"Utilization of Golden Pennycress in Broiler Diets" by Marley M. Knowles

Graduation Term

Spring 2025

Degree Name

Master of Science (MS)

Department

Department of Agriculture

Committee Chair

Nicholas Heller

Committee Member

Drew Lugar

Committee Member

Jennifer Earing

Committee Member

Justin Rickard

Abstract

The objective of this study was to evaluate performance in broiler chickens fed diets containing golden pennycress meal (GPCM), with and without a flavor additive. Golden pennycress (Thlaspi arvense) is a winter cover crop grown in the Midwest that is rising in popularity as a cash crop used for biofuel production. After oil is pressed out of the seeds, a meal remains that is usually discarded. Incorporation of this meal (23% protein, 15% fat) into feedstuffs for broilers would be an efficient way to make biofuel production more sustainable. In one study, Cornish Cross three-day-old chicks (n=12) were individually housed and fed one of three randomly assigned diets. Diet one served as the control with no flavor additive or GPCM meal, diet two contained 10% GPCM, and diet three contained 10% GPCM with 3% dried molasses. Each diet was offered for five days, followed by a three-day washout period during which the same diet that was offered pre-study was fed, after which a different diet was administered for the same time period. A washout between each diet change utilized was to negate effects of sudden diet change. Applications of diets continued until all units had received all the treatments, or that the chicks had reached four weeks of age. Effectiveness of the diet and performance of the chickens was assessed through metrics including feed intake, water intake, body weight (BW), and feed conversion. A premeasured amount of feed and water was allotted each day and the amounts remaining were measured to assess feed and water intake. Body weight was recorded every day to track growth and to calculate feed conversion. No significant differences in weight gain were found between sequences of diets (P=0.8085). Carryover effects had no significant difference, meaning previous order of diet received did not impact the broiler’s performance (PX1=0.5598; PX2=0.2497). Period yielded significant results, which was to be expected as treatment diets were offered at different stages of growth (PP=0.6390) and contributed effectively zero variance. Results of this study indicate that golden pennycress can be included in broiler diets as there was no reduction of palatability as evidence by performance for the first four weeks of a broiler chicken’s growth when compared to the control diet(P=0.8118). Use of a flavor additive may not be necessary in diets fed to poultry containing golden pennycress meal as the inclusion of molasses as a palatant did not influence intake. Future studies should assess growth and performance of broilers fed diets containing golden pennycress meal at higher inclusion rates over a longer period of time.

The objective of the second study was to evaluate performance in broiler chicken fed diets containing GPCM meal at various inclusion levels ranging from 0-20%. Cornish Cross three-day-old chicks (n=16) were randomly assigned one of four diets. Diet one served as the control with no GPCM, diet two contained 10% GPCM, diet three contained 15% GPCM, and diet four contained 20% GPCM. Diets were offered for eight weeks until finishing. Effectiveness of the diet and performance of the chickens was assessed through the following metrics: feed intake, water intake, body weight (BW), daily gain, and body measurements. A premeasured amount of feed and water was allotted daily and remaining amounts were measured 24 hours later to assess feed and water intake. Body weight along with body measurements were recorded daily to track growth and to calculate feed conversion. After eight weeks on the assigned diets, birds were returned to their owner and euthanized. Measurements were taken on dead weight, live weight, right and left breast weight, right and left tender weight, right and left thigh weight, kidney weight, and liver weight. Then a sensory panel was performed to assess differences in flavor, aftertaste, and overall acceptability. Statistical analysis showed no significant differences across diet treatments in body measurements and metrics assessing growth and performance. Body weight and daily gain were found to be not significantly different when compared to the control (P=0.5907; P=0.6863). Respectively, no significant differences were observed in a majority of carcass measurements, apart from dead weight and right thigh weight (P=0.0292; P=0.0181). Post hoc tests revealed only significant differences in right thigh weight and dead weight between the control and diet 2 (10% GPCM). In participant responses regarding flavor, aftertaste, and overall acceptability, no significant differences were detected across samples when compared to the control (P >0.05). These results suggest that GPCM can be included in rates of at least 20% inclusion into the diet with no significant differences in growth, performance, and meat quality. The successful integration of GPCM into broiler diets promotes sustainable agricultural practices by utilizing a potentially unused product from a cover crop. As an alternative protein source, inclusion of GPCM into broiler diets could reduce feed costs for poultry producers, while reducing waste from biofuel production. Further studies could assess long term effects of golden pennycress consumption on broiler performance at increased inclusion rates.

Access Type

Thesis-Open Access

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