Net benefits of smallholder dairy cattle farms in Senegal can be significantly increased through the use of better dairy cattle breeds and improved management practices.

Senegal, located in West Africa, is an example of a low- to middle-income country where the government has prioritized improving livestock production self-sufficiency, with a strong focus on dairy. Among other initiatives, the use of exotic dairy cattle has been promoted, despite no evidence for the potential livelihood benefits (or otherwise) to smallholder farmers on adopting the new genetics. The current work fills this evidence gap by performing a farm-level economic study comparing the keeping of different breed and cross-breed types of dairy cattle under different management levels. Data for the study were obtained by monitoring 220 smallholder dairy cattle farms, with a combined cattle population of about 3,000 animals, over an almost 2-yr period. Findings of the study suggest that the most net-beneficial and cost-beneficial dairy cattle enterprise that could be used by the smallholder farmers was to keep crossbred indigenous zebu by exotic Bos taurus animals under management standards that are considered good compared with local standards. This dairy enterprise type was 7.4-fold more net beneficial and had a 1.4-fold more favorable cost-benefit ratio than the traditional system of keeping indigenous zebu animals under poor (low-input) management. Interestingly, the keeping of (near) pure B. taurus dairy cattle resulted in the highest milk yields and thus benefit from milk, but was not the most net beneficial due to the high costs of keeping these animals, particularly in terms of feed. We also found that increasing the management level of any of the breed or cross-breed types under consideration, including the indigenous zebu animals, resulted in an increased net benefit of 2.2- to 2.9-fold. Results of this economic analysis are discussed as part of a broader trade-off analysis, resulting in recommendations to strengthen the Senegal dairy sector. The combined intervention of improved dairy cattle genetics and management is considered a promising intervention to improve livelihoods of the rural poor as well as livestock production self-sufficiency for Senegal; some other system constraints are addressed.

The greenhouse gas abatement potential of productivity improving measures applied to cattle systems in a developing region.

Developing countries are experiencing an increase in total demand for livestock commodities, as populations and per capita demands increase. Increased production is therefore required to meet this demand and maintain food security. Production increases will lead to proportionate increases in greenhouse gas (GHG) emissions unless offset by reductions in the emissions intensity (Ei) (i.e. the amount of GHG emitted per kg of commodity produced) of livestock production. It is therefore important to identify measures that can increase production whilst reducing Ei cost-effectively. This paper seeks to do this for smallholder agro-pastoral cattle systems in Senegal; ranging from low input to semi-intensified, they are representative of a large proportion of the national cattle production. Specifically, it identifies a shortlist of mitigation measures with potential for application to the various herd systems and estimates their GHG emissions abatement potential (using the Global Livestock Environmental Assessment Model) and cost-effectiveness. Limitations and future requirements are identified and discussed. This paper demonstrates that the Ei of meat and milk from livestock systems in a developing region can be reduced through measures that would also benefit food security, many of which are likely to be cost-beneficial. The ability to make such quantification can assist future sustainable development efforts.

Effect of dwarf (dw) and frizzle (F) genes on the performance of layers under Senegalese conditions.

The influence of sex-linked dwarf (dw) and incompletely dominant frizzle (F) genes on growth, egg production and quality were investigated. The experimental stock comprised 100 chicks of four genotypes: normal feathered, normal size (ffDw): normal feathered, dwarf (ffdw); frizzle, normal size (FfDw); and frizzle, dwarf (Ffdw). The dwarf gene reduced the body weight, shank length, feed intake, egg production and egg weight. The frizzle gene also reduced most of these traits, except for egg production, the interaction between the two genes being positive only for growth traits and egg number. Neither of the two genes significantly influenced egg quality. It was concluded that the dwarf gene may have some practical interest in tropical environments, while more needs to be known about the frizzle gene.

Blood polymorphism in west African breeds of sheep.

This paper reports the blood groups and blood protein distribution in West African sheep breeds. About 100 animals of the Djallonke, Fulani and Touabire breeds were sampled for blood polymorphism analysis. Their blood groups were typed by haemolytic and agglutination reactions, and their blood proteins by starch gel electrophoresis. Almost all the loci analysed showed variability in the three breeds, with the Touabire and Fulani being closer to each other than to the Djallonke.

Note on transferrin, hemoglobin types, and packed cell volume in Senegalese trypanotolerant Djallonke sheep.

In this study we examined transferrin (Tf) and hemoglobin (Hb) types and frequencies and their relationship with Packed Cell Volume (PCV), which is considered as a selection criterion for the trypanotolerance trait. Blood samples were collected from 96 sheep and were typed for Tf and Hb. The frequencies of the alleles TfA, TfB, TfC and TfD were respectively 0.276, 0.005, 0.109, and 0.609. At the locus Hb, all animals were monomorphic B. The lowest PCV value was observed in animals homozygous for TfC, while the highest value was found in heterozygous (CD) animals; however, the difference was not significant.

[Anatomy of the parathyroid glands of the zebu (Bos indius)]. / Anatomie des glandes parathyroides du zébu (Bos indicus).

In this study, the anatomy of the parathyroid glands is examined in zebu cattle. Data have been collected on 61 parathyroids, belonging to 18 Gobra, Maure or Cross breeds animals. Four parathyroid glands have been identified: 2 cranial and 2 caudal. The former are located, either between the lateral retropharyngeal lymph node and the mandibular salivary gland in relation with the common carotid artery or on the latero-dorsal face of the pharynx at the emergency of the cranial laryngeal nerve. The later are located near the thyroid gland. Parathyroid glands are small (length = 1.1 cm, width = 0.6 cm), brown dark glands whose average weight is 169 mg. They can be easily collected in zebu cattle but attention must be payed to lymph and hematic nodes, thymus and fat connective tissue.

[Growth hormone, a potential way to improve livestock productivity in Africa]. / L'hormone de croissance, un moyen potentiel d'accroître la productivité du bétail en Afrique.

This paper reviews experimental data on exogenous pST administration effects on growth and carcass performances in pigs to show the importance pST could have for pigs breeding in Africa. In Europe and USA pST breeding conditions induced growth rate increase (+18.7%) and a decrease of the feed intake (-14.6%) and the feed/gain ratio (-26.5%). The carcass muscle percentage was increased (+17.8%) and the fat rib was decreased (-25.6%) in treated animals compared to controls. pST induced a generalised thoracic and abdominal organs hypertrophy which can partly explain the slight decrease of dressing percentage. On the meat quality pST didn't have any pronounced detrimental effect. According to these interesting results, pST effects must be tested in Africa breeding conditions.

[Genetic variability of growth in sheep grown at the animal husbandry research center of Dahra]. / Variabilité génétique de la croissance chez les moutons élevés au centre de recherche zootechnique (CRZ) de Dahra.

Data on growth performances of 778 Peulpeul and Touabire sheep were collected over five years (1983-1987) in APRC of Dahra. Studied parameters were: birth weight (BBW), one month weight (MBW), weaning weight (WBW) yearling weight (YBW) and growth rate between adjacent stages of growth. BBW, MBW, WBW and YBW are: 3.6 +/- 0.6 kg, 9.5 +/- 1.8 kg; 17.5 +/- 3.5 kg; 30.6 +/- 4.3 kg. Growth rates were 197.0 +/- 51.2 g between birth and one month (MGR), 87.2 +/- 28.1 g, between one month and weaning (WGR) and 50.8 +/- 15.3 g, between weaning and yearling (YGR). Year and season of birth, dam parity, prolificity, sex and race had significant effect on most of the parameters studied. The heritability estimates were 0.50 +/- 0.14 (BBW), 0.52 +/- 0.15 (MBW), 0.71 +/- 0.18 (WBW), 0.44 +/- 0.13 (MGR) and 0.60 +/- 0.16 (WGR). High and positive correlations existed between BBW and the other growth components.

Performance, plasma hormones, histochemical and biochemical muscle traits, and meat quality of pigs administered exogenous somatotropin between 30 or 60 kilograms and 100 kilograms body weight.

Forty-five Large White barrows were injected daily i.m. with either excipient from 30 to 100 kg BW (CTRL), excipient from 30 to 60 and porcine somatotropin (pST; 100 micrograms/kg BW) from 60 to 100 kg BW (pST-60), or pST (100 micrograms/kg BW) from 30 to 100 kg BW (pST-30). Somatotropin accelerated overall growth rate (+4 and +9% for pST-60 and pST-30, respectively), increased longissimus (+10.3 and +14.7%) and semitendinosus (+17 and +13%) muscle weights, and decreased backfat (-49 and -58%) and leaf fat (-49 and -53%) weights. The administration of pST resulted in a similar increase in muscle fiber size for all fiber types in both longissimus (LM) and semispinalis (SS) muscles (+21%). Somatotropin had otherwise little effect on muscle fiber types and biochemical traits of LM, whereas dramatic changes were observed in SS. The relative area occupied by Type IIB fibers was increased (+22 and +29%) and that of Type I fibers was decreased (-10 and -15%). In pST-30 animals, myosin ATPase activity (+15%) and native myosin fast isoform proportion (+10%) were augmented, and energy metabolism was more glycolytic (lactate dehydrogenase: +25%) and less oxidative (citrate synthase: -13%; beta-hydroxyacyl-CoA dehydrogenase: -21%). Compared to CTRL animals, administration of pST increased muscle water concentration (LM: +.8 and +1.1%: SS: +3.3 and +3.3%) and decreased intramuscular fat (LM: -29 and -27%; SS: -39 and -50%). The pH measured 45 min and 24 h postmortem, glycogen content, reflectance, and index of light diffusion were mostly not affected by pST treatment. In conclusion, pST had a very favorable effect on growth performance without any important effect on meat quality traits except for the reduction in intramuscular lipid content. The results indicated that the effects of pST on muscular histochemical and biochemical characteristics were different in LM and SS muscles.