Crossbreed or Purebred, Which Is Better?

Abstract

The worldwide goat population has surpassed one billion individuals and there are more than 300 different goat varieties in the world, including purebred and crossbred. Presently, many studies on the characterization of local goats have been conducted to determine genetic diversity and find associations with specific traits, both for optimal performance improvement and adaptation to the environment. Purebred goats have very high adaptability to various environmental conditions, while crossbreds may not be as adaptable as purebreds. Farmers and associations were interested in increasing production and stabilizing performance by using better selection approaches. The selection for a standard appearance helped in the reinforcement of breed identity. The new commercial breed trend threatens to reduce the diversity of the global gene pool, whose diversity ensures goat survival in a changing future. Crossbreeding is most effective when the strengths and weaknesses of different breeds are identified and the appropriate role of a breed in a crossbreeding program is determined. Some exotic goats have been crossed with indigenous varieties in an attempt to increase milk and meat production, but the results have been mixed. The risk of genetic degradation in native pure breeds can be reduced while increasing performance and production through controlled crossbreeding.

1. Introduction

Domestication of goats began around 8000–7000 BC in the mountainous regions of West Asia. Domesticated goats (Capra aegagrus hircus) are descended from three groups of domesticated wild goats: bezoar goats (C. aegagrus) and the majority of goats raised in Asia are of the bezoar breed [1]. Local goats are used widely in countries all over the world. Presently, many studies on the characterization of local goats have been conducted in order to determine genetic diversity and find associations with specific traits, both for optimal performance improvement and adaptation to the environment [2, 3, 4]. Exploration of genetic diversity is particularly valuable for collecting information on genetic quality improvement and the conservation of local goats [5]. There is evidence that goats spread widely and contributed significantly to the development of Neolithic agricultural techniques wherever they went [6]. Nowadays, there are more than 300 different goat varieties in the world, including purebred and crossbred. The worldwide goat population has surpassed one billion individuals [7]. Goats have very high adaptability to various environmental conditions. According to several reports, goats can thrive in a wide range of environments, including human settlements, tropical rainforests, dry and hot deserts, and cold highlands. Therefore the history of each current breed must be determined, and genetic markers must be identified through DNA analysis [8].

Farmers were interested in increasing production and stabilizing performance by using better selection approaches. The selection for a standard appearance helped in the reinforcement of breed identity. On the one hand, such practices limit breed diversity. Breed identity, on the other hand, protects distinct genetic packages that would otherwise be lost in modern breeds. This new commercial breed trend threatens to reduce the diversity of the global gene pool, whose diversity ensures goat survival in a changing future. This is why we must secure our indigenous and heritage breeds. Goats are classified into three types based on their characteristics: meat goats, dairy goats, and hair goats. It’s possible to classify dual-purpose goats as a fourth category, but there is no successful dual-purpose breed. Crossbreeding between native local goats and imported goats with differing appearances and performances has been carried out in Indonesia and numerous other Asian nations. Numerous studies over the past ten years have assessed breeds based on crossbreeding [9, 10, 11]. It is necessary to assess goat breeds with the potential for genetic enhancement of meat and meat products. The diversity of breeds and their husbandry techniques, diet, climatic conditions, natural vegetation, and terrain, labor surplus to household requirements, availability of trained personnel and equipment, social and cultural attributes, and economic reality must all be taken into account in order to develop breeding strategies that effectively exploit the biological ceiling of the species.

A new approach to livestock breeding called genomic selection has been successfully used for purebred population selection. Additionally, the genomic selection provides more chances to take into account data from crossbreds and choose for crossbreed performance. Even though the study utilized genomic data, it was less complex than the Wei and van der Werf model since there was only one breeding value for each animal and no phenotyping of purebred animals. A methodology for genetic assessment put out by Wei and van der Werf made use of data from both purebred and crossbred animals. Crossbreeding is most effective when the strengths and weaknesses of different breeds are identified and the appropriate role of a breed in a crossbreeding program is determined. In comparison to pure breeding, crossbreeding has two distinct advantages: heterosis and breed complementarity. The superiority of crossbred offspring over their purebred parents is known as heterosis. Another significant advantage of crossbreeding is breed complementarity. It refers to the fact that no breed is perfect, and that each breed has its own set of strengths and weaknesses [12, 13]. Breed resources are combined in a systematic crossbreeding program to balance the positive and negative aspects of each breed.

2. Materials and methods

This chapter gives an overview and summary of purebred and crossbred goats. This chapter was created using material collected from scientific publications such as journals, conferences, yearly progress reports from various international institutes and organizations, technical bulletins, statistics yearbooks, and others. This chapter contains general information about goat husbandry, tools and procedures, goat populations, and features of purebred and crossbred goats. The author’s report in the publication is used to determine the accuracy of the information gathered.

3. Purebred dairy goats

The majority of the world’s dairy goat production and consumption occurs in Asia, while Europe, particularly France, has the most organized market for goat milk [6]. In 2017, the worldwide dairy goat population was predicted to reach 218 million and total global goat milk production was estimated at 18.7 million tonnes [14]. Milk, meat, leather, manure, and other high-quality animal products may be produced from dairy goats, but dairy goat farming is designed to produce large amounts of milk. There are many different varieties of dairy goats found all across the world, the American Goat Society Inc. registers purebred dairy goats from nine recognized breeds of Alpine, LaMancha, Nigerian, Dwarf, Nubian, Oberhasli, Pygmy, Saanen, Sable, Toggenburg. Therefore, the specialist dairy goat breeds employed in high-income countries have a high genetic potential for milk production. Superior dairy goat breeds are more common in Europe and America because they have stronger development and selection programs than in Asia and Africa. These breeds have been transferred to many developing nations via live animal transport and sales of frozen semen or embryos (Figure 1).

Figure 1.

World dairy goat population (heads) from 1961 to 2017 [15].

The data clearly demonstrated that the gross chemical composition and physical properties of goat’s milk were significantly influenced by animal breeds. Milk from graded goats was generally richer in chemical composition and had higher physical properties values than milk from pure breeds. Graded goat’s milk has higher general average milk fat (4.28%), protein (4.31%), total solids (13.92%), ash (0.8%), titratable acidity (0.16%), specific gravity (1.0399), and viscosity (2.18 centipoise) [16].

4. Purebred meat goats

The way to increase meat production is to increase the population and improve genetic quality. Key opportunities for increasing productivity include increasing reproductive efficiency through selection and crossing, increasing the genetic potential for growth, and improving nutrition and management practices to improve reproductive rates, child survival, and growth rates and composition. Improving daily nutrition and management offers opportunities to increase productivity [17]. Many types of meat goats are available for use in commercial operations. The popular meat goat breeds in the United States are described here. To be registered with their respective breed organizations, some breeds need to meet specific requirements, namely: Spanish or Brush, Boer, Kiko, Myotonic, Savanna, Pygmy or Cameroon Dwarf, and Nubian goat.

5. Performance of purebred

A purebred is the offspring of true breeding. True breeding is a technique for producing offspring with the same phenotype as the parents. When both parents are homozygous for certain traits, the result is a purebred. True breeding has the tendency to reduce the gene pool. A large gene pool indicates more genetic diversity.

Basically, genetics and environment influence performance. Moreover, reproductive system performance is controlled by both genetics and the environment. The massive development of molecular biology methods has opened up broad insights into genetic analysis [18]. Currently, there is a lot of genetic information related to the characteristics and diseases of goats. The search for genetic markers is very possible to find associations with certain traits. Based on data covering the reproductive performance from 2010 to 2012, including data from 23 multiparous does (11 does of pure Boer goats, 12 does of Boer x PE crossbred), the reproductive performance of pure Boer goats and crosses F1 and G2 (S/C, days open, kidding interval, and litter size) were compared and no significant difference was found [19] (Figure 2).

Figure 2.

Indonesian local goats; A: Peranakan Etawah (PE) goat, B: Kacang goat [20].

Reproductive performance is one of the most important drivers of production in goats, and it is determined by the combination of genetic and environmental variables. Peranakan Etawah goats are descended from crosses of Kacang (Indonesian native goat breed) and Etawah (Jamnapari) goats. Reproductive data from 1.5-year observations of 480 dams; 200 Kacang and 280 Peranakan Etawah goats showed that the average litter size was 2.06 and 1.56; the birth weight was 3.8 and 5.4 kg; the survival rate to weaning was 97% and 92%; and the maximum calving interval was 205 and 450 days, respectively [21]. This comparison of reproductive performance data revealed that the Kacang goat (purebred) performs better in various segments except that the birth weight is lower than the Etawah Peranakan breed. The terminal crossbreeding of Murciano-Granadina goats with Boer bucks improved carcass and meat qualities [22].

The majority of goats reach puberty at a young age. Despite significant differences between genotypes, the sexes must be divided by or before 5 months of age. Yao and Eaton [23] discovered live sperm in the epididymis of dairy goats at 110 days. According to Rogers et al. [24] suggested that pygmy goats may reach sexual maturity as early as 3 months.

Earlier research on crossbreeding suggested that the majority of the advantages were due to heterosis observed in a single cross involving two divergent inbred populations originating from pure breeds. The heterosis of crossbred between Mexico’s local breed and five goat breeds on estimated genetic parameters was various ranging from positive and negative values (Table 1). The heterosis in birth weight ranged from −1.04 to 1.69. The heterosis in monthly weight ranged from −1.05 to 0.8. The heterosis in litter size ranged from −0.15 to 0.82. the positive heterosis was found in Nubia Saanen, Toggenburg, and Alpine on birth weight and monthly weight. Otherwise, the negative heterosis occurred in Granadina on birth weight and monthly weight. Only Saanen has negative heterosis in litter size.

Sire Genotype	Heterosis	Standard Error	P (het ≠ 0)
		Birth weight
Nubia	0.30 (10.6%)	0.10	0.0025
Granadina	−1.04 (44.2%)	0.13	0.0001
Saanen	0.50 (17.1%)	0.12	0.0001
Toggenburg	0.44 (15.3%)	0.16	0.0006
Alpine	0.68 (23.1%)	0.09	0.0001
Overall	1.69 (60.8%)	0.0001
Nubia	0.50(7.1%)	Monthly weight; 0.27	0.0636
Granadina	−1.05 (1%)	0.33	0.0017
Saanen	0.80 (10.9%)	0.33	0.0142
Toggenburg	0.60 (8.4%)	0.45	0.1752
Alpine	0.15 (2%)	0.25	0.5552
Overall	0.73 (10.2%)	Litter size	n.s.
Nubia	0.82 (46.6%)	0.09	0.0001
Granadina	0.14 (8.2%)	0.12	0.2510
Saanen	−0.15 (9.7%)	0.11	0.1845
Toggenburg	0.24 (14.3%)	0.16	0.1448
Alpine	0.09 (5.8%)	0.09	0.3145

Table 1.

Estimates of genetic parameters and heterosis for birth weight, one-month weight, and litter size at birth in five goat breeds.

This data is from Meza-Herrera et al. [25].

6. Performance of crossbred

In developing countries, the crossbreeding program is initiated in the 19th – 20th century by crossing between local and exotic breeds. The success of this program varies greatly and depends on the potential of local genetic resources and local conditions or environment [26]. The crossbreeding program is carried out to improve livestock performance and productivity. In addition, the crossbreeding program supports the socio-economic sector by increasing the income of farmers [27].

In general, the aims of the crossbreeding program are:

1. To benefit from the phenomenon of the heterosis effect

2. To get breeds effect and complementarity

3. To provide a base population of the established new breed

4. To improve performance and productivity

Crossbreeding programs could be classified into four different categories. The difference in these categories is based on heterosis use, use of adapted genes, conservation of local breeds, and genetic composition of the product. Those crossbreeding types are terminal crossing, rotational crossing, breed substitution/upgrading, and synthetic breed creation [28]. The success of the crossbreeding program is determined by several factors such as the determination of foundation breeds, the contribution of each breed, the mating system, and the recording system.

7. Effect of crossbreed on dairy production

In many countries, the crossbreeding program was performed to increase goat productivity in milk production and quality. Some dairy goat breeds with good milk production such as Alpine, Anglo-Nubian, Toggenburg, and Saaenen are commonly used to crossbreed with the local goat. Previous studies reported that the effect of the crossbreeding program successfully increased the milk production in F1 crossbred of the Alpine goat breed (♂) and Albanian goat breed (♀) [29]. Alpine goat is an imported dairy goat breed in Albania that has good milk yield and meat production. On the other hand, the Albanian goat is a local goat that has a good ability to deal with severe environmental conditions. The milk production of the crossbred showed shorter milking days and higher daily milk production compared to the local goat parents (Table 2). These improvements showed that there was the heterosis effect resulted in crossbreeding. It will be an important reason for crossbreeding.

Genotype	Heads no.	Milking day	Daily production (kg)		Total Production (kg)
			Average ± SD	CV (%)	Average ± SD	CV (%)
Local breed	45	178.01 ± 2.1a	0.724 ± 0.03a	27.8	129.2 ± 4.9a	26.1
F1 Crossbred	58	171.86 ± 2.0b	0.967 ± 0.03b	23.4	167.1 ± 5.2b	24.2
Alpine breed	82	218.56 ± 4.1c	1.313 ± 0.04c	27.6	284.3 ± 9.7c	29.7

Table 2.

The least-square means of the performances of lactation in relation to genotypes.

SD, standard deviation; Cv, coefficient of variation. a-c Values within columns with different superscripts are significantly different (P < 0.05) [29].

In addition, a crossbreeding program was also performed between Saanen and the local dairy goat (Etawah grade) in Indonesia. The F1 crossbred is well-known as the Sapera goat. The male Saanen goat was crossbred with the female Etawah grade to produce the Sapera goat (Figure 3). Suranindyah et al. [30] reported that the F1 crossbred has a higher milk production (1647 L/head/day) compared to the Etawah grade (1340 L/head/day).

Figure 3.

Crossbreeding model between Saanen and Etawah grade [30].

8. Effect of crossbreed on meat production

Some goat breeds are raised for two purposes (dairy and meat goat) including the Saanen goat. This breed was widely used to crossbreed with the local goat to improve meat production and quality. In Turkey, the Saanen goat was crossbred with the indigenous Hair goat as Turkey’s local goat. Yilmaz et al. [30] reported the effect of crossbreeding programs on carcass measurements and meat quality of kids under an intensive production system. There were 3 genotypes of goat used in this study i.e. indigenous Hair goat (purebred), F1 crossbred (Saanen x Hair goat), and B1 back-crossbred (Saanen x Hair goat).

The result showed that there were no significant effects of breed on carcass measurements (Table 3). It indicated that the crossbred was not superior to indigenous Hair goat kids in terms of carcass measurements and meat quality characteristics. On the other hand, F1 crossbred and B1 back-crossbred have better tenderness on the sensory characteristics of meat.

Characteristics	Hair		Saanen x Hair, F1		Saanen x Hair, B1		F
	Mean	SE	Mean	SE	Mean	SE
----------Carcass Measurements----------
Empty body weight (kg)	13.60	0.65	15.19	2.04	14.26	1.44	0.324^NS
Hot carcass weight (kg)	6.78	0.39	7.61	1.17	7.02	0.80	0.280^NS
Dressing percentage (%)	49.71	0.78	49.27	1.12	48.78	0.74	0.307^NS
Carcass length (cm)	57.44	0.60	59.60	2.08	59.33	1.80	0.621^NS
Leg length (cm)	18.24	0.26	18.89	0.62	18.56	0.42	0.544^NS
Carcass width (cm)	16.19	0.52	16.86	0.80	16.33	0.52	0.323^NS
Buttock width (cm)	12.96	0.16	13.04	0.74	13.50	0.98	0.186^NS
Internal carcass length (cm)	51.36	0.69	54.04	1.20	52.85	1.32	1.579^NS
Hind limb length (cm)	27.93	0.41	29.74	0.76	29.44	0.57	3.001^NS
Thoracic depth (cm)	23.10	0.32	23.79	0.87	23.71	0.73	0.359^NS
Carcass compactness (g/cm)	131.76	6.71	138.57	18.83	130.93	11.99	0.104^NS
Hind limb compactness (g/cm)	37.09	1.77	40.13	5.53	35.56	3.77	0.364^NS
Chest roundness index	0.70	0.02	0.71	0.01	0.69	0.01	0.701^NS
-----------Sensory Characteristics----------
Kid odor intensity	5.52	0.11	5.39	0.13	5.63	0.11	0.943^NS
Tenderness	5.19^a	0.15	4.71^b	0.17	4.73^b	0.15	3.107*
Juiceness	5.15	0.14	4.82	0.16	4.88	0.15	1.478^NS
Flavor intensity	5.13	0.13	4.91	0.15	5.30	0.13	1.919^NS
Flavor quality	5.29	0.12	5.14	0.14	5.30	0.12	0.470^NS
Overall acceptability	5.21	0.12	5.11	0.14	4.98	0.13	0.867^NS

Table 3.

Carcass measurements and sensory characteristics of meat samples of hair and hair x Saanen crossbred (F1 and B1) kids.

NS, Not significant (P > 0.05), †SE, Standard error, a,b, Differences between the means of genotype groups carrying various letters in the same line are significant (* = P < 0.05) [31].

9. Effect of crossbreeding on reproduction traits

Reproduction traits are one of the aspects affected by crossbreeding programs. The influence of crossbreeding was reported in Boer F1 crossed with base breeds in the United States [9]. The reproductive traits and survival rates were observed in the various genotypes (Boer, Kiko, Spanish, Boer x Kiko reciprocal F1 crosses, and Boer x Spanish reciprocal F1 crosses). In this study, Boer goats showed lower reproductive rates among the genotypes (P < 0.05). The survival rate of Boer was significantly lower than the Kiko goat (P < 0.05). All crossbreds had similar reproductive rates compared to the parents (Kiko and Spanish goat). In this study, the crossbreeding program successfully improved the reproductive and survival rates (Table 4).

Genotypes	Kidding rate (%)	Weaning rate (%)	Survival rate (%)
Boer	18.4 ± 12.7^b	11.1 ± 9.7^b	53.2 ± 11.8b
Kiko	81.7 ± 9.6^a	67.1 ± 15.4^a	84.8 ± 3.3a
Spanish	84.9 ± 8.3^a	73.7 ± 13.5^a	79.1 ± 3.8ab
Boer x Kiko	73.5 ± 12.4^a	60.7 ± 13.5^a	78.1 ± 3.9ab
Boer x Spanish	70.9 ± 13.2^a	61.0 ± 16.6^a	79.1 ± 4.1ab

Table 4.

Effect of doe breed and doe age on whole herd reproductive and survival rates.

^ab

LS means (±SE) within a class and trait not sharing common superscript differ (P < 0.05) [9].

10. Conclusion

The selection for a standard appearance helped in the reinforcement of breed identity. On the one hand, such practices limit breed diversity. This new commercial breed trend threatens to reduce the diversity of the global gene pool, whose diversity ensures goat survival in a changing future. This is why we must secure our indigenous and heritage breeds. Crossbreeding can be done by combining the desirable characteristics of two or more breeds. If this program is carried out properly, the strength of one breed can complement the weakness of another breed through the phenomenon of the heterosis effect and breed complementarity. Controlled crossbreeding can increase performance and productivity and also reduce the threat of genetic erosion on native pure breeds. In developing countries, two-breed cross offspring developed from exotic breeds that have proven significant promise for greater production in their country of origin, and local goats (native) with superior adaptation are thought to be more productive under local conditions. This misconception has encouraged generations of unintentional crossbreeding, frequently leading to an upgrade to exotic breeds and resulting in the loss of vital traits like adaptability, fecundity, and disease resistance as well as a narrowing of the genetic base that negatively affects the performance of the crossbred population. In order to crossbreed animals from particular breeds, it is necessary to assess the likely sources of breeding animals in each country.

Acknowledgments

The authors would like to acknowledge the scientists, researchers, and academicians who contributed a lot in the area of goat research.

Conflict of interest

There is no conflict of interest.