.05) vary. Loin total and accumulation of muscle on it was significantly higher (p<0.05) in Borana breed, but Loin bone and fat did not significantly (p>0.05) vary. Rack total, bone and accumulation of muscle on it was significantly higher (p<0.05) in Borana breed, but fat did not significantly (p>0.05) vary. Breast and Shank total, bone and accumulation of fat on it was significantly higher (p<0.05) in Borana breed, but muscle did not significantly (p>0.05) vary. Shoulder and neck total, muscle and accumulation of fat on it was significantly higher (p<0.05) in Borana breed, but bone did not significantly (p>0.05) vary. Primal cut proportions, total fat and muscle did not significantly (p>0.05) vary between the two breeds but the total bone was different between the two breeds. Generally Borana breed was preferred for good carcass yield than Kereyu breed in natural grazing management.

Introduction

Ethiopian’s economy is based on agriculture, accounting for 55% of the national GDP. The livestock sub-sector accounts for about 40% of the agricultural GDP and 20% of the total GDP with out considering the contribution of livestock in terms of draught power, manure and transport service. The live stock population (in millions) is estimated at 44.3 cattle, 23.6 sheep, 23.3 goats, 2.3 camels, 6.6 equines and 42.9 chickens (Markos Tibbo 2006).

Beef consumers desire disease free animal, cuts of beef that are lean, nutritious and possess desirable eating characteristics such as tenderness, juiciness, color, texture and flavour. Several factors affect these carcass characteristics such as breed, age of the animal and feed. Even though, little work has been done concerning carcass and growth evaluation in Ethiopia (Tesfaye et al.1993; Nega et al 2002) that were accomplished by different institutions, which are available related to factors affecting carcass characteristics. But no detailed investigations have been conducted for these factors in relation to economically important traits (fat thickness, rib eye area, ect) for beef cattle, so beef producers, exporters and consumers in Ethiopia have inadequate information regarding the role of breeds and age on carcass quality and yields. In addition to generate information on carcass, this study will assist to what traits should be considered in the future breed improvement program in the country.

Materials and methods

The experiment was conducted at Adami Tulu Agricultural Research Center (ATARC) situated at a latitude of 70 9'N and 380 7'E longitude with an altitude of 1650 meter above sea level in the semi-arid middle rift valley of Ethiopia. The soil is fine sandy loam with sand silt and clay in the proportion of 34, 48 and 18%, respectively. It receives bimodal unevenly distributed average annual rainfall of 760.9 mm (ATARC 1998). The area is mainly dominated by pennesitum; cinchrus grass species, forbs and acacia trees.

A total of 32 Borana and 32 Kereyu bulls of four age groups (2, 4, 6, 8,) were bought from Borana and Fentale markets respectively. The animals were dewormed and sprayed against internal and external parasites before commencement of the experiments respectively. After two weeks of adaptation period all animals were set aside in to good management natural pasture for grazing and no provision of supplements at day and night for both breed and for all age groups. The grazing time was only 8 hours (8.00 am - 4.00 pm). Each animal was weighed at the beginning of the experiment and every successive weeks thereafter. Average daily gains (g/d) were calculated as differences between final and initial body weights divided by number of days of feeding.

At the end of experiment the animals were fasted for 16 hours with free access to water and were weighed before slaughtered and dressed in the center's abattoir. The empty gut and dressed carcass were weighed separately. Hot carcass weight, and fat deposit (scrotal fat, kidney fat, pelvic fat and omental fat) were also recorded.

Carcass were chilled at -10⁰C and at approximately 24 hrs postmortem the following measurement were taken: Longissimus muscle area at 12th ribs, fat thickness, muscles, fat and bone weight of different parts (leg, loin, shoulder and neck as well as shank and breast). Waterproof paper was used for measuring the rib eye area and fat thickness was measured by using a ruler at the mid point of the 12th and 13th ribs.

Analyses involved 2x4 factorial arrangement with breed (Borana and Kereyu) and age groups (2, 4, 6, 8 years). All data were analyzed using PROC GLM (SAS 2000).

Analyses were conducted with the model that included age groups and breed as a main effects. The following statistical model was used for the analyses:

Result and discussion

Natural pasture grazing performance

Age and breed effect

The natural pasture grazing performance indicator parameters showed an increasing trend across age groups for Borana breed. As indicated on figure 1, the highest average daily body weight gain were registered at the older age (4, 6 and 8 years) respectively and the lowest at younger age (2 years).

The Borana breed with an estimated age of 6 and 8 years, gain averagely close to 0.65 kg per day. The Kereyu breed at the age groups of 4 year gain the highest average body weight from the other age groups of the same breed (0.66 kg) where as lower with increasing and decreasing ages. This is in agreement with the reports at Bako agricutural research center (unpublished) of 90-days experiment to examine the economical age at fattening Horro-Fresian crossbred bulls. The results show that though older animals (37-48 months) ate more feeds and gained more weight than the younger (12-24 months).

As indicated on table 1 no significant difference (p>0.05) was observed between the two breed among different age groups of bulls with regard to average total weight gain (ATG) and average daily gain(ADG) under natural pasture grazing management with no any supplementations.

Table 1. Mean and standard error of Average body weight gain of the two indigenous Ethiopia cattle breed
Traits	Age groups
	2		4		6		8
	Borana	Kereyu	Borana	Kereyu	Borana	Kereyu	Borana	Kereyu
Average total body weight gain	43.88 ± 2.14^a	45.50 ±3.06^a	56.25 ± 2.90 ^a	59.25 ± 2.38^a	58.63 ±2.55^a	55.38 ±3.78^a	58.50 ±3.01^a	54.17 ± 4.57^a
Average daily body weight gain	0.49 ± 0.02^a	0.51 ± 0.03^a	0.63 ± 0.03^a	0.66 ± 0.03^a	0.65 ± 0.03^a	0.62 ± 0.04 ^a	0.65 ±0.03^a	0.60 ± 0.05^a
*Different letters across row with the same age groups indicate significance (p<0.05)

This is in agreement with the reports of Tatek et al (2006 under publishing), There is no significant difference (p>0.05) in Average daily gain (ADG) and Total gain (TG) between the two breeds at each of the same age groups under feedlot management.

Borana breed managed under similar condition deposited significantly higher (p<0.05) pelvic, scrotal and kidney fat than Kereyu breed (Table 2).

Table 2. Mean and standard error of carcass yield performance of the two Ethiopian indigenous cattle breed
Parameters	Breed
Parameters	Borana	Kereyu
Hot carcass, kg	128.08 ± 11.89^a	106.29 ± 9.96^b
Dressing percentage	47.49 ± 2.08^a	44.93 1.16^a
Pelvic fat, g	559.09 ± 90.43^a	266.65 ±103.56^b
Scrotal fat, kg	1.26 ± 0.17^a	0.77 ± 0.12^b
Heart fat, g	507.54 ± 218.19^a	135.85 ± 54.66^a
Kidney fat, kg	1.66 ± 0.22^a	0.98 ± 0.15^b
Fat thickness, mm	4.25 ±0.71^a	3.25 ± 0.55^a
Rib eye area	223.17 ± 14.70^a	173.50 ± 12.50^b
*Different letters across row indicate significance (p<0.05)

Similarly hot carcass and rib eye area were recorded higher (p<0.05) in Borana breed than Kereyu breed. Fat thickness and dressing percentage of Borana breed higher than Kereyu breed, even though not statistically significant (p>0.05). This is in agreement with the reports of Tesfaye Lemma et al (2007) on the effect of four different basal diets on the carcass composition of finishing Borana bulls, There was no significant difference in heart and Omental and mesenteric fat weights, and back fat thickness among rations.

Least squares means of carcass components for Borana and Kereyu breed are presented in tables 3 and 4.

Leg total and accumulation of muscle on it was significantly higher (p<0.05) in Borana than Kereyu breed, but leg bone and fat did not significantly (p>0.05) vary (Table 3).

Table 3. Mean and standard error of carcass component yield performance of the two indigenous Ethiopia cattle
Carcass components		Breed
Primal Cuts	Components, kg	Borana	Kereyu
Leg	Leg total	22.00 ±1.76^a	18.65 ± 1.35^b
	Bone	3.92 ± 0.33^a	3.88 ± 0.33^a
	Muscle	15.82 ±1.22^a	12.93 ±0.98^b
	Fat	1.81 ± 0.31^a	1.38 ± 0.16^a
Loin	Loin total	7.38 ± 0.69^a	6.12 ± 0.4^b
	Bone	1.29 ± 0.09^a	1.36 ± 0.11^a
	Muscle	4.79 ± 0.46^a	3.70 ± 0.29^b
	Fat	1.05 ± 0.17^a	0.89 ± 0.15^a
Rack	Rack total	9.13 ± 0.82^a	7.58 ±0 .52^b
	Bone	2.51 ± 0.16^a	2.21 ± 0.14^b
	Muscle	5.23 ± 0.51^a	4.43 ± 0.37^b
	Fat	1.17 ± 0.21^a	0.91 ± 0.13^a
Breast and Shank	Breast and Shank total	7.71 ± 0.72^a	6.10 ± 0.45^b
	Bone	2.05 ± 0.13^a	1.86 ± 0.12^b
	Muscle	4.08 ± 0.45^a	3.42 ± 0.24^a
	Fat	1.38 ± 0.23^a	0.78 ± 0.09^b
Shoulder and neck	Shoulder and neck total	19.93 ± 2.19^a	15.79 ± 1.37^b
	Bone	3.96 ± 0.37^a	3.58 ± 0.32^a
	Muscle	14.40 ± 1.82^a	11.02 ± 0.93^b
	Fat	1.57 ± 0.29^a	1.13 ± 0.19^b
*Different letters across row indicate significance (p<0.05)

Loin total and accumulation of muscle on it was significantly lower (p<0.05) in Kereyu than Borana breed, but Loin bone and fat did not significantly (p>0.05) vary.

Rack total, bone and accumulation of muscle on it was significantly higher (p<0.05) in Borana than Kereyu breed, but fat did not significantly (p>0.05) vary.

Breast and Shank total, bone and accumulation of fat on it was significantly higher (p<0.05) in Borana than Kereyu breed, but muscle did not significantly (p>0.05) vary.

Shoulder and neck total, muscle and accumulation of fat on it was significantly higher (p<0.05) in Borana than Kereyu breed, but bone did not significantly (p>0.05) vary.

Primal cut proportions (leg, loin, breast and Shank and Shoulder and neck) did not significantly (p>0.05) vary within the two breed (Table 4).

Table 4. Mean and standard error of carcass component yield performance of the two indigenous Ethiopia cattle
Carcass components		Breed
Carcass components		Borana	Kereyu
Primal cut proportions	Leg proportion	33.607 ±0.777^a	34.353 ± 0.660^a
	Loin proportion	11.245 ±0.630^a	11.286 ± 0.344^a
	Rack proportion	13.824 ±0.318^a	14.072 ± 0.428^a
	Breast and Shan proportion	11.740 ±0.403^a	11.466 ± 0.670^a
	Shoulder and neck proportion	29.585 ±0.809^a	28.824 ± 0.799^a
Total parts	Total bone	21.722 ±0.793^b	24.358 ± 0.664^a
	Total muscle	68.205 ±0.991^a	66.438 ±0.647^a
	Total fat	10.073 ±1.021^a	9.204 ± 0.601^a
*Different letters across row indicate significance (p<0.05)

Total muscle and total fat did not vary (p>0.05) between the two breed, but the total bone was significantly (p<0.05) vary between the two breeds.

This result is similar with the report of Tesfaye Lemma et al (2006) on the effect of four different basal diets on the carcass composition of finishing borana bulls, There is slight variations were observed in bone, fat and lean meat weight for different primal cuts, the difference among rations was not significant except for loin muscle, rack muscle and breast and shank muscle weights.

Generally Borana breed was preferred for good carcass yield than Kereyu breed in natural grazing management.

Conclusion and recommendation

Acknowledgement

We want to thank Ethiopia Institute Agricultural Research (EIAR) for funding this experiment. Lastly, also Mideksa Assefa, Tesfaye Baye and Meseret Terefa contributed in animal management and data record.

References

ATARC (Adami Tulu Agricultural Research Center) 1998 Thirty years of research experience. Oromiya Agricultural Research Coordination service. Bulletin no 1

Nega Tolla, Tadele Mirkena and Asfaw Yimegnuhal. 2002 Comparision of the efficiency of compensatory growth of Borana and Arsi cattle in Ethiopia. Ethiopian Journal of Animal Production 2 (1):11-23

Tesfaye Alemu Tucho and Abule Ebro 1993 Economics of feeding old oxen for beef production. pp. 246-250. In Proceedings of the 4^th National Livestock Improvement Conference held in Addis Ababa, Ethiopia, Nov. 13-15, 1991 IAR, Addis Ababa 312.pp

Tesfaye Lemma and Tesfa Geleta 2006 Study of carcass quality of Kereyu bulls on different finishing rations. In proceedings of the 14^th annual conference of the Ethiopian Society of Animal Production (ESAP) held in Addis Ababa, Ethiopia, August 5-7, 2006, ESAP, Addis Ababa. Pp. 53-57

Comparison of body weight gain performance and carcass characteristics of the two Ethiopian cattle breeds under natural pasture grazing management

Mohammed Negash, Tesfaye Lemma, Takele Feyera, Hailu Dadi, Tatek Woldu, Tesfaye Alemu and Birhanu Shilima

Adami Tulu Agricultural research center, P.O.Box 35, Ziway, Ethiopia
bedhane@yahoo.com

Abstract

Introduction

Materials and methods

Result and discussion

Natural pasture grazing performance

Age and breed effect

Conclusion and recommendation

Acknowledgement

References

Comparison of body weight gain performance and carcass characteristics of the two Ethiopian cattle breeds under natural pasture grazing management

Mohammed Negash, Tesfaye Lemma, Takele Feyera, Hailu Dadi, Tatek Woldu, Tesfaye Alemu and Birhanu Shilima

Adami Tulu Agricultural research center, P.O.Box 35, Ziway, Ethiopia bedhane@yahoo.com

Abstract

Introduction

Materials and methods

Result and discussion

Natural pasture grazing performance

Age and breed effect

Conclusion and recommendation

Acknowledgement

References

Adami Tulu Agricultural research center, P.O.Box 35, Ziway, Ethiopia
bedhane@yahoo.com