The growth performance of growing pigs during feed restriction and re-alimentation in a humid tropical environment

Thirty two crossbred (large white x landrace) pigs were used in a 56 days restriction and 56 days realimentation study to evaluate the effect of restricting growing pigs at 90, 80 and 70% of the ad libitumfeed intake of the control. The pigs averaged 35.23 ± 0.560 kg at the start of the study. There were four treatments (control, 90, 80 and 70%). Each treatment had eight pigs allotted to 2 replications of fourpigs each. The pigs received a 16% crude protein and 12.08 MJME/kg diet. Results indicated that average daily gains (ADG) of the control pigs were significantly superior to the others during the restriction period. However, at the end of the 56 days re-alimentation, pigs on the 80% and 70% feeding regime had superior ADG than the pigs on the control and 90 percent feeding regime. Data on the body length (BL) and height at shoulders (HS) followed the same trend as observed for ADG. Feed intakes of pigs were significantly affected during the restriction and re-alimentation period. There was a significant (p < 0.05) decrease in feed intake as level of restriction increased. Also, during realimentation pigs on the 70% level had the highest feed intake. Pigs on the 80% level of restriction had the best feed cost/kg gain values at restriction and re-alimentation. It is concluded that restrictinggrowing pigs at 80% of the ad libitum intake of the control yields best performance and economic benefit

Motility and fertilizing capacity of boar semen stored in raffia palm (Raffia hookeri) sap extender at 15°C

Two separate experiments were conducted to test the ability of new semen extenders containing various levels of tropical raffia palm sap in sustaining the motility and fertilizing capacity of boar spermatozoa during storage at 15°C. Highly significant variations (P < 0.01) occurred in the ability of extenders to sustain progressive motility from days 1 to 4 of storage. One of the new extenders, raffia palm extender 2 (RPE–2) was superior to other trial extenders including the control (coconut milk extender, CME) in sustaining progressive motility of boar sperm from 24 - 72 h of storage; average motility scores at 24 and 72 h were 73.0 and 50.0% for RPE-2, 65.0 and 41.0% for CME (control), 55.0 and 36.0% for RPE-1 and 45.0 and 6.5% for RPE-0. Sperm tail vibratory movement was observed in sperm stored in RPE-1 and RPE-0 from day 2 of storage. Sperm in RPE-0 and RPE-1 lost motility completely at 96 h while motility of sperm in RPE-2 showed a sharp drop in motility values from 72 – 96 h relative to control. Average conception rates in 24 gilts inseminated per treatment with semen stored for 24, 48 and 72 h respectively were 83.3, 66.6 and 16.6% for RPE-2, 50, 16.6 and 0.0 percent for RPE-1, 16.6, 0.0 and 0.0% for RPE-0 and 75.0, 50.0 and 26.6% for CME (control). Average number of piglets born using semen stored for 24, 48 and 72 h respectively were 8.0, 8.0 and 6.5 for RPE-2 and 8.2, 8.2 and 6.0 for the control. RPE-2 supported better fetal survival rate than other trial extenders and control. Highly significant variations (P < 0.01) occurred among extenders in conception rate and number of piglets born. These results portray RPE-2 as a reliable short-term liquid semen storage medium for swine artificial insemination in the humid tropics

Reproductive characterization of three species of Giant African land snails (GALs) in captivity

Duration of reproductive activities (courtship latency, courtship and mating) were studied in three (3) species of Giant African land snails (GALs) namely, Achatina fulica, Archachatina marginata and Achatina achatina using mature snails gathered from rural Nigeria. The snails were housed singly for 90 days to acclimatize; shed already fertilized eggs from previous mating and develop strong desire to mate. Thereafter, monocultures of each species were formed namely, A. fulica x A. fulica (F x F); A. marginata x A. marginata (M x M) and A. achatina x A. achatina (A x A) for pre-mating trials. These were observed for one week and any two snails that showed consistent association for more than 10 min were isolated and kept together as potential mating pairs. Parameters measured were duration of courtship latency (DCL), duration of courtship (DC), duration of mating (DM), duration from mating to oviposition (DMO), egg weight (EW), egg length (EL) and weight of hatchlings (WH). Number of mated pairs and ovipositors per species were noted and mating propensity was calculated as the percentage of tested snails that mated in each species. Result shows significant (P&lt;0.05) differences between snail species in all traits studied.Key words: Land snails, courtship, copulatory duration, tentacular contact, monocultures

Heterosis For Litter Traits In Native By Exotic Inbred Pig Crosses

Inbred strains generated from native and exotic pigs were compared with their F1 and F2 backcross populations for a range of litter performance traits. Animals were intensively reared and at 81/2 months of age, the inbred genotypes from each strain were reciprocally mated to each other togenerate F1 crossbred genotypes; while gilts from each crossbred group were backcrossed to their male parents to obtain four backcross progeny groups. Results of the study showed that the litter performances were better in the crossbred groups than in the inbred parents and this improvement could be ascribed to the dominant genes from the exotic parents. Significant (

Testicular development and relationship between body weight, testis size and sperm output in tropical boars

Ten boars selected from each group of local Nigerian (LNB), Large White (LW) and LNB x LW (F1) crossbred boars were studied to determine the pattern of testicular development by external testicularmeasurements (length and width of testis) and to find out the relationship between external testicular dimensions body weight and sperm output. The results showed that LW boars were superior to bothLNB and LNB x LW (F1) boars in all testicular and body weight measurements, while LNB x LW (F1) boars showed remarkable improvement over the LNB parent in all measurements. Rapid growth of the testis occurred in LNB from 14 – 30 weeks of age and 14 – 32 weeks of age in the crossbreds. Rapid growth of testis occurred from 12 – 32 weeks in the LW boars. These periods coincided with the phaseof rapid gain in body weight in the various groups. Significant (P < 0.05) between genotype differences were observed in body weight and testicular measurements. Sperm output/48h was highest in LW boarsand lowest in LNB boars. Correlations between body weight testicular measurements and sperm output per 48 h were positive and highly significant (P < 0.01) in all groups with r2 value ranging from 0.74 –0.90. Sperm output was highly correlated (P < 0.01) with body weight in all genotypes with r2 values ranging from 0.85 – 0.91. The results generally indicate that measurements of external testis dimensions, body weight and sperm output characteristics can accurately guide the assessment of the reproductive performance of boars

Effects of management systems on semen characteristics of indigenous and exotic layer type cocks

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