Bibliography: leaves 359-376.

Two experiments measured winter feed waste when cows were fed forage on snow. In the first experiment, feed waste was different (P<0.01) when alfalfa meadow brome mixed hay was fed by bale unroller or bale processor; waste was12.9% vs.19.2%, protein losses were 23.3% and 21.5% respectfully. Feed waste, nutrient replacement and additional equipment costs increased winter feeding costs by $52.50 and $56.25 per head respectfully for a 175 day feeding period. Hay processed into portable bunk feeders, experienced 0% feed waste. In the second experiment, feed waste when barley cereal silage fed either as high moisture round bale silage or chopped pit silage was fed on snow was not different (P>0.05) at 23.2% and 26.8% respectfully. When chopped barley cereal silage or high moisture round bale silage was fed into bunks, feed waste was 0%. Protein losses were 27.1% and 24.2% for the pit and round bale silage. Feed waste, nutrient replacement and additional equipment costs increased winter feeding costs by $164.50 for pit silage and $126.00 for bale silage over a 175 day feeding period. / Animal Science

The objective of this study was to evaluate the influence of cow age on grazing distribution relative to mountain riparian areas. In each of two years, sixty cow-calf pairs were stratified by age into the following treatments: 1) thirty first calf heifers (442 kg, body condition score (BCS)=4.5), and 2) thirty mature cows (5-7 years of age; 569 kg, BCS=5.0). From late July to early September, treatments were randomly assigned to four pastures with treatments reversed in Year 2. Analysis of hourly cattle locations observed during 4-d periods early (d 15 to d 18) and late (d 36 to d 39 in Year 1; d 29 to d 32 in Year 2) during the grazing bout revealed a three-way interaction between cow age, time of day, and grazing bout (P<0.01). In the morning hours of the early grazing bout, mature cows distributed farther from the stream (P<0.10), and occupied the riparian vegetation type less (P<0.10) than first calf heifers. No differences (P>0.10) in distribution occurred between age classes from 1300 h until dark. Similarly, during the late grazing bout, no differences were observed (P>0.10) between the distribution of the age classes. While no difference (P=0.20) occurred between age classes in total minutes spent grazing, first calf heifers foraged longer during the morning and evening bouts (P<0.10). The forage utilization pattern and the fecal deposits within 1-m of the stream were not different (P>0.10) between age classes. While mature cows tended (P=0.17) to have higher dry matter intake (DMI), first calf heifers consumed more feed per unit of body weight (BW) (P=0.08). Though first calf heifers tended (P=0.13) to gain more BW, no differences occurred between age classes in BCS change (P=0.69), or calf average daily gain (ADG) (P=0.34). In summary, mature cows distributed farther from water and spent more time outside the riparian vegetation zones during the morning hours early (d 15 to d 18) in the trial compared to first calf heifers. / Graduation date: 2003

Seven experiments were carried out to investigate the involvement of carbohydrate and lipid metabolism on the incidence of Sudden Death Syndrome (SDS) in broiler chickens. Hepatic arachidonate level decreased after 1 h postmortem. The decreased level of hepatic arachidonate previously observed in SDS birds was, therefore, associated with the post-mortem aging. Broiler chickens fed diets high in glucose monohydrate (cerelose) were more susceptible to SDS mortality than broilers fed diets high in corn starch or corn-soy. Feeding broilers a high cerelose diet increased the levels of plasma calcium, total protein, triacylglycerol, and uric acid compared to broilers fed corn starch diet. Broilers fed cerelose diet also showed the higher incidence of leg abnormality than broilers fed corn starch or corn-soy diets. Daily intraperitoneal injection with 0.25 ml of L(+) lactic acid solution (100 mg lactic acid/ml) to broilers over a 7-d period failed to reproduce the SDS incidence, whereas intravenous injection of 40% lactic acid solution (200 mg lactic acid/kg body weight) resulted in 100% incidence of SDS-type mortality. No SDS-type mortality was observed with the intravenous injection of 40% sodium lactate solution (200 mg sodium lactate/kg body weight). Disturbance of physiological acid-base balance might be a factor in the SDS-type mortality. Suboptimal thiamin level in broilers fed cerelose diets was observed. Thiamin supplementation to cerelose diet improved the thiamin status of the broilers. Mortality due to SDS was decreased when thiamin hydrochloride was supplemented to cerelose diet at the level of 0.6 and 2.8 mg thiamin hydrochloride/kg diet, respectively. Thiamin supplementation, however, did not change the liver pyruvate dehydrogenase activity and the proportion of pyruvate dehydrogenase in the active form. Disturbance of acid-base balance was postulated to be associated with the incidence of SDS. Other genetic, nutritional, and environmental factors are likely to modify the incidence by affecting the acid-base status of the chicken. / Graduation date: 1993

Thesis (MVoeding)--University of Stellenbosch, 2006. / Bibliography.

Hyolingual biomechanics and kinematics in three species of two odontocete genera were investigated to compare adaptations and performance of divergent feeding strategies. Ram and suction feeding are two ends of a continuous spectrum that is poorly-studied in odontocetes. Comparative anatomy identified characters associated with feeding patterns of morphologically dissimilar and evolutionary distant genera. Hyolingual investigations included measurements of hyolingual muscle vectors and hyoid surface area/robustness. ANOVA's revealed Kogia basihyal and thyrohyal surface areas were significantly greater than T. truncatus. However, most predicted muscle tension values were not significantly different between genera. The presence of lateral gape occlusions, broad basihyal and thyrohyals near the caudal oral cavity, and a broad, short tongue were likely responsible for Kogia's effective suction mechanism. These features were absent, or reduced, in T. truncatus. The feeding kinematics of dwarf and pygmy sperm whales (Kogia sima and K. breviceps), and bottlenose dolphins (Tursiops truncatus) were characterized and compared incorporating the Ram-Suction Index (RSI). Mean RSI data support a suction feeding strategy for the phylogenetically basal Kogia (-0.67; S.D.±0.29) and a ram feeding strategy for the more-derived Tursiops (0.94; S.D.±0.11). Tursiops displayed two ram-based feeding behaviors, closed gape approach, where gape increased near food items, and open gape approach, where gape was at least 50% of maximum in the first video field. Four feeding phases were identified in both odontocetes: preparatory, jaw opening, gular depression, and jaw closing. The mean Kogia feeding cycle duration (470 ms; S.D.±139) was significantly shorter (P<0.003) than all Tursiops groups (pooled: 863 ms; S.D.±337, closed gape approach: 662 ms; S.D.±207, open gape approach: 1211 ms; S.D.±207). Kogia mean maximum gape angle (39.8°; S.D.±18.9), mean maximum opening, and closing gape angle velocities (293°/s; S.D.±261 and 223°/s; S.D.±121, respectively) were significantly greater (P<0.005) than pooled Tursiops mean maximum gape angle (24.8°; S.D.±6.6), mean maximum opening and closing gape angle velocities (84°/s; S.D.±56 and 120°/s; S.D.±54, respectively). Negative Kogia RSI values were correlated with increasing maximum hyoid depression and retraction, wide gape angle, and rapid opening gape velocity. Kinematic data support functional hypotheses that odontocetes generate suction by rapid depression of the hyoid and tongue.

Feeding biomechanics and foraging behavior are likely contributors to loggerhead sea turtle (Caretta caretta) bycatch in the pelagic longline fishery. To investigate these contributions, loggerhead bite performance was measured in several size classes of captive-reared juveniles, captive sub-adults and adults, as well as wild loggerheads. A kinematic study was conducted to investigate loggerhead interactions with modified longline hooks. Kinematic and behavioral variables were assessed in relation to five longline hooks to determine if loggerhead feeding behavior is modulated relative to hook type, size, and offset. The bite force study demonstrated that mean maximum post-hatchling bite force was 2.5N and mass was the best predictor of post-hatchling bite force. Mean maximum bite force of juveniles with mean straight carapace length (SCL) of 12, 31, 44, and 65 cm were 27, 152, 343, and 374 N, respectively. Sub-adult and adult mean maximum bite force was 575 N. Maximum bite force had a positive linear relationship with all head and body morphometrics (P<0.001). Carapace width was the best predictor of bite force throughout ontogeny. The kinematic study demonstrated no differences between hook treatments in all kinematic variables analyzed. The results of this study suggest loggerhead feeding behavior may be stereotypical. Only 33% of all interactions resulted in “hooking” events. “Hooking” was lowest in 16 gage circle hooks with no offset and the 18 gage circle hooks with 10°offset which may be indicative of a lower possibility of the turtle drowning. “Hooking” was highest in the 16 gage circle hooks with 10°offset. The proportion of turtles “hooked” in the mouth was significantly greater than those “hooked” in the throat (P=0.001). Sixteen gage circle hooks with 10° offset had the highest percentage of throat “hooking”, and the 18 gage circle hooks without offset resulted in the lowest percentage of throat hooking. When interacting with J hooks with a 25° offset (9 gage), turtles mostly oriented their head away from the hook offset; however, when interacting with the 16 and 18 gage circle hooks with 10° offset, turtles mostly oriented their heads toward the hook offset. These data suggest that turtles may distinguish between small and large offsets, and may modulate their feeding behavior accordingly. Alternatively, turtles may be detecting hook size or hook shape. A more thorough characterization of loggerhead bite performance and feeding kinematics will be useful when developing or modifying longline fishery gear aimed at reducing loggerhead bycatch.

The Psittacidae is one of the most endangered families of birds in the world. Knowledge of its nutrition is important for understanding their survival and productivity in the wild, as well as for their adequate husbandry in captivity. Hand-rearing is a common practice for this group. However, research on their requirements is limited. Analysis of the crop content of chicks can provide new insights into psittacine nutrition, but it is limited by the small sizes of samples which can be obtained. We sampled the crops from free-living chicks of scarlet macaws and red-and-green macaws from southeastern Peru, Cuban parrots from the Bahamas, lilac-crowned parrots from northwestern Mexico, and thick-billed parrots from northern Mexico. The predicted metabolizable energy, protein, fat, minerals, profile of essential amino acids and profile of fatty acids of the crop samples, as well as from 15 commercial hand-rearing formulas, were analyzed and contrasted. Near Infrared Spectroscopy was shown to be a valid technique for the nondestructive, low cost prediction of a variety of nutritional attributes of crop samples as small as 0.5 g dry weight, expanding the possibilities of wild animal nutrition research. The diets of the five studied species presented remarkable similarities and common patterns. The predicted dietary metabolizable energy and fat concentrations were particularly similar among species, the thick-billed parrot being the one with the most unique nutrient profile. The fatty acid profile of the crop contents differed markedly among genera, with the thick-billed parrot closer to the macaws than to the parrots. In comparison with the crop samples, the hand feeding formulas presented lower fat, Mg, arginine, and valine concentrations. The wide variation in nutrients suggests that there is not yet a consensus among manufacturers concerning the correct nutrition for growing psittacines. It is suggested that a single formulation could be used to hand-rear macaws and parrots from half its nesting time to fledging, and further research should focus on their nutrition during the first half. Our results suggest that manufacturers should evaluate if increasing the concentrations of crude fat, Mg, arginine, and valine in commercial formulas enhances psittacine chick growth and health.

Undernutrition is a major public health problem, contributing to 33% of deaths in infants and young children globally. In Kygryzstan, Central Asia, Mercy Corps provided 6 metric tons of rice, flour and oil as well as nutritional education to kindergartens in 40 rural regions, serving 41,000 children, for one year. Anthropometric measurements were collected at the beginning and end of the program. Children, who were stunted, wasted and underweight at baseline, recovered by follow-up, with rates of recovery of 50%, 65% and 50%, respectively. The prevalence of stunting, wasting and underweight in the population decreased from 13.8%, 3.4% and 3.2%, respectively, to 8.6%, 2.1% and 2.3%, respectively. This study shows that preschool feeding programs have the potential to improve nutritional outcome. These results are particularly significant as the dearth of research on preschool feeding’s impact on growth and nutrition has led to this particular intervention being deemed ineffective for improvement of nutritional outcome.

Graduation date: 1993