Animal and Wildlife Scienceshttp://hdl.handle.net/2263/17472024-03-19T03:40:52Z2024-03-19T03:40:52ZUnderstanding the underlying genetic mechanisms for age at first calving, inter-calving period and scrotal circumference in Bonsmara cattleReding, Jason JackVan der Westhuizen, Robert R.Berry, Donagh P.Van Marle-Koster, Estehttp://hdl.handle.net/2263/951752024-03-13T22:47:08Z2023-08-24T00:00:00ZUnderstanding the underlying genetic mechanisms for age at first calving, inter-calving period and scrotal circumference in Bonsmara cattle
Reding, Jason Jack; Van der Westhuizen, Robert R.; Berry, Donagh P.; Van Marle-Koster, Este
BACKGROUND : Reproduction is a key feature of the sustainability of a species and thus represents an important
component in livestock genetic improvement programs. Most reproductive traits are lowly heritable. In order to gain
a better understanding of the underlying genetic basis of these traits, a genome-wide association was conducted
for age at first calving (AFC), first inter-calving period (ICP) and scrotal circumference (SC) within the South African
Bonsmara breed. Phenotypes and genotypes (120,692 single nucleotide polymorphisms (SNPs) post editing) were
available on 7,128 South African Bonsmara cattle; the association analyses were undertaken using linear mixed
models.
RESULTS : Genomic restricted maximum likelihood analysis of the 7,128 SA Bonsmara cattle yielded genomic
heritability’s of 0.183 (SE = 0.021) for AFC, 0.207 (SE = 0.022) for ICP and 0.209 (SE = 0.019) for SC. A total of 16, 23 and 51
suggestive (P ≤ 4 × 10-6) SNPs were associated with AFC, ICP and SC, while 11, 11 and 44 significant (P ≤ 4 × 10-7) SNPs
were associated with AFC, ICP and SC respectively. A total of 11 quantitative trait loci (QTL) and 11 candidate genes
were co-located with these associated SNPs for AFC, with 10 QTL harbouring 11 candidate genes for ICP and 41 QTL
containing 40 candidate genes for SC. The QTL identified were close to genes previously associated with carcass,
fertility, growth and milk-related traits. The biological pathways influenced by these genes include carbohydrate
catabolic processes, cellular development, iron homeostasis, lipid metabolism and storage, immune response, ovarian
follicle development and the regulation of DNA transcription and RNA translation.
CONCLUSIONS : This was the first attempt to study the underlying polymorphisms associated with reproduction in
South African beef cattle. Genes previously reported in cattle breeds for numerous traits bar AFC, ICP or SC were
detected in this study. Over 20 different genes have not been previously reported in beef cattle populations and may
have been associated due to the unique genetic composite background of the SA Bonsmara breed.
DATA AVAILABILITY : The datasets generated and/or analysed during the current study are available
at https://DOI.org/10.6084/m9.figshare.21800117.
2023-08-24T00:00:00ZThe effect of Monensin vs. Neem, and moringa extracts on nutrient digestibility, growth performance, methane, and blood profile of merino lambsDu Preez, Danah A.Akanmu, Abiodun MayowaAdejoro, Festus AdeyemiHassen, Abubekerhttp://hdl.handle.net/2263/951542024-03-12T22:46:26Z2023-11-14T00:00:00ZThe effect of Monensin vs. Neem, and moringa extracts on nutrient digestibility, growth performance, methane, and blood profile of merino lambs
Du Preez, Danah A.; Akanmu, Abiodun Mayowa; Adejoro, Festus Adeyemi; Hassen, Abubeker
Plant secondary compounds are potential rumen modifiers that can improve nutrient
utilization in ruminant animals. This study evaluated the effect of Moringa (Moringa oleifera) and
Neem (Azadirachta indica) leaf extracts on nutrient digestibility, growth performance, and enteric
methane production in South African Mutton Merino lambs. Forty 4-month-old ram lambs with
a mean body weight of 35 2.2 kg were blocked by weight and from each block, lambs were
randomly allocated into one of the following treatments: (i) diet only (fed a total mixed ration TMRnegative
control), (ii) Monensin (fed TMR containing Monensin sodium, 15 mg/kg DM), (iii) Moringa
(fed TMR, drenched with Moringa extract 50 mg/kg feed DM intake), and (iv) Neem (fed TMR,
drenched with Neem extract 50 mg/kg DM intake). Extracts were administered via oral drenching at
a concentration determined based on the previous week’s feed intake. There were no differences in
dry matter intake, average daily gain, feed conversion efficiency, digestibility, and nitrogen retention
across the treatments. However, the extracts tended to reduce methane emitted both in g/head/day
(p < 0.08) and g/ kg dry matter intake (p < 0.07). Extracts did not influence any of the blood metabolites
in the ram lambs. Although the benefits of utilizing these medicinal plants as rumen modifiers under
prolonged feeding conditions is justified, further evaluation is recommended to test Moringa and
Neem leaf extracts at higher inclusion levels. Our research group is currently exploring a variety of
phytogenic tools for the identification and standardization of key bioactive compounds linked to
methane inhibition, in these leaf extracts.
DATA AVAILABILITY STATEMENT : The authors confirm that the data supporting the findings of this study
are available within the article.
2023-11-14T00:00:00ZThe effect of a Bacillus probiotic and essential oils compared to an ionophore on the rumen microbiome composition of feedlot cattleLinde, Dina AlidaSchokker, DirkjanDu Toit, Cornelius Jacobus LindequeRamkilawon, Gopika DeviVan Marle-Koster, Estehttp://hdl.handle.net/2263/951532024-03-12T22:46:42Z2023-09-15T00:00:00ZThe effect of a Bacillus probiotic and essential oils compared to an ionophore on the rumen microbiome composition of feedlot cattle
Linde, Dina Alida; Schokker, Dirkjan; Du Toit, Cornelius Jacobus Lindeque; Ramkilawon, Gopika Devi; Van Marle-Koster, Este
The rising concern of antibiotic growth promoter use in livestock has necessitated the
investigation into alternative feed additives. The effect of a probiotic and essential oils to an ionophore
on the rumen microbiome composition of Bonsmara bulls raised under feedlot conditions was
compared. Forty-eight Bonsmara weaners were allocated to four groups: a group with basal diet
(CON) and three groups supplemented with monensin (MON), probiotic (PRO), and essential oils
(EO). During the 120 days feeding period, rumen content was collected from four animals per group
within each phase via a stomach tube for 16S rRNA and internal transcribed spacer (ITS) sequencing
as well as volatile fatty acid analysis. In the starter phase, MON had a significantly lower acetate to
propionate ratio and a higher Succinivibrionaceae abundance. The abundance of Lachnospiraceae was
significantly higher in EO compared to MON. In the finisher phase, PRO had a significantly higher
bacterial diversity. The alpha diversity did not differ between the fungal populations of the groups.
The abundance of Proteobacteria was the lowest in PRO compared to the other groups. Limited
variation was observed between the rumen microbiome composition of monensin compared to the
other treatment groups, indicating that these alternatives can be considered.
DATA AVAILABILITY STATEMENT : Data were deposited in the Sequence Read Archive of the NCBI with
the accession number PRJNA721531.; SUPPLEMENTARY MATERIALS : TABLE S1: The relative abundance (in percentage) of the rumen bacteria/archaeal phyla and families of the control, essential oil, monensin, and probiotic groups in the starter, grower, and finisher phases, TABLE S2: The relative abundance (in percentage) of the rumen fungal phyla and families in the control, essential oils, monensin, and probiotic groups in the starter, grower, and finisher phases.
2023-09-15T00:00:00ZIncorporating new technologies in breeding plans for South African goats in harsh environmentsVisser, CarinaSnyman, Margaretha A.http://hdl.handle.net/2263/951132024-03-08T22:48:01Z2023-10-01T00:00:00ZIncorporating new technologies in breeding plans for South African goats in harsh environments
Visser, Carina; Snyman, Margaretha A.
• Angora and meat producing goats play an important role in food
security and sustainable livelihoods of livestock producers in South
Africa. To maintain their role, it is important to select animals that
can thrive in the harsh South African climate, especially under the
envisioned climate change conditions.
• Several phenotypes have been identified as selection criteria for adaptation.
These include litter size at birth, litter size at weaning and
litter weight at weaning (reproduction), weaning weight (growth),
fecal egg counts, FAMACHA score, packed cell volume, tick counts,
hair length, and coat type (endo- and ecto-parasite resistance) and
coat type, coat thickness, color of skin and coat, rectal temperature
(heat tolerance). Many of these phenotypic indicator traits have limitations
such as low heritabilities or being difficult to measure.
• The application of new technologies in breeding and selection is
under-utilized in goats in general, and especially in South African
goats. The use of validated causative mutations affecting traits relating
to adaptation to harsh environments in selection programs
would facilitate genetic progress in herds where phenotypic recording
is challenging.
• In addition, increased investments by various role players in applying
new technology in the systematic collection of phenotypic indicator
traits (especially for traits related to adaptation), can be used to improve
the rate of animal improvement in the South African goat breeds.
2023-10-01T00:00:00Z