Publications

Breeding objectives were developed for meat sheep in smallholder production circumstances in the tropics. The traits considered were litter size, lambing frequency, pre-weaning, and post-weaning lamb survival to 12 months, ewe survival, lamb live weight at 12-month, mature ewe live weight, consumable meat, kg of manure DM sold per ewe per year and residual DM feed intake. Three evaluation situations were considered: (i) base with constant number of ewes, (ii) fixed feed resource and (iii) setting feed costs to zero. Sensitivity analysis of economic values to price levels of inputs and meat production was carried out. The fixed feed resource situation appropriately describes smallholder production circumstances. In the base situation, meat production accounted for about 88% of revenue and manure the remaining 12%. Variable costs represented about 95% of the total cost. For the fixed feed resource situation, economic values (US$ per ewe per year) were 12.94 for litter size, 10.18 for lambing frequency, 0.19 for pre-weaning lamb survival, 0.24 for post-weaning lamb survival, 0.36 for ewe survival, 1.02 for 12-month lamb live weight, 0.14 for mature ewe live weight, 0.51 for consumable meat, 0.08 for kg of manure DM sold (per ewe per year) and −0.04 for residual DM feed intake. Litter size and lambing frequency were the most important traits in a breeding objective for smallholder production. Relative to the base situation, setting feed costs to zero had similar results as the situation with restricted feed resource but resulted in larger differences. Sensitivity analysis of economic weights to changes in prices and production circumstances indicated that future economic values for traits might change dependent on levels of output and prices. The exceptions, with regard to changes in meat price are kg of manure DM sold per ewe per year and residual DM feed intake, and with regard to feed costs are consumable meat and kg of manure DM sold per ewe per year. Economic values for 12-month lamb live weight, mature ewe live weight, consumable meat, kg of manure DM sold per ewe per year and residual DM feed intake were not sensitive to changes in management and marketing circumstances. Caution is recommended when the breeding objectives presented here are applied not to disadvantage smallholders in poor climatic years, when farmers are at their most vulnerable situation.

Spanish wether and doeling kids (4.5 months of age; 13.4kg initial BW) were used to determine influences of different quality diets consumed continuously or after a lower quality diet on characteristics of growth. The experiment consisted of two 9-week periods. Diets were low quality forage (L, prairie hay supplemented with soybean meal), high quality forage (H, dehydrated alfalfa pellets) and 70% concentrate (C). Kids on two treatments consumed L in Period 1, with half switched to C and half to H in Period 2 (LC and LH, respectively). The CC treatment entailed C consumption in both periods, and HH kids were fed H in both periods. For HC, H was fed in Period 1 followed by C in Period 2. DM intake ranked (P<0.05) LC and LH

Spanish wether and doeling kids (4.5 months of age; 13.4kg initial BW) were used to determine influences of different quality diets consumed continuously or after a lower quality diet on characteristics of growth. The experiment consisted of two 9-week periods. Diets were low quality forage (L, prairie hay supplemented with soybean meal), high quality forage (H, dehydrated alfalfa pellets) and 70% concentrate (C). Kids on two treatments consumed L in Period 1, with half switched to C and half to H in Period 2 (LC and LH, respectively). The CC treatment entailed C consumption in both periods, and HH kids were fed H in both periods. For HC, H was fed in Period 1 followed by C in Period 2. DM intake ranked (P<0.05) LC and LH

The effects of dosage of follicle stimulating hormone (FSH), vehicle and time of injection on ovulation rate and prolificacy were evaluated during the anestrous season. Ewes on four farms (n=445) were treated with a CIDR-G® device for 5 days and exposed to rams upon removal of the insert (CRRI, day 0). A 3×2×2 factorial arrangement tested effects of dosage of FSH (Folltropin®; 0, 42 or 68mg NIH-FSH-P1), vehicle (saline:propylene glycol 1:4, v/v [PGL], or 50% polyvinylpyrrolidone K 29–32 [PVP]) and time of injection (12 or 36h before CRRI). Follicular growth was monitored by ultrasonography in four ewes per treatment at injection of FSH, at CRRI, and on days 1–3 post-CRRI. All ewes were examined by ultrasonography on days 10–14 for ovulation rate, and on days 26–31 and 46–51 for pregnancy and number of embryos. The largest follicle (F1) increased in diameter (mm) between FSH injection (5.3±0.1) and day 1 (6.1±0.1; P<0.01). The F1 was larger at CRRI (P<=0.05) in ewes receiving 42 than 0mg FSH, and 68 than 42mg FSH. The F2 increased in diameter (P<0.05) from FSH injection (4.7±0.2) to CRRI (5.2±0.2) and to day 1 (5.8±0.2), but was not affected by treatment. Number of small follicles (<=4mm) did not differ with time or treatment. Number of medium follicles (5mm) declined (P<0.05) between FSH (1.5±0.2) and days 1 (0.8±0.2), 2 (0.9±0.2), and 3 (0.5±0.2). Number of large follicles (>=6mm) increased from FSH (0.6±0.3) to CRRI (1.4±0.3; P<0.05), and day 1 (2.3±0.3; P<0.05), then declined by day 3 (0.6±0.3; P<0.05). There were more large follicles at CRRI (P<0.05) with 68mg (2.1±0.3) or 42mg (1.6±0.2) than 0mg (0.5±0.4) FSH. Ovulation rate (mean 2.12±0.05) increased with FSH given 12h, but not 36h before CRRI (dosage × time, P<0.05). Estrous response, conception rate, percentage of ewes lambing or prolificacy did not differ. However, number of corpora lutea not represented by embryos increased with dosage of FSH (P<0.01; 0.25±0.14, 0.55±0.09, 0.71±0.09 for ewes treated with 0, 42, and 68mg FSH, respectively).

The effects of dosage of follicle stimulating hormone (FSH), vehicle and time of injection on ovulation rate and prolificacy were evaluated during the anestrous season. Ewes on four farms (n=445) were treated with a CIDR-G® device for 5 days and exposed to rams upon removal of the insert (CRRI, day 0). A 3×2×2 factorial arrangement tested effects of dosage of FSH (Folltropin®; 0, 42 or 68mg NIH-FSH-P1), vehicle (saline:propylene glycol 1:4, v/v [PGL], or 50% polyvinylpyrrolidone K 29–32 [PVP]) and time of injection (12 or 36h before CRRI). Follicular growth was monitored by ultrasonography in four ewes per treatment at injection of FSH, at CRRI, and on days 1–3 post-CRRI. All ewes were examined by ultrasonography on days 10–14 for ovulation rate, and on days 26–31 and 46–51 for pregnancy and number of embryos. The largest follicle (F1) increased in diameter (mm) between FSH injection (5.3±0.1) and day 1 (6.1±0.1; P<0.01). The F1 was larger at CRRI (P≤0.05) in ewes receiving 42 than 0mg FSH, and 68 than 42mg FSH. The F2 increased in diameter (P<0.05) from FSH injection (4.7±0.2) to CRRI (5.2±0.2) and to day 1 (5.8±0.2), but was not affected by treatment. Number of small follicles (≤4mm) did not differ with time or treatment. Number of medium follicles (5mm) declined (P<0.05) between FSH (1.5±0.2) and days 1 (0.8±0.2), 2 (0.9±0.2), and 3 (0.5±0.2). Number of large follicles (≥6mm) increased from FSH (0.6±0.3) to CRRI (1.4±0.3; P<0.05), and day 1 (2.3±0.3; P<0.05), then declined by day 3 (0.6±0.3; P<0.05). There were more large follicles at CRRI (P<0.05) with 68mg (2.1±0.3) or 42mg (1.6±0.2) than 0mg (0.5±0.4) FSH. Ovulation rate (mean 2.12±0.05) increased with FSH given 12h, but not 36h before CRRI (dosage × time, P<0.05). Estrous response, conception rate, percentage of ewes lambing or prolificacy did not differ. However, number of corpora lutea not represented by embryos increased with dosage of FSH (P<0.01; 0.25±0.14, 0.55±0.09, 0.71±0.09 for ewes treated with 0, 42, and 68mg FSH, respectively).

A two by two factorial design including natural helminth infections (dewormed ‘D’ or not dewormed ‘ND’) and different levels of diet (basal ‘B’ or basal diet plus supplement ‘S’) was used to assess the effect of helminth infections and plane of nutrition on health and productivity of F1 (West African Dwarf (WAD) × Sahelian) crosses. The pasture composed the basal diet and supplemented animals received cottonseed and rice bran. Feed composition analysis revealed that the pasture did not provide sufficient nutrients for reproduction requirements. Feed supplementation had a significant effect on weight gain of does during pregnancy and lactation, and milk off-take was significantly higher in supplemented does compared to non-supplemented ones (31.3±2.5l versus 17.7±2.5l respectively, P<0.01). A peri-parturient rise in strongyle egg output was noted, and diet supplementation tended to reduce faecal egg count and to increase packed cell volume (PCV), mainly during the dry season. Deworming had a significant effect on red blood cell (RBC) count, PCV and haemoglobin (Hb) concentration, mainly during the period of peak strongyle egg output (season × deworming: P<0.001 for RBC and PCV and P<0.05 for Hb). Helminth infections combined with a basal diet seriously affected weight gain but the interaction of deworming and diet was not significant. In groups receiving the basal diet, dewormed animals had a significantly higher milk yield than those that were not dewormed (23.5±3.3l versus 12.0±3.7l, respectively; interaction diet × deworming: P<0.05). The higher daily weight gains of offspring born from dewormed does might be explained by the fact that, in addition to the effect of deworming on milk yield in animals receiving basal diet, the kids were less exposed to helminth eggs, whereas does that were not dewormed constituted a greater source of helminth infection for their kids.

A two by two factorial design including natural helminth infections (dewormed ‘D’ or not dewormed ‘ND’) and different levels of diet (basal ‘B’ or basal diet plus supplement ‘S’) was used to assess the effect of helminth infections and plane of nutrition on health and productivity of F1 (West African Dwarf (WAD) × Sahelian) crosses. The pasture composed the basal diet and supplemented animals received cottonseed and rice bran. Feed composition analysis revealed that the pasture did not provide sufficient nutrients for reproduction requirements. Feed supplementation had a significant effect on weight gain of does during pregnancy and lactation, and milk off-take was significantly higher in supplemented does compared to non-supplemented ones (31.3±2.5l versus 17.7±2.5l respectively, P<0.01). A peri-parturient rise in strongyle egg output was noted, and diet supplementation tended to reduce faecal egg count and to increase packed cell volume (PCV), mainly during the dry season. Deworming had a significant effect on red blood cell (RBC) count, PCV and haemoglobin (Hb) concentration, mainly during the period of peak strongyle egg output (season × deworming: P<0.001 for RBC and PCV and P<0.05 for Hb). Helminth infections combined with a basal diet seriously affected weight gain but the interaction of deworming and diet was not significant. In groups receiving the basal diet, dewormed animals had a significantly higher milk yield than those that were not dewormed (23.5±3.3l versus 12.0±3.7l, respectively; interaction diet × deworming: P<0.05). The higher daily weight gains of offspring born from dewormed does might be explained by the fact that, in addition to the effect of deworming on milk yield in animals receiving basal diet, the kids were less exposed to helminth eggs, whereas does that were not dewormed constituted a greater source of helminth infection for their kids.

Eight yearling Boer×Spanish wether goats (36.6±2.3kg average initial BW) with ruminal and duodenal cannulae were used in an experiment with two simultaneous 4×4 Latin squares to study effects of dietary level of CP, the ratio of ruminally degraded intake N or protein (DIP) to TDN and source of supplemental DIP on site of digestion with a high concentrate diet. Diets were formulated to be (DM basis) 9.2% CP, without inclusion of urea (U0) or soybean meal (SBM; S0); 11.3%, CP achieved with 0.73% urea (U1) or 4.48% SBM (S1); 13.3% CP, via use of 1.46% urea (U2) or 8.90% SBM (S2); or 15.2% CP, derived through use of 2.16% urea (U3) or 13.2% SBM (S3). The ratio of DIP:TDN was 0.073, 0.104, 0.136, 0.167, 0.073, 0.093, 0.113 and 0.132 for U0, U1, U2, U3, S0, S1, S2 and S3, respectively. Diets contained 30% cottonseed hulls and were corn-based and fed at 2% BW (DM basis). Apparent ruminal N digestibility increased quadratically as level of supplemental CP rose (−71.6, −39.9, −20.5, 8.5, −60.3, −12.5, −8.4 and −3.5% for U0, U1, U2, U3, S0, S1, S2 and S3, respectively; S.E.=6.6). Microbial OM and N flows to duodenum decreased linearly as CP level increased. Ruminal and total tract NDF digestibilities (e.g. total tract: 51.3, 57.6, 57.7, 57.4, 49.7, 52.3, 53.2 and 53.2% for U0, U1, U2, U3, S0, S1, S2 and S3, respectively) increased linearly and tended to change quadratically as CP level increased. In conclusion, a dietary CP concentration of 11–13% and DIP:TDN ratio of 0.10–0.11 were adequate for maximal total tract OM digestibility in meat goats consuming a corn-based, high concentrate diet, regardless of supplementation with a source of non-protein versus natural protein, although magnitudes of difference in digestibility with lower levels were not marked. A dietary CP concentration of 9–10% and ratio of DIP to TDN of 0.073 were sufficient for highest microbial protein production. With ample tissue N reserves, the ability of meat goats to recycle N may preclude realization of substantial benefits from supplementing high concentrate diets around 9% CP with additional DIP, and high concentrate diets appear to satisfy microbial needs for non-ammonia nitrogenous compounds.

Eight yearling Boer×Spanish wether goats (36.6±2.3kg average initial BW) with ruminal and duodenal cannulae were used in an experiment with two simultaneous 4×4 Latin squares to study effects of dietary level of CP, the ratio of ruminally degraded intake N or protein (DIP) to TDN and source of supplemental DIP on site of digestion with a high concentrate diet. Diets were formulated to be (DM basis) 9.2% CP, without inclusion of urea (U0) or soybean meal (SBM; S0); 11.3%, CP achieved with 0.73% urea (U1) or 4.48% SBM (S1); 13.3% CP, via use of 1.46% urea (U2) or 8.90% SBM (S2); or 15.2% CP, derived through use of 2.16% urea (U3) or 13.2% SBM (S3). The ratio of DIP:TDN was 0.073, 0.104, 0.136, 0.167, 0.073, 0.093, 0.113 and 0.132 for U0, U1, U2, U3, S0, S1, S2 and S3, respectively. Diets contained 30% cottonseed hulls and were corn-based and fed at 2% BW (DM basis). Apparent ruminal N digestibility increased quadratically as level of supplemental CP rose (-71.6, -39.9, -20.5, 8.5, -60.3, -12.5, -8.4 and -3.5% for U0, U1, U2, U3, S0, S1, S2 and S3, respectively; S.E.=6.6). Microbial OM and N flows to duodenum decreased linearly as CP level increased. Ruminal and total tract NDF digestibilities (e.g. total tract: 51.3, 57.6, 57.7, 57.4, 49.7, 52.3, 53.2 and 53.2% for U0, U1, U2, U3, S0, S1, S2 and S3, respectively) increased linearly and tended to change quadratically as CP level increased. In conclusion, a dietary CP concentration of 11–13% and DIP:TDN ratio of 0.10–0.11 were adequate for maximal total tract OM digestibility in meat goats consuming a corn-based, high concentrate diet, regardless of supplementation with a source of non-protein versus natural protein, although magnitudes of difference in digestibility with lower levels were not marked. A dietary CP concentration of 9–10% and ratio of DIP to TDN of 0.073 were sufficient for highest microbial protein production. With ample tissue N reserves, the ability of meat goats to recycle N may preclude realization of substantial benefits from supplementing high concentrate diets around 9% CP with additional DIP, and high concentrate diets appear to satisfy microbial needs for non-ammonia nitrogenous compounds.

Effect of supplementation with non-conventional agro-industrial by-products on rumen fermentation pattern and microbial nitrogen supply was studied in sheep fed grass hay for 9 days. Diets consisted of hay alone (control); hay supplemented with tela atella (traditional brewery residue); katikala atella (liquor residue); lentil hull; rough pea hull and field pea hull. Thirty indigenous rams weighing 22.6±0.97kg, were stratified into weight groups and randomly assigned to dietary treatments independently. Supplementation reduced (P<0.05) rumen pH, but improved (P<0.001) rumen ammonia, total VFA, microbial nitrogen supply (P<0.01) and microbial efficiency (P<0.05). Supplement types did not affect (P>0.05) rumen fermentation and microbial nitrogen supply, but showed difference (P<0.001) for propionate and butyrate concentrations. Type of atella supplements showed variation, whereby rumen pH was low (P<0.05), but rumen ammonia, VFA, molar proportions of acetate, propionate and butyrate were high (P<0.001) for katikala atella compared to tela atella. Lentil hull had higher (P<0.01) rumen ammonia concentration, microbial nitrogen supply and microbial efficiency than other pulse hull supplements. It was concluded that both atella and pulse hulls have potential as supplements for ruminants. More specifically lentil hull and katikala atella seemed to be superior in their diverse nutritive characteristics among the supplements studied.

Effect of supplementation with non-conventional agro-industrial by-products on rumen fermentation pattern and microbial nitrogen supply was studied in sheep fed grass hay for 9 days. Diets consisted of hay alone (control); hay supplemented with tela atella (traditional brewery residue); katikala atella (liquor residue); lentil hull; rough pea hull and field pea hull. Thirty indigenous rams weighing 22.6±0.97kg, were stratified into weight groups and randomly assigned to dietary treatments independently. Supplementation reduced (P<0.05) rumen pH, but improved (P<0.001) rumen ammonia, total VFA, microbial nitrogen supply (P<0.01) and microbial efficiency (P<0.05). Supplement types did not affect (P>0.05) rumen fermentation and microbial nitrogen supply, but showed difference (P<0.001) for propionate and butyrate concentrations. Type of atella supplements showed variation, whereby rumen pH was low (P<0.05), but rumen ammonia, VFA, molar proportions of acetate, propionate and butyrate were high (P<0.001) for katikala atella compared to tela atella. Lentil hull had higher (P<0.01) rumen ammonia concentration, microbial nitrogen supply and microbial efficiency than other pulse hull supplements. It was concluded that both atella and pulse hulls have potential as supplements for ruminants. More specifically lentil hull and katikala atella seemed to be superior in their diverse nutritive characteristics among the supplements studied.

The prevalence of Babesia infection was studied in sheep and goats in Mashhad area from 1998 to 2000. A total of 391 sheep and 385 goats from 77 flocks were clinically examined for the presence of Babesia blood smears and any tick species on the body of the animals. The study revealed that 26.1% of sheep and 14.8% of goats were infected with Babesia. The prevalence of Babesia ovis and Babesia motasi in sheep and goats were 23.5%, 0.5% and 14%, 0.5%, respectively. Double (mixed) infections occurred in 10 sheep (2.5%) and 1 goat (0.25%). The prevalence of Babesia infection between male and female and between different age groups of sheep and goats were statistically non-significant. Seasonally, the prevalence of Babesia infection in sheep reached highest level in August (56%), while a decrease was observed in September reaching the lowest level In February and March. The monthly prevalence of Babesia in goats was not significant. The clinical signs of Babesiosis were observed in 8% of infected sheep and 6.8% of infected goats. The percentage of infected sheep with higher parasitemia was more than infected goats. In this study, five ixodid species were collected from sheep and goats. The Rhipicephalus sanguineus and Hyalomma marginatum, were the most common species in sheep and goats. Other tick species encountered were Dermacentor daghestanicus in goats and Hyalomma anatolicum, Hyalomma asiaticum in sheep. The attachment sites of R. sanguineus and H. marginatum, H. anatolicum were around the anus, but D. daghestanicus was in the shoulder region.

The prevalence of Babesia infection was studied in sheep and goats in Mashhad area from 1998 to 2000. A total of 391 sheep and 385 goats from 77 flocks were clinically examined for the presence of Babesia blood smears and any tick species on the body of the animals. The study revealed that 26.1% of sheep and 14.8% of goats were infected with Babesia. The prevalence of Babesia ovis and Babesia motasi in sheep and goats were 23.5%, 0.5% and 14%, 0.5%, respectively. Double (mixed) infections occurred in 10 sheep (2.5%) and 1 goat (0.25%). The prevalence of Babesia infection between male and female and between different age groups of sheep and goats were statistically non-significant. Seasonally, the prevalence of Babesia infection in sheep reached highest level in August (56%), while a decrease was observed in September reaching the lowest level In February and March. The monthly prevalence of Babesia in goats was not significant. The clinical signs of Babesiosis were observed in 8% of infected sheep and 6.8% of infected goats. The percentage of infected sheep with higher parasitemia was more than infected goats. In this study, five ixodid species were collected from sheep and goats. The Rhipicephalus sanguineus and Hyalomma marginatum, were the most common species in sheep and goats. Other tick species encountered were Dermacentor daghestanicus in goats and Hyalomma anatolicum, Hyalomma asiaticum in sheep. The attachment sites of R. sanguineus and H. marginatum, H. anatolicum were around the anus, but D. daghestanicus was in the shoulder region.

Body growth, feedlot performance and carcass characteristics of ram lambs (n=16) immunized against luteinizing hormone-releasing hormone (LHRH) at 10 weeks of age with recombinant LHRH fusion proteins were investigated. Recombinant fusion proteins, ovalbumin–LHRH-7 and thioredoxin–LHRH-7 were produced using recombinant DNA technology. Animals were immunized (n=8) against LHRH with ovalbumin–LHRH-7 and thioredoxin–LHRH-7 recombinant protein mixture in the Freund’s complete adjuvant. The immunization group received two booster injections 4 and 8 weeks later, with Freund’s incomplete adjuvant. Animals in control group (n=8) were not treated. Animals were kept at relatively poor pasture until 27 weeks of age. This was followed by a 70 days finishing period that involved housing in groups and ad libitum feeding with concentrate. Carcasses were evaluated after chilling for 24h at +4°C. Live weights, finishing weight, weight gain and average daily weight gain were similar between groups (P>0.05). Carcass measurements, loin eye muscle area and back fat thickness were not affected from immunization. Immunization did not affect hot and cold carcass weights, dressing percentage, offal items and wholesale cuts weights. Immunized animals had smaller testis, chop and bone weights than control animals (P<0.05). It was concluded that immunological castration could be achieved at 10 weeks of age in ram lambs using new recombinant LHRH fusion proteins and used in finishing programs without adverse effect on growth rate, feedlot performance and carcass characteristics. Nevertheless, the effectiveness of these proteins should be further evaluated with more animals.

Body growth, feedlot performance and carcass characteristics of ram lambs (n=16) immunized against luteinizing hormone-releasing hormone (LHRH) at 10 weeks of age with recombinant LHRH fusion proteins were investigated. Recombinant fusion proteins, ovalbumin–LHRH-7 and thioredoxin–LHRH-7 were produced using recombinant DNA technology. Animals were immunized (n=8) against LHRH with ovalbumin–LHRH-7 and thioredoxin–LHRH-7 recombinant protein mixture in the Freund’s complete adjuvant. The immunization group received two booster injections 4 and 8 weeks later, with Freund’s incomplete adjuvant. Animals in control group (n=8) were not treated. Animals were kept at relatively poor pasture until 27 weeks of age. This was followed by a 70 days finishing period that involved housing in groups and ad libitum feeding with concentrate. Carcasses were evaluated after chilling for 24h at +4°C. Live weights, finishing weight, weight gain and average daily weight gain were similar between groups (P>0.05). Carcass measurements, loin eye muscle area and back fat thickness were not affected from immunization. Immunization did not affect hot and cold carcass weights, dressing percentage, offal items and wholesale cuts weights. Immunized animals had smaller testis, chop and bone weights than control animals (P<0.05). It was concluded that immunological castration could be achieved at 10 weeks of age in ram lambs using new recombinant LHRH fusion proteins and used in finishing programs without adverse effect on growth rate, feedlot performance and carcass characteristics. Nevertheless, the effectiveness of these proteins should be further evaluated with more animals.