Crossbreeding

Evaluation of the productivity of the Brahman, with other breeds and their crosses in East and Southern Africa

ABSTRACT

Studies from Southern Africa, were reviewed, where Brahmans were compared with other breeds. Genotype x environment interactions were apparent and of important magnitude. In general, the Brahman sire and dam performed well and under difficult conditions (eg. Swaziland) the crossbred Brahman excelled. Fitness traits below.

Growth of progeny with Brahman breeding compared well with other breeds, especially 18 month weight. Feedlot performance was poor, primarily due to a lack of appetite. Carcass quality (eye muscle area and intra-muscular fat) of two year old progeny was also poor, indicating a slow maturing animal.

INTRODUCTION

Optimal productivity of a beef enterprise can be significantly influenced by the selection of the appropriate breed, or breed combinations, and environment. The numerous breeds of cattle in East and Southern Africa can be classified into three basic types: indigenous; Bos Taurus; and Bos Indicus. Indigenous cattle, also termed Sanga cattle (Mason and Maule, 1960), are characterised by a Bos Taurus and Bos Indicus.

These breeds are thought to have originated from crosses between humpless and zebu (Bos. Indicus) cattle in the horn of Africa between 5 000 and 1 500 B.C. As people migrated southwards along the east coast of Africa they brought these cattle with them. The B. Taurus (British and European) and B. Indicus (namely the Brahman) cattle are recent introductions to Africa. The Brahman was developed in the southern United States from Indian B. Indicus breeds.

Until 15 years ago, information on the relative performance of beef breeds and their crosses in East and Southern Africa was scant. Agricultural research and commercial production emphasized reproductive performance and growth rate in exotic cattle. In general, maternal traits and production from cattle indigenous to Africa were ignored. Hetzel summarized the results of comparative studies carried out in a number of countries in East and Southern Africa. Some of the findings of this review were:

  • Breed x environment interactions are apparent.
  • Indigenous cattle are generally productive due to their ability to reproduce to a hard environment.
  • Maternal performance is not enhanced by crossing indigenous cattle with Bos Taurus or Bos. Indicus.
  • Crossbreeding to improve progeny growth rate using superior indigenous breeds as dams and exotic B. Taurus or controlled breeding is feasible.
  • Sanga and B. Indicus (eg Brahman and Boran) crosses should be evaluated in stressful environments.
  • A need to study adaptive traits.

Since Hetzel’s review, a comprehensive analysis of a large crossbreeding study in Zimbabwe has been completed which includes post-weaning growth and carcass information. Findings from both the National Beef Cattle Breeding Programme in Swaziland and the Beef Cattle Performance and Progeny Testing Scheme of South Africa have also been reported. These three reports all included an evaluation of the Brahman and will be used to update Hetzel’s review, with attention focused on the Brahman.

The mature weight of the cow is an important aspect to consider for sustainable production and generally, smaller cows are suited to harsher environments. The use of a smaller breed, however, can compromise growth rates. The mature weight of the Brahman female was found to be intermediate when compared with the smaller Sanga (Mashona, Nguni and Nkone) and the larger European B. Taurus type cow (Charolais and Simmental) (Table1, Table 2 and Table 3).

It is generally accepted that the Brahman is a sexually late maturing breed and has low levels of fertility. However, data from South Africa (Table 2) and Swaziland (Table 3) show that the Brahman is intermediate with respect to age at first calving. The Angus, Sussex, Bonsmara, Pinzgauer and Simmental breeds on average calved when they were three months younger and Drakensberger and Afrikaner breeds when they were three to four months older than the Brahman (Table 2).

Conflicting results were found with respect to fertility (expressed as either calving interval or calving rate). The Brahman was found to be intermediate in Zimbabwe and South Africa (Tables 1 and 2) but relatively poor in Swaziland and Botswana (Tables 3 and 4). Hetzel also noted that the calving rate of the Brahman was high in the Zimbabwean study (Table 1) and attributed this to the hardiness of the breed in “low” performance environments.

However, his classification of “Low” and High” performance environments was partly based on the calving rate of the Afrikaner. The cows in the Zimbabwean study were not culled for infertility, but after simulated culling for two consecutive failures the calving rate of the Afrikaner dam was increased from 56 to 62 percent. This compared with 67 percent in the Botswanan study (Table 4). In the Zimbabwean study, large differences were found between reciprocal crosses with the Afrikaner. The fertility of a cow sired by an Afrikaner was markedly depressed when compared with the fertility of a cow from an Afrikaner dam.

The survival rate of purebred and crossbred calves from purebred Brahman cows tended to be the lowest of the breeds evaluated (Tables 1,2 and 4) and concurs with findings  the United States and South America. This was most noticeable in the Botswanan study, where the survival rate of calves born to Bonsmara and Brahman cows was 14 to 16 percent lower than those of calves born to Sanga cows (Tswana, Tuli and Afrikaner; Table 4). In contrast, the survival rates of calves born to Brahman cross cows were among the highest (Tables 1, 2 and 4).

Lowest calf birth weights were recorded in the small Sanga breeds (Mashona and Nguni; Tables 1, 2 and 3). The birth weights of calves born to Brahman cows were also very low and ranged from 10 to 30 percent (three to 10kg) lighter than calves born to other breeds, especially those of the larger European breeds (Tables 1, 2, 3 and 4). The ability of the Brahman cow to restrict the size of her calf has been well documented.

Weaning weight of calf, as a trait of the dam, showed extreme variation across studies (Tables 1. 2, 3 and 4), indicative of the presence of breed x environment interactions. The weight of calf weaned from the Brahman cow was among the lowest of the cow genotypes in the Botswana study (Table 4), intermediate in South Africa (Table 2) and among the best, together with Brahman crosses, in Zimbabwe and Swaziland (Tables 1 and 3).

In the Zimbabwean study, Brahman and Afrikaner x Brahman dams gained the least weight between parturition and weaning (7 kg as compared with 20 kg for all other genotypes). This indicates that the Brahman cow devotes more energy to milk production, rather than replenishing her body reserves, which may account for the improved weaning performance. Turner reported similar findings, nothing that the Brahman cow may devote excess energy to her calf to the detriment of subsequent fertility.

Information on weight of calf at 18 months as a trait of the dam was only available for the Zimbabwean and Botswanan studies (Tables 1 and 4). The superior pre-weaning growth rate of crossbred calves from purebred Brahman cows in the Zimbabwean study continued post-weaning, where calves were between 8 and 13 percent heavier than calves from other purebred dams evaluated. None of the progeny from crossbred dams were heavier than the progeny from the purebred Brahman dams (Table I).

It is noteworthy that of the five crosses that showing similar performance to the Brahman, four were Brahman crosses. Similar results were shown in Botswana, although calves from Bonsmara dams were heavier at 18 months than calves from Brahman dams (Table 4). Among the crossbred dam genotypes, weight of 18 month old calves from Simmental and Brahman crossbred dams were five to seven percent superior to calves from Tuli and Bonsmara crossbred and purebred Tswana dams (Table 4).

Realistic measures of cow productivity take into account fertility, calf survival and growth, and cow weight. Expressing rates. Weight of calf per unit weight of cow attempts to include maintenance costs as well, thus enabling the comparison of cows of differing mature weight. However, this assumes that breeds are equally adapted, ie. environment constraints do not affect breeds differently. These are biological indices; economical values depend on other factors as indicated by Hetzel.

When productivity was expressed as weight of calf weaned per cow exposed, the Brahman was the poorest in the Botswana study (Table 4), intermediate in South Africa and Swaziland (Tables 2 and 3), but was one of the best cow genotypes in the Zimbabwean study (Table 1).

Brahman crossbred cow genotypes evaluated were intermediate in Botswana (Table 4), among the best in Zimbabwe (Table 1) and outstanding in Swaziland (Table 3).

When weaning production was expressed per unit metabolic weight (weight .75), despite the relatively low growth rate of their progeny, the small Sanga cattle were among the most productive genotypes because of their relatively high fertility and calf survivability and low mature weight (Tables 1, 2 and 3). Even when weight of cow was taken into account, the Brahman female performed well, being intermediate in Swaziland (Table 3) and among the best genotypes in Zimbabwe (Table 1) and South Africa (Table 2). Similar trends to the above were shown for 18 month weight cow calf expressed either per cow or per unit weight of cow.

SIRE EFFECTS

Literature, describing sire influences on comparative growth of the Brahman and other breeds in east and southern Africa, is available from a limited number of studies only: Zimbabwe (Moyo, 1990); Botswana (Trail et al., 1977; Apru, 1979); South Africa (Mentz et al., 1979a,b; Scholtz, 1988).

The birth, weaning and 18 month weight data from the Zimbabwean and Botswanan (Apru, 1979) studies have been summarized in Table 5. In the Botswanan study the first set of data compared five sire breeds across stations and the second set compared seven at one station. Birth weight of calves sired by Brahman were among the heaviest, together with calves sired by Italian (Chianina, Marchigiana and Romagnola), Simmental and South Devon bulls (Table 5). In the Zimbabwean study calves sired by Brahmans were intermediate within a narrow weight range (Table 5). However, sire*s effects may have been masked because they were mated to a range of purebred and crossbred cows.

Weaning weight of calves sired by Brahman bulls were intermediate (Table 5; Mentz et al., 1979a) to the other sires evaluated. Calves were three to nine percent lighter than those sired by Simmental and Charolais and were six to12 percent heavier than those sires by Aberdeen Angus, Tuli, Tswana and Afrikaner. However, 18 month weight of progeny sired by Brahman were among the heaviest and were only two percent lighter than those sired by Simmental, Holstein-friesian and Italian breeds and eight percent heavier than those sired by the Sanga breeds (Tuli, Tswana and Afrikaner; Table 5).

CARCASE TRAITS

Moyo presented sire and dam genotype influences on carcass traits (Tables 6 and 7). At 19 months of age, all animals were taken off the range and put into a feedlot. They were allocated within sex and sire group to three different amounts of their appetites, determined their length of stay in the feedlot.

While progeny from Brahman sire and dam genotypes were among the heaviest at induction into the feedlot (18 month weight; Tables 1 and 5), their appetite in the feedlot was small and similar to that of Afrikaner and Tuli sired progeny (Ward and Dlodlo, 1986). Thus the pre-slaughter and carcass weights of progeny from the Sanga (Afrikaner, Mashona, Nkone and Tuli), Brahman and crosses among them were the lowest. Similar trends were reported in South Africa where the average daily gain of the Afrikaner, Brahman and Nguni in the feedlot were the lowest. Progeny with B. Taurus breeding had the highest pre-slaughter and carcass weight, since small differences were found in carcass length.

Progeny with Brahman breeding had the smallest eye muscle area together with Afrikaner, Hereford and Holstein-Friesian sired progeny. Largest eye muscle area were from progeny with Charolais and Simmental breeding. Carcasses with Brahman breeding were intermediate for sub-cutaneous fat cover, but contained least intra-muscular fat. Aberdeen Angus sired progeny had the highest quantities of sub-cutaneous fat, while progeny with Charolais and Simmental breeding had the least sub-cutaneous fat.

SUMMARY

Interpretation of data requires care, especially when attempting to extrapolate to different environments in the presence of genotype x environment interactions. The studies evaluated here show that the Brahman sire and dam performed well and have a role to play in Southern Africa. The productivity of the Brahman dam did not exceed that of the indigenous Sanga breeds.

However, crosses with the Brahman offered great potential particularly under extensive conditions, for example in Swaziland, where Brahman x Nguni first cross females showed more than 50 percent improvement in productivity compared to the purebred parents. Maternal traits which need to be monitored and improved include fertility and calf survivability.

Growth of Brahman progeny (pure and crossbred) was similar to that of the best genotypes, particularly at 18 months of age. However, the Feedlot performance of this progeny was poor and similar to that of the indigenous Sanga breeds. Carcass qualities, namely eye muscle area and intra-muscular fat, were also poor. However, only a feedlot system of finishing was evaluated and this may not be suited to all genotypes, particularly late maturing breeds.

Kruisteling


Evaluasie van die produktiwiteit van die Brahman en sy kruisings in vergelyking met ander rasse en hul kruisings in Oos- en Suidelike Afrika.

OPSOMMING

Studies in Suidelike Afrika waar die Brahman met ander rasse vergelyk is, is ondersoek.  Genotipe x omgewing interaksies was duidelik en van beduidende omvang.  Oor die algemeen het die Brahmanvaar en -moeder goed presteer en onder moeilike omstandighede  (bv. Swaziland) het die Brahmankruisings  uitgeblink . Fiksheidseienskappe hieronder.

Groei van nageslag met Brahmanteling het goed vergelyk met ander rasse, veral 18-maande gewig. Voerkraalprestasie was swak, hoofsaaklik weens ʼn gebrek aan aptyt. Karkaskwaliteit (oogspieroppervlakte en binnespierse vet) van tweejaaroud nageslag was ook swak, wat dui op ʼn laatrypdier.

INLEIDING

Optimale produktiwiteit van ʼn vleisbeesonderneming kan betekenisvol beïnvloed word deur die seleksie van die geskikte ras, of raskombinasies, en omgewing. Die talryke beesrasse in Oos- en Suidelike Afrika kan in drie basiese tipes geklassifiseer word: inheems, Bos Taurus en Bos Indicus. Inheemse beesrasse, ook bekend as Sangabeeste (Mason and Maule, 1960), toon beide Bos Taurus- en Bos Indicus-invloed.

Hierdie rasse het vermoedelik ontstaan uit  kruisings tussen skoflose en zebu (Bos Indicus)- beeste in die horing van Afrika tussen 5 000 en1 500 v.C. Namate mense suidwaarts lang die kus van Afrika migreer het, het hulle hierdie beeste met hulle saamgebring.  Die B. Taurus (Britse en Europese) en B. Indicus (meer spesifiek die Brahman)-  beeste is eers onlangs na Afrika gebring. Die Brahman is in die Suidelike Verenigde State ontwikkel uit Indiese Bos Indicus-rasse.

Tot 15 jaar gelede was inligting oor die relatiewe prestasie van vleisbeesrasse en hul kruisings maar  karig.  Landbounavorsing en kommersiële produksie het reproduktiewe prestasie en groeitempo in eksotiese beeste beklemtoon. Oor die algemeen is maternale eienskappe en reproduksie van beeste inheems aan Afrika geïgnoreer. Hetzel het die resultate van vergelykende studies in ‘n aantal lande in Oos- en Suidelike Afrika opgesom. Sommige van die bevindings van hierdie oorsig was:

  • Ras x omgewing interaksies was duidelik.
  • Inheemse beeste is oor die algemeen produktief weens hul vermoë om in ‘n strawwe omgewing te reproduseer.
  • Maternale  prestasie word nie verhoog deur die kruising van inheemse beeste met  Bos Taurus of Bos Indicus nie.
  • Kruisteling om nageslaggroei te verhoog deur gebruik van meerderwaardige inheemse rasse as moeders en eksotiese Bos Taurus of gekontroleerde teling is haalbaar.
  • Sanga en B. Indicus (bv. Brahman en Boran)-kruisings behoort in ʼn stressvolle omgewing geëvalueer te word.
  • ʼn Behoefte om aanpassingskenmerke te ontwikkel.

Sedert  Hetzel  se oorsig is ʼn omvattende ontleding van ʼn groot kruisteeltstudie wat naspeen groei en karkasinligting insluit In Zimbabwe afgehandel. Bevindings van beide die Nasionale Vleisbeesteeltprogramme in Swaziland en Vleisbees – Prestasie – en Nageslagtoetsskema in Suid-Afrika is ook gerapporteer.  Hierdie drie verslae het almal ‘n evaluasie van die Brahman ingesluit en sal gebruik word om Hetzel se oorsig op datum te bring met spesiale fokus op die Brahman.

● Tabel 1: Vergelykend maternale produktiwiteit van vleisbeesrasse in Zimbabwe
● Tabel 2: Vergelykende maternale produktiwiteit van vleisbeesrasse in Suid-Afrika
● Tabel 3: Vergelykende maternale produktiwiteit van vleisbeesrasse in Swaziland
● Tabel 4: Vergelykende maternale produktiwiteit van vleisbeesrasse in Botswana
● Tabel 5: Effekte van ras van vaar op nageslaggroei (kg) tot 18 maande ouderdom
● Tabel 6: Effekte van ras van vaar op karkaseienskappe van voerkraalnageslag
● Tabel 7: Effekte van ras van moeder op karkaseienskappe van voerkraalnageslag

Die volwasse gewig van die koei is ʼn belangrike aspek om in aanmerking te neem vir volhoubare produksie en oor die algemeen is kleiner koeie beter aangepas vir strawwe omgewings. Groeitempo kan egter belemmer word deur die gebruik van ʼn kleiner ras. Dit is bevind dat die volwasse gewig van die Brahman vroulike dier  intermediêr is in vergelyking met die kleiner  Sanga (Mashona, Nguni en Nkone) en die groter Europese  B. Taurus- tipe koei (Charolais en Simmentaler) (Tabel1, Tabel 2 en Tabel 3).

Dit word algemeen aanvaar dat die Brahman ʼn seksueel laatryp-ras is en lae vlakke van vrugbaarheid het.  Data vanaf Suid-Afrika (Tabel 2) en Swaziland (Tabel 3) toon egter dat die Brahman intermediêr is wat ouderdom met eerste kalwing betref.  Die Angus-, Sussex-, Bonsmara-,  Pinzgauer- en Simmentalerrasse het gemiddeld op ouderdom drie maande jonger en Drakensberger- en Afrikanerrasse op drie tot vier maande ouer as die Brahman gekalf (Tabel 2).

Teenstrydige resultate t.o.v. vrugbaarheid (uitgedruk as kalfinterval, of kalftempo) is gevind.  Die Brahman is as intermediêr in Zimbabwe en Suid-Afrika bevind (Tabelle 1 en 2), maar betreklik swak in Swaziland en Botswana (Tabelle  3 en 4).  Hetzel het ook opgemerk dat die kalwingstempo van die Brahman hoog was in die  Zimbabwe-studie (Tabel 1) en het dit toegeskryf aan die gehardheid van die ras in “lae” prestasieomgewings.

Sy klassifikasie van “lae”- en “hoë” prestasie-omgewings was egter gedeeltelik gebaseer op die kalwingstempo van die Afrikaner.  Die koeie in die Zimbabwe-studie was nie geprul vir onvrugbaarheid nie, maar na gesimuleerde prul  vir twee agtereenvolgende mislukkings is die kalwingstempo van die Afrikaner verhoog van 56 na 62 persent.  Die vergelykende persentasie in die Botswana-studie was 67 (Tabel 4). In die Zimbabwe-studie is groot verskille gevind tussen omgekeerde kruisings met die Afrikaner.  Die vrugbaarheid van ʼn koei wat deur ʼn Afrikaner verwek is, was merkbaar laer in vergelyking met die vrugbaarheid van ʼn koei van ʼn Afrikanermoeder.

Die oorlewingstempo van rasegte en kruisgeteelde kalwers van rasegte Brahmankoeie was geneig om die laagste te wees van die rasse wat geëvalueer is (Tabelle 1,2 en 4) en stem ooreen met bevindings in die Verenigde State en Suid-Amerika.  Dit was die opmerklikste in die Botswana-studie, waar die oorlewingstempo van kalwers wat van Bonsmara- en Brahmankoeie gebore is, 14 tot 16 persent laer was as diè van Sanga-koeie (Tswana, Tuli en Afrikaner; Tabel 4).  In teenstelling hiermee was die oorlewingstempo van kalwers wat van Brahmankruisingkoeie gebore is, van die hoogstes (Tabelle 1, 2 en 4).
Die laagste kalfgeboortegewigte is in die Sanga-rasse (Mashona en Nguni; Tabelle 1,2 en 2) aangeteken Die geboortegewigte van kalwers wat van Brahmankoeie gebore is, was ook baie laag en was van 10 tot 30 persent (drie tot 10kg) ligter as diè van kalwers gebore uit ander rasse, veral die groter Europese rasse (Tabelle 1, 2, 3 en 4).  Die vermoë van die  Brahmankoei om die grootte van haar kalf te beperk is goed gedokumenteer.

Speengewig van kalf, as ʼn eienskap van die moeder het uitermatige variasies oor studies getoon (Tabelle 1, 2, 3 en 4) – ʼn aanduiding van ras x omgewing interaksies. Die gewig van kalwers gespeen van die Brahmankoei was van die laagste van die koeie-genotipes in die Botswana-studie (Tabel 4), intermediêr  in Suid-Afrika (Tabel 2) en van die beste, saam met Brahmankruisings, in Zimbabwe en Swaziland (Tabelle 1 en 3).

In die Zimbabwe-studie het Brahman-  en Afrikaner x Brahman-moeders die kleinste gewigtoename tussen geboorte en speen getoon (7 kg in vergelyking met  20 kg vir alle nader genotipes). Dit dui aan dat die  Brahmankoei meer energie bestee aan melkproduksie, eerder as om haar liggaamsreserwes uit te put, wat  ʼn verklaring mag wees van die verbeterde speenprestasie.  Turner het soortgelyke bevindings gerapporteer, en opgemerk dat die Brahmankoei ʼn oormaat energie aan haar kalf bestee tot nadeel van latere vrugbaarheid.

Inligting oor gewig van kalf op 18 maande as ʼn eienskap van die moeder was slegs vir die Zimbabwe- en Botswana-studies (Tabelle 1 en 4) beskikbaar.  Die hoër voorspeense groeitempo van kruisgeteelde kalwers van rasegte Brahmankoeie in die Zimbabwe-studie het geduur tot in die naspeenstadium waar kalwers tussen 8 en 13 persent  swaarder was as kalwers van ander rasegte moeders wat geëvalueer is. Geen van die nageslag van kruisgeteelde moeders was swaarder as die nageslag van die rasegte Brahmanmoeders nie (Tabel 1).

Dit is opmerklik dat van die vyf kruisings wat soortgelyke prestasies as die Brahman gelewer het, vier Brahmankruisings was.  Soortgelyke resultate is in Botswana getoon, alhoewel kalwers van Bonsmara-moeders op 18 maande swaarder as die kalwers van Brahmanmoeders was (Tabel 4).  Onder die kruisgeteelde moeder-genotipes was die gewig van 18 maande oue kalwers van Simmentaler en Brahman kruisgeteelde moeders vyf tot sewe persent hoër as kalwers van kruisgeteelde Tuli en  Bonsmara en rasegte Tswana moeders (Tabel 4).

Realistiese metings van koeiproduktiwiteit neem vrugbaarheid, kalfoorlewing en -groei, en koeigewig in berekening.  Gewig van kalf per eenheidgewig van koei poog om onderhoudskoste ook in te sluit, om sodoende die vergelyking van koeie met verskillende volwasse gewigte moontlik te maak. Dit veronderstel egter dat rasse eenders aangepas is, i.e. omgewingsbeperkings affekteer rasse nie verskillend nie.  Hierdie is biologiese indekse;  ekonomiese indekse is afhanklik van ander faktore soos aangedui deur Hetzel.

Waar produktiwiteit uitgedruk is as gewig van kalf gespeen per koei gedek, was die Brahman die swakste in die Botswana-studie (Tabel 4),  intermediêr in Suid-Afrika en Swaziland (Tabelle 2 en 3), maar onder die beste genotipes in die Zimbabwe-studie (Tabel 1).

Brahman kruisgeteelde genotipes wat geëvalueer is,  was intermediêr in Botswana (Tabel 4),onder die bestes in Zimbabwe (Tabel 1) en uitstaande in Swaziland  (Tabel 3).

Waar speenproduksie uitgedruk is per eenheid metaboliese gewig (gewig.75), nieteenstaande die relatief lae groeitempo van hul nageslag, was die klein Sanga-beeste van die mees produktiewe  genotipes  weens hul relatiewe hoë vrugbaarheid en oorlewingsvermoë van kalwers en lae volwasse gewig. (Tabelle 1, 2 en 3). Selfs wanneer koeigewig  in aanmerking geneem is, het die vroulike Brahman goed presteer  deur intermediêr in Swaziland  gelys te word (Tabel 3) en onder die beste genotipes in Zimbabwe (Tabel 1) en Suid-Afrika (Tabel 2).  Neigings soortgelyk aan bostaande is getoon vir 18 maande kalfgewig uitgedruk beide per koei of per eenheidsgewig van koei.

VAAREFFEKTE

Literatuur wat vaarinvloede op vergelykbare groei van die Brahman en ander rasse in Oos- en Suidelike Afrika beskryf, is slegs beskikbaar van ʼn beperkte aantal studies: Zimbabwe (Moyo, 1990); Botswana (Trail et al., 1977; Apru, 1979); Suid-Afrika (Mentz et al., 1979a,b; Scholtz, 1988).

Die geboorte- speen- en 18 maande-gewigdata van die Zimbabwe- en Botswana-studies (Apru, 1979) is in Tabel 5 opgesom.  In die Botswana-studie vergelyk die eerste datastel vyf vaarrasse oor stasies  en die tweede stel vergelyk sewe op een stasie. Geboortegewig van kalwers wat deur Brahman verwek is was onder die hoogstes, saam met kalwers wat deur Italiaanse, (Chianina, Marchigiana en Romagnola), Simmental-  en South Devon bulle verwek is (Tabel 5). In die Zimbabwe-studie is kalwers wat deur  Brahmane verwek was, intermediêr binne ʼn smal gewigsreeks (Tabel 5).  Vaareffekte kon egter verberg gewees het omdat hulle met ʼn verskeidenheid rasegte en kruisgeteelde koeie gepaar is.

Speengewig van kalwers wat deur Brahmanbulle verwek is was intermediêr (Tabel 5; Mentz et al., 1979a) teenoor die ander vaars wat geëvalueer is. Kalwers was drie tot nege persent ligter as diè wat deur Simmental en Charolais verwek is en ses tot 12 persent swaarder as diè wat deur Aberdeen Angus, Tuli, Tswana en Afrikaner verwek is. Die 18 maande gewig van nageslag verwek deur Brahman was egter onder die swaarste en was slegs twee persent ligter as diè wat deur Simmental, Holstein-Fries en Italiaanse rasse verwek is, en agt persent swaarder as diè verwek deur die Sanga-rasse (Tuli, Tswana en Afrikaner;  Tabel 5).

KARKASEIENSKAPPE

Moyo het vaar- en moeder genotipe invloede op karkaseienskappe ondersoek (Tabelle 6 en 7).  Op 19 maande ouderdom is alle diere van die veld geneem en na ʼn voerkraal geneem.

Nageslag van Brahmanvaar- en moedergenotipes  was van die swaarste met opname in die voerkraal, (18 maande gewig; Tabelle 1 en 5), maar hul aptyt in die voerkraal was klein en soortgelyk aan diè van Afrikaner-  en Tuli-verwekte  nageslag (Ward en Dlodlo, 1986).  Die vòòr-slag– en karkasgewigte van nageslag van die Sanga (Afrikaner, Mashona, Nkone and Tuli), Brahman en kruisings onder hulle was derhalwe die laagste. Soortgelyke tendense is in Suid-Afrika gerapporteer waar die gemiddelde daaglikse toename van die Afrikaner, Brahman en Nguni in die voerkraal die laagste was.  Nageslag met B. Taurus-invloed  het die hoogste vóór-slag– en karkasgewig gehad, aangesien klein verskille in karkaslengte gevind is.

Nageslag met Brahman-invloed het die kleinste oogspieroppervlakte gehad, soos ook Afrikaner-, Hereford- en Holstein-Friesverwekte nageslag. Die hoogste oogspieroppervlakte was van nageslag met Charolais- en Simmentaler-invloed.  Karkasse met Brahman-invloed was intermediêr vir onderhuidse vetbedekking, maar het die minste binnespierse vet bevat.  Aberdeen Angus-verwekte nageslag het die grootste hoeveelheid onderhuidse vet gehad, terwyl nageslag met Charolais-  en Simmentaler-invloed die minste onderhuidse vet gehad het.

OPSOMMING

Interpretasie van data moet versigtig geskied, veral  wanneer daar gepoog word om na verskillende omgewings te ekstrapoleer in die teenwoordigheid van genotipe x omgewing interaksies. Die studies wat hier geëvalueer is, toon dat die Brahmanvaar en -moeder goed presteer het en ʼn rol in Suidelike Afrika te speel het. Die produktiwiteit van die Brahmanmoeder het nie diè van die inheemse Sanga-rasse oorskry nie.

Kruisings met die Brahman het egter groot potensiaal gebied, veral onder ekstensiewe toestande, soos in Swaziland, waar Brahman x Nguni eerste kruising vroulike diere meer as 50 persent verbetering in produktiwiteit getoon het in vergelyking met die rasegte ouers. Maternale eienskappe wat gemonitor en verbeter moet word, sluit vrugbaarheid en kalfoorlewingsvermoë in.
Groei van Brahman nageslag  (suiwer en kruisgeteel) was soortgelyk aan diè van die beste genotipes, veral op ouderdom 18 maande.  Die voerkraalprestasie van hierdie nageslag was egter swak en soortgelyk aan diè van die inheemse Sanga-rasse.  Karkaskwaliteite, nl. oogspieroppervlakte en binnespierse vet, was ook swak.  Dit moet in gedagte gehou word dat die  voerkraalstelsel die enigste metode van afronding was wat geëvalueer is, en dit mag dalk nie geskik wees vir alle genotipes nie; veral nie laatryp-rasse nie.